BEING as happy as a lark or as mad as a March hare may not be as silly as it sounds, according to a visiting American biologist, who says animals have emotions just like us.
Professor Marc Bekoff, an ethologist from the University of Colorado who is in Australia for a series of public lectures, says animals are emotional and empathetic beings that can experience joy, happiness, grief, fear, pain, resentment and jealousy.
Scientists now believe the way animals behave is influenced by their emotions, not just "animal instinct", he says.
Just like us, some animals wake up in the morning depressed while some wake up raring to go.
"We are learning that animals and humans share very basic brain structures that underlie emotions.
"There is really good evidence that animals process what they are feeling, and that factors into how they behave.
"Animal emotions aren't all that mysterious. Just look at them, listen to them and see what happens when they interact with friends and foes -- look at their face, tail, body, gait and eyes.
"What we see on the outside tells us a lot about what is happening inside animals' heads and hearts. The more we look, the more we are finding very complex emotions."
Dr Bekoff says research shows that elephants can experience grief, mice empathy, rats excitement about playing with a friend, sharks anger and koalas likes and dislikes.
Animals also have personalities, he says.
Crocodile mothers care for their young, squid can be shy, fish can have addictive personalities and even coyotes get the blues.
"Even coyotes at two weeks of age have very distinct personalities," he said
Much of Dr Bekoff's research is based on the observation of dogs, wolves and coyotes in nature, but he has also studied rats, mice, fish and birds and is interested in dolphins and whales.
His trips have been sponsored by the Whale and Dolphin Conservation Society, which is interested in his views on the aquatic mammals.
"We can't see them, they don't look like us, but whales and dolphins are extremely emotional beings," he said.
A vegan, he hopes his findings will have a significant effect on animal welfare issues.
"It has a huge impact on how we interact with animals," he says. "People talk about a carbon footprint, but we need to spend more time and research looking at a compassion footprint
-- how we make the world a better place for humans and animals."