Call it a global positioning system for elephants. Their powerful rumbles — mostly too low in pitch for humans to hear — keep family members from wandering too far, new research suggests.

African elephants form tightly knit families centred around dominant females. Family members spread out while looking for food but always reunite, says Katherine Leighty, a behavioural ecologist at Disney’s Animal Kingdom in Lake Buena Vista, Florida, who led the new study.

Research on the elephants in the wild has hinted that their low-frequency calls, which can travel more than 2 kilometres, work like GPS, she says. But proving that in the wild requires tracking the movements and subsonic calls of multiple elephants — all relative to one another.
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