The world’s smallest species of penguin makes the most of many eyes when it comes to hunting schools of fish, a new study suggests.
The study, which used penguin-mounted cameras to track the hunting activities of little penguins (Eudyptula minor), is published on Thursday in PLOS ONE.
While hunting in groups means the penguins have to share the fish they find, it’s a lot safer and makes it easier to detect prey in the first place, said lead author Ms Grace Sutton from Deakin University.
Little penguins – often called fairy penguins – are just 30 centimetres high and weigh just one to 1.5 kilograms.
Like quite a few other species of penguins, the animals are known to forage in groups but no one really knows why.
“So we tried to figure out why they do this,” said Ms Sutton, who carried out the research as part of an honours year research under supervisor Dr John Arnould at Deakin University.
Ms Sutton and her colleagues studied the behaviour of two breeding colonies of little penguins from south-eastern Australia.
Miniature cameras strapped to penguins’ backs
They strapped miniature video cameras to the backs of 21 animals and analysed what the animals were doing second-by-second while they foraged.
The penguins were only seen foraging in groups when hunting schooling prey, said Ms Sutton.
She said while dolphins are known to work together in such situations to concentrate prey into a smaller area, making it easier to catch, the little penguins gained no such benefit from hunting in a group.
Instead, she said, it appears hunting in a group simply made it easier for the penguins to spot the prey in the first place.
There is also evidence that hunting in a group means the penguins are less likely to be eaten themselves, said Ms Sutton.
Of course the downside of collective foraging is that you have to share what you find.
“There is that trade off,” she said.
“Individuals may forage in groups to improve detection of prey or avoid predation but, once they find prey, it is every penguin for themselves.”