Though wild elephants are known to cover huge distances, those housed in zoos are denied this opportunity. However, while fencing in such large animals is obviously going to have repercussions for their physical and mental health, a new study in the journal PLOS ONE indicates that, on the whole, the biological and emotional welfare of elephants in zoos is more affected by social factors than the size of their enclosure. Not only does this finding provide an insight into the social and cognitive complexity of these incredible creatures, it could also help zoo management officials tailor their practices to the needs of elephants.
To conduct their research, the authors raked through a back catalog of studies relating to the welfare of African and Asian elephants in 68 North American zoos. From these, it is apparent that elephants in captivity exhibit a wide range of symptoms indicating sub-par wellbeing, including poor reproductive health, foot and joint problems, obesity and stereotypic behavior, which refers to the performance of abnormal behavior.
In the wild, both African and Asian elephants live in complex social structures, normally based around matrilineal descent groups. Removing elephants from their kinship groups can therefore be a highly traumatic experience for the animals, which is why it is hardly surprising that social factors are so vital to their overall health when in captivity.
Spending time with young elephants is good for the overall wellbeing of adults. worradirek/Shutterstock
For instance, the researchers found a direct correlation between the amount of time zoo elephants spend alone and rates of stereotypic behavior. Conversely, their research suggests that elephants that live in larger groups, have regular contact with juveniles and spend little time alone tend to be less likely to exhibit this behavior.
Furthermore, several of the studies included in this research indicate that the more times an elephant is transferred between zoos, the more likely it is to begin behaving abnormally, probably as a result of the extreme social stress of repeatedly being introduced to new groups.
Interestingly, the study authors also found that the reproductive health of female elephants is closely connected to their levels of mental stimulation and engagement. For example, captive females have been found to have high rates of both ovarian acyclicity and hyperprolactinemia, which is an endocrine disorder resulting in an inability to produce milk. However, elephants living in zoos where food is hidden around their enclosure or in trees, rather than just dumped in one spot, were found to suffer from lower rates of both conditions.
The authors speculate this may be because “elephants have a flexible reproductive strategy,” whereby their biological capacity to procreate is influenced by an evaluation of their surroundings. As a result, zoo elephants that find no food when foraging in their enclosure may assume that their environment is low in resources, leading to poor reproductive health.
Surprisingly, however, the study authors report that “exhibit space was found to be less influential than expected.” For instance, elephants living in larger enclosures were not found to move around more than those in smaller spaces, and actually tended to have worse foot and joint health.
One aspect of enclosure design that does appear to be significant, however, is the division between indoor housing and open air space. Elephants with access to both types of environment were found to exhibit less stereotypic behavior, potentially because their increased opportunities for making decisions about their surroundings supports their mental health. On the flip-side, though, elephants that frequently move from indoor to outdoor settings have worse foot and joint health, with the researchers speculating that this may be a result of frequent temperature changes or exposure to varying surface types.
Elephants are highly intelligent animals, with complex social needs. feelphoto/Shutterstock