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Otters (水獭) are known to be very social and intelligent creatures, but a new study by the University of Exeter has given new insight into their intellect.

Researchers gave otters “puzzle boxes (智力训练箱)”, some of which contained familiar food, while others held unfamiliar natural prey (猎物) — shore crab and blue mussels, which are protected by hard outer shells. For the familiar food — meatballs, a favorite with the Asian short-clawed otters in the study- the scientists had five different types of boxes, and the method to extract (提取) the food changed in each version, for example pulling a tab or opening a cap. The unfamiliar food presented additional problems because the otters did not know if the crab and mussels were safe to eat and had no experience of getting them out of their shells.

In order to decide whether food was safe and desirable to eat, the otters, which live at Newquay zoo and the Tamar Otter and Wildlife Centre, watched intently (专注地) as their companions inspected what was in the boxes and mimicked their behavior if the other otters sampled the treats.

However, they preferred to spend more time trying to figure out how to remove the meat from the shells on their own and relied less on the actions of their companions. Of the 20 otters in the study, 11 managed to extract the meat from all three types of natural prey.

“Much of the research into the extractive foraging (觅食) and learning capabilities of otters has centered on artificial food puzzles,” said the lead author, Alex Saliveros, of the Centre for Ecology and Conservation on Exeter’s Penryn campus in Cornwall. “Here, we were interested in investigating such skills in the context of unfamiliar natural food, as well as in relation to artificial food puzzles.”

Other animals employ social learning to decide what is safe to eat; rats, for example, prefer novel food types that they have smelled on the breath of other rats.

Scientists hope that understanding how otters cope with unfamiliar foraged food in their natural environment can help them train the animals to survive in the wild. “The captive (圈养的) otters in this study initially struggled with natural prey, but they showed they can learn how to extract the food,” said Saliveros. “Our findings suggest that if you give one otter pre-release training, it can pass some of that information on to others.”