Wildlife experts have been stumped by images that appear to show a kingfisher hanging sticklebacks out to dry.
Sticklebacks are common prey for the resident kingfisher at the Scottish Wildlife Trust’s Montrose Basin visitor centre and wildlife reserve, which kills the fish by striking them against its perch.
This softens the stiff spines of the sticklebacks, making them easier to swallow.
However, the bird appears to have gone a step further by using the spines to pin three sticklebacks to its regular branch.
Anna Cheshier, the Scottish Wildlife Trust’s Angus ranger, said: “The kingfisher visits the reserve almost every day and can be easily seen from our hide.
“The photographer who took the images didn’t realise what he had captured until he took them into the visitor centre the following day.
“It’s hard to tell if the kingfisher has hung the fish on the branch accidentally or on purpose, but this is really unusual behaviour that no-one seems to be able to explain.
“We’d like anyone who has seen anything like this before to get in touch.”