It was a big day for Mo, a black-headed caique.
He is a small parrot, not as big as a pigeon, with green wings, a white belly, and a black and yellow head.
Mo lives by himself in a large cage at the Brandywine Zoo in Wilmington, Delaware.
Lead animal keeper Katlyn Muse just brought in a bunch of new toys: bells (one of his favorites); a reed tunnel; and a cardboard box with shredded newspaper inside.
Mo crawled into the tunnel, dug under the newspaper, and flew around the cage to find all the hidden treats.
“We give them things that will encourage natural behavior,” Muse said.
Some of the toys that Mo, the black-headed caique, will play with at the Brandywine Zoo.
(Kimberly Paynter/WHYY)
This is called enrichment, a kind of play, and it’s important work for zoos, explained assistant curator Mandy Fischer.
“There are some species where play is very important, so a lot of our primate species, for baby animals in particular, play is how they learn some of those life skills that they need for hunting, or for breeding behavior, or caring for young … can all be done through play,” Fischer said.
To figure out which animals play, whether they’re learning or just for a workout, think about it from an animal’s point of view, said Gordon Burghardt, a professor in the departments of psychology, ecology and evolutionary biology at the University of Tennessee. Knoxville.
“Our … prejudices … prevent us from looking at other animals from a less anthropomorphic point of view … and seeing that something like play is really deeply embedded in our biological roots, our evolutionary heritage,” he said.
Burghardt has become one of the experts in the field of animal play, and he recently came up with a stricter definition of it, to try to break the boundaries of a human-centered perspective.
To put it very simply, what counts as play for animals is when they do it voluntarily over and over again, only when they are not stressed, and it is something other than a serious version of that behavior.
For example, play is not the same as serious fighting.
And one particular type of spider will actually play when having sex when it is not yet mature.
It is play and not real sex, because the females eat the males much less afterwards.
Learning how to tell when something is playing may be one of the reasons animals do it, said Marc Bekoff, professor emeritus of ecology and evolutionary biology at the University of Colorado, Boulder.
Play is important for social, physical and cognitive development, but it also prepares animals for the unexpected, he said.
Play behavior can vary so much; animals must be able to tell when something is playing out as real aggression or a mating display.
For example, chimpanzees have something called a “play face”, and dogs do something called a “play bow” – rump high in the air with the front paw on the ground.
Dogs sometimes do a “play bow” to show they want to play.
Animals that cannot play can have serious consequences.
Think about how barren zoos used to be, Burghardt said: The design philosophy was all about making them easy for people to clean.
“Lions could be in a tile, concrete type enclosure that could be sprayed every day, and there was virtually nothing in there … that would interfere with efficient cleaning,” he said.
Bored caged animals can develop tics, such as pacing, or bar biting.
Ravens are another good example of how animals can suffer from a lack of stimulation.
Rebecca Michelin, director of wildlife rehabilitation at the Schuylkill Center for Environmental Education, nurses nurse injured animals back to health before releasing them back into the wild.
In a previous job she worked with many ravens, and she said that while ravens are cured, they still need stimulation.
“Keeping them entertained is really challenging because they are so intelligent that they need regular changes in their environment,” she said.
“They need mental challenges to entertain them and keep them engaged, otherwise they will actually start listening out of boredom and unhappiness.”
Bored and stressed ravens will peck at their own feathers, she said, or even beat the side of a cage so hard with their wings that they are seriously injured.
Boredom is also a major problem for research animals.
Mice and rats in labs must live in enclosed spaces, and researchers make sure to give them tubes to crawl inside and sticks to chew on.
Tara Martin, veterinary faculty at the University of Michigan, said that when research animals are bored and stressed, that’s bad for the animals — and it’s also bad for science.
“An animal living in an infertile environment is a pretty stressed animal,” Martin said.
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