In a paper published on Monday in Proceedings of the National Academy of Sciences, researchers presented the first on-camera evidence of rare animal behaviour. The video was taken by a camera trap of an itchy puffin who was making a burbling sound and scratching its chest with the sharp end of a twig.
Around five years ago, Annette Fayet, a puffin expert from the University of Oxford saw a puffin doing something she had never seen before. The bird which was floating on seawater held a stick in its beak. Moments later, it started scratching its back with the stick. At that time she did not have any evidence of the rare tool used by the bird but in July 2018 she saw the same behaviour again while studying a group of puffins in Grimsey Island in Iceland.
Following the incident, she planted camera traps on the island and recorded loads of puffin behaviour until the camera caught another puffin with a scratching stick. The video which she shared showed the bird spotting a stick and grasping it with its beak before making a burbling sound. It then turns and starts scratching its chest feathers with the stick's pointy end. Watch the video here:
Fayet sent the recording to her colleague Dora Biro, an animal behaviour expert at the University of Oxford who got immediately excited. She said that tool use had never been reported in sea birds before. Together, with their colleague Erpur Snaer Hansen, the biologists described puffin tools in the study. This behaviour fits all current definitions of tool use, said University of Oxford zoologist Alex Kacelnik, who has studied toolmaking crows and was not a member of the puffin research team.
Studying animal tools can help scientists understand the origins of the Stone age, which began when humans started using rocks around 2.6 million years ago. Several bird species use tools. Crows in the Pacific, for instance, use hooked twigs to catch grubs. But back-scratching is an unusual form of tool use that the scientists called body care. The only other type of body care observed in wild birds, Biro said, is anting, in which birds cover their bodies in insects. Bug juices, biologists suspect, can act as chemical defences against bird parasites or fungi.