It is easy to look at caged or cooped up animals and think that, like people, they must get bored with such a confined existence.
While it’s impossible to know what other creatures are thinking, a new study is the first to experimentally demonstrate signs of boredom in animals that aren't given much to do.
For the study, researchers from the University of Guelph, Canada, worked with 29 captive mink. Some animals were housed in plain wire-mesh cages, where they lived for seven months before the experiments began.
Another group lived in identical cages but they could access a tunnel that took them to an even bigger space that included opportunities for stimulating activities, including shelf-like structures for climbing, rubber dog toys and other objects for play, as well as water for wading and dipping their heads in. Every month, these animals got new stuff.
When it finally came time to start the experiments, the researchers presented each animal with a series of new experiences, including puffs of air, scented candles and moving toothbrushes.
It didn't matter whether the stimulus was rewarding, stressful or neutral for the animals, the researchers report today in the journal PLOS ONE. Animals raised in boring cages showed more interest in new things.
They also snacked more on food made available during the experiments, even though they weren't hungry. They also spent more time lying around awake than the animals given a more enriching home life.
All of those behaviors, the researchers concluded, are potential signs of feeling bored.
Boredom is a hard emotion to define. Among people, responses to it vary from apathy to depression to immersion in extreme adventures. Still the researchers say, their study is a valuable first step in figuring out if and how various animals get bored and what can be done to make their lives more satisfying.
"Although we cannot yet determine with certainty whether the subjective experience of the animals is similar to that of humans who self-report feeling bored, their behavior was consistent with that state," they wrote. "Reducing boredom is often a stated aim of enrichment and yet to date we have had no means of judging its success at achieving that aim."