Do animals experience emotions? And how can we know when we can't ask them?
For the sake of animal welfare, we should focus on studying the positive emotions of animals rather than the negative, says animal behaviour expert Ximena Nelson.
Photo: Unsplash / Simone Fischer
“That allows us to evaluate whether the animals in our care are living a full and rich life", she tells Kathryn Ryan.
Ximena Nelson is a professor of biology at the University of Canterbury, specialising in animal behaviour.
Because humans and animals don't have a shared language, we study their behaviour - such as how they play and the sounds they make - for an indication of their feelings.
“Unlike negative emotions, where typically there’s a really clear behavioural response such as fleeing in response to fear, with positive emotions it’s much for subtle.”
There’s increasing evidence that rats and kea make sounds that are comparable to human laughter, Nelson says. These are created using the same pathways in their brains and produce the same kind of positive results.
In one study, rats were tickled and responded with ultrasonic sounds that can’t be heard by the human ear.
“One of the reasons we think these are analogous to laughter is not just because it’s a physiological response to the annoying tickling but also they produce these sounds when they are bonding socially and getting a food reward – in pleasurable situations.”
Photo: Unsplash / Koen Eijkelenboom
There are lots of hypotheses why animal play may have evolved, Nelson says.
Sometimes it's functional, i.e. the process of learning how to hunt can be seen in kitten play.
“Learning social bonds is another big one so in social animals you have to play by the rules of engagement, you have to be able to respond appropriately to other members of your group and a lot of that learning is facilitated by play in youngsters.”
While the idea is somewhat controversial, play could also just be for play’s sake, Nelson says.
“I’ve seen kea fly to the top of a snowy roof and slide on their backs down the snow to the bottom.
“You might argue that maybe the kea had to get from A to B and flying was the best way to do it but when that kea flies up to the top of the roof again and slides down again, that argument is a little bit less likely, and it seems like that might just be for the fun of it.”
