Otters juggle stones when hungry. This explains the strange behavior of animals in captivity, which sometimes throw and catch rocks. The research by scientists from the University of Exeter is published in the Royal Society Open Science journal.
Scientists often observe how otters living in zoos lie on their backs and "juggle" stones, throwing them up and catching them in the air. Due to the fact that only adult otters behave this way, the researchers believed that in this way they train their young to get food.
In a new study, researchers have found that this behavior does not hone foraging skills - in fact, it means that otters are waiting to be fed.
To find out, scientists analyzed stone juggling in Asian otters (Aonyx cinereus) and smooth otters (Lutrogale perspicillata), which live in several zoos. Although these species are similar, the former feeds on shellfish, while the latter feeds on fish.
The researchers gave the animals several puzzles to solve in the hope of finding differences in the speed of problem solving between otters, juggling stones, and those who did not exhibit such behavior.
The work showed that there are no differences - this prompted scientists to think that with the help of juggling animals let zoo keepers know that they are hungry and it is time to feed them.
Oleg Sabitov