The hidden senses of cetaceans

Researchers at the Centre d'écologie fonctionnelle et évolutive in Montpellier (France) have shown that pilot whales are capable of perceiving tastes and/or odors, whereas these cetaceans were thought to be devoid of gustatory and olfactory capacities.

Are cetaceans capable of perceiving tastes and odors and using this information to search for food or communicate with each other? For a long time, these animals were thought to lack the senses of smell and taste... To find out, Aurélie Célérier and Bertrand Bouchard, researchers at the Centre d'écologie fonctionnelle et évolutive, spent 1 month criss-crossing the Mediterranean off the coast of Spain to meet a species of dolphin: the pilot whale. " We deployed a device to diffuse substances that stimulate their olfactory and/or gustatory senses, and then observed their reactions," explains the marine biologist. Equipped with a drone and underwater cameras to observe the cetaceans' movements, and hydrophones to measure their acoustic activity, the researchers deciphered the pilot whales' behavior in the presence of DMS, a chemical compound emitted naturally at the surface of areas of high marine productivity, which is thought to be an indirect indicator of the presence of food. " Our observations confirm that these animals react to chemical stimuli in their natural environment", explains Aurélie Célérier. In the longer term, these fundamental results could be used to help safeguard these essential aquatic species. "In particular, the use of repellent compounds perceived through these sensory modalities could be envisaged to keep cetaceans away from danger zones such as fishing grounds and human shipping lanes".

The expedition in pictures

Photos © Cyril Fresillon/CEFE/CNRS Photothèque