Elephants Have The Best Sense Of Smell

Everybody can recognize an elephant with its distinctly long trunk, what people will be less familiar with is the fact that the elephant has a large number of genes dedicated to its sense of smell. In a study of 13 mammals, it was found that the African elephant was the best sniffer, possessing the largest amount of genes related to smell, which is twice as many as dogs and five times as many as humans.

“Rats had the record for the largest number of [these] genes,” said the study’s lead researcher Yoshiihito Niimura, a researcher of molecular evolution at The University of Tokyo in Japan. “Elephants have much more. It’s almost double, so it’s very surprising.”

The African elephant has the ability to smell the difference between two Kenyan tribes. The Maasai whose young men spear elephants in order to prove their virility and the Kamba who usually tend to leave elephants alone according to a study published in 2007 in the journal of Current Biology. Elephants use their sense of smell to identify family members and forage for food. The female African elephant is receptive to breeding only for a few days every three years and according to the research, male elephants can smell when a female is receptive says Bruce Schulte of Western Kentucky University.

“When you watch the animal, even in captivity, the trunk is constantly moving. It’s constantly checking out the environment,” Dr. Schulte said.

The researchers took a close look at the number of olfactory receptor genes of each mammal they were studying. The genes are responsible for coding proteins that are located in the nasal cavity and attach themselves to nasal molecules. Nerve cells send the information to the brain which then identifies the smell.

The number of these receptor genes depend on each species and range from 296 for the orangutan to 1948 for the African elephant. The research suggests that the common ancestor for all 13 mammals in the study had 781 of this type of gene. This suggests that over time the number of these genes has increased in elephants and decreased for primates such as humans who have 396 receptor genes.