By analyzing stress hormones in elephants that lost their mothers, a team of researchers led by Colorado State University has found that young, orphaned elephants appear to physically benefit from the support of other young elephants. The study revealed that elephants with more similarly aged “friends” in their group had lower stress levels than their more solitary conspecifics. Thus, “social support” appears to be crucial in reducing the stress caused by the loss of a mother in these highly intelligent and social animals.
“If you’re out in the field, watching elephants, you can just tell that family life is everything,” said study lead author Jenna Parker, an ecologist at Colorado State University. “Calves are rarely more than maybe ten meters from their mother until they’re about eight or nine years old. And if some of the elephants go off, you’ll hear them calling to one another. They want to know where each other are all the time.”
Between 2009 and 2013, there was a marked increase in poaching for ivory in the two reserves in Kenya where this study took place, leaving a large number of young elephants orphaned. “I wanted to follow that up and look at what happens physiologically for these orphans,” Dr. Parker said.
Together with her colleagues, Dr. Parker followed groups of African elephants for over a year and analyzed their fecal samples to measure stress hormone levels. By carefully monitoring 25 young orphaned elephants that had lost their mothers between one and 19 years earlier, the researchers found that those with more similarly aged companions had significantly lower stress hormones than others.
These findings are similar to previous research done on humans which discovered that orphaned children who had a strong level of social support from family and peers were less likely to develop post-traumatic stress disorder after losing their parents. “And what we seem to find in elephants is that those with their family and social support maintain more normal stress hormone levels in the long term,” Dr. Parker said. “I just think it’s really cool that such a social animal has evolved so separately from humans, and that we still seem to converge on how important social ties are.”
According to the scientists, this study could inform future conservation efforts of these endangered animals. By better understanding their social structure – characterized by strong elephant-to-elephant support in the face of loss – conservationists could devise better initiatives to help these animals adapt to the myriad threats that they face.
The study is published in the journal Nature Communications Biology.