Matronly elephants hold the key to their family's well-being, according to a study published today in Science. These females guard the clan's social knowledge, which is essential for successful breeding.
The wisdom these gray elders possess is the ability to distinguish friend from foe among other elephant families, which they encounter about 25 times a year in the Amboseli Elephant Research Project area in Kenya. This skill is important because other elephants can harass calves or start disputes, disrupting the family.
The team of researchers, based in the U.K. and Kenya, used high-powered hi-fi equipment to replay recorded calls from other elephants and test whether matriarchs could distinguish them from their kin's calls. They then observed if, in response to the calls, the elephants huddled together and smelled the air to figure out who was coming. These tests indicated that families with older matriarchs were better at identifying who was approaching.
The results were impressive: families with matriarchs 55 years old or older were several thousand times more likely to bunch together defensively when hearing the calls of families they rarely encountered. Families with younger matriarchs (around 35 years old) were only 1.4 times more likely to bunch together in the same setting. Families led by older matriarchs also turned out to have more offspring per female per year throughout the study. This led the scientists to propose that an inability to distinguish friend from foe can leave a family on the defensive during times when they could be reproducing.
"We believe this to be the first statistical link between social knowledge and reproductive success in any species," Karen McComb, lead author of the study, explains. "The results highlight the disproportionate effect the hunting and poaching of mature animals might have for elephant populations."