Most of us can look at two meal plates and easily tell which one has more food on it. But if someone turns out the lights, we’re out of luck. Not so for Asian elephants. A new study reveals that the pachyderms can judge food quantity merely by using their sense of smell, the first time an animal has been shown to do this.
To conduct the research, scientists presented six Asian elephants (Elephas maximus) at an educational sanctuary in Thailand with two opaque, locked buckets containing 11 different ratios of sunflower seeds, a favorite treat. The elephants could not see how many seeds each bucket contained, but they could smell the contents through small holes in the lids.
The animals chose the bucket with the greater quantity of food 59% to 82% of the time, the team reports today in the Proceedings of the National Academy of Sciences. (Even dogs, with their famed sense of smell, fail this test, other research has shown.)
The discovery makes sense, the scientists say, because elephants are known to have the highest number of genes associated with olfactory reception of any species (about 2000 versus dogs’ 811). They can distinguish between the scent of Maasai pastoralists and Kamba farmers, and rely on their sense of smell to navigate long distances to find food and water (up to 19.2 kilometers). The researchers hope their findings could help mitigate human-elephant conflicts in Asia and Africa, because wandering herds use odors to decide where to travel; enticing scents might help lure them away from agricultural fields, for instance.