Friendship matters especially in the dolphin world. Dolphins get to know their friends by tasting their pee, a news study finds. By sampling sips of each other's urine, dolphins demonstrated a type of social recognition that begins with an exchange of whistles that are unique to specific individuals — much like human names.
According to Live Science, by tasting each other's urine and recognizing the source, the dolphins showed that they could keep track of dolphin identities using two types of sensory input. This means the animals could create and store a mental concept of other dolphins, according to the new study.
Researchers discovered that dolphins do this kind of identification via pee-tasting while investigating if the animals are truly calling each other by name when they copy whistles. The scientists conducted what is known as a cross-modal study, in which experiments test if an animal can recognize an object or another animal across multiple cues received from different senses.
Researchers found that dolphins spent roughly three times as long sampling urine from unfamiliar dolphins as they did from familiar ones. This suggested that the animals could identify known fellows by taste.
More fundamentally, these findings could open new avenues of dolphin research.