Researchers from the University of St Andrews in the UK reported on Wednesday in scientific progress 》"Only the first case study published in the Journal of animal perception," we wrote
It has long been known that individual dolphins can identify themselves and others through their unique and iconic whistles, but new research shows that dolphins can track the arrival and departure of their companions through taste.
"In the open ocean, the use of taste is very beneficial because the urine plume will last for a period of time after the animals leave," the study report said
Researchers studied dolphins at Dolphin Quest facilities in Bermuda and Hawaii. They found that when dolphins were exposed to urine samples from other dolphins they lived with, they stayed three to four times longer than when they were exposed to urine samples from strange dolphins.
In another phase of the experiment, the scientists played the iconic whistle of dolphins that matched the urine sample or the whistle of different, mismatched dolphins. It's a bit like showing a picture of a friend and playing their voice clip or someone else's voice clip at the same time.
Similarly, when the urine sample matches the whistle from the dolphin, the dolphin stays on the urine sample longer. All this suggests that dolphins judge their companions by tasting their urine.
It is reported that dolphins' sense of smell is not developed. Research shows that their taste is limited to saltiness. Perhaps this helps them distinguish their partner's urine from the surrounding saline ocean.
"Given the recognition skills revealed in our study, we believe that dolphins are likely to be able to extract other information from their urine, such as reproductive status, or use pheromones to influence each other's behavior," the researchers explained. These findings suggest that dolphins can recognize and mark objects, which "may be used for psychological operations such as planning, psychological time travel or simulating social scenes".