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Opinionatedly Yours

"Opinionatedly Yours"
#23: June 15, 2005
No Way Will I Be Mute About
Swans
By Barry Kent MacKay
Let me ask you a question: Would you kill a swan?
Some people would certainly want to kill a swan if the
opportunity to do so presented itself, but most of us would not.
Indeed, while we may benefit directly, and certainly indirectly,
from other people killing various kinds of animals, most of us don’t
really want to kill any animals beyond the odd nuisance fly or
mosquito, or maybe a mouse in the pantry if we have to, and
certainly most of us have no desire to kill something as magnificent
and harmless to us as a swan.
Of course there are exceptions.
But let me rephrase the question. Would you want to kill a swan
who was threatening the very life of your child, or someone else’s
child, in circumstances where there was no other way to protect the
youngster?
That’s an absurdly extreme and hypothetical question, to be sure,
but I present it to show that there are limits to the natural
reticence we have to killing. The vast majority of us would say yes
in a heartbeat, with no discussion.
Mind you, most of us would kill another human to protect our own
child’s life, if really necessary, so it does not deviate from what
I would say was the social norm: most of us do not want to end the
life of a sentient, long-lived, beautiful animal unless there is a
damn good reason.
Between those extremes there are limits that vary from person to
person. For example, I think most of us living in North America
would, perhaps reluctantly, kill a swan for food when other options
for obtaining food were not available. Many would kill a swan to
protect property, again assuming that a less brutal means of
resolving the concern were not practical, and acknowledging that
others, myself included, would not.
Only a relatively few among us would kill a swan for food when
not necessary, or for sport, but to be sure, our native tundra swans
are legal game in many parts of the United States (although not in
Canada — baby seals maybe, but not swans, although in both countries
the majority of people would rather kill neither).
Of course people vary in their values and sensitivities. Even the
trumpeter swan, which is a species native to western North America
(for sure; how far east it bred is an important question to be
explored below) that was almost wiped out by the nineteenth century
(in good part by the fur trade, which in those days also traded huge
numbers of bird skins and plumes) but is staging a comeback with
lots of human effort and cost, is hunted in some areas of the U.S.
by a tiny minority of Americans. This happens even as the struggle
to re-establish depleted trumpeter swan populations continues.
But there is a third species of swan found in North America — the
one most familiar to a great many people — that many individuals,
organizations, and even government agencies want dead, down to the
last bird. It is called the mute swan, and it is the one that has
the graceful curved neck and the orange beak with the black knob on
top. The wings are often fluffed into stylish sails.
The mute swan is all grace and innocent dignity, with snowy white
plumage, elegant curves and often a seeming friendliness toward
people, except when in charge of eggs or nestlings. Its fierce
protectiveness of family and home is, to some, an endearing
character of the bird. But for others it is one of several reasons
why the swans should be killed.
What is wrong with mute swans?
Well, apart from the just mentioned passion of their territorial
defense, as I will discuss later, they are not native to North
America.
So what? Neither are most of us. Even those among us who are
native-descended from ancient, ice-age ancestors who reached North
America via the Bering land bridge when so much of the world’s
oceans were frozen into ice, and that strait that now separates
Alaska from Siberia was dry land. A lot of species crossed that land
bridge to establish themselves in what we now call the Americas, and
we consider them, like our aboriginal peoples, native. What is
different about the mute swan?
There is a bias against the species in the minds of some because
it did not cross that land bridge, or if it did, it subsequently
died out, like the horse, once native to North America where,
although abundant, it died out sometime around the end of the last
ice age. It was brought back, just a few thousand years later, by
the first conquistadors from Spain, as a domestic animal that got
away to become the wild mustang.
Indeed, there are from North America fossil remains of relatively
recent origin that resemble, if not the modern mute swan, something
very much like it. Because mute swans seem most closely related to
species from the southern hemisphere, including the black swan of
Australia and the black-necked swan of South America, these
"proto-mute" swans may have reached what is now North American from
the south, and then died out.
The modern species we call the mute swan was found, historically,
in Eurasia, from the British Isles east through much of Europe and
central Asia, all the way to the Pacific Ocean, although with breaks
in its range, at least in recent times when ornithologists had the
means and desire to map where it is to be found.
Alas the range of the wild mute swan is badly fragmented, now, in
Asia and the bird is in decline in the eastern hemisphere, although
doing quite well in western Europe, where its numbers are augmented
by birds who have escaped from captivity. Also, European birds are
much better protected than the ones to the east, in Asia. We can
only speculate on how much more abundant it must have been before
hunting and the destruction of important habitat took its toll.
I know too much about the movements and habits of birds to
categorically deny that the mute ever has reached North America
under power of its own wings, perhaps assisted by a strong tail
wind, at least a few times in all the thousands of years before
there were humans around to take note of such things.
Many species of waterfowl, including other species of swans, that
share a somewhat similar range in Eurasia, have certainly crossed
the narrow North Pacific and into North America, or have crossed the
North Atlantic to reach our east coast. Some, like the tufted duck,
and the Eurasian wigeon, regularly occur in North America, and may
even have started to breed here. Certainly that has happened with
several Eurasian species of gull that have established viable,
breeding populations in North America within my own lifetime. (And
in case you’re wondering about that, I’m mature, yes, but not yet
elderly. My good friend, Jim Richards, photographed the first North
American nest of the little gull, previously native to Eurasia, in
Whitby, Ontario, not far from where I live, in 1962.)
Those birds are not feared and hated the way the mute swan is, so
what is different about it?
Well, it was brought here not by wind or ocean currents or by
walking across a prehistoric land bridge, but by humans, in crates,
on ships, a long time ago. That, in the minds of the swan haters,
renders it "exotic" or "invasive" or "alien."
Again, so what? Ring-necked pheasants, brown trout, apple trees,
and all the earthworms in my garden are also alien, and no one is
proposing to subject them to all-out warfare. Look across a summer
meadow, and see the daisies growing there in bright profusion. They
aren’t native, and yet they are so much a part of my own
environment, evocative of lazy summer days when bobolinks gurgled
and sang high above the fields of daisies bobbing in summer breezes,
the origin of the charming daisy chains once strung together by
little girls at play (this was long before Nintendo — I told you I
am mature). Stand in any field in southern Ontario, and look around,
and most of the species of plants you see are not native.
And no one cares.
Or do they?
Certainly the earthworms come at the expense of once native
worms, and the fact that I would not be aware of that but for being
told such esoteric information by books (not many people have read
The earthworms (Lumbricidae and Sparganophilidae) of Ontario,
by John W. Reynolds, Royal Ontario Museum Life Sciences
Miscellaneous Publications, 1977, but I have) does not mean there is
not a net cost to "biodiversity."
And those daisies are weeds to many, and are among a wide variety
of plants that grow at the cost of the lives of some native plant
species, to be sure, apart from being a nuisance to some farmers and
perhaps some gardeners, however much I enjoy their beauty. Many
children who innocently hand cheerful dandelion bouquets to
tolerantly smiling moms grow up to hate those same plants. Not all.
I like dandelions in my lawn, and would not want to dump poison
there to eliminate their sunny presence, in spite of my suburban
neighbors’ mania for solid green lawns consisting of but a single
kind of grass, also alien, also existing at the expense of "native"
species of flora and the animals that depend upon them.
But, while in the interest of everyone’s health I wish they would
avoid poisons, if my neighbors want to dig up their dandelions I
won’t fuss. The native worms are gone so while I may think it was
wrong in some absolute, theoretical way to lose them, I’m grateful
that the exotic ones are doing such a good job of aerating the soil
and involuntarily feeding baby robins.
But we were talking about swans. Show me a person who would kill
a dandelion, or a daisy, or any number of zebra mussels, without
qualm, and I will show you a person who, odds are, would prefer not
to kill a swan. Or cut down an apple tree or get rid of all the Coho
salmon now to be found in Lake Ontario (although I, for one, would
not put another one into the lake, and would be happy if they all
died out, in time).
There has to be, as I said, a damn good reason to kill mute
swans, or to get the public to support the concept, and I don’t
believe there is.
But the swan haters do and they’ve gone after the hearts and
minds of the public with a plethora of reasons this essay will
examine at some length. It is meant to help those who would defend
mute swans in North America, or at least who are trying to make up
their minds about it.
And by "they" I refer specifically to the wildlife management
"industry," both governmental and non-governmental, whose
inextricable affiliation with the sport hunting, fishing, and
trapping interests we explored in the previous edition
of Opinionatedly Yours.
Actually, they have not really gone to the public so much as to
the legislators. The swan-haters would consider much of the public
to be something of a lost cause, consisting of emotional
sentimentalists who are simply awed by the ethereal beauty of mute
swans and not to be trusted with an understanding of the core
reasons why the swans have to go.
Two (Plus) Populations
For all we know, mute swans could have come over on the
Mayflower. Or even, although unlikely, on Viking vessels that
probed the rugged coasts of what is now Newfoundland and Labrador a
thousand years earlier. What we do know is that throughout Europe
they were, and are, a very popular bird to keep on estates, in zoos,
and in waterfowl collections. They occur in very early art and
literature. They were seen by Shakespeare, swimming on the Avon, and
mentioned in his writing. Their images grace medieval
tapestries.
We also know that they do well in captivity, become extremely
trusting of people when not protecting young or nests, and that they
glided across many an ornamental pond or private lake during the
earliest days of civilization.
But they can fly very well. Some of the birds being kept in
estates got loose, or were released, and eventually a population of
birds living outside captivity was established in the mid-Atlantic
region of the U.S. A second population became established where I
live, in the lower Great Lakes region. Smaller "fronts" have been
established in western North America.
None of that is unusual, given the popularity of the species, and
there are now also such free-living populations established in South
Africa, Australia and New Zealand, as well as in Japan, where they
presumably were once "native," at any rate.
The first records of wild nesting mute swans in North America
date from about 1910, along the Hudson River. By 1986 there were an
estimated 5,300 of them to be found in 11 Atlantic states.
That second front seems to have started in Michigan, with the
first breeding birds found around 1919 or 1920. It was not a matter
of one great break-out. The birds are often put in open ponds and if
they are not pinioned (which means that if their wings are not
surgically altered to prevent growth of the outer flight feathers)
and the ponds are not roofed over, they may well fly away and nest
outside captivity. Clipping their wing feathers can keep them
grounded for a season, but not after that if new wing feathers are
allowed to grow back in.
So far as can be determined, the first nesting in my home
province of Ontario was in Georgetown, Halton County, in 1958. Now
they are abundant, particularly along the shorelines of the lower
Great Lakes, but also, increasingly, inland. When I was a kid they
were not to be seen when I visited the marshes and shorelines near
home; now they are everywhere.
Indeed, recently a very small number has been seen in the James
Bay lowlands, far to the north of any source of captive birds,
leading to speculation that at least a few species have joined with
flocks of native, northbound, migrant waterfowl, dispersing to
rugged boreal regions remote from the gentler rolling farmland they
favor on both sides of the Atlantic.
According to Kenneth F. Abraham and R. Kenyon Ross, in their
paper, "Mute Swans in the Hudson Bay Lowlands" (Ontario
Birds, Volume 23, Number 1, April 2005):
There are three reasonable (and non-exclusive) hypotheses about
the course of arrival of the Mute Swans reported here. First, they
may have come north from natal or breeding locations in southern
Canada or the northeastern United States on molt migration or
exploratory wanderings. Second, they may have migrated with Tundra
Swans from wintering areas along the Atlantic Coast of the United
States. Third, they may have migrated with [the] large [eastern
race of] Canada Geese from the lower Great Lakes.
Alien Invasions
I want no misunderstanding: as a guiding principle I oppose the
introduction of non-native flora and fauna via direct human
intervention.
In an ideal world the only wild plants and animals we would see
in North America would be those that either evolved here or arrived
as a result of non-human intervention. Even then, my reasons reflect
my subjective values, and imply that there is some great divide
between humans and the rest of nature, a view held by many humans,
myself not among them. Thus there is an inherent inconsistency in my
position somewhat tangential to the discussion about mute swans.
So to keep it simple, my concern, which is essentially widely
shared by conservationists, naturalists, environmentalists, and
ecologists, is that when any non-native species is introduced into
an entirely new environment, whether it gets there on its own,
arrives because of changes made by humans, or is either
intentionally or unintentionally physically transported to the new
environment, if it survives it very well may create either social
costs, or some sort of ecological cost (up to and including the
extinction of entire species) or a combination of both negative and
positive results, in terms of various conservation and social
concerns.
What you just read was an extremely qualified statement, but the
fact is that the possibilities of what might happen when an alien
species becomes established are multitudinous.
Of course the establishment of a new species in an environment
where it did not previously occur may have relatively little social
or ecological cost, may have strong social benefits, or, most
likely, will have some intricate mixture of costs and benefits.
Prudence, based on past negative experience, might suggest to
some that we err on the side of precaution and do what we can to
avoid moving species around. The reality is that there is almost no
political incentive to pay the costs associated with such a
precautionary approach, at least not until after the damage has been
done.
But before we rectify that damage, we should, at a minimum,
examine if it is real.
If I were to ask a reasonably well-informed member of the public,
a naturalist, or an ecologist to list alien species in North
America, the list would probably be heavily weighted toward those
species of plants and animals that have usurped native species
causing them to become rare, or that have had a social cost attached
to their success, often because (as many plant species have done)
they have displaced many native species.
Many of us have heard horror stories of current or predicted
calamities resulting from the appearance, somewhere in North
America, of the snakehead (a large, aggressive, hard-to-destroy
highly predatory fish from Asia); the walking catfish (an Asian
species that first appeared in the wild in Florida in the 1960s,
that can move across land to colonize new ponds and rivers); zebra
mussels and round gobies (scourges of the Great Lakes that
originated in eastern Europe and escaped into North America from
bilge water in ships, the mussels eating tiny food items required by
native fish and clogging up intake pipes and weighing down ship
hulls; the gobies, a small fish that also takes food required by
other fish and may play a role in spreading botulism); purple
loosestrife (a European wetland plant that allegedly threatens to
clog up local wetlands , although that threat now seems to have been
greatly exaggerated); garlic mustard (a European plant that thrives
in non-acidic woodland soil where it out-competes native flowers,
ultimately destroying ground cover for native wildlife); and many
more.
Such long-established species as the common starling, German
cockroach, rock pigeon (aka rock dove or simply the "pigeon"), house
sparrow, Norway rat, house mouse, black rat, and others have long
"plagued" us, to varying degrees. To some naturalists, trees of
heaven may be an anathema, but the fact that they grow in the dingy,
concrete-lined bowels of the city where all other trees wilt and die
endear them to street urchins in grit-textured city slums where the
chirp of the house sparrow or the gurgling of a common starling are
the only natural noises to be heard amid the honk of horns and the
wail of sirens.
The Asian ladybug has not only displaced our pretty and harmless
native ladybugs, but unlike them it clusters in great numbers that
enter our homes, and it bites! The honeybee that provides most of
the honey that is so ubiquitously located through our commercial
food supplies originates from Europe, and has escaped to the wild
carrying a tiny mite that has pretty well wiped out large numbers of
native species of bee. And we have all heard the horrific stories of
the fabled "killer bees," originally from Africa, but now
established in the New World tropics, with some fearing that global
warming will allow them to colonize north of the Rio Grande. The
emerald ash borer, an insect native to China, has destroyed
virtually all ash trees within its recently established presence in
Michigan, and is rapidly spreading outward in all directions,
threatening literally all native ash trees in its path. Even worse,
perhaps, is the Asian long-horned beetle, also established now in
the lower Great Lakes, and posing a threat to many species of
hardwood trees of great economic, esthetic, and environmental
value.
The greatest threats to the very survival of animal and plant
species exists on islands that host "endemic" species, meaning
species found only there, and nowhere else in the world.
Some endemic species have limited populations with nowhere to go
and often with very little in the way of an ability to defend
themselves. Many island birds, like the dodo, which became extinct
within about 80 years of being discovered by Europeans in the
Mauritius Islands of the Indian Ocean, or the great auk of the North
Atlantic islands, are flightless. Humans killed off those two
species, the dodo and the auk, but often the extinction of island
bird species derives from the introduction of non-native rats, cats,
mongooses, or even snakes.
There is a book I highly recommend, And No Birds Sing: A True
Ecological Thriller Set in a Tropical Paradise, by Mark Jaffe
(Barricade Books, Inc., 1997) which describes how, to the amazement
of skeptical experts, a single species of non-native reptile, the
brown tree snake, managed to wipe out various wildlife species in
Guam, as well as create enormous social problems. The same species,
in its native New Guinea, poses no such threats, but on the much
smaller island of Guam, its arrival was a disaster of epic
proportions, as Jaffe explains in his book.
What tropical snakes have to do with mute swans is simply that
both are alien species, in places where they now live. But let me
quote a very relevant passage from Jaffe’s book:
Much study has been devoted to the relation of predators and
prey and the cycles of ascent and decline the two populations go
through, for as a predator wipes out its prey, it shifts the
advantage from the hunter to the hunted. The survivors suddenly
have more resources at their disposal and reduced numbers may make
it harder for the predator to find them. If the prey population
falls, invariably the population of predators soon follows, and if
the predator reduces the prey base below some vital minimum, it is
the predator itself that is in trouble.
All this had a certain relevance to the brown tree snake. Like
many invading species, when it got to Guam, it found a virgin
territory and experienced an ecological release as its population
exploded.
Usually, the release ends at some point as a new equilibrium is
established. The problem on Guam was that the snake population
kept going until there were perhaps two million snakes. The
species appetite turned out to be so eclectic that even when it
had wiped out birds, rats, and shrews, it dined on skinks, geckos
and spareribs. [Note: the species was noted for seeking out human
food sources, not excluding barbecues.] The real prey base ... was
other reptiles, which reproduced as an even faster pace than the
snake.
This is similar to an evocation I have made numerous times: in a
naturally evolved predator-prey relationship, it is the population
of the prey that determines the size of the population of the
predator. But the key part of the statement is "naturally evolved
..."
The most extreme example of how damaging an introduced species
can be relates to a place most folks have never heard of, and a bird
species that lived only there, becoming extinct in 1894, the same
year that it was discovered. And the entire population was
exterminated by a single introduced predator, a pet cat named
Tibbles
The place is Stephen Island, which is a piece of land about one
square mile in size, and which rises only about a thousand feet
above the waters of Cook Strait, which separates North Island of New
Zealand from South Island.
Until the cat arrived a tiny bird we now call the Stephen Island
wren, also sometimes called the Stephens wren, lived in harmony with
its restricted world. The bird is posthumously famous among
ornithologists for having what was probably the smallest range (area
in which it was found) of any species of bird in the world. It was
also the only known songbird to be, probably, quite flightless. And
finally, there was the remarkable story of how it became known to
science, and how it became extinct, all at the same time, thanks to
Tibbles.
There was a lighthouse keeper on the island by the name of Mr.
Lyall. Tibbles was his cat. And the cat, allowed out, began bringing
Mr. Lyall the bodies of a small, drably streaked brown bird with a
tail so short as to be nearly non-existent, and a slender beak. It
was not a wren at all, although it bore a superficial resemblance to
the familiar winter wren, native to both North America and
Eurasia.
The species, and its appearance, might never have been known had
it not been for the fact that Mr. Lyall (whose name is recognized in
the Stephen Island Wren’s scientific name, Xenicus lyalli)
had not been something of a naturalist, with some training in
preserving biological specimens.
Lyall was the only human ever to see and record the habits of the
little bird, which he saw only twice, before his cat ended such
observations forever.
Both sightings were in the evening, and the little brown birds
were observed to run, quickly, like scurrying mice among the
boulders. None was seen to fly, and given the blunt contours of the
wings of the specimens Mr. Lyall preserved, it is concluded that the
birds were almost certainly flightless. The cat soon stopped
bringing in any of the birds to Mr. Lyall, and they were never again
to be found.
In 1905, the famous New Zealand ornithologist, Sir Walter Buller,
quoted an anonymous correspondent’s sage advice, following the loss
of the Stephen Island Wren. "And we certainly think that it would be
as well if the Marine Department, in sending lighthouse keepers to
isolated islands where interesting specimens of native birds are
known or believed to exist, were to see that they are not allowed to
take any cats with them, even if mouse-traps have to be furnished at
the cost of the state."
If one reviews the extremely long and growing list of birds that
have become critically endangered, or extinct, since the dodo
disappeared sometime around the middle to last quarter of the
seventeenth century, we see that there are many possible causes, but
most fall into a relatively small number of categories, with,
however, exceptions to every single one. Birds and other wildlife
species that have small populations, particularly those isolated on
islands, are typically most vulnerable. Other than that, again and
again we see that causative factors in the endangerment or
extinction of entire species include over-hunting; destruction of
habitat; and introduction of non-native species of fauna. Often it
is a combination of such factors, and sometimes others, that drive a
species toward endangerment and extinction, but it is clear that the
introduction of non-native wildlife species can cause serious
problems, particularly on islands.
The non-native species that cause the most harm tend to be either
predators, or brood parasites. In the latter category, for example,
is the shiny cowbird, an iridescent bird native to South America.
Within recent times a population has, presumably without direct
human intervention, arrived on the island of Puerto Rico. There are
many species of birds endemic to Puerto Rico, including the
yellow-shouldered blackbird.
Shiny cowbirds lay their eggs in the nests of other birds, and in
Puerto Rico, the cowbirds found the nests of the yellow-shouldered
blackbird to be particularly suitable.
The trouble is that the yellow-shouldered blackbirds’ own babies
do not survive when they have to share the nest with the cowbird
babies, and the yellow-shouldered blackbird, once abundant across
the island, now is pretty well restricted to Mona Island, off the
extreme southwest corner of Puerto Rico, and to a few areas on the
main island.
The precipitous decline in the yellow-shouldered blackbird
following the arrival of the shiny cowbird over the last few decades
has been well documented. Habitat destruction also contributed, it
appears, to the decline in yellow-shouldered blackbirds. Since the
cowbirds also use nests of other species, they are not dependent on
the yellow-shouldered cowbird for survival, any more than Tibbles
depended on Stephen Island wrens for food. He could, and did, kill
every one (or at least enough to reduce their ability to survive as
a species) without consequences to himself. The loss of
yellow-shouldered blackbirds does not mean a significant decline in
brood hosts for the shiny cowbirds; they simply switch to other
species.
A similar situation exists on the northern peninsula of Michigan,
which provides the nesting habitat for an endangered songbird called
the Kirtland’s warbler. Here the problem is a native North American
relative of the shiny cowbird, called the brown-headed cowbird.
Originally native to the west, where it apparently followed bison
herds, and parasitized the nests of prairie songbirds, the
brown-headed cowbird moved east, with the clearing of land and the
introduction of cows and other livestock in the eighteenth and
nineteenth centuries.
Like the shiny cowbird, the brown-headed lays its eggs in many
kinds of nests, and either it destroys the host birds’ eggs or its
babies tend to destroy the nestlings of the host parents. In the
case of common, widely spread species this may be not be an
important conservation issue, but the Kirtland’s warbler’s breeding
range is restricted to just a few counties in northern Michigan, in
very restricted habitat (jack pines of a certain age, neither too
young nor too old).
With the arrival of the brown-headed cowbirds, Kirtland’s warbler
numbers plummeted. In response, government agencies declared war on
the cowbirds, killing many. In 2003 it was reported that since 1972,
in Michigan’s attempt to save the Kirtland warbler, 130,251 cowbirds
were trapped, without, it was concluded, significantly causing any
decline in cowbirds. The warblers, however, did experience an
increase in breeding birds.
It’s not quite that simple, though, as the Kirtland’s warbler
also has a very restricted wintering range: the Bahamas. There much
of its habitat of native pines has been converted to golf courses,
and many experts think it is the loss of winter habitat, more than
the arrival of the cowbirds, that is primarily responsible for the
decline in the already rare Kirtland’s warbler.
Of course it is politically a lot easier to kill cowbirds than to
restrict tourist development in the Bahamas. Killing cowbirds is one
thing; discouraging vacationing golfers quite something else.
Even though the Kirtland’s warbler will only nest within jack
pines of within a certain age, there is a great deal of such habitat
adjacent to where it is found in Michigan (including my home
province of Ontario, where the welcome mat is out), giving further
indication that while the cowbirds are a factor in the rarity of the
warbler, the real limited factor in the size of the population is
the wintering range.
And What about Mute Swans?
What has all this got to do with mute swans? It is a question
that will pop up a lot in this essay because to explain why people
want to kill off mute swans, one has to understand underlying
arguments and motives that are indirect, if not outright
Byzantine.
Perhaps it is appropriate here to look at, and respond to, a
speech given by a man who has been used by the U.S. hunting cartel,
most specifically including the U.S. Fish and Wildlife Service, to
make its case.
Once, again, myths are involved. Like all good myths, they are
often based on a tiny nucleus of fact, which is why, above, I have
gone to such lengths to explain that yes, I understand that there
may be serious problems associated with the introduction and
establishment of non-native species of animals or plants. I oppose
the introduction of non-native wildlife, something neither the U.S.
Fish and Wildlife, nor the man whose speech I am about to examine,
will do.
But there may also be few or no such problems associated with any
given introduced species. And what may be one person’s perceived
problem may not faze the next person.
In fact, there may even be no real problems beyond the very
subjective concern that humans have now had a major influence on
future evolution. Ten thousand years from now there will be "North
American" species of animals and plants that have evolved from what
we put here. From the point where species originating outside our
continent are separated from their origins, they will experience
different pressures and factors influencing which will survive to
pass on traits to their offspring. There will be few differences
discernable in any given human’s lifetime (although some have
certainly been recorded), but given enough generations, ultimately
new species will invariably evolve.
For example, while there are already subtle differences between
house sparrows living in North America (which continued to evolve
after being put here) and those in Europe (which would also continue
to evolve from when some of their numbers were moved to North
America, but in isolation from the North American birds), to the
naked eye they still all look the same. Ten thousand years from now,
they may well be different enough to tell one from the other at a
glance, without resort to careful comparisons now required. And one
hundred thousand years from now, indeed, probably in far less time
than that, they may well be very different in appearance and habits,
indeed.
The Speech
The man who gave the speech was the Honorable Wayne T. Gilchrist
(R-MD 1st), and he gave the speech, appropriately enough, on April 1
— April Fool’s Day — in the House of Representatives.
He stated,
Mr. Speaker, today I am introducing legislation to reform the
Migratory Bird Treaty Act (MBTA) to clarify that human introduced
exotic avian species are not covered by the provisions of this
landmark law.
Earlier the courts had correctly interpreted the law, the MBTA,
to mean what it said. And what it said was that waterfowl, including
swans, were legally protected. It identified families of birds that
should be protected, under what it called a "uniform system of
protection. And in 1936, the U.S. signed on to the Mexico
Convention, which very clearly states that it is to protect
migratory birds, "whatever may be their origin," and again specifies
groups of birds by families.
In 1972, the United States signed another treaty, this one with
Japan, that again called for protection of migratory birds, without
reference to whether the birds many be "native" or not. And in 1976
a treaty signed with Russia also stipulated protection of migratory
birds without exempting "non-native" species.
But Gilchrist focused on the Migratory Bird treaty, which does
call for protection of birds at the family level.
"Families," in ornithology, are assemblies of one or more
species, or genera, linked together by various commonalities that
they share with each other, but not other assemblies. The family
that swans belong to is called Anatidae, and includes birds called
swans, geese, ducks, whistling-ducks, mergansers, scoters, magpie
geese, shelducks, pygmy geese, wigeon, teal, shovelers, scaup,
pochards, eiders, and so on. They have the three front-facing toes
joined by webs (small webs in a few species, like the Hawaiian
goose), waterproof plumage, and beaks that have thin, plate-like
straining structures, called lamellae, that strain food from
water.
Gilchrist continued,
The United States is currently a party to four international
treaties to protect and conserve populations of migratory birds.
Two years after the signing of the first treaty with Great
Britain, Congress enacted the Migratory Bird Treaty Act of 1918.
This act is our domestic implementing law and it statutorily
commits this Nation to the proper management of certain families
and species of birds.
So far so good. It should be noted that Great Britain acted on
Canada’s behalf in this matter, back in 1916. At the time there had
been enormous destruction of North American and other birds, around
the world (see www.api4animals.org/494.htm), both for meat and for
feathers. As mentioned above, one of only two swan species
unquestionably endemic to the New World, the trumpeter swan, was
very nearly extinct in the wild, primarily because of this
slaughter, not only for its meat, but for its skins, very much a
part of the overall fur trade. Tiny birds, including the
hummingbirds, which made colorful brooches, were slaughtered in
uncountable numbers, even as naturalists realized that these birds,
quite apart from their subjective esthetic appeal, might also play
significant rolls in keeping down populations of insects whose own
habits were deleterious to human interests, or eat seeds of various
weed species that caused problems for farmers. The treaty and the
laws that followed were too late for some species of birds, but in
balance the Migratory Bird Treaty Act was well-thought-out, overdue,
and effective. Species such as the beautiful snowy egret were saved.
Eastern bluebirds, scarlet tanagers, and Baltimore orioles no longer
adorned ladies’ hats.
Gilchrist continued:
After reviewing these treaties, it is clear that the list of
covered species is not exhaustive, there is an inconsistency
between migratory and nonmigratory birds and no distinction is
made between exotic and native species.
Exactly. That is how they were written, and there was no reason
to believe anything else was intended.
With regard the Migratory Birds Convention Act, some species that
I believe should have been included, such as the birds of prey, were
left off, as their role in nature was still poorly understood, and
it was believed that they were "bad" birds because they competed
with humans for "game." That, however, is not Gilchrist’s concern.
He did not want to expand its ability to protect birds; he wanted to
reduce that ability.
The original list was also made at a time when it was less well
understood that nature is not static, that new species would arrive
and establish themselves. Apart from that, at the time of the
listing there was still very much interest in, and support for,
bringing to North America birds from other continents to be
established in the wild. It is hard to believe now, but in the late
eighteenth century, men were hired to shoot shrikes on the Boston
Common, in order to protect the newly introduced house sparrow, then
called the English sparrow, which was a favorite food of the
shrikes.
Now shrikes are fiercely protected (with one of our two native
species, the loggerhead shrike, endangered or extirpated through
much of its range) while house sparrows are reviled and if they are
protected under law, it certainly is not enforced. That is ironic,
as is the fact that the house sparrow, and the common starling, both
originally imported from Europe, may be thriving here, but have
experienced alarming declines back in Europe. Indeed, the U.K.
recently sought to provide them with increased protection out of
concern for their survival.
And finally, the definition of "migratory" at the time was vague
— it was thought that most birds would fly south for the winter, and
north in the spring, and that this included essentially all of the
songbirds, although species such as the northern cardinal, the house
finch, the Bohemian waxwing, the red crossbill, the American
goldfinch, and others might be called "non-migratory" since birds
may spend their lives close to where they were born, or may move
irregularly, staying put some winters, moving others, and not
necessarily south. Some bird species may also migrate
"altitudinally" down into the lower reaches of mountains in the
fall, and up to the higher levels to breed.
The legislation was broad, and clearly meant to protect birds
that needed to be protected.
Gilchrist continued:
Despite this fact, for over 80 years, there has never been a
debate over whether exotic species should be protected under this
act. Federal wildlife authorities have consistently treated exotic
birds as falling outside of the provisions of the
MBTA.
Here is where I start to seriously part company with the
honorable Mr. Gilchrist, or those advising him. In fact, although I
am not American, I live in a country with a similar law, enacted for
the exact same reason, to support the same treaty that Canada and
the U.S. earlier signed, and I have never made the assumption that
Mr. Gilchrist attributes to "federal wildlife authorities." They do
not represent most of us; they disproportionately represent the
dwindling minority who hunt.
And they did not write the law.
Law is supposed to be interpreted in courts. But as I have said
consistently in the last few columns, wildlife managers are a breed
apart from us mere mortals, beholden to, and part of, an informal,
powerful alliance of pro-hunting interests consisting of government,
industry, pro-hunting NGOs and that small percentage of the
population who hunt for sport. I will explain later why I believe
they think that it is in their interest to destroy North America’s
population of mute swans. For now, as I stated at the outset of this
essay, they need reasons to do so that are compatible with the
values of ordinary people who so greatly outnumber them, or at least
legislators who hope for re-election, and the media, whose views
mold public opinion.
Gilchrist continued,
However, three years ago, a U.S. District Court of Appeals
Judge, in the Hill v. Norton case turned this policy on its head
by ruling that exotic mute swans, which are native to Europe and
Asia, are covered because they are in the same avian family as
native tundra and trumpeter swans.
The U.S. District Court of Appeals Judge did what U.S. District
Court of Appeals Judges are supposed to do: rule on matters of law.
It is not up to you, me, or wildlife managers to change what the law
means because it does not appease hunters.
We all represent our various "special interest groups." I won’t
hide the fact that my "special interest" is not in killing wildlife,
but in protecting it. That means that if some were seriously
threatened by mute swans, I might not like them being killed, and
would seek a more humane way to reduce their impact, but I would not
be such an active opponent to the concept of removing them from the
environment, since I put the protection of species ahead of
protection of individuals (in distinction from much of the "animal
rights" movement, whose concern usually lies more with the
individual, but of course who also recognize that species consist of
individuals).
In fact, many years ago, when mute swans first started appearing
in Ontario, in the wild, I did, perhaps naïvely, urge the federal
authorities in Canada to start to neutralize their eggs, before this
alien species became established. It was not because I believed they
would cause problems, but because I know that the potential to do so
is there. For that reason I would do what Mr. Gilchrist and his
advisors never suggest, and ban the import of non-native wildlife
for private use in the first place.
Gilchrist’s bill may have been spurred by situations pertaining
specifically to the mute swan, but it effectively removes protection
from over 100 species of birds living in America. As I said at the
outset of this article, I’d prefer that non-native species not be
introduced in the first place. Let us see if Mr. Gilchrist had
anything to say about that, in his April Fool’s speech.
He next said,
As a result, neither the States nor the U.S. Fish and Wildlife
Service can effectively manage mute swans.
What he means is, they can’t just wade in and kill them. But
should they have to?
Gilchrist continued,
This species contributes to the degradation of Chesapeake Bay
habitats by consuming large amounts of submerged aquatic
vegetation and has destroyed nests and young of Maryland-stated
listed native colonial waterbirds: least terns and black
skimmers.
Wait right there. We’ll talk about "the degradation of Chesapeake
Bay" and "submerged aquatic vegetation" later. Meanwhile, I think
that it is possible, even likely, that the majority of people
reading this, hunters, non-hunters, and anti-hunters alike, have not
seen a least tern or a black skimmer, and have only a vague idea
what they are.
But birds are my life. I’ve seen both species, I cherish them,
and I would do nothing to cause their declines.
So the question is: Have mute swans hurt them?
I have gone into extensive detail, above, to show that alien
species most certainly can be a threat to native species,
particularly on islands. The islands of Hawaii, for example, or the
state of Florida and adjoining parts of states with similar
sub-tropical habitat, are probably susceptible to the kinds of
problems that brown tree snakes have caused in Guam, and since the
snakes reached Guam via boat, I have never opposed any plans to
fumigate the holds of ships docking at tropical or subtropical
ports, even though it may mean the killing of brown tree snakes on
board, or on the island. As I type, plans are in effect, in Hawaii,
to do just that, as there have been reports of brown tree snakes
reaching land. I am not happy about killing them, but even more
distressed at the loss of still more of Hawaii’s rapidly decreasing
endemic fauna.
I have long been in favor of sterilizing bilge water, to prevent
the kinds of problems that have resulted from zebra mussels, round
gobies, and spiny water-fleas reaching North American waters via
that route. It is not something I "like," and whenever possible I
would favor non-lethal over lethal controls.
But has the mute swan really been so serious a problem to our own
native birds that every single mute swan living in the wild in North
America should be killed (such level of eradication being widely
promoted, and really the only reason to prevent this obviously
adaptable species from living as a wild species in North
America)?
That question is so pivotal that I would also like to reserve my
response to it for later, but right now I’ll just point out that by
equating the mute swan with the loss of these beautiful native
birds, the least terns and black skimmers, Gilchrist has further,
and dramatically, sought to demonize the swans in a way that would
gain sympathy with naturalists and conservationists. No one wants to
lose black skimmers or least terns.
Gilchrist finished his point:
The population of exotic mute swans has dramatically increased
in the Chesapeake Bay from five birds that escaped captivity in
1962 to more than 3,600 today. There are more than 14,000 mute
swans living in the Atlantic flyway.
Next, he said,
As a result of this Federal court decision, an argument can now
be made to apply the MBTA provisions to other introduced, feral
populations of exotic birds, such as, Eurasian collared doves,
house sparrows, English starlings, Muscovy ducks, pigeons and a
host of other species. These species were introduced by humans
after the enactment of the 1918 Act and to varying degrees they
are extremely destructive to the ecosystems in which they reside.
Pigeons, or rock doves, are alone responsible for up to $1.1
billion annually in damages to private and public property. They
are the single most destructive bird in the United
States.
His facts were wrong. House sparrows, "English" starlings,
pigeons and various other species were introduced well before
the MBTA was placed in effect. The people who wrote the legislation
knew that such birds were present. Society often sought to protect
them and import still other species. A negative side to such a
policy had yet to be realized.
Indeed, to this day, wildlife managers happily transport all
manner of game birds, game fish, and game or fur-bearing mammals
around the continent, hoping to establish wild populations for the
hunters, trappers, and fishers they see as their sole constituents.
Here in Ontario, as recently as my childhood, I recall efforts made
to bring Capercaillie, a grouse from Eurasia that is nearly the size
of a turkey, to Algonquin Park, in Ontario. It is perhaps fortunate
that the effort failed.
But Gilchrist, or his advisors, are trying to create an illusion,
a sense that well-written laws have somehow erred, creating a
loophole that has loosed a monster in our midst, and while the
monster is beautiful enough to attract the admiration of a naïve
public, it is, we must be made to believe, still a monster.
Gilchrist continued,
On December 16th of last year, my Subcommittee on Fisheries
Conservation, Wildlife and Oceans conducted an oversight hearing
on exotic bird species and the Migratory Bird Treaty Act. At that
hearing, a diverse group of witnesses testified that Congress must
reform the 1918 statute. For instance, the U.S. Fish and Wildlife
Service testified that ‘affording the protection of the MBTA to
introduced birds that are not native to the United States is
ecologically unsound, contrary to the stated purposes of the MBTA
and contrary to efforts by the Federal government to control
invasive species.’
But the U.S. has many birds that are not native, and few, if any,
years go by when still other birds reach the U.S. for the first time
on their own, attracting the rapt attention of birders. Most don’t
stay or establish themselves as breeding populations, but some do.
Whatever the agent that brings them — human, strong winds or
currents, or something else — birds, plants, and other wildlife
populations frequently move into new areas. In fact, it is more
normal for them to do so than not. When volcanic eruptions on sea
islands have completely wiped out all plants and animals, we find
that in a remarkably short time new species arrive and colonize the
barren rocks. Such dispersal and colonization is the norm, and no
species has done it more exhaustively than our own.
Wildlife agencies, at the state and provincial levels, often
encourage the establishment of such alien species as the ring-necked
pheasant, indeed, particularly the ring-necked pheasant, without any
wildlife biologist arguing against it. It is not the "alien-ness" of
a species that makes it wrong; it is what it does that creates the
problem. Until groups like API kicked up a fuss, the governments of
both Pennsylvania and Ontario wanted to kill native great
horned owls, a couple of years ago, to protect imported non-native
ring-necked pheasants. Obviously the "native-ness" of the species
did not concern them.
We will explore the concept further, later, but to continue,
Gilchrist made his next point:
It is my firm belief that it makes absolutely no sense to spend
millions of dollars trying to control nonnative invasive species
like the snakehead, brown tree snake, nutria, mitten crab, Asian
carp and zebra mussels, while at the same time expending precious
resources to achieve the same conservation standards afforded
native species under the MBTA for introduced avian
species.
The gloves are off. Chukar partridge, ring-necked pheasants, and
brown trout, all species well established in North America, but
native to Eurasia, are not mentioned. The brown tree snake is.
Nothing is said about Norway maples, Scots pines, or the plethora of
large, hoofed antelopes, Axis deer, and other exotic "big game" now
running around Texas for the amusement of "sportsmen." No. The
association is with the most notorious of invasive species — those
with the most negative reputations — lumping the mute swan in with
the really bad guys that most people would deem to be ugly, as
well.
Gilchrist continued,
Exotic, invasive species are having a huge impact on this
Nation's native wildlife and fisheries, economic interests,
infrastructure and human health. In fact, it has been estimated
they are costing our economy about $100 billion each
year.
Always question such figures. Wherever it comes from, the counter
question is, How much do they bring in? and more to the question, Is
the mute swan a contributing factor in such an amount? Gilchrist
does not elaborate.
Yes, mute swans may eat grain, but so do native waterfowl and
other native wildlife. Being non-native is not the factor. The mute
swan does not slither around eating rare, island birds and skinks,
or breaking into houses, like the brown tree snake on Guam; it does
not voraciously consume native fishes, as does the snakehead; it has
never eaten sturgeon eggs, clogged intake valves, or harbored
dangerous lung parasites, like the Chinese mitten crab; and while it
can uproot emergent vegetation, like a German carp, or nutria, after
many hours watching this activity I can assure you it cannot do so
to a degree that poses the slightest threat to any wetland
whatsoever.
We will look at exactly what it is that it is being claimed the
mute swan can do, that is so bad as to necessitate killing it off,
below. But first let’s explore more of Mr. Gilchrist’s odd, April
Fool’s Day speech. He next said:
Mr. Speaker, I have carefully read the testimony and concluded
that we can not idly sit by and allow exotic species to undermine
the fundamental core of the Migratory Bird Treaty Act which is to
conserve native species.
There is nothing like re-defining what an act does. It was
designed, primarily, to protect birds that were shared by the U.S.
with Canada.
He went on to say,
My bill is a simple common sense solution. It will restore a
nearly century-old policy that reserves the application of the
MBTA to native species. It will again allow Federal and State
wildlife biologists to effectively manage exotic species at levels
that do not conflict with the Federal and State obligations to
conserve native species and habitats.
The point is, of course, that the "policy" was illegal. Why not
simply obey the law? There is nothing in the MBTA that would prevent
the protection of property from mute swan damage, provided that
there was real economic loss, and other methods failed. What is
wanted for reasons we can surmise, but Mr. Gilchrist is careful
never to mention, is the eradication of mute swans in North America
and the establishment of a marginally less "invasive" species on the
east coast, as I shall address in a moment.
He continued,
My bill has been endorsed by a number of governmental,
conservation and environmental groups including the International
Association of Fish and Wildlife Agencies, the American Bird
Conservancy, the Izaak Walton League, the Maryland Ornithological
Society, Environmental Defense, the Nature Conservancy and the
National Wildlife Federation. I urge my colleagues to join with me
in support of the Migratory Bird Treaty Reform Act of
2004.
The bill was, however, opposed by many other organizations, and
most ordinary citizens.
One can question the motives of groups like the American Bird
Conservancy, which I, with a lifetime passion for birds and devotion
to their protection, would normally support, but even some very
reasonable conservationists and kind-hearted environmentalists of my
own acquaintance fear mute swans. The demonizers have done their job
well.
The Swan Mr. Gilchrist Ignored
In the copy of Mr. Gilchrist’s speech, introducing a bill I
consider odious, I see no mention of what I, and many champions of
the mute swan, think is the reason why the bill was presented in the
first place: the trumpeter swan.
Let me put this simply. The mute swan is not native to North
America. The trumpeter swan is. The trumpeter swan historically bred
in the western and northern regions of North America. In terms of
its ability to trample on the eggs of least terns and black
skimmers, or other species, in the voraciousness of its appetite, in
its size and the degree to which it defends its nesting territory
against other waterfowl species (and sometimes humans), the
trumpeter swan is fundamentally no different than the mute swan.
Those of you familiar with the trumpeter swan may wish to skip
this section, especially if you agree with my belief that it never
bred east of the Great Lakes, and go directly to the section "And Why Does it
Matter," below.
But for others, I think it is important to discuss the trumpeter
swan, since Mr. Gilchrist, like most of the folks who want to get
rid of mute swans, tend to downplay or ignore the link between
trumpeter and mute swan introductions.
Did I say "introductions"? It is valid to wonder how you can
introduce an already native species. Well, the point is that based
on the best available evidence, the trumpeter swan is native to
western and far northern North America, as a breeding species, and
at one time a percentage of migrants almost certainly spent the
winter on a small part of the east coast (although probably only a
small portion of the overall population did so; we will never know
the exactly what it did hundreds of years ago, as such facts were
not recorded and are lost in times long gone).
Remembering that its numbers were greatly reduced before it was
possible to document its range with great accuracy, it seems that it
was a bird that bred from Alaska down through the Rockies into what
is now the Pacific Northwest of the U.S.
How far east it bred is impossible to determine accurately,
although it almost certainly reached Hudson Bay’s western shoreline.
Perhaps it bred as far east as northwestern Ontario, although there
is no proof it bred on the shores of James Bay.
The one thing that seems most obvious is that this was primarily
a bird of the North American west and far north, and that is how it
was regarded until relatively recently.
Any of the older publications on North American birds makes the
point, but let me just refer to two of the most widely available.
Birds of America was first published by Garden City Books in
1917, as a wonderful big and beautifully illustrated book all about
the birds of North America, and has been more or less in print and
available in book stores and libraries ever since. Its
editor-in-chief was T. Gilbert Pearson, then President of the
National Association of Audubon Societies. I own two copies, the
first a wonderful Christmas present to the child I was in 1955.
Under the species account for the trumpeter swan, it gives, as
distribution,
Interior and western North America; breeds from the Rocky
Mountains to western shore of Hudson Bay and from the Arctic Ocean
to about latitude 60°; fromerly [sic] bred south to
Indiana, Missouri, Nebraska, Montana, and Idaho, and casually west
to Fort Yukon and British Columbia; winters from southern Indiana
and southern Illinois south to Texas, and from southern British
Columbia to southern California; casual in migration in the Rocky
Mountain region of United States; accidental in New York and
Delaware. Now of rare occurrence nearly everywhere.
The other venerable reference is the famous series of life
histories of North American birds by Arthur Cleveland Bent, now
available in reprint form courtesy Dover Press. Bent’s Life
History of North American Wild Fowl, Part Two, first published
in 1925 as Smithsonian Institution United States National Museum
Bulletin 130, has this to say about the distribution of the
trumpeter swan:
Breeding range. — Probably still breeds sparingly in the wilder
portions of Wyoming (Yellowstone Park), western Montana, Alberta,
British Columbia (Skeena River), and northwestern Canada. Has bred
in the past east to James Bay (Norway House), Manitoba (Shoal
Lake, 1898 and 1894), Minnesota (Heron Lake, 1883), and Indiana.
South to Iowa (Hancock County, 1883), Nebraska and Missouri west
to British Columbia (Chilcoten) and Alaska (Fort Yukon).
Winter range. — Western United States. South to the gulf of
Mexico and southern California. North to west-central British
Columbia (Skeena River) and the central Mississippi Valley. Now
too rare everywhere to outline its range more
definitely.
Actually, Norway House is not all that near James Bay, but was
first established, north of Lake Winnipeg, as an early fort
maintained by the Hudson’s Bay Company in Manitoba. James Bay,
itself, is located within the boundaries of Ontario and Quebec. It
was a clearing house for furs (including swan skins) brought in
mostly from points west.
Re-inventing History
Starting in the 1970s, a zealous effort has been made by a number
of people to convince anyone who cared that the trumpeter swan bred
farther east than originally recorded, even suggesting the birds
were found breeding as far east as Newfoundland, the easternmost
point in North America. However, there is no material evidence that
trumpeters have bred anywhere in Ontario. The only reason for
including the northwestern part of the province, and the James Bay
region, is because we know there was (and is) habitat there that
just might have been suitable for the species, and there were some
early records from near that general region.
It should be noted that up until the middle of the twentieth
century, and the advent of technologically sophisticated telescopes,
binoculars, and cameras in the hands of competent observers drawn
from the ranks of hobby birdwatchers and professional scientists,
ornithologists such as Pearson and Bent would only base initial
records of bird species on actual, preserved specimens. This
conservative approach was necessary in terms of being sure that
identifications were accurate.
Even now, when a bird species shows up in a new area for the
first time, some such solid evidence as a well-documented
photograph, if not the actual specimen, is required for "official"
documentation.
This conventional approach is the means by which we can be sure
of where birds nested, historically. There are many such specimens
recorded from the northwest, which is why, until recent decades, the
trumpeter swan was always considered a breeding bird of the
mountains of the northwest, and rare, as a breeding species, south
of the Canadian border. There was no dearth of documented breeding
trumpeter swans in the northwestern quadrant of the continent.
What has changed?
Early Personal Interest
My interest in the trumpeter swan introduction program in the
east started abruptly one warm day in July 1982. I was visiting
Ontario Place, a park in Toronto on the north shore of Lake Ontario,
watching a female mute swan with her two babies, when I did a
double-take. She had two babies, but they did not resemble other
mute swan babies of the same age I had seen. What was happening?
They were obviously young swans, but not mute swans. I was
intrigued.
I began some research and discovered that, without public
consultation, the Ontario Ministry of Natural Resources and the
Canadian Wildlife Service were experimenting with methods to
"re-introduce" the trumpeter swan to the shores of Lake Ontario.
They had replaced the mute swan’s own eggs with dummy eggs. The
mother mute swan continued to incubate the fake eggs.
Then, on the evening of Thursday, June 24, Ministry of Resources
waterfowl biologist Harry Lumsden replaced the two dummy eggs with
real eggs, but of a different species — the trumpeter swan. The eggs
had come from Alberta. They eventually hatched into the two swans I
had seen.
The previous December, Toronto’s Christmas Bird Count had
recorded 56 mute swans, then the highest number ever recorded on the
Toronto count, but still low enough that the birds could be
"eliminated," or replaced with trumpeter swans, so theory went.
I had always read that the trumpeter swan was native to the
northwest. "No," I was told by Mr. Lumsden. "It used to breed in
Ontario." That was news to me, mutely accepted.
It seemed like a win-win situation: humanely remove a non-native
species by replacing it with a native one. And when Lumsden solemnly
assured me that the trumpeter swan had once nested in Ontario, I
simply believed him, and wrote an article for The Toronto
Star that essentially praised the effort to replace, in
non-lethal manner, the non-native species with the native one.
My major concern at the time was my expectation that the
trumpeter swans, growing up under mute foster-parents, would act
more like mute swans than wild trumpeter swans. And in fact, that
started to happen, and one could visit popular shoreline parks and
hand-feed both mute and trumpeter swans, joined together in groups,
like families. In fact, one still can find tame trumpeters among
tame mutes.
I really was surprised to learn that trumpeters once bred in
Ontario, and after writing that non-critical article, I began to do
a bit of research, although not as much as Bill Whan has done
recently, when, in company with Gerry Rising, he sought to oppose
the "re"-introduction of the trumpeter swan.
Is the Trumpeter Swan Really an Extirpated Easterner?
Whan and Rising support removal of mute swans, but they are more
consistent than the waterfowl biologists in challenging the
"re"-introduction of trumpeters into eastern North America (see www.acsu.buffalo.edu/~insrisg/nature/swans.html)
and in refuting the rationales for doing so (see www.acsu.buffalo.edu/~insrisg/nature/refutations.htm).
I shall be drawing upon their work, in part, in this section, but I
refer you to their information for the details. I am grateful to
Gerry Rising for meeting with me and providing me with some
information for this essay.
Defenders of records of trumpeter swans in the east remind me of
defenders of the theory that UFOs are of extraterrestrial origin.
There is evidence, but never hard proof. And yet how do you "prove"
a negative? How do you prove there are no UFOs (maybe there are)?
How do you prove that trumpeter swans never nested on the east coast
(maybe they did)? Of the two, I’m more inclined to believe in UFOs,
but won’t do so without physical proof, in either case.
With regard the swans, it seems incomprehensible that they could
have nested in so much of eastern North America where it is now
claimed that they did so, and not a single set of eggs or preserved
specimen of a suitably young bird exists. At the time the continent
was being diligently searched by eager collectors of birds and their
nests specifically bent on proving what nested where. Or so I
believed.
In 1992 Harry Lumsden, the force behind the "re"-introduction of
trumpeters in Ontario, went so far as to suggest that the trumpeter
once nested in Nova Scotia, in Atlantic Canada. The "evidence" was a
single sentence from a French explorer, Diereville, who visited the
region in 1699 and 1700 and said, according to Lumsden, that he
could "... go Bird-nesting for the eggs of the Swan, wild Geese, and
a thousand other birds of that character."
Huh? Anecdotal evidence and the ability of non-ornithologists to
correctly identify bird species are both notoriously unreliable.
Whan, cited above, provides an erudite examination of the
meanings or possible meanings of words used by the explorer,
including "outardes," which is the French word for "bustard,"
a type of bird that is not a waterbird and does not occur in the New
World, and never has. That should prove that at least caution, if
not doubt, should pertain to the French word "cygnes," which
certainly means "swan," but does not mean that swans were seen.
Whan believes that various goose species may have been referred
to, although even that seems in doubt to me, as the explorer claimed
his observations were on a coastal island, and seems to be
describing the kinds of dense nesting colonies of nesting seafowl
found there, in numbers so great, as the explorer said, that when
disturbed the birds obscured the sky. It does not quite sound like
nesting geese to me, not even nesting snow geese.
Whan then quotes Lumsden as describing the coastal marshes of the
Bay of Fundy as being "good nesting areas" for trumpeter swans and
Canada geese. In fact, as Whan points out, trumpeter swans nest
inland, in mountain lakes and marshes, not in salt water
conditions.
My own guess is that the birds mentioned were northern gannets.
Gannets no longer nest in, or even near, the Bay of Fundy, but
indications are that these white, goose-sized seabirds were once far
more abundant along the east coast of North America than now, and
I’m willing to guess they could have been there as late as the end
of the seventeenth century, when the observations were made.
The horrendous decline in seabirds, including gannets, and other
northwest Atlantic wildlife is described by Canadian author, Farley
Mowat, in his depressing but important book, Sea of
Slaughter, published by McClelland and Stewart Limited in
1984.
John Lawson, an explorer who carefully documented his visit to
colonial America early in the eighteenth century, focused his work
on the Carolinas. He was a pretty good naturalist, and a reliable
observer with a keen interest in the Native tribes of the area. His
careful, non-judgmental reporting stood in contrast to less
reliable, more colorful and biased narratives more typical of the
explorers of his era.
Lawson wrote:
Of the Swans we have two sorts: the one we call Trompeters,
because of a trompeting Noise they make. These are the largest
sort we have, which come in great Flocks in Winter, and stay,
commonly, in the fresh Rivers till February, that the Spring comes
on, when they go to the Lakes to breed. A Cygnet, that is, last
Year’s Swan, is accounted a delicate Dish, as indeed it is. They
are known by their Head and Feathers, which are not so white as
Old ones. The sort of Swans call’d Hoopers, are the least. They
abide more in the Salt-Water, and are equally valuable, for Food,
with the former. It is observable, that neither of these have a
black Piece of horny Flesh down the Head, and Bill, as they have
in England.
The last reference was, of course, an allusion to the mute swan.
The swan he called "Hoopers" would be the smaller species we now
call the tundra swan. (There is a close relative of the trumpeter
swan in Eurasia, called the whooper swan, but Lawson would not have
known of it. It has occurred in North America as an accidental
species, arriving under its own power, thus lending weight to the
likelihood that on occasion the similarly-sized mute swan has done
the same.)
Other than on a list of species in the region, Lawson did not
again reference trumpeter swans. Because of the detail given, it has
lead to many to believe that tundra swans must indeed have wintered
on or near the Carolina coastline. To me it is compelling evidence
that they indeed did so.
Recent radio-telemetry studies of tundra swans that nested in the
far northwestern corner of Canada have conclusively shown that they
may migrate not in the "Pacific flyway," to join wintering flocks of
tundra swans in California, but on a northwest to southeast axis,
winding up on the coasts of the Carolinas. There is no reason to
think that part of the population of the more southern trumpeter
swan might not have had a somewhat similar west-to-east migration
route, thus accounting for the birds Lawson recorded.
But there are those zealots I mentioned, and to them Lawson’s
paragraph is proof that the birds also nested in the region, because
Lawson said that they went to "... the Lakes to breed."
As Bill Whan points out, Lawson mentioned "swans" eight times in
his overall work. "Other than the two above specific mentions of
trumpeter swans," writes Whan, "he brings up swans as food near
Bulls Island, S.C. on 2 January, flocks of swans on the Yadkin River
later that month, swans as food again in January, swans as food in
December, a trivial mention of a ‘Swan-Shot’ as ammunition, and
‘swan’ as an entry in a dictionary of Indian languages. He does not
mention ‘Hoopers’ other than in the passage cited above. All of
Lawson’s reported swan sightings occurred during the winter, when
both species were present. Never does Lawson recount an observation
of swans of either species in the nesting season."
Lawson, himself, never visited any inland lake in the Carolinas,
restricting his observations to "Percoarsons," or pocosins, which
are depressions or swamps. He mentions that there are "suppos’d" to
be lakes near the headwaters of the Santee River, but he never
visited them
Whan goes into detail I will spare you, except to refer doubters
to his essay, but it appears that, in fact, there were no such
lakes, then or now. The lakes were part of aboriginal myth and lore
that included what were clearly imaginary creatures, not to be taken
literally. In those days the country inland was mysterious and
largely unknown, but certainly there were tales of great lakes
within the forested interior. As Whan wrote:
An educated Englishman of his [Lawson’s] day would have read
accounts of explorers in the interior vastness of North America,
with their stories of endless forests and chains of huge lakes or
"sweet oceans," as well as unimaginably huge hordes of waterfowl,
but these distant realms would have had a semi-legendary quality
for a distant inhabitant of England, or even the coastal Carolina
colony. Lawson’s sojourn to the Carolinas took place only three
years after Hennepin published his wildly popular account of
LaSalle’s passage through the Great Lakes in search of the mouth
of the Mississippi.
Lawson might well have concluded that there were, somewhere not
too far inland, some vast lakes that generated the enormous flocks
of wintering waterfowl he encountered on the coast.
Some other early writers referred vaguely to some lakes somewhere
to the north. One contemporary, John Brickell, wrote in 1737 that
there were, indeed, two kinds of swans, and emphasizes that the
"Trumpeters" remain until February.
There were no such "lakes" in the Carolinas, then or now. This
has been understood by scholars, and any sense that trumpeter swans
were anything other than a winter visitor remained intact until
1978, when, according to Whan, members of The Trumpeter Swan Society
wrote, but did not publish, an assertion that trumpeters once bred
in the Carolinas, based on Lawson’s writings. They finally
published, twenty years later ... at a time leading up to the
determined effort to rid the continent of the mute swan. Even they
admit that Lawson, who everyone agrees was a reliable observer, can
only be cited as a source indicative that the trumpeters bred in the
Carolinas, if he is credited with "direct observation." But as Whan
so clearly indicated, the evidence indicates otherwise. Lawson never
saw the lakes, never saw trumpeter or tundra swans, himself, except
in winter.
As Whan says, "The assertion of a Carolina breeding population of
trumpeter swans rests on no direct evidence, but rather on selective
interpretations, unwarranted inferences, and speculations, guided by
what seems to be wishful thinking." While the initial advocates,
"... avoid direct assertion, repeatedly using the word ‘postulation’
to describe their hypotheses, and locutions such as the evidence
‘supports the possibility of’ their suppositions ..." those
postulations have increasingly become accepted as "fact."
But the precautions, and the fact that no evidence of trumpeter
swans breeding in Ontario or points east or anywhere remotely near
the east coast has ever been produced, is all ignored by an
influential core of zealots telling government what they all want to
hear, that the trumpeter swan once bred in eastern North
America.
Ontario?
An insight into Lumsden’s view that the
trumpeter swan bred in
Ontario is summarized by Lumsden, himself, in abstract to his paper,
"The Pre-settlement Breeding Distribution of Trumpeter Cygnus
buccinator, and Tundra Swans, C. columbianus, in Eastern
Canada," published in the Canadian Field Naturalist, Volume
98, Number 4, October-December 1984:
Explorers and fur traders reported swans present and sometimes
abundant on the St. Lawrence, the Lake St. Clair area, and the
Hudson Bay Lowlands of Manitoba, Ontario, and Quebec. Many of
those records were probably of Trumpeter Swans (Cygnus
buccinator) which have not bred in the east for more than a
century. Their bones have been found in a number of archaeological
sites, the easternmost being the Port au Choix site in
Newfoundland. The second richest find of Trumpeter Swan bones in
North America is the Jesuit mission site at Ste.
Marie-among-the-Hurons, Midland, Ontario. Tundra Swans (Cygnus
columbianus) breed only north of the tree line. They were
probably exterminated in the southern Hudson Bay region during the
period of the fur trade, and recently have reoccupied parts of
their range on the coasts of Manitoba, Ontario, and Quebec.
Possibly Tundra Swans originally bed on Ungava Bay, and perhaps
locally in Labrador. Trumpeter Swans disappeared from much of
their range well before English-speaking settlers reached the
plains. It is likely that Indians could not kill many swans with
bows and arrows, but once they got firearms they reduced or
exterminated Trumpeter Swans over wide areas. Trumpeter Swans
maybe have bred to the east of the currently accepted limits of
their range in areas with an ice-free period exceeding 145–140 d.
and where calcium levels in the soils and food plants were high,
particularly where glacial lakes and post-glacial seas had
inundated the land, and where limestone forms the
bedrock.
Ste. Marie-among-the-Hurons, now a popular tourist site about a
two-hour drive north of where I live in Markham, Ontario, was, long
ago, a gathering site for natives, including, no doubt, those
bringing furs (including bird skins and bones) from the west.
There is quite solid reason to think trumpeter swans migrated
from western breeding range to southeastern wintering range (much as
tundra swans still do, although the tundras generally nest above the
treeline, while trumpeters prefer mountain and forest wetlands below
the treeline), and so the fact that a few (very few, actually,
particularly when you discount the "worked" bones that were
obviously trade-items and could have originated a long distance
away) trumpeter swan bones have been found in eastern archeological
sites does not prove breeding; in the absence of bones from young
birds not full-grown at time of death, one cannot tell the old bones
of migrant birds from those of breeding ones.
In the interest of not taxing the reader’s patience with still
more detail, the kindest thing I can say about the 1984 paper is
that if you really want to believe trumpeter swans bred in Ontario,
you will perhaps take the unsubstantiated sightings of white birds,
or of "swans," as proof, but to me there is no such proof contained
in the paper. It does not prove otherwise, it simply opens up as a
matter of interest the possibility that trumpeter swans could
theoretically have bred in Ontario in undetermined numbers and
undetermined places but somehow failed to leave any incontrovertible
proof that they did so.
Typical, I think, of Lumsden’s way of arguing is his statement
that, "Early explorers in eastern Canada did not distinguish
Trumpeter from Tundra Swans and it is not certain which species they
referred to. Jacques Cartier ... saw ‘many swans’ on the St.
Lawrence River downstream from Montreal between 19 and 28 September,
1535. Samuel de Champlain ... also reported ‘an abundance of river
fowl ...’ on the St. Lawrence and included swans on his list, but he
did not give the date or place of his observation."
Mid-September seems early for migrant tundra swans, and possibly
even for migrant snow geese — white birds that have historically
passed through that region during migration in huge numbers —
although such large population sizes are, ironically, now generally
denied to have existed since to admit to them would be to
acknowledge that snow geese were once more numerous than they now
are (see Opinionatedly Yours #s 6 and 19). But none of it proves
that trumpeter swans bred there. You have to want to believe to see
any "proof" that they did.
Others share my own doubts that Lumsden made much of a case for
trumpeter swans breeding extensively, if at all, in Ontario prior to
1700 (although it certainly would have occurred during migration)
leading him to publish his "History of the Trumpeter Swan in
Ontario" in the Proceedings of the Trumpeter Swan Symposium,
Metro Toronto Zoo, Toronto, Ontario, 1997. The paper begins, "There
have been doubts expressed that trumpeter swans ever bred in Ontario
in early settlement days."
Lumsden blames Indians for their role in wiping out trumpeter
swans before anyone with the skill and will to do so was able to
preserve actual evidence that they bred in the east. He says, "The
richest archeological site in trumpeter swan bones (375) in North
America is at Cahokia in Illinois. This was an Indian City with
10,000 inhabitants which was abandoned just before the arrival of
Europeans ..."
Given that number of people and the number of bones per bird, it
does not suggest to me a large population of trumpeter swans, but
rather, a number easily accounted for by migrant birds or traded
bones. But Lumsden cites authors of an unpublished manuscript who
"... thought that the Cahokia swans may have been from a molting
population and not a migrating groups [sic] of birds."
Which is another way of saying they may not have been from
a molting population, and I see no reason to assume there was.
But, goes the argument, a lot of guns preceded competent
naturalists, explorers, and collectors into the Ontario, and other,
wilderness. Lumsden theorizes that in the absence of guns Indians
would have had poor luck hunting swans other than when the birds
were in their summer molt, and thus flightless. Therefore it was the
presence of guns ahead of the presence of competent naturalists and
collectors (who would have preserved actual proof of breeding birds)
that allowed the Indians to wipe out eastern trumpeter swans prior
to confirmation of their breeding being established to the standards
applied by ornithologists determining what species of birds breed in
what locations.
And so, by the end of the eighteenth century and the early
decades of the nineteenth, when the likes of Lewis and Clark, John
James Audubon, Alexander Wilson, William Bartram, and many other
such competent luminaries were scouring eastern and temperate North
America looking for, and collecting, birds and their nests, it was
too late; the breeding swans were, according to the theory,
gone.
Please understand that to me that is an interesting conjecture of
the kind I greatly enjoy. I don’t know that trumpeter swans never
bred in Ontario; perhaps they did and I like the idea of them having
done so.
I happen to believe, based on historic accounts and literature,
that in much of temperate and Atlantic coastal North America, prior
to the nineteenth century, there were vastly more individual animals
of many, but not all, species native to the region than we can even
begin to imagine. Nowadays, when a species of wildlife becomes
abundant past a certain population level, many of us think there is
something wrong, and use terms like "population explosion" or
"over-abundance" to define what is seen as some sort of disastrous
imbalance that triggers endless worry about impacts on other species
or vegetation and habitat. We don’t realize that the "norms" we are
used to are but impoverished shadows of past abundance, prior to the
arrival of Columbus.
We know, certainly, that there was once billions of passenger
pigeons, their numbers not figuratively, but literally, eclipsing
the sun. The species is now extinct and certainly such abundance
would be incompatible with contemporary society. All the things we
accuse other species of doing today, when they become "too common,"
the passenger pigeons did in large measure. They damaged trees and
habitat, for example, and the noise of them was deafening. Their
excrement accumulated to degrees deeply offensive to human
sensibilities and the growth of vegetation alike. No doubt they were
potential carriers of disease and destroyers of crops.
But that is what they did; that is the niche they evolved to
occupy and the primal environment in which they evolved supported
them, in their billions.
And we know that many North American wildlife species and
subspecies — such as the eastern races of the elk and the cougar;
the sea mink; Steller’s sea cow; and the spectacled cormorant —
failed to survive contact with the very earliest stages of the
invasion of North America by Eurasian adventurers.
Much later the vast herds of prairie bison were wiped out in a
very short time, destroying a human culture that co-existed with the
bison.
Other species — such as the Labrador duck, the eastern race of
greater prairie-chicken (the "heath hen"), the Carolina Parakeet,
and the Eskimo curlew — lingered longer, some even well into the
twentieth century, before becoming extinct, but for most of them the
origin of their demise commenced with the introduction of the
firearm, the net, the trap, poisons, city sprawl, and other such
manifestations of a growing inventive, rapacious, and rapidly
industrializing western civilization.
But even long before that, in the late Pleistocene period ending
the last ice age, there was a massive extinction of large (and
other) mammals and other wildlife species coincident to the arrival
of the first, far less mechanized, humans in North America. It’s
hard to look back some 15,000 years and know with certitude what
happened, but we can certainly make two accurate observations:
humans walked the land for the first time (although there is some
evidence emerging, still contested, that they arrived much, much
earlier), and a large number of animals, over 130 mammal species,
quickly became extinct.
Three theories for the relatively abrupt loss of native American
elephants, camels, horses, stag moose, saber-tooth tigers, giant
sloths, giant beavers, short-faced bears, dire wolves, maned lions,
cheetahs, and so many other species of large herbivores and their
predators have been put forth.
- The "blitzkrieg" theory holds that the animals were quite
overwhelmed by the prowess of armed and hungry hoards of human
hunters suddenly in their midst, and failed to survive first
contact, just as the Stephen Island wren failed to survive first
contact with a single cat. Detractors question that humans could
have such an impact on so many species in so little time employing
such primitive weapons as were available to paleoindians during
the stone age.
- The climate theory points to the rapid changes in climate
coincident with the arrival of humans and the loss of so many
large (and some small) animals in the late Pleistocene. Detractors
point to a past history of such dramatic climate changes to
suggest that if the animals survived such changes before, they
could have done so again, the only new factor being the arrival of
humans.
- Finally, there is a new theory, championed by Dr. Ross D. E.
MacPhee, a mammalogist with the American Museum of Natural
History, who thinks the arrival of disease, or as he calls it,
hyperdisease, could be the villain. Humans are still to blame, but
their impact is inadvertent and passive, not unlike the horrific
impact European disease had on native American people, killing far
more with diseases they brought with them than by use of firearms,
and in fact exterminating some tribes and cultures.
I think it likely that a combination of factors, and possibly
others (although I can’t imagine what they were), were involved.
Late Pleistocene extinctions happened in Eurasia, as well, which may
support disease and/or climate theories, although still begging
unanswered questions, and certainly not ruling out humans using
primitive weapons.
But while MacPhee puts forth credible argument, as an admitted
non-expert I am not yet willing to relinquish the first theory.
MacPhee has been quoted as saying that it is too much for him to
believe that "a few thousand Indian men with pointed sticks could
run around a continent and bring to extinction 135 species in maybe
400 years." Maybe, and if he’s right it might even give a bit of
support to my thought that it’s too much to believe that the arrival
of guns before naturalists in temperate eastern North America would
eliminate all proof of breeding trumpeter swans prior to the arrival
of the competent naturalists. There would have to be another reason
for their absence and the best reason is that they weren’t there, as
breeding birds, in the first place.
But with regard the loss of late Pleistocene fauna, given that
northern Eurasian and all North American wildlife had never
previously encountered humans, I agree with those experts (who,
unlike me, really are competent to discuss such things) who think
that it was the tameness of the animals, in conjunction with a
strong human tendency to kill far more than ever is needed, that
might have led to the eradication of species already stressed by
climate change.
Such tameness persists in many animals in places where humans are
not native (such as the Galapagos Islands, where I’ve had the
pleasure of playing tug-of-war with a boat’s rope grabbed by a
perfectly wild, but unafraid, sea lion and had birds tug at my hair
and shoelaces for nesting material) or where humans are in scant
supply, such as my own province’s north country, where birds such as
great grey owls, boreal owls, gray jays, spruce grouse, and other
denizens of lonely boreal forests tend to be very unafraid of
humans.
I don’t think that such tameness would pertain to fifteenth
century trumpeter swans. It is true that waterfowl will become
unafraid when left alone, and not hunted. But you can’t have it both
ways; if they were hunted, they were probably wary of people, and
while I agree that it is possible the old muzzle-loading single-shot
guns of that era could tip the scale, I find it hard to believe that
enough such guns preceded competent naturalist-collectors into the
temperate eastern wilderness to so quickly eliminate breeding
trumpeter swans before specimens of either eggs or young were
obtained.
And Why Does It Matter?
And what has any of this to do with mute swans?
Nothing if it were, as I would like to see it regarded and as it
has been truly presented, just an intriguing theory as to what may
or may not have happened. For example, when Lumsden writes of an
early missionary, Father Louis Hennepin, claiming to see swans in
the Detroit River and Lake St. Clair in August 1679, a very early
date indeed, I find it fascinating, indeed.
It all is, for me, a delightful ambiguity that may or may not
have as the answer the presence of breeding trumpeter swans. Like
those who believe UFOs are alien craft that visit the Earth, there
is overwhelming supportive evidence I cannot otherwise explain, but
still no proof.
But the theory has become, in the minds of certain people, fact,
and the fact has dictated public wildlife management policy, and the
policy has been to demonize mute swans with a view for nothing less
than their eradication off the continent of North America.
Why?
There have been hints at what I think is the right answer, which
I think goes something like this:
There is a serious and more or less continuing decline in hunters
in the U.S. and Canada, with a coincident decline in revenues that
pay for the salaries and research studies, conferences and other
cool things engaged in by government wildlife biologists interested
in remaining employed with lots of neat activities.
Thus, it is seen as important to encourage hunting "as a wildlife
management tool," hunting being an essential source of the needed
income.
One way to do this is to increase hunting opportunities, and one
way to do that is to increase game species and numbers.
Mute swans do not qualify as game. They tend to be big, bumbling,
tame, residential, and beloved and familiar to ordinary men, women,
and children who admire them and don’t want them shot.
Wild swans are different to the degree that they are unfamiliar
to the majority of urbanites and don’t waddle up to you looking for
handouts or glide with serene grace and elegant beauty through urban
waterways. There already is legal hunting of tundra swans, without
most folks even being aware of it.
"Wild" swans are untamed birds who fly high overhead, make a
tremulous honking sound that stirs the blood the dedicated
outdoorsman, and provide relatively sporting targets as they come in
to land.
If trumpeter swan numbers could be increased they, too, could be
hunted, assuming that they acted as they used to act, and as tundra
swans still do, being wild and wary migratory waterfowl. If nothing
else their presence guarantees decades of need for population
monitoring by the self-same wildlife management biologists
championing their "re"-introduction.
As a matter of fact, believe it or not trumpeter swans already
are legally hunted, in the western U.S., even as efforts to restore
them continue. Those efforts are at least in areas where the bird
unquestionably bred. The problem there is that hunters (or anyone
else) can’t be expected, under hunting conditions, to distinguish
between tundra swans (legal game in some western states) and
trumpeter swans (protected because of their rarity, but sometimes
mistaken for tundras, and shot).
Since shooting the protected trumpeter was illegal, and since
numbers of trumpeters shot illegally did not seem to significantly
impede the growth of the population overall according to the
government wildlife biologists’ very own studies (what a surprise!),
it was deemed more hunter-friendly to open a limited "take" of
trumpeters, than to inconvenience the hunters to the degree involved
when they goofed and shot the wrong birds.
In other words, an "oops" factor was built into the regulations
so that if tundra swan hunters shot a trumpeter swan — oops —
they were not in violation of the game laws because their hunting
licenses would allow a limited take of trumpeters.
Wildlife management agencies are nothing if not hunter-friendly.
Some of the folks involved in the not-always-easy task of
re-establishing the trumpeter swan in the west got their hackles up
at the thought of the birds they were struggling so hard to boost
ever higher off the endangered list were suddenly legal game, and
worried that hunters, by virtue of focusing on migrating birds,
might kill the very birds (migrants) most valuable to their
restoration efforts (non-migrating trumpeter swans tend to die in
winter as their marshland homes freeze up and thus do not contribute
to restoration of the species but the high flying migrants the
hunters were shooting, do), but of course the hunters won the day,
for all the usual reasons.
All of that is a story that relates to the west, where the deer
and the buffalo, trumpeter and tundra swans all roam, or used
to.
But what about in the east?
West Meets East
Let me clarify that there is nothing new in wanting to add a
species to the fauna of a region where it does not otherwise exist.
There are starlings in our midst because back in the Victorian era
there was a guy who felt that all the birds named by Shakespeare in
his plays and sonnets should also live in America. The starling was
named once in Shakespeare’s writing. Harry Lumsden, talked about
above as the driving force behind trumpeter swan "re"-introduction
into Ontario, once wanted, I recall from my childhood, to introduce
a large species of Eurasian grouse, the undoubtedly non-native
capercaillie, in the 1950s. I’ve heard him suggest, in casual
conversation, that by releasing young Canada geese into Toronto
harbor many years ago, he may be responsible for the huge and not
always appreciated population of urban geese now found in the city.
The late Norm Scollard, then head of the defunct and non-lamented
Riverdale Zoo of Toronto, used to make a similar claim. The fact is
that urban Canada geese are established in numerous cities without
either gentleman’s help; cities fulfill latent needs of Canada geese
by providing so much turf grass to eat.
And let me also clarify that I don’t think that all people
involved in releasing trumpeter swans in eastern North America think
of themselves as aiding the aspirations and needs of the wildlife
management and hunting community. And no doubt many of them believe
with great sincerity that they are introducing into the east as a
breeding species a western bird that once bred there. From UFOs to
trumpeter swan nests on the east coast, we believe what we want to
believe, and evaluate or discard evidence accordingly.
But the bottom line is that all parties — trumpeter swan
releasers, government wildlife biologists, and hunting interests —
tend to support the release of trumpeter swans in the east, and so
do many naturalists, birders and environmentalists, if, and it is a
big "if," they believe that they belong there, and are native as a
breeding species. They have found the means to convince themselves
that it is.
What stands, and waddles, in the way of those plans is none other
than the mute swan.
And why is the mute swan an impediment?
Well, although no truly clear reason has been given for why the
mute swan is truly inimical to trumpeters in my presence, I’ve heard
lots of unclear reasons. For example, a bit of Googling on the
Internet turned up this gem, from the Wisconsin Department of
Natural Resources Outdoors and Conservation News for May 14, 1997
(www.dnr.state.wi.us/org/caer/ce/news/on/1997/on970514.htm):
"The Department of Natural Resources initiated a program this spring
to control mute swans — an exotic Eurasian species ... with the
ultimate goal of eliminating them from the wild in the state by the
year 2005."
Why? They go on to say, "Mute swans ... compete with trumpeter
swans for nesting and feeding sites. They are more aggressive than
trumpeters, and are more tolerant of other swans within their
breeding territory, according to Pat Manthey, an avian ecologist
with the DNR Bureau of Endangered Resources. These factors tend to
favor the continued expansion of mute swans over the reintroduction
of trumpeters, she said. ‘We need to act now to control mute swans
before the populations become unmanageable.’ Manthey said. ‘While
their population is only 150 to 250 now, it is increasing at a rate
of about 17 percent annually.’"
In fact I have yet to find evidence that trumpeter swans are more
docile in their relations to other waterfowl, or anything else, than
mute swans.
At least three things can be said in a positive vein about
Wisconsin’s plan: one is that they sought to implement humane
control of mutes, and not resort to shooting, at least in 1997;
second, they are if not in, at least close to, historic breeding
range of the trumpeter swan; and third, well, in their words:
"Finally, Manthey says, the DNR is recommending that mutes
[sic] swans be listed as injurious or nuisance animals under
proposed changes in the state’s captive wildlife law." If that means
that people will be prevented from keeping mute swans in captivity
in the first instance, it at least reflects a degree of consistency
of concern significantly greater than that displayed by the
Honorable Wayne T. Gilchrist, who simply wanted the swans killed,
without bothering to address the root cause of alien species getting
loose and establishing themselves.
Some defenders of mute swans have told me that the effort is to
establish trumpeter swans as breeding species on the east coast.
I’ve found no direct proof of that, but it is what will happen
anyway, whether wanted or not.
What is wanted is impossible: wild trumpeter swans nesting in
their historic breeding range (pushed far east of where we have
proof that it was, in order to make it all the easier) and migrating
down to the east coast to winter, but not linger, as it used to be
when Europeans set up what were to become permanent settlements in
what is now America, so very long ago.
Efforts underway to "teach" introduced trumpeter swans to migrate
include first training them to follow ultralight aircraft, and then
leading them along the desired migration routes, not from what we
know to be historic breeding grounds, but the controversial eastern
sites, to the east coast.
There has been limited success with this method used for other
species, such as that most famous of rare birds, the whooping crane.
But the jury is out. As I was completing this essay, in late
April/early May 2005, word came of stray whooping cranes entering
Ontario, one heading due east into Quebec. Such "lost souls" occur
within many bird species (it is part of what keeps birders on their
toes, always looking for rarity far from their normal habitat; just
as excitement over the wandering whooping cranes was ebbing, came
word from near Point Pelee, Ontario, of a neotropic cormorant, the
first of its kind ever seen so far north). But within such a small
population as exists for whooping cranes, each individual counts
much more toward the continuation of the species, than is true of
the odd stray white-winged dove or neotropic cormorant.
What we should have learned by now (and I think outside of
government wildlife management circles, most of us have) is that
migration, at least for waterfowl, is a rather plastic and variable
sort of thing. It used to be thought that birds were something like
automatons, their urge to migrate and the routes they chose
programmed into their very being, encoded and virtually immutable.
The continent was divided into a series of north-south "flyways" of
particular importance to waterfowl, with the birds dutifully taking
off in the fall from northern breeding grounds, and streaming into
the Pacific, Central, Mississippi, Eastern, or Atlantic Flyway, to
wind up in southern climes.
The first issue identified, above, is that mute swans breed at
greater densities than to trumpeters. But do they? The problem is
that of comparing apples and oranges. Breeding density is to a very
large degree a function of habitat. What that means is that if mute
swans nest in richly-vegetated marshes filled with emergent
vegetation, and trumpeter swans nest in cold mountain lakes, the
habitat of the former supports more birds than does the habitat of
the latter. Should trumpeter swans nest were there is more food, one
can expect nesting density to increase.
If the trumpeter swan was a bird of the wilderness, the mute swan
is already part of the fauna of eastern North America, and has a
well-established, viable population that fits within a largely
contrived and managed farm, urban, and suburban landscape that
mimics that of the Eurasian part of its current range.
Regardless of whether the trumpeter swan bred in the east or only
visited the east as a migrant, what then existed in eastern North
America is gone, and has been replaced by a very different
environment, much closer to the European environment, with a greater
number of shared plant species.
The mute swan has been criticized for eating so much eel grass on
the east coast, most particularly in Chesapeake Bay. So did the
trumpeter swan, at least in winter, before it was wiped out, and by
all accounts combined numbers of wintering tundra and trumpeter
swans were enormous, and would have had a huge, if seasonal, impact
in absolute numbers. If, as appears to me to be inevitable, the
trumpeter swans begin nesting on the coast, why is their impact less
significant than that of the current mute swans? From the
perspective of eel grasses (or the other species are fed upon) it
hardly matters whether they are consumed by mute swans or by
trumpeter swans of equal number, weight, size, and appetite.
I would agree that it might matter if, as was likely the case in
pre-Columbian North America, the great flocks of trumpeter and
tundra swans that fed in Chesapeake were seasonal, and highly
migratory, while the mute is a year-round resident, but not only has
the case been made that the trumpeter was also a year-round resident
in at least parts of temperate eastern North America, the
current-day reality is that the trumpeters being introduced into
temperate eastern North America are largely not migratory (and the
habitat in which they evolved as a migratory species in the east
does not exist). They occupy wetlands, just like mutes (although at
the local level they can be found in wetlands from which mutes are
absent, and vice versa) and are as aggressive as mutes and have
essentially the same metabolic needs.
A couple of years ago an organization called Bird Studies Canada
wrote a letter to the Canadian government, urging the total
eradication of mute swans in North America. I responded with a
lengthy critique, dated August 29, 2003, which forms much of this
part of the current essay. I sent it to every director of Bird
Studies Canada. In a unified show of rudeness, not one responded. My
concern was that while BSC was gung ho to eliminate mutes, it was
silent on the issue of trumpeters in the east.
The BSC letter was virtually a model of mute swan hate
literature. For example, it stated that, "Mute Swans have recently
been hybridizing with Trumpeter Swans on the Pacific coast."
I may be naïve, but I would have expected better than this from
BSC, an organization that does good work when it does not get
political, under the influence of the pro-hunting and wildlife
management members of its board.
All geese, ducks, and swans are notorious for hybridization, and
the fact of an isolated incidence of hybridization where mute swans
do not have a stronghold (it is generally considered that they are
"feral" only in eastern North America, essentially in the Great
Lakes region to the U.S. mid-Atlantic coastal region) and where
trumpeter swans do have an established population, hardly threatens
the survival of the latter species. My heavens, tundra swans are far
more likely to hybridize with trumpeters (they are very closely
related) than are mutes, especially in non-captive situations.
Goose, duck, and swan hybrids abound. Surely if hybridization is an
issue, BSC might begin by taking a position against the release of
mallards in eastern North America, since mallards hybridize with a
number of other species, including the American black duck, which is
pretty much endemic to eastern North America and surely is more at
risk than trumpeter swans of losing its genetic integrity than ever
is the trumpeter swan.
"Hybrid swarms" do occur naturally. If we want to be
philosophical, we can speculate that if humans are result of nature,
we are a part of nature, and therefore so is human endeavor, with a
physical translocation of a bird in a cage inherently, biologically,
and ecologically no different in any categorical way than a
translocation caused by a windstorm, or continental drift.
BSC and the Swans
The BSC letter was dated July 23, 2003, and addressed to to Mr.
Steve Williams, U.S. Fish and Wildlife Service, and signed by
Michael Bradstreet, on behalf of BSC, and Scott Petrie, apparently
on behalf of Long Point Waterfowl and Research Fund, with a copy to
Trevor Swerdfager, Director General of the Canadian Wildlife
Service.
The letter, as strong an indictment against the mute swan as one
might expect, stated, "It is well known that exotic waterfowl can
have negative ecological impacts on native species, particularly if
the introduced species is aggressive, competes with other waterfowl
for food or habitat, and/or hybridizes with native species."
Even though modern studies of bird population changes (including
those ably documented by BSC, for which the organization is to be
commended) are of relatively short duration, we have, in the few
centuries (at most) when records have been kept and observations
reliably made, seen significant shifts in breeding ranges of many
bird species. This is particularly true of birds of the Northern
Hemisphere. The mute swan is native to the Northern Hemisphere, and
while we may draw arbitrary geopolitical lines to separate
subsections of the Northern Hemisphere, there is no reason to assume
that the mute has never previously been, nor ever could eventually
be, found within the North American side of such geopolitical
boundaries in the absence of human intervention.
Those recent studies (ironically documented by one of the
recipients of my 2003 letter) of mute swans in the James Bay
lowlands indicate dispersal ability. Interestingly, fossil remains
of what were identified as a mute swan–type swan (by Alexander
Wetmore; see Birds of the Pleistocene in North America, A.
Wetmore, Smithsonian Miscellaneous Collections, Vol. 138, No. 4)
have been reported from California.
A North American mute swan or mute swan progenitor is to be
expected given that mute swans are most closely related to Southern
Hemispheric swan species, specifically the black-necked swan of
southern South America. They have common ancestry that existed in
North America. The presence of the black-necked swan demonstrates
that there be a common mute/black-necked swan progenitor
(characterized by the straight trachea that prevents these species
from having the loud voices of the tundra/trumpeter/whooper swan
complex of the northern hemisphere) occupying range in the western
hemisphere between Eurasia and South America; a form lost in the
north during those same Pleistocene extinctions discussed above.
We cannot know as much as we would like to about what great
changes in animal distribution occurred during the ebb and flow of
glaciers since the beginning of the last great ice age, about 1.9
million years ago, but we do know that the climatic conditions in
which the mute swan–type fossils would have been laid down in what
is now California were much more like those now found in its current
undisputed "natural" range in Eurasia, and its new range in eastern
North America.
We also know that other Paleoarctic swans, specifically including
the whooper swan, with its obvious close relationship to the
trumpeter swan (some authorities lump them as a single species) and
the Eurasian race of the tundra swan (which some authorities give
full species status to, as the "Bewick’s" swan) do enter North
America via Alaska, from time to time.
There is no scientific merit in assuming that the mute swan never
has done so, even though we can probably assume that in modern times
it has not done so and was not, prior to European intervention, an
established breeding species in North America (although
interestingly it did appear in a display of mounted birds in the
1876 U.S. Centennial Exposition, in Philadelphia, called "Wildlife
of the Rocky Mountains" and it appears in the earliest artistic
renderings of east coast colonial America, from the seventeenth
century).
Therefore the concept of the bird being non-native is at least
potentially moot, with "native" being a somewhat relative term.
Since the end of the fifteenth century until the beginning of the
industrial era, in the nineteenth century, I think it was relatively
simple to determine if range expansions of birds were largely or
exclusive "natural" or anthropogenic in origin. But after that the
distinction becomes blurred, and is a matter of degree.
In terms of holarctic species, the gulls excellently illustrate
what I mean. Do we consider the black-headed gull to be non-native
in North America? What about the little gull, the lesser
black-backed gull (now becoming common in North America), the
black-tailed gull, the band-tailed gull, the kelp gull, the
yellow-legged gull, the slaty-backed gull, and the Ross’s gull?
Arguably most or all of these species were not "originally" native
to North America, and yet while some may have been "overlooked" in
early avifaunal inventories, demonstrably at least some have
expanded their range within, or into, North America, in recent times
and some have pioneered new breeding range in North America within
living memory. Furthermore, to the degree that at least some of
these species are scavengers, human endeavor in the form of garbage
production and management have undoubtedly increased carrying
capacity and thus aided the survival of pioneer individuals, and
thus aided range expansion.
In critiquing the Migratory Bird Treaty Reform Act of 2004,
Priscilla Feral of Friends of Animals also addressed the highly
variable nature of bird distribution:
For example, naturalist William Bartram referred to a bird who
could have been a king vulture (Sarcoramphus papa) being
sighted in Florida in the late 18th century. A case
could be made that king vultures were native to North America and
might even be a candidate for reintroduction.
Certainly as much a candidate as the trumpeter swan! The king
vulture is still found in Mexico, as much a part of the continent as
is the western range of the trumpeter.
Feral continued:
The red-breasted goose (Branta ruficollis) has been
recorded on the Chukotsk Peninsula of Siberia, 40 miles west of
the Seward Peninsula of Alaska.
According to The Sibley Guide to Bird Life and Behavior,
"Several Florida records of the Cuban grassquit (Tiaras
canora) may be escapees, or they may be natural wanderers,
from Cuba or the Bahamas, where the species has been introduced
...
In fact, there is a plethora of West Indian bird species that
have either been recorded in the U.S. within contemporary times, and
continue to show up quite regularly, or were known to have once been
in the U.S. For example, the Key West quail-dove gets its name from
having once lived in Florida's Key West, but the entire population
was wiped out. It still occurs in much of the West Indies.
Thus, unless BSC opposes the presence of such species as the
lesser black-backed gull in North America, it would appear safe to
guess (since the organization won’t say) that the absence of a
species within North American avifauna at the time of the beginning
of permanent European colonization of the continent is not an issue
for BSC.
If it is, then the question is begged, what of the large number
of gull and waterfowl species that appear in North America, but
either breed exclusively in Eurasia or did so up until recent times?
There is no indication that BSC opposes the presence (in some cases
the demonstrably increasing presence, even breeding) of such species
as the whooper swan, Eurasian race of the tundra swan, bean goose,
pink-footed goose, emperor goose, barnacle goose, spot-billed duck,
falcated duck, Eurasian race of the green-winged teal, Baikal teal,
Eurasian wigeon, garganey, common pochard, tufted duck, or smew.
When I asked, no one answered.
In their letter I believe that Bradstreet and Petrie were making
a distinction, however, between those species whose range expansion
is not entirely of human cause, and those that are. No one had
caught up large numbers of lesser black-backed gulls or tufted ducks
and released them in North America (although the latter most
certainly is very frequently kept in captivity in zoos and private
waterfowl collections in North America, and a captive origin cannot
be ruled out, without further evidence, for any given tufted duck
appearing in temperate North America; similarly the other waterfowl
species named above are also, in varying degrees, but commonly, kept
in captivity in North America), but notwithstanding anomalies
mentioned above, the mute swan significantly or exclusively owes its
current North American population to human endeavor.
BSC’s position then begs the question of whether or not it has a
policy against all such introductions, or if the mute swan has been
singled out. If we can put geopolitical boundaries out of our minds
(they are of no interest to the birds), and simply oppose
introductions of a given species from a part of the planet where it
"naturally" occurs to a part of the planet where it does not, the
question becomes should BSC also be opposed to the presence of the
house finch in eastern North America? To be consistent BSC should
also be opposed to the presence of the mallard in eastern North
America, and particularly so as unlike the case with the house
finch, the mallard introductions from Prairie Provinces and States
to eastern North America were deliberate and are ongoing and the
threat they pose to at least one other species, American black duck,
through hybridization is widely believed to exist.
So far as I can tell, BSC has also not taken a position against
the introduction, also accidental, of the northern bobwhite to
eastern Ontario, where it appears not to be an historically
occurring species, but where it escapes from game farms.
Of course it could be argued that all three examples are
different not in matters of degree but in kind, because the
translocations are within the same continent, but I would again
suggest that the distinction is somewhat arbitrary, particularly for
a waterfowl species as water, even ocean water, is not a barrier to
ducks, geese, or swans.
Unfrozen water is usually a significant barrier to Galliformes
(chicken-like birds, such as quail, grouse, pheasants, partridges,
and turkeys), and without human intervention such species as
chukars, gray partridges, and ring-necked pheasants would not occur
in North America. But they do. Does BSC support eradication of North
American populations of these species? Surely if their Eurasian
origins are the issue, it should do so. Using the quality of "logic"
favored by Bradstreet and Petrie, one could point to the decline of
native Galliformes, specifically the sharp-tailed grouse and the
greater prairie-chicken, coincident to the establishment of the
alien ring-necked pheasant and gray partridge.
If not, might we assume that it is, in fact, not the
"non-nativeness" of the mute swan that is the reason for support not
only of lethal culling, but of eradication? Logic dictates that if
simply being alien is not the issue (assuming, of course, that BSC
is not simply hypocritical, an assumption I can’t make until my
query is answered, and after two years I am not holding my breath),
there must be another reason why a bird that is enormously popular
with the general public should be eradicated.
The Bradstreet and Petrie letter goes on to say of the mute swan,
"The species’ size, extremely aggressive disposition, and voracious
appetite, make Mute Swans a strong competitor that has substantial
regional impacts on native waterfowl and their habitats."
In an email exchange with Michael Bradstreet on August 22, in
response to my question he averred that BSC had not considered
ramifications in the re-introduction of the trumpeter swan into
eastern North America (and certainly the Bradstreet-Petrie letter
seems to be inherently favorable to the re-establishment of eastern
trumpeter swans, although in his email to me Michael Bradstreet
seems to share my own belief that the historic proof of trumpeter
swans breeding in the east is not 100 percent solid — that is
something we probably will never know for sure and the level of
burden of proof will vary among people depending on their own biases
and values).
Why has BSC taken the extraordinary position that the
introduction of a species that is so similar to the mute swan in so
many ways that BSC finds objectionable, should not first be
considered? The mute swan is already part of the fauna of eastern
North America, and has a well-established, viable population that
fits within a largely contrived and managed farm, urban, and
suburban landscape that mimics that of the Eurasian part of its
current range.
But when anthropogenic in origin, many translocations of species
have caused concerns that arguably at least have some merit within
socially accepted value systems. The best example of such a concern
involving waterfowl I can think of at the moment that is entirely
anthropogenic in origin involves an Eurasian species, the
white-headed duck, which has extremely fragmented, patchwork
distribution in Asia, plus a small number of year-round residential
birds breeding in small, isolated pockets in Spain, Portugal and
France, Algeria and Tunisia. A closely related North American
species, the ruddy duck, has escaped captivity in England. The ruddy
duck is migratory, and interbreeds with this western population of
white-headed ducks, a genuinely endangered species. There has been
approximately a 60 percent decline in white-headed ducks over one
decade, although heroic conservation efforts in Spain, Portugal, and
France are slowing rates of decline, with no clear idea of overall
population size.
While habitat degradation and loss has been identified as the
main root cause of the decline, fish nets, hunting pressure, and
lead shot toxicity have also contributed to the reduction of the
white-headed duck. Thus there has been concern that hybridization by
the ruddy duck will degrade the genetic integrity of the western
population where conservation effort has been most promising, a
process that could eliminate the pure form. Whether this is "good"
or "bad" depends on subjective value systems, but the point I would
make is that such a threat could not be considered valid if
advocated by a group that worried about mute swans hybridizing with
trumpeter swans, or other such nonsense contained in the BSC
letter.
Consider what is probably only to a lesser degree than is true of
ruddy and white-headed ducks, an anthropogenic-driven hybrid swarm
here in North America.
On the northern Pacific coast, the glaucous-winged gull is
native, while on the southern Pacific coast, the western gull is
native.
But there is now — no doubt thanks to increased human activity
that most significantly includes open garbage disposal, commercial
fishing producing lots of "waste," and fast-food outlets where gulls
love to scrounge — a wide hybrid zone from northern California up
into British Columbia.
If you are in that zone, finding "pure" western or
glaucous-winged gulls is a challenge requiring DNA workups to
meet.
Here the threat to the genetic integrity of either species is at
least as great, I would argue greater, than that posed by ruddy
ducks with respect to white-headed ducks, the significant difference
being that both gull species are, respectfully, abundant.
Still, both could be "lost" into a third, hybrid-derived form, if
nothing is done.
The removal of all glaucous-winged gulls, western gulls, and
hybrids between Central California and central British Columbia
would reduce or eliminate the likelihood of that happening. Is such
a slaughter of birds the next action that BSC will promote? If not,
why on earth would the organization raise the specter of
hybridization being in any way relevant to how much submerged and
emergent vegetation exists in Chesapeake Bay, except to villainize
the mute swan far beyond the realm of anything remotely connected to
a real concern, and, of course, placate hunter-driven interests
which, in turn, drive so much wildlife policy in both countries (and
support so much research funding).
The letter continues, "Populations of feral Mute Swans in North
America have been growing at an astounding rate! Despite limited
efforts to control them, the Atlantic Flyway population (U.S.
portion) grew from a few birds in 1962 to close to 15,000 birds
today. Mute Swans have also been colonizing the Great Lakes
watershed and the population is now nearly 10,000 birds."
So? At the very least this tells us that the habitat appears to
be viable for mute swans, as indeed would seem to be true for what I
would think would be obvious reasons. The highly altered habitat of
eastern North America, one of the most heavily populated and
industrialized regions on Earth, clearly more closely resembles the
"native" environment occupied by mute swans in Eurasia, including
equally populated and industrialized regions in western Europe, than
it does the pristine, continuously forested landscape that existed
prior to the extirpation of whatever trumpeter swans lived in the
east.
Waterfowl are enormously adaptable, when not persecuted.
For example, in Toronto, near where I live, there has been in the
last few decades an enormous increase in breeding gadwall,
historically a prairie species of small duck, right in the downtown
core, where it abuts Lake Ontario. And just recently another prairie
duck, the canvasback, bred on the Leslie Street Spit, on the city’s
waterfront. Throw in the American black ducks, mallards, and Canada
geese already nesting in the city in large numbers, and you have a
situation which seems to irritate traditionalists who romanticize
wild and wary "wildfowl."
And so it is inevitable that, in time and with enough effort put
into the task, trumpeter swans may also adapt to this environment,
so greatly altered from the land of their ancestors.
Mutes clearly have done so, whether or not trumpeters ever
will.
But all indications being that trumpeters will simply be another
large urban waterfowl species inhabiting waterfronts and maybe
marshlands in temperate eastern North America, chasing as many or
more birds as mutes, eating as much food as mutes, biting as many
fingers as mutes, eating as much vegetation as mutes, depositing as
much excrement as mutes, and not especially distinguishable from
mutes by the general public.
Or so it seems.
The crested myna is a jay-sized songbird native to warmer parts
of Asia, particularly southeast and central China and Taiwan.
However, in the 1890s they were released into the city of Vancouver.
By the 1920s the population there was estimated at 20,000 birds, and
they were showing up as far away as the U.S. border. Crested mynas
are in the same family as the common starling and there was panicked
concern that the species might emulate the starling and spread
across the continent, possibly to the detriment of native
species.
Even though crested mynas are, like common starlings, highly
insectivorous, their diets are variable enough to conceivably
threaten crops, such as the fruit orchards of the Okanogan Valley of
the British Columbia interior to the east, and the orchards and
vineyards of Washington, Oregon, and California, to the south. In
1935 the United States government solemnly demanded that "every
precaution" be taken to check the population to "prevent its spread
into the U.S."
Sound familiar? But as has happened with so many introduced
species, after expanding into virgin habitat the numbers peaked, and
then went into decline, and in fact, recently the last North
American bird died, hit by a car while hanging about where its mate
had earlier met a similar end. (There have been intriguing tales of
survivors, à la the ivory-billed woodpecker, but by most accounts
the species is gone). To imply, as BSC does, that initial growth
rates of newly arrived species will inevitably thus continue until
there is major ecological destruction is as unwarranted as it was
when the same sort of fear-mongering was directed toward the crested
myna.
We have seen common starling, house finch and house sparrow
numbers peak and decline as well. The cattle egret, a species native
to the Old World that reached the New World via South America by
means unknown (probably natural dispersal, but possibly via human
cause, perhaps as stowaways on boats), rapidly expanded through
North America in the middle part of the previous century, even
pushing its breeding range into Ontario, but has since settled down
to smaller numbers, filling, like the mute swan, an ecological niche
that did not exist prior to European colonization of North America,
at least in the east. Exponential growth is not without limit; newly
established populations often expand greatly at first, but
ultimately level off at lower than peak levels, or may enter cyclic
change — no population level is static.
We have set the table for the mute swan, we have seated it at the
table, so now before we punish it for what we have done, surely we
should ascertain that there are real, not silly, or contrived,
grounds for doing so. But the Bradstreet and Petrie letter goes on
to say:
The rapid growth rate of Chesapeake Bay’s Mute Swan population
(as well as other populations) can probably be attributed to a
number of factors:
1) Chesapeake Bay is climatically similar to the native
Eurasian range of Mute Swans,
2) there are few natural predators of Mute Swan nests, cygnets
or adults on the Bay,
3) Mute Swans are dominant over all other members of the
Chesapeake Bay waterfowl community,
4) minimal interference by humans as they are protected under
the Migratory Bird Act,
5) reduced availability of lead artifacts (Mute Swans are
highly susceptible to lead artifact ingestion),
6) the recent warming trend, as cold winters result in reduced
over-winter survival and future reproductive output,
7) Mute Swans have large clutch sizes and are capable of laying
replacement clutches.
There is a subtle bias inherent to some of these points; they are
again more politically, than scientifically, motivated.
I agree with the first point, but consider the second one: "2)
there are few natural predators of Mute Swan nests, cygnets or
adults on the Bay ..."
Arguably this is, at the very least, debatable, and is the sort
of poorly considered statement that seems designed to increase the
process of demonizing the mute swan rather than seriously
considering the situation as it stands. In North America, including
the vast region of Chesapeake Bay, there are arguably as many or
more potential predators of mute swans, and their eggs and cygnets,
than in many, most, or perhaps all of their Eurasian range.
Surely such mammals as the raccoon, gray fox, Virginia opossum,
and coyote are potential egg and/or cygnet predators that are native
to North America, but not to Eurasia. Great horned owls and snapping
turtles have no ecological equivalent through much of the range of
the mute swan in Eurasia. Red foxes are common to both sides of the
Atlantic, as are several species of avian raptor, but I think it is
sloppy to suggest that the limiting factors represented by predators
potentially at play in the Eurasian part of the species’ range are
somehow greater than in the North American part, particularly as it
appears the reverse is true.
At any rate I doubt that predators are a significant limiting
factor anywhere in the mute swan’s range beyond the level of the
individual, or in some isolated instances, such as island
populations, and this red herring is, I suggest, part of a
fear-mongering approach to the demonization of the species,
politically driven, yes, but not based on common sense or science.
It is radical extremism.
And now consider the third point: "3) Mute Swans are dominant
over all other members of the Chesapeake Bay waterfowl community
..."
This represents further demonization, another cheap shot that
brings no pride to BSC, and in fact, if the "Chesapeake Bay
waterfowl community" is meant to include migrant waterfowl, it is
nonsensical. I don’t doubt that mute swans are well adapted to the
environs of Chesapeake Bay, but I would question that they are in
some way better adapted than any other species to all of the bay at
all times of the year, and that they out-compete all geese, diving
ducks, and dabbling ducks (and presumably American coots, grebes,
and other non-Anatid waterbird species) that occur in the bay. Below
I will explore their relationship with other species more
thoroughly.
But first, please consider the fourth point: "4) minimal
interference by humans as they are protected under the Migratory
Bird Act ..."
Yes, they are protected as the result of a recent U.S. court
decision which showed that the U.S. Fish and Wildlife Service had
been misrepresenting the Act. The Court clearly understood the
species fits the definition provided by law, and thus the no one has
the "right" to demand its total eradication.
That said, however, there is another point to be made. The
decision reflects hard work by dedicated people who champion the
species. Their value systems may be different from those of hunters
or those people who would kill swans, but if they are to be
discounted, surely solid reason, not non-sequitor, illogical,
elitist, and inconsistent arguments and red herrings, should be
presented.
Humans are part of the environment (and ironically, ultimately no
more "native" to North America than the mute swan) and so our
actions also impact on the environment — in the case of Chesapeake
Bay, far more so than anything a bird species could accomplish, and
people who realize such facts are most certainly not wrong in doing
so, whatever they may conclude as a result of honest and logical
deduction.
The fifth point is perhaps strangest of all, but also perhaps
indicative of a deeply subtle and political motivation. It
identifies: "5) reduced availability of lead artifacts (Mute Swans
are highly susceptible to lead artifact ingestion) ..." as a factor
in the feared population expansion in mute swans (how this explains
the success of other species introduced to environments where they
can flourish, from zebra mussels in Lake Ontario to European rabbits
in Australia, is not explained ... clearly lead or its absence is
not a relevant factor in a fairly easy-to-understand biological
phenomenon of successful colonization by a newly arrived
species).
Lead is one of the most seriously toxic substances in the
environment, and there have been significant die-offs of millions of
birds as a result of lead poisoning from ingested lead "artifacts,"
which in reality usually means lead shot (and also lead weights used
by sport anglers) fired by waterfowl hunters (See
Opinionatedly Yours
#20).
Yes, mute swans are highly susceptible to lead "artifact"
ingestion, and so are trumpeter swans and so are other species who
are obligatory consumers of grit. Grit is the term given to small
stones or gravel that grain-eating birds consume to aid digestion.
The material lodges in their gizzards, where it helps to grind up
the grain the birds eat. But the birds cannot differentiate between
small pebbles that they can safely swallow, and highly toxic lead
shot fired from shotguns.
It surely is a good thing that there has been a "reduced
availability of lead artifacts" but that would hardly account for
growth in mute swan populations above carrying capacity of the
environment or to a degree that significantly compromises survival
of other species.
The birds evolved in the absence, not the presence, of "lead
artifacts" and the presence of such lead, and its toxicity, is
hardly to be considered a natural limiting factor in populations of
any species. If we were to put more lead into the environment there
might be fewer mute swans, but also fewer everything else
susceptible to lead poisoning. Of course there are hunters’ groups
who don’t care about all that, they want their ammunition of choice
and have lobbied against the legislation that forced waterfowlers
(but not other hunters) to use non-lead shot.
The sixth point reads, "6) the recent warming trend, as cold
winters result in reduced over-winter survival and future
reproductive output ..."
Of course the "recent warming trend" is not all that "recent" a
"trend" and if the concerns about global warming continually
expressed by experts are meritorious (and I can’t imagine how much
more proof is needed that global warming is a reality), the effects
of warmer winters will extend far into the future with accumulating
effects on species’ ranges and population densities we can only try
to imagine, but with some species increasing, some decreasing, with
some species ranges moving northward.
Nothing is clear cut since the intricacies of cause and effect
interrelationships of changes in climate occasioned by global
warming are too many and too varied to be successfully plotted on
some model, but we can guess that winter survival will be enhanced
for many species, not just mute swans, so it is premature to assume
a net decrease in other species in response to a projected increase
in mute swans as a function of global warming, as that appears to be
the concern.
Finally, we read: "7) Mute Swans have large clutch sizes and are
capable of laying replacement clutches ..." It is normal for all
waterfowl to be capable of laying replacement clutches, and the
statement that mute clutch sizes are "large" is simply not true in
any relative sense.
For mute swans the clutch size is about 5 to 7 average, 4 to 12
exceptionally.
For tundra swans the clutch size is about 5 average, 3 to 7
exceptionally.
For trumpeter swans the clutch size is 5 average, 2 to 9
exceptionally.
For Canada geese the clutch size is 5 to 6 average, 2 to 11
exceptionally.
For mallards the clutch size is 19 to 12 average, 7 to 16
exceptionally, with second broods common in translocated birds such
as those in eastern North America.
For American black ducks the clutch size is 8 to 10 average, 6 to
15 exceptionally.
For blue-winged teal the clutch size is 8 to 12 average, 6 to 16
exceptionally.
And so on. The success young birds have in surviving is based on
multitudes of factors ... for example, while the trumpeter swan lays
fewer eggs than the mute on average, incubation period is shorter,
which may (or may not) convey a survival advantage to cygnets.
The bottom line is that it is not clutch size that determines
survival, it is the overall ability of the environment to sustain
the organisms. Mature northern cod lay millions of eggs, but that
has not prevented them from becoming endangered. The endangered
white-headed duck, mentioned above, lays 5 to 8 eggs, exceptionally
10, or about the same as the mute swan, but is still in decline.
The most abundant bird species ever recorded in North America,
the passenger pigeon, had only 1 or 2 eggs per clutch, but required
an environment (the same one that hosted the eastern population of
cougars, elk, eastern bison, heath hens, wolves, and, at least as
visiting migrants, trumpeter swans) that no longer exists, and
neither does the bird, which was extinct by 1914.
But the environment that replaced the original one is
particularly suitable for mute swans, whose populations are already
showing signs of leveling off in areas where they have been
particularly successful. The changing nature and suitability of the
environment for mute swans was made in point one, "1) Chesapeake Bay
is climatically similar to the native Eurasian range of Mute Swans
..." with which I would agree except that obviously it should be
expanded to include temperate eastern North America. Were we to
restore eastern North America to primal conditions found by the
first European invaders, mute swans would be far less likely to
survive, but that is not going to happen.
The letter continues, "This rapidly growing Mute Swan population
is of concern for numerous reasons. Mute Swans are one of the most
aggressive species of waterfowl in the world; they regularly attack
other species of waterfowl, as well as other wetland dependant
birds. They are also known to attack humans."
Once more, if this kind of radical and extreme fear-mongering
discredits BSC, greatly. Arguably the "most aggressive
waterfowl species in the world" is the trumpeter swan, which also
regularly attacks other species of waterfowl as well as other
wetland dependent birds — oh, and people. If aggression were a
concern, surely BSC should first address its objection to the
"re"-introduction of trumpeter swans into eastern North America. I
believe there is a record of one attacking a small plane. They carry
the same weight as a mute swan, have the same strong wings, the same
nail at the end of what is, if anything, a slightly longer beak, so
surely if the emergency wards of our hospitals are going to fill
with swan-bite victims (I wonder if visitors to Stratford on the
Avon know the risk), and this is a BSC concern, BSC should
immediately be pulling out all stops to prevent any more effort to
bring back the trumpeter swan before it is too late.
I apologize for the sarcasm but such a high level of foolishness
is hard to respond to without sarcasm. Such anti-animal biases
harken to the darkest days of early "wildlife management" and market
hunting mentality where there were good birds and bad birds.
Consider that a medium-sized hawk called the northern harrier is
another relatively recent arrival to North America, but one that has
been here long enough (probably post-glacial, or less than ten
thousand years) to have evolved into a distinct subspecies, but
certainly now a holarctic species with paleoarctic origins. In other
words, like the mute swan, it originated in Eurasia. There are no
other harriers in North America, and I can easily imagine that had
the northern harrier (called "hen harrier" in English-speaking
Europe) arrived on the watch of Bradstreet and Petrie, especially
via anthropogenic means, there would have been great alarm raised
over a predator that kills far more waterfowl and other marshbirds
than swans ever could (indeed, it is exceptional, not normal, for
swans to kill any).
Not only that, these northern harriers lay 4 to 6 eggs, on
average, and exceptionally up to 12! And they often do so right in
the midst of the best duck-breeding marshes there are! They love to
eat ducklings! In the old days that was all quite enough
justification to list them as one of the bad birds to be shot on
sight. They have been known to attack humans (and with talons,
too)!
And yet, aside from whatever opinion Bradstreet and Petrie and
BSC may have of them, decades of increasing understanding of ecology
and predator-prey relationships have led us to understand that they
are not a threat to other bird species, however easy it is to so
portray them (and however much such portrayal used to occur).
I regret that such understanding has yet to permeate BSC’s
policy-making process, or that of wildlife agencies on both sides of
the Canada/US border, and that simplistic "bad bird/good bird"
mentality lingers.
I would strongly urge these kinds of people to stop dreaming up
reasons to hate birds and stroll along waterfronts of many North
American towns and cities where, each day, thousands of interactions
occur between adults and children and mute swans without ambulances
running a jitney between shoreline and medical centers. Yes, a mute
swan can hurt someone, but a canoe ride or the drive from Toronto to
Long Point or from San Francisco to Point Reyes for a picnic or some
birding is far more fraught with far, far greater risk than any
peril posed by the mute swans in our midst.
The letter continues, "Mute Swans maintain large territories
(>6 ha) during mating, nesting, brood rearing and foraging; they
have even been reported to occupy territories throughout the
year."
Unless mute swans nest in the middle of Chesapeake Bay, they
obviously are not a problem in terms of consuming eel grass ... they
can’t be both on territory and in the middle of the Bay. Again there
is to this sentence a touch of worst-case-scenario fear-mongering
that leads to images of angry mute swans killing anything that dares
cross the boundary of immense territories maintained year round.
That is in stark contrast to field experience I am sure many readers
of this document have had, where mute swans are among many species
co-habiting wetland environments. But at any rate, they are no more
aggressive than trumpeter swans. The real question, here, is that if
the species is so destructive, what is its impact on the same and
similar species elsewhere?
That is a point I will address in greater detail, below.
Meanwhile, personal observation will point out that not only do
those territories include many other marshland fauna, they tend to
exclude Canada geese, which presumably is a "good" thing given the
desire by so many government agencies, particularly in the U.S. at
the municipal level, to depress numbers of urban Canada geese. So
far trumpeter swans seem slightly more likely than mutes to nest
away from urban areas (particularly in the seemingly unlikely event
they regain their "wildness") and thus are far more likely to be a
limiting factor in wetland ability to sustain waterfowl than mutes,
which tend to nest where trumpeters do not, on average — although
even that is changing; in the absence of persecution we are seeing
more Anatid and other waterbird species, such as the Red-necked
Grebe, nesting in urban wetlands; the dramatic increase in nesting
(and wintering — those who winter in Toronto are not "selected
against" by shotguns) gadwalls along Lake Ontario’s northern shore
has corresponded to the increase in mute swans — one wonders how
they manage with all those bloodthirsty mute swans sharing the same
environment, but there they are, for any of us to see.
The letter states: "By displacing other waterfowl from preferred
feeding areas, the amount of wintering habitat available to native
species of ducks, geese and swans on the Bay is effectively reduced.
This probably reduces the carrying capacity of coastal wetlands
(with respect to number of birds and capability of birds to acquire
body fat) for wintering waterfowl."
"Probably"? Instead of such absurd speculation, look at the
facts. Mute swans exist in Eurasia, in the wild, in some of the best
temperate wetland birding locations I have ever visited. Why, if
they are such a threat, have they not wiped out the species with
which they associate in Eurasia? Let us consider just Western
Europe, since it is geographically and ecologically closest to
eastern North America, and shares a great many of the same species
of plants and birds. Why would the same species thrive in the
company of mute swans over there, and fail to do so here?
Consider: Among the coastal bird species found in both Europe and
Atlantic North America, including Chesapeake Bay are:
horned grebe eared ("black-necked") grebe red-necked
grebe brant mallard northern pintail northern
shoveler common Teal greater scaup common eider common
scoter white-winged ("velvet") scoter long-tailed
duck common goldeneye common ("goosander")
merganser red-breasted merganser common moorhen various
shorebirds such as the black-bellied (grey) plover red
knot sanderling ruddy turnstone dunlin whimbrel and
various gulls and terns herons
and so on.
Additionally, while there are many species found in North America
in the range of the mute swan that are rare or absent in Eurasia,
the reverse is true, and in many instances there are more or less
ecological counterparts; for example, the redhead is a North
American diving duck, the very closely related common pochard is
Eurasian; the two species of yellowlegs are north American
sandpipers, the two species of redshanks are closely related
Eurasian species. We have the great blue heron, they have the
ecologically similar grey heron. We have the ring-necked Duck, they
have the tufted duck. There is no decline in either numbers or
number of species of birds in Eurasia as a result of mute swans and
one can visit wildlife sanctuaries and see large numbers of wide
varieties of birds co-existing with mutes.
But BSC ignores all that, and in vilifying the mute swan,
continues, "Mute Swans have also been reported to kill ducks, Canada
Geese (Branta canadensis), Pied-billed Grebes (Podilymbus
podiceps), and herons, and cause nest abandonment in Least Terns
(Sterna albifrons), Black Skimmers (Rynchops niger),
Forster’s Terns (Sterna forsteri) and Common Terns (Sterna
hirundo). Therefore, while the quality and quantity of wetland
habitat continues to decline in North America, increasing
populations of aggressive Mute Swans serve to further reduce the
carrying capacity of remaining habitats for waterfowl as well as
other wetland dependant avifauna."
Wow ... that’s quite an indictment. Surely it is too silly for
words. But since the words are there, let’s examine the
argument.
I’m surprised that while supporting the U.S. Fish and Wildlife
Service’s plans (indeed, going beyond them) to reduce the mute swan
population in North America, there is no such concern about the fact
that if mute swans reduce Canada geese, they are doing something
commendable ... or is the death a Canada goose at the hands ... I
mean beak ... of a mute swan somehow less acceptable than the U.S.
Fish and Wildlife Service’s choice of death by rounding up
flightless birds and gassing them, as has been done in so many
communities in the U.S.?
Has anyone noticed a reduction in Canada geese within the North
American breeding range of the mute swan? If there’s a problem here,
one would assume that it would prevent Canada geese from becoming
established where there are already mute swans established. That
would be Europe. Lots of mute swans, and, guess what ... lots of
Canada geese, too, as a newly established, non-native "alien." I
wish Canada geese had not been introduced to Europe just as I wish
mute swans had not been introduced to North America, but they were,
and in the process proved that the contention that mute swans
negatively impact Canada geese is absurd.
If the level of science to be used by BSC is so low as to be able
to say, with a straight face, that mute swans are reducing the
carrying capacity of the environment for Canada geese, then how can
any statement about any species made by BSC be trusted?
So far as pied-billed grebes are concerned, they are not native
to Europe (although birders will tell you that when they arrive in
Europe as strays, which sometimes happens, they tend to stay a long
time, thus are able to survive even in native mute swan
environments). The little grebe, which is native to Eurasia, shares
much of the same habitat as the mute swan, and in size and habitat
preferences and so on, is comparable to the slightly larger
pied-billed grebe. The very first great crested grebes I ever saw
were in St. James’s Park, in downtown London, England, where I was
told that they breed, along with a huge assortment of waterfowl
species, including both species found in North America and ones that
are similar to North American species, and including, yep, mute
swans.
I have spent perhaps several dozen hours, in total, observing,
sketching, and photographing these various birds at St. James’s
Park, and while I’ve certainly seen mute swans chase other birds,
I’ve yet to see the carnage this letter would seem to imply is
inevitable, nor any indication of a statistically decreased carrying
capacity for waterbirds even in this very small, discrete urban
wetland environment, as a result of the presence of mute swans. If
waterfowl can thrive in a relatively small pond in a park in the
heart of London, with mute swans, I’m rather inclined to think they
might be able to hang on in the vast expanse of Chesapeake Bay, with
mute swans.
Herons are mentioned, with no species given, nor is it explained
how mute swans can kill or displace a significant number of herons.
Does this simply refer to some recorded observation of a swan
chasing a heron? Sure herons get chased, even herons chase herons,
but so what? Surely the depredations of herons by swans are
statistically insignificant. One can again not take my word for it,
just look; herons and mute swans do share wetlands. There are many
predators that climb up into trees in heronies after eggs and young,
but mute swans are not among them. A peregrine falcon may stoop upon
a heron, but mute swans don’t do that. A fox may carefully stalk and
pounce on a night-heron, but mute swans are not so inclined. I again
point out that on both sides of the Atlantic herons and mute swans
share habitat without bloodflow.
Least terns are endangered in North America, but the very similar
little tern is less so in Eurasia, which makes no sense if mute
swans are going around causing nest abandonment. Of course were a
mute swan, human, horse, dog, beach-buggy, or anything else to
blunder into a least tern nesting colony, there could be nest
abandonment, and I’m pretty sure a search of the literature will
reveal instances of this happening. It is something that, given the
status of the least tern, should be guarded against, but not by
eliminating all of North America’s mute swans, humans, horses, dogs,
or beach-buggies, although if BSC were to support the last one, I
would cheer it on.
The vast percentage of the breeding and wintering range of the
Forster’s tern and black skimmers lies outside the North American
range of the mute swan. Once more, the fact that terns will abandon
nests if disturbed is both well known and hardly grounds for
extirpation of any species that may cause such abandonment. And that
brings us to the common tern, which certainly co-exists in mute swan
habitat throughout much of the Northern Hemisphere, including
Ontario and the Atlantic seaboard.
Long after writing my unanswered letter to BSC, while preparing
this essay, I spoke to the state official who had first reported
mute swans trampling nests of least terns and black skimmers. It
seems that the problem had been that swans had managed to trod all
over two small "oyster bars" where the terns and skimmers were
nesting, trampling the eggs. Mute swans do have big feet, but no
bigger than those of trumpeter swan, who would do exactly the same
sort of thing if present during the breeding season. While the
evidence that they ended nesting success for the two locally rare
(and in the case of the least tern, rare overall) species is
circumstantial, it is convincing to me. I have no doubt that nests
were trampled by the swans, and subsequently abandoned. Such things
do happen. Native predators, such as herring or great black-backed
gulls, could do similar things. Certainly introducing yet another
big swan that will ultimately breed there is hardly a solution to
the identified problem.
It is not good science to mount a theory (mute swans are bad
birds) and then support it by searching the literature for every
reference, no matter how obscure, of some problem, no matter how
minor, that can be placed at the webbed feet of the species to be
villainized, and then draw the conclusions made by Bradstreet and
Petrie, and other detractors of the mute swan in North America. On
the contrary, it is sloppy, political, silly, and an affront to
rationality.
The letter says, "Competition in waterfowl will most likely occur
on wintering and/or spring staging areas where food is most
limiting. Whereas Chesapeake Bay wetlands are most important as
wintering habitat for native waterfowl, these habitats are now being
used year round by Mute Swans."
I addressed this concern, above, by pointing out that native
waterfowl of North America are greatly similar to native waterfowl
of Eurasia, where the horrific scenarios implied in the Bradstreet
and Petrie letter have not played themselves out in thousands of
years and that mute swans cannot simultaneously be both on and off
their territories. I am not trying to trivialize concerns about the
ecological integrity of Chesapeake Bay, but those concerns are not
resolved by killing off the birds, of whatever species, who eat the
vegetation.
Bradstreet and Petrie continue: "Being primarily herbivorous
aquatic foragers, Mute Swans consume daily at least 3-4 kg (wet
weight) of submerged aquatic plants, including leaves, stems, roots,
stolons, and rhizomes. Because adults also tend to paddle and rake
the substrate to dislodge food for them and their cygnets,
additional vegetation is estroyed [sic] and uprooted, further
decreasing the availability of food for native waterfowl."
Because I had heard so much about Mute Swans destroying and
uprooting emergent vegetation, a few years ago I decided to closely
watch the behavior. Yes, they do uproot some plants, but marshes are
dynamic ecosystems, and continually filling in through the process
of succession. Animals such as carp (also not native), muskrats
(which are quite native to North America) and mute swans tend to
slow this process (a little), and nowhere did I see levels of plant
destruction that seemed to be significant as a result of mute swans
pulling up, and seeming to "play" with, emergent vegetation. Yes,
adult mute swans do paddle (how dare they!) and even manage
"dislodge" food for their cygnets, but they have been doing so for
hundreds of thousands of years in habitats like that which exists in
temperate eastern North America. Their paddling and uprooting to
feed cygnets is not the issue with regard Chesapeake Bay, so much as
their winter feeding, addressed below. The many real threats to
Chesapeake Bay do not include paddling swan feet.
In saying, "At high densities, Mute Swans can overgraze an area,
causing a substantial decline in the availability of submerged
aquatic vegetation, before they move to a new area ..." there is
reference to subjective values familiar to those of us who have had
to deal with traditional wildlife, fishery, and forestry management
practices that serve limited and immediate human interests.
"Overgraze" is such a value-laden statement.
This point may be sophisticated (although I don’t think so) but
in ecology "over"-utilization of a resource by a component of that
resource is something of a non-sequitor. It is a non-viable
paradox.
What is meant is that grazing can occur to a level objectionable
to a human interest or value. The swans "can" graze more than the
U.S. Fish and Wildlife Service wishes them to graze. This is a
little like what the situation would have been had the Indians of
pre-Columbian southern Saskatchewan complained that because they
wanted to live in forests, Bison were over-grazing (and that is not
a far fetched scenario in the world of wildlife management, where
elephants have been charged with "overgrazing" African veldt or
whales with eating too much krill and fish, to the detriment of
other oceanic wildlife species). To the degree that mute swans rely
on a replicating (or renewable) "resource" the lack of that resource
will control mute swan populations.
The letter continues: "In extreme cases, Mute Swans can even
eliminate some plant species from an ecosystem." In "extreme cases"
anything can happen; that is why they are extreme.
What is "extreme" about Chesapeake Bay is the amount of
environmental degradation visited upon it as a result of surrounding
human populations and supportive industrial infrastructure. Surely
anyone claiming to be a conservationist should look at silt deposit
patterns, upstream erosion patterns, toxic pollution levels, water
current alterations, boat traffic, global warming, and other factors
in reducing loss of carrying capacity for all wildlife. If the
environment once sustained what the literature suggests could have
been enormous (compared to today) flocks of trumpeter and tundra
swans, brent, canvasbacks, and other waterfowl, can we honestly
think that its current failure to do so, a failure that predates
colonization by mute swans, is nevertheless the fault of mute
swans?
Why was there a die-off of eel grass in the early 1930s? I don’t
think even Bradstreet and Scott would blame that on mute swans
(although maybe they would, their letter places me in the mind frame
of Alice exploring a Wonderland where magic trumps cause-and-effect
reality).
In fact, it is surely at least as "scientific" to point out that
the recovery of Zostera eel grass nicely coincided with the
arrival of the mute swan, and therefore eel grass benefits when new
species of waterfowl enter the scene. It is surely as foolish, as
well, and my point is that it is absurd to postulate a two-species
food chain and super-simplistic cause and effect relationship
because it is felt that waterbirds, of any species, eat too
much.
The letter from BSC continues, "Mute Swans increase their feeding
rate during spring and summer because more food is required before
feather moult and egg laying which probably influences the
availability of submerged aquatic plants to wintering waterfowl."
Well, at least they placed the qualifying "probably" into that
sentence, but if eel grass is the issue, there is a strange
supposition that eel grass beds are a prime source of food at a time
of year when so much other food is available (breeding season) and
in places more compatible with mute swan (and other waterfowl and
waterbirds) nesting habitat.
However, it is not just eel grass we need be concerned about,
according to BSC. Again we see the qualifying "quite likely" and
"could" when the letter continues, "During winter, Mute Swans quite
likely consume nutrient storage and over-wintering structures
(tubers), which could have a long-term impact on aquatic plant
availability and species composition. For instance, perennial
species such as Vallisneria americana and Scirpus
americanus, [survive] over winter as vegetative buds and the
survival of these structures is the main determinant of the next
season’s growth. Therefore, feral Mute Swan populations reduce the
carrying capacity of Chesapeake Bay wetlands for native waterfowl
directly via aggressive interactions (reduced space) as well as
indirectly through resource depletion (reduced food)."
Scirpus (bulrush) is a widely distributed genus, with many
species somehow managing to survive in wetlands where mute swans
have lived for uncounted thousands of years. I can find no
indication that these prolific plants are elsewhere (or anywhere)
seriously threatened by mute swans. The health and population levels
of Scirpus are more dependent on such factors as water depth,
water level fluctuations, exposure, sediment loads and water
salinity, and shading by taller emergents than on lack of
consumption by birds. If we are going to speculate so freely as BSC
is inclined to do, we could argue that mute swans "quite likely" can
assist Scirpus to the degree that they reduce such shading
and scatter plant fragments capable of re-establishment.
Vallisneria (wild celery) is predominately a freshwater
plant that can survive in saltwater environments (chloride susfate,
sodium, magnesium, and calcium) at concentrations as high as 20
percent. In Chesapeake Bay, it appears that the presence of wild
celery in Chesapeake Bay varies as a function of changes in local
salinity levels, at least some (if not most) of which are
anthropogenic — caused by humans — although other factors are
complex and interactive. In the Bay wild celery lives where salinity
is 3,000 to 5,000 ppm. But when water reaches more than 6,660 ppm it
becomes toxic to the plant. Freshwater flow apparently can increase
salinity tolerance for Vallisneria, in the transition zone of
the Potomac River (that feeds into Chesapeake Bay) where the plant
dies off when the salinity surpasses 13,000 ppm, and is unable to
survive upstream chlorine contents. We can’t blame mute swans for
such variables which are proven factors in Vallisneria growth
and distribution. Chlorine is put in the water by us, not swans.
I am not suggesting that mute swans and other waterfowl do not
eat water plants; they do. But they have done so from time
immemorial, and declines in these plants in absolute terms are
anthropogenic. Because these species of water plants have such
effective reproductive strategies, their predators would become
extinct long before they would, and even if there was a significant
depletion as a result of predation by waterbirds, so long as other
factors, mentioned above, did not prevent it, robust regrowth would
be inevitable.
If, however, the factors mentioned above are in play, too much
salinity or chlorine, for example, extirpation is inevitable with or
without any species of waterfowl involved. We see the same or
ecologically similar species of wetland plants co-existing with
waterfowl, including mute swans, for all recorded, indeed,
pre-recorded, time.
BSC’s letter continues, "Given the similarity of climate between
Eurasia and North America, the unparalleled competitive abilities of
Mute Swans, and almost total lack of predators, it seems highly
probable that Mute Swans will continue to increase exponentially on
Chesapeake Bay."
Here we go again. The "exponential growth fear" that so often is
evoked to justify a political mandate to destroy wildlife by evoking
fear of nature "out of control."
The only species that can experience unlimited exponential growth
is one that has unlimited resources, and there is no such
species.
Yes, human growth has been exponential with only regional checks
(for example, mass die-offs from starvation and disease in parts of
Africa), but that is because of relatively recent access to
technology that provides huge non-metabolic energy sources
unavailable to any other species. It cannot continue indefinitely.
Not to get silly, but even if an unlimited source of food, water and
energy could be made available to every human for all time,
exponential growth would still ultimately reach a limit when every
millimeter of the planet was occupied by humans too tightly packed
to allow fornication.
But when a species, any species, encounters a new and supportive
environment, growth may be exponential until limiting factors kick
in, as they most certainly appear to have done with the mute swan in
the most established parts of its North American range, as carrying
capacity is reached, and it certainly has done with the mute swan in
its Eurasian range (although carrying capacity has changed, upward
in some places, downward in others, in that Eurasian range; only
where it has increased upward do we hear rumblings of "too many"
mute swans in Eurasia).
The letter, having set up a pair of straw dogs (that predation is
a significant limiting factor in waterfowl population growth — which
I challenge — and that there are fewer mute swan predators in North
America than in Eurasia, where the species is most assuredly not
experiencing exponential growth nor harming other species — which is
simply not true, there are, it would seem, more potential mute swan
predators in eastern North America than in western Europe), then
goes on to say, "Therefore, as natural causes are unlikely to limit
the population in the near future, it seems prudent to control the
species before the population becomes much larger. Given that ‘only
about 10% of the historic levels of submerged aquatic vegetation
(SAV) remain in the Bay’ and that Chesapeake provides continentally
critical wintering waterbird habitat, we feel that anything less
would be irresponsible."
I don’t know what constitutes "less" but I would argue that
unless the reasons that the levels of SAV have so declined in
Chesapeake Bay are addressed (and surely that is the business of
conservationists), whatever the mute swan may do is moot.
Such loss of SAV has been "exponential" predating the arrival of
the mute swan, so that whether or not the mute swan, canvasback,
American coot, or any other species that eats SAV is a factor in SAV
depletion, and no matter what degree, none are the primal or root
cause of reductions.
Conservationists should understand that the effects of human
population are the cause of the loss of SAVs in Chesapeake Bay. Of
course if pollution kills all but three plants and a duck or goose
or swan eats that last three, we could say that the bird was
responsible for the loss of the plant, but surely that is absurd —
the tactic of those who wish to deny human culpability.
And yet that is exactly what BSC is doing, joining the U.S. Fish
and Wildlife Service in looking not at the primary factors
contributing to the degradation of this once richly
wildlife-populated wetland, but a scapegoat that can be demonized as
an alien invader.
I have sadly come to expect this sort of thing from the U.S. Fish
and Wildlife Service and from the current presidential
administration but surely not from what I would hope would be a
scientifically accurate Canadian conservation organization seeking
public support for its work and staffed by people at least some of
whom ought to have more knowledge of ornithology and of conservation
principles.
The letter continues: "Control programs have been implemented in
a number of eastern U.S. states with varying degrees of
effectiveness. Rhode Island began a control program of egg addling
and pricking in 1979; despite the fact that 9378 eggs were destroyed
in 1629 nests over a period of 22 years, the population increased by
over 500%. Vermont, in contrast, reported no Mute Swans in 2000,
apparently as a result of a lethal control program. This is
supported by the fact that population models indicate that the most
effective way to reduce population growth for a long-lived species
such as the Mute Swan is to reduce adult survival rates. This could
be done through capture and removal programs, or through culling.
Swan captures and removal during wing moult may be an appropriate
solution in some situations, but it is costly and doubtful that a
sufficient number of repositories exist for these birds. Several
hundred birds would have to be captured and removed annually and
measures would have to be taken to ensure that captured birds are
never released back into the wild. Apart from the difficulty of
finding places to deposit them, it seems doubtful that sufficiently
large numbers could be captured in a cost-effective manner."
I don’t believe a valid case has been made to remove mute swans,
and find the concept hypocritical in the absence of similar concern
for the introduction of the trumpeter swan. Therefore I don’t
believe it appropriate for a "conservation" organization to muse on
how to resolve a problem that does not exist.
That said, why am I not surprised that somehow BSC is leaning
toward lethal control?
The Bradstreet and Petrie letter continues, "We do realize that
lethal control measures are not appropriate in all cases. Therefore,
we strongly support Integrated Population Management as proposed in
the draft Environmental Assessment for the Management of Mute Swans
in the Atlantic Flyway. Under the proposed action, the Atlantic
Flyway (U.S. portion) Mute Swan population would be reduced from an
estimated 14,300 birds to 4,675 in five to ten years, while a number
of non-lethal control measures would also be implemented. While we
support and commend this proposed population reduction, we suggest
that the FWS consider implementing a nationwide Depredation Order
for this exotic species with a goal of eliminating wild Mute Swan
populations. There is no biological basis for ‘maintaining’
populations of Mute Swans while there are sound ecological reasons
to eliminate all wild populations."
If there are sound "ecological" reasons to "eliminate all wild
populations" they should be presented. Instead, as I’ve pointed out
at length, all that BSC has put forth is some half-baked fears and
emotive scare tactics.
Since the Mute Swan is protected under the Migratory Birds
Convention Act in the U.S., it is incumbent upon the U.S. government
to "maintain" it. The undisclosed, undetermined, theoretical number
of ducks in any way "displaced" by Mute Swans pales to
insignificance compared to the number easily saved by simply not
removing a percentage the millions killed each year by the small
percentage of the human population on the east coast that still
engages in sport hunting, but there is a political reason why that
won’t happen, why the tens of thousands of American black ducks,
scoters, and eiders that could be allowed to survive to breed in
habitat that is available, won’t.
But what could happen, and what I personally think conservation
organizations should work to make happen, is a reduction in
those primary factors that contribute to loss of habitat for
all waterfowl species. As we’ve seen, extensively, in
both North America and in Eurasia various waterfowl species quite
easily cohabit with mute swans, and BSC is simply very wrong to
think otherwise. But they cannot cohabit as easily with toxic
pollution, drainage, siltation, shotgun blasts, droughts, loss of
nest-sites, excessive human disturbance, etc.
Astoundingly, the letter goes on to say, "It is our desire that
the United States Fish and Wildlife Service and the Canadian
Wildlife Service collectively decide not to support the maintenance
of viable populations of this invasive species and that they
ultimately coordinate their efforts to eliminate free-flying feral
population of Mute Swans throughout North America. We firmly believe
that there is ample scientific and anecdotal evidence to support the
reduction and eventual elimination of Mute Swans in the wild. As
such, an EIS should not be necessary for this exotic species,
depredation permits should be continued to be issued, and a General
Depredation Order implemented in the future."
This approach is nothing less than Hitlerian, and should not, in
my opinion, be tolerated by conservationists, humanitarians, or
scientists. It reflects at the very least a lack of understanding of
the nature of ecology and disregard for the opinion of a large
majority of people whose values are not shared.
I want to emphasize, here, that I do not, in principle, object to
the complete removal of the entire population of an alien species
where there is a real and scientifically demonstrable threat to a
native species, or indeed, a significant population of a native
species, and one can cite many such examples, from the loss of the
entire population of the Stephen Island Wren to a single cat, as
described in detail above, to the kinds of problems caused by rats
in Alcid (puffin, auk, and murre) colonies off Britain, to goats and
other alien species in the Galapagos, to the threat caused to
flightless, ground-nesting endemic birds in New Zealand by
non-native ferrets, cats, and other species.
But it makes an outright mockery of such genuine and clearly
legitimate conservation concerns to concoct such specious argument
as put forth by BSC to eliminate a continental population of a
species that is well beloved by so many people and which fits, as
BSC acknowledges, an existing ecological niche, albeit one derived
from human activity.
I believe that it is entirely hypocritical of BSC to have had
such a casual attitude, as indicated by Michael Bradstreet in his
email to me, toward the "re"-introduction of the trumpeter swan into
the very same highly modified environment without first considering
that the ecological ramifications would at the least reach, and
could easily surpass, those posited for the mute swan.
It is hypocritical to single out the mute swan for elimination as
a wild species in North America because of its non-native origin
without similar policy toward the ring-necked pheasant, chukar and
gray partridge, if the "non-native" status of the species is the
issue, since clearly the "ecological" concerns raised are highly
speculative at best, foolish at worst, and not borne by the
day-to-day reality visible in the field on both sides of the
Atlantic.
BSC’s position is a microcosmic indicator (and perhaps not so
"micro-" at that) of what the last essay in this series examines:
the total infiltration of, and control over, the decision-making
processes by which wildlife policy is set in North America,
primarily to benefit the funding provided by the ever-decreasing
minority of North Americans who hunt wildlife; who would kill a
swan. At the time I wrote the letter at least two directors of BSC
were on the staff of the Long Point Waterfowl and Wetlands Research
Fund.
According to its own literature, "LPWWRF was established in the
late 1980s through the conservation-minded efforts and funding
provided by the Bluff’s Club, a private hunting and conservation
organization concerned with the long-term welfare of waterfowl at
Long Point. LPWWRF is administered by Bird Studies Canada and
continues to be supported primarily by Bluff’s Club members. LPWWRF
also receives generous support from Ducks Unlimited Canada, the
Waterfowl Research Foundation, the Sydenham Conservation Foundation
and the Ontario Federation of Anglers and Hunters, as well as from
concerned individuals and interested corporations. LPWWRF is managed
and directed by a Board of Directors and a Scientific Advisory
Committee, which includes representatives of Bird Studies Canada,
the Canadian Wildlife Service, the Ontario Ministry of Natural
Resources, Ducks Unlimited, the University of Western Ontario, the
Bluff’s Club and other private interests."
Follow the money.
Other government wildlife biologists (hunter-dependent as they
are) are on board including at least one of the major architects of
the great snow goose hoax, wherein we are supposed to believe that
unprecedented numbers of snow geese are ravaging the arctic tundra
to the detriment of wildlife living there. The number of hunters on
the board would be disproportionate to the percentage within the
human population, as is true of Ducks Unlimited, although both such
organizations can claim with straight faces that they are there as
conservationists, not shills for hunters, and both can claim far
more accurately that they do actually accomplish some good work,
along with their pro-hunt lobbying.
As I completed this essay in May 2005, I received word that
trumpeter swans were nesting in the area of Rochester, NY, on the
south side of Lake Ontario. I guess they "migrated" the 22 miles
across the lake. They are tame, they are big, and the inevitably
will sooner or later become regarded as an urban wildlife nuisance,
a bigger one than the mute swan for a reason illustrated by the
respective names of the two species. Mute swans can hiss, but
trumpeter swans are loud-mouths who inevitably will annoy some
urbanites for all the reasons that make mute swans "bad" plus the
noise.
What then? Surely hunters will argue, as they always do, that
they should be shot, and wildlife managers, always trying to
convince taxpayers that they are earning the money we pay them, will
be delighted to argue that here is yet another problem for them to
address, even if it is one of their own making. If tundra swans,
which are not urban and which bother no one, are fair game, why not
trumpeters? And if trumpeters can be taught to migrate (although it
seems to be a big "if" overall) all the better; they can make more
sporting targets. And if both trumpeters and tundras are on the game
list, there is no worry about the "oops" factor; you can shoot
either species.
If you want to.
Most of us don’t want to kill a swan.
Those few who do are the ones establishing wildlife policy for
North America, and they are basing it all on exaggerations, lies,
hyperbole, fear-mongering, and utter nonsense. That’s how the system
works. |