A team of researchers in the UK created a series of puzzles baited with food, and found smooth-coated otters (Lutrogale perspicillata) watched and copied each other’s problem-solving techniques, with young animals more likely to copy than their parents. Surprisingly, another species called the Asian short-clawed otter (Aonyx cinerea) showed no sign of copying each other.
Ladds et al found evidence for social learning in smooth-coated otters (Lutrogale perspicillata). Image credit: Ladds et al, doi: 10.1098/rsos.170489.
The two otter species — smooth-coated otters, known to hunt fish cooperatively in the wild, and Asian short-clawed otters, which feed individually on prey requiring extractive foraging behaviors — were studied in zoos and wildlife parks in the United Kingdom.
They were given puzzles such as Tupperware containers with clips on the lid, screw-top lids or pull-off lids. The puzzles were baited with treats such as peanuts or fish heads.
The most difficult task was one where a block of frozen shrimp was attached to a bamboo cane that had to be moved upwards and to the right to extract from a box – and less than half of the otters managed to solve it.
“It was amazing to see otters copying each other to unscrew containers and undo clips to get to their reward: sprats or shrimp provided great motivation,” said lead author Zosia Ladds, of Anglia Ruskin University.
“They have complex social relationships, even within families, and their group dynamics are always changing.”
“Social learning has been studied in many species, but never in otters,” added co-author Dr. Neeltje Boogert, from the University of Exeter.
“Our results suggest smooth-coated otters adopt a ‘copy when young’ strategy.”
“The offspring in our study learned how to solve these puzzles much quicker than their parents — more than six times faster.”
“The order in which the young otters solved the puzzles followed the strength of their social ties. This indicates that the juveniles copied those siblings they spent most time with.”
The team had expected to find social learning behavior in both otter species, so the apparent lack of this in Asian short-clawed otters was a surprise.
“Asian short-clawed otters are not known to forage in groups, and their natural diet consists mainly of prey such as shellfish and crabs that do not require group-hunting strategies,” Dr. Boogert explained.
“As a result, they may have less of a tendency to turn to each other to see how to solve a puzzle such as how to extract food from a new source.”
“In the wild, smooth-coated otters show coordinated group-hunting strategies such as V-shaped swimming formations to catch fish — so it makes sense that they would be naturally inclined to watch each other for foraging information.”
The research is published in the current issue of the journal Royal Society Open Science.
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Zosia Ladds et al. 2017. Social learning in otters. R. Soc. open sci 4 (8): 170489; doi: 10.1098/rsos.170489
