Elephants are renowned for their acute senses of hearing and smell, both of which play central roles in their everyday life. But until now, it was not known how important these senses were for basic, everyday tasks. (See: "Elephant Photo Gallery.")
"This is one of the first times, to our knowledge, that elephants were shown to use olfaction [smell] in a basic intelligence test," said Joshua Plotnik, an animal behavior scientist from the University of Cambridge, U.K., who led the study, recently published in the journal Animal Behavior.
The results of the study offer insights into how elephants think and could be used to figure out ways they might be dissuaded from raiding farmers' food, suggest the study authors. The authors also suggest that scientists may underestimate the smarts of pachyderms (and other animals) by relying too much on intelligence tests tied to sights or sounds, instead of smells.
Food IQ Test
In the study, seven Asian elephants first had to choose between two buckets that were potential sources of food (one bucket had food and one didn't), a standard "location test" of animal smarts in monkeys, birds, dogs, and other creatures.
The elephants were cued with a sound, the shaking of a closed bucket to reveal whether it contained sunflower seeds. In this first test, the elephants' odds of picking the full bucket were no better than chance.
In the second part of the study, however, the elephants were allowed to smell one of two buckets, either an empty one or one that smelled of food. The elephants had to choose between the bucket they had smelled and a new, mystery bucket. Elephants that were first exposed to an empty bucket always rejected this bucket and selected the "mystery" bucket instead.
This suggests that elephants are using smell as part of their decision-making process. They remember that the first bucket did not smell of food and choose the other option.
The results are surprising, say the researchers, because elephants are gifted when it comes to acoustic communication, so it is not hard to imagine that, if needed, they could use sound to find food. (See video: "Elephants Communicate While at Play.")
"Although elephants probably do not use sound to find food [in the wild], we did think that the elephants would be able to find the food in a task where only auditory cues were provided," says Plotnik.
The findings have important implications on many levels. For instance, it advances our understanding of how these animals interact with their environment.
"Our research suggests that their sense of smell may play a more important role in their decision-making process than it does for other species, and that this may have important implications for the design of future studies of their intelligence," says Plotnik.
It also could provide valuable tips for avoiding human-elephant conflicts. Plotnik explains, "If we know how elephants find crops to raid, perhaps we can find ways—using olfactory deterrents, for instance—to stop them before they raid."
The study results could be used to help scientists design more accurate animal-behavior experiments, on elephants and other species, said experts not involved with the study.
"For too long, we have tested all sorts of animals on stimuli that we, humans, find most salient," explains primatologist Frans de Waal of Emory University in Atlanta. "We thus stack the deck against animals that differ from ourselves, and sometimes conclude from negative results that they are dumber than us."
This means that future studies of animal behavior ought to focus more on discovering each animal's special abilities before anything else.
"[This study] shows just how primate-centric some of our cognitive tests really are," adds Yale evolutionary psychologist Laurie Santos. "If we really want to understand elephant cognition, we need to start thinking outside the visual-auditory box."