The common cuckoo, notorious for evading parental duty by hiding her eggs in the nests of other brooding birds, is even more devious than previously thought, scientists revealed on Monday.
After laying an egg, the female distracts the owner of the nest — a reed warbler in this case — essentially by frightening the poor bird out of its wits, they said. The cuckoo gives a “chuckle” that mimmicks the call of the sparrowhawk —which loves to snack on warbler flesh — before abandoning her egg among the warbler's clutch and flying off to freedom.
“This hawk-like chuckle call increases the success of parasitism by diverting host parents' attention away from the clutch and towards their own safety,” a duo of Cambridge University researchers wrote in the journal Nature Ecology & Evolution.