Magpies recognise and "scold" humans who they perceive to be threats to their nests, scientists have found.
During a routine nest-monitoring study a research team in South Korea discovered that the birds recognised an individual that had previously climbed up to and disturbed their nests. When that person approached trees in which the birds were nesting, the magpies called out and pursued him.
The findings are published in the journal Animal Cognition.
One of the researchers, Sang-im Lee from Seoul National University, explained that the findings were "accidental observations".
