Food can be a great motivator, whether you’re a journalist with a chocolate addiction or an elephant with a penchant for fresh fruit. And animals often get creative when they’re in the mood for a meal or treat. Crows will fashion sticks into tools to reach bugs. Chimpanzees use stone hammers to crack open nuts. Archerfish shoot jets of spit to knock an insect off a leaf. Now comes video evidence of Asian elephants using cleverly aimed puffs of air to blow apples, leaves and other food close enough to grab and eat.
Kaori Mizuno and colleagues at the Graduate University for Advanced Studies in Hayama, Japan, worked with two female Asian elephants, Mineko and Suzuko, that lived at the Kamine Zoo in Ibaraki Prefecture, Japan. In 2011, Mizuno had observed Mineko blowing with her trunk to obtain food and decided to investigate the behavior.
The enclosure for the two elephants is surrounded by a U-shaped ditch, a dry moat that the animals cannot enter or cross. The moat is just shallow enough that an elephant can reach an object on the bottom with its trunk, but not if that object is on the far side of the moat. This let Mizuno’s team set up a challenge for the elephants. They regularly set out tasty treats — apples, bamboo, hay, potatoes or fallen leaves — on the far side of the ditch. They then recorded the elephants’ behavior. They report their findings November 5 in Animal Cognition.
Both elephants were caught on film blowing their trunks to draw the food closer. Each would reach out her trunk, aim backwards a bit and blow out a few puffs of air, driving the food close enough to grab. Mineko, though, was the master — she used fewer puffs, blew longer and aimed better. Suzuko sometimes got her food only just close enough that she could grab it if she raised one of her rear legs for balance.
This wasn’t the first time such behavior has been recorded, the researchers note. Charles Darwin wrote in The Descent of Man in 1874:
I have seen, as I daresay have others, that when a small object is thrown on the ground beyond the reach of one of the elephants in the Zoological Gardens, he blows through his trunk on the ground beyond the object, so that the current reflected on all sides may drive the object within his reach.
But now that tool use is no longer considered to be solely the realm of humans, it’s worth reexamining the behavior. Is trunk-blowing considered tool use? The classic definition of a tool is “the external employment of an unattached environmental object.” Air may not qualify — and neither would the archerfish’s water jet. But what may be more important to consider is the cognitive processes that underlie the behavior, Mizuno and colleagues say.
“Our results suggest that elephants seem to understand causality and physical reasoning,” they write. And while they are unsure how the elephants picked up the behavior, whether it was trial-and-error, problem solving or something else, the fact that two females living together are both exhibiting it suggests that social learning may be involved.
Perhaps other elephants can learn the behavior — because elephant leaf blowers might be a lot better sounding, and more entertaining, than the gas-powered ones that drown out nature every fall.