Photos: New York City Department of Parks and Recreation Employees from the United States Department of Agriculture corralled geese on Randalls Island into a metal pen.

A gaggle of geese who were, at least temporarily, calling Randalls Island home were the target on Wednesday, the third day of a citywide roundup of geese that is expected to result in the destruction of some 2,000 birds. Authorities say the operation is a necessary measure to keep civil aviation safe, but animal rights activists have excoriated the culling, calling it unnecessary and inhumane.

The geese are being removed from more than 40 city-owned parks and other facilities within five miles of the citys airports. The operation is a response to the bird strike that resulted in the nearly disastrous ditching of US Airways Flight 1549 in the Hudson River in January.

Officials say the geese must be rounded up and destroyed to protect aircraft.

DDozens Protest Killing of Geese Near Airports

Rachel Cernansky for The New York Times
Demonstrators protested a proposal to remove at least 2,000 geese from more than 40 city-owned parks and other sites within five miles of the citys airports.

Just a few blocks north of Union Square, a crowd gathered outside the headquarters of the Port Authority of New York and New Jersey on Tuesday afternoon to protest New York Citys plan to kill at least 2,000 geese during their molting season, a time when the geese cannot fly. The protesters accused the mayors office of planning the action in secret, in conjunction with the federal Agriculture Department and the Port Authority.

The Port Authority brushed off the protest, insisting that the culling was necessary to prevent bird strikes and adding a rhyme for good measure. Our responsibility is to think about safety for people before peace for geese, a Port Authority spokesman, Stephen Sigmund, said.

The authorities announced the plan to kill the geese on Thursday, in response to the bird strike that resulted in the nearly disastrous ditching of US Airways Flight 1549 in the Hudson River in January. The first 100 geese were killed on Monday.

The protesters asserted that the geese culling was both inhumane and ineffective.

This is absurd, said Edita Birnkrant, New York director of Friends of Animals, the group leading the protest. This is not going to solve any problems. This wont make planes any safer.

The geese that took down Flight 1549 on Jan. 15 were migratory geese, while the geese that are going to be killed in the next few weeks are resident birds, the protesters pointed out. The disruption of their habitats would not have prevented the accident in January, they said.

Ms. Birnkrant said that the Port Authority was passing the buck and that officials there told her they would have looked into nonlethal methods, but the decision to destroy the birds had already been made by the Agriculture Department. Ultimately, Ms. Birkrant argued, it was up to the mayor to approve the action.

This is a terrible precedent to set, that anytime there is a problem with wildlife to just slaughter them is not a way to solve the issue, she said. The Humane Society of the United States says that Canada geese can be effectively managed with nonlethal techniques like aversive conditioning, egg addling and landscape management.

At the protest, as many as 30 people chanted slogans such as How many geese did you gas today? Asked whether the protest was having any effect, Ms. Birnkrant said: A lot of people are giving the thumbs up and are supporting us. Some people dont even know that this is going on.

For their part, the authorities have said that the removal of the geese is necessary and comes on top of other steps to protect the aviation system.

This new initiative will build on measures the Port Authority is already taking to eliminate wildlife hazards at the airports, Chris Ward, the Port Authoritys executive director, said in a statement last week, including the installation of a state-of-the-art bird radar trial program at J.F.K. Airport, hiring a second wildlife biologist two of only seven airport biologists in the nation expanding shotgun training for field supervisors, and returning to Rikers Island for the sixth straight year of roundups.

Martin Lowney, director of the Agriculture Departments Wildlife Services program, said last week that research had shown that resident Canada geese in several New York studies stay within five miles of a particular location and that 74 percent of wildlife strikes occur at or near the airport. Removing the geese will improve public safety without harm to the species as a whole, he maintained.