Stereotypical behaviors (abnormal repetitive behaviors) are commonly seen in animals kept in captivity. Polar bears and other large carnivories are notorious for repetitive pacing type behaviors. Grazing animals kept in unnatural or confined environments often resort to chewing on bars or fences or obsessive licking. Other animals rock back and forth, obsessively groom themselves or engage in other unnatural behaviors. We see these types of behaviors at least sometimes in all species kept in unnatural conditions– zoo animals, laboratory animals, farm animals and even pets.
In her newest book, Animals Make Us Human, Temple Grandin outlines ways stereotypical behaviors develop. Here are the reasons:
- The animal is suffering now.
- The animal was suffering sometime in the past but isn’t suffering now.
- The animal is using the stereotypy as a coping mechanism. A stereotyping animal in a bad environment may be soothing or stimulating itself, whereas the nonstereotyping animal may have just given up and become totally withdrawn and depressed.
Stereotypical behaviors are sometimes used to measure the welfare of animals. But, a stereotypical behavior might not be caused by current suffering. It could have been caused by past events and then repeated over and over until it became habit. So, we should consider the animal’s other current behaviors, the environment, and the animal’s past history before making judgement calls related to welfare.
Interestingly, enrichment and stimulation early in life seem to have some impact on brain development and the probability of stereotypies. Grandin discusses how zoo animals kept in identical conditions are much less likely to develop stereotypies if they are wild-born rather than raised in captivity. Animals raised in barren or deprived environments seem to be much more susceptible to developing abnormal behaviors if placed in less than optimal conditions.
Of course, given the dwindling numbers of wild animals, this does not mean zoos should stop raising captive animals. Instead, it means they should consider how they can improve the conditions and environments animals are raised in. This will foster correct development and prevent abnormal behaviors from developing later in life.