Otters learn skills from each other, just like humans. But they also solve some puzzles alone.
Research from the United Kingdom looked at how 20 Asian short-clawed otters (Aonyx cinereus), living at the Newquay Zoo and the Tamar Otter and Wildlife Centre, learn from each other to investigate unfamiliar prey hidden inside puzzle boxes. This involved meatballs (a familiar food), hidden inside five variations of puzzles that involved pulling tabs and flaps to open. They were also given natural prey as a control, including rainbow trout, shore crabs and blue mussels.
“Much of the research into the extractive foraging and learning capabilities of otters has focused on artificial food puzzles,” says lead author Alex Saliveros, from the University of Exeter. “Here, we were interested in investigating such skills in the context of unfamiliar natural prey, as well as in relation to artificial food puzzles.”
While otters used their own wits to figure out how to extract the food items from the puzzles, they relied on each other to know if the meat was safe and desirable to eat – almost waiting for each other to be the royal food testers!
“Our group of Asian short-clawed otters are a cohesive group, and spend most of the time together and eat quite socially, “ says Matt Golebiowski, an exotics keeper at the Adelaide Zoo. “When given new items, like a puzzle feeder or a new form of behavioural enrichment, they will stick together and be cautious in their approach to investigating those items.”
Only 11 out of the 20 otters in the study managed to extract the meat from all three types of natural prey.
“The captive otters in this study initially struggled with natural prey, but they showed they can learn how to extract the food,” says Saliveros.
Age may also play a part in how quickly otters can solve puzzles.
“Though otters are really smart, the younger otters do take longer than the more experienced elders to work out and solve problems,” says Golebiowski. “Once they have had a few go’s, we see them learning and getting quicker each time. An easier puzzle takes a couple of minutes to solve, while a harder puzzle, such as frozen food inside a feeder, could take up to 15 minutes.”
The social interactions were tracked between the 20 otters, where otters that were within one body length of another were associated. This was to find out if social learning could be measured by the level of closeness between individuals, where otters learned more quickly by watching their family.
The otters at the Adelaide Zoo are part of an Australia-wide breeding program, where at least 70 otters have been bred since the program’s inception.
“Otters are social and close-knit for life,“ adds Golebiowski. “A family group consists of parents and a few generations of litters, with the older litter helping to raise the next set. As animals get to a dispersal age they will leave their families to start forming their own groups. When there is danger, they tend to look out for each other and defend each other, rather than each individual just fending for itself.”
While four to twelve are normal sized groups for the Asian short-clawed otter, an extended family of 20 have been seen in the wild.
“Asian short-clawed otter populations are declining in the wild, and understanding their behaviour can help in the development of conservation and reintroduction programs,” says Saliveros. “Our findings suggest that if you give one otter pre-release training, it can pass some of that information on to others.”
The study has been published in Royal Society Open Science.
Qamariya Nasrullah holds a PhD in evolutionary development from Monash University and an Honours degree in palaeontology from Flinders University.
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