As regular CFZ-watchers will know, for some time Corinna has been doing a column for Animals & Men and a regular segment on On The Track... particularly about out-of-place birds and rare vagrants. There seem to be more and more bird stories from all over the world hitting the news these days so, to make room for them all - and to give them all equal and worthy coverage - she has set up this new blog to cover all things feathery and Fortean.

Friday, 8 September 2017

Scientists expose true extent of cuckoo's cunning


September 4, 2017

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.

"As a result, the female cuckoo might have 'the last laugh' in this particular battle."

The bird whose behaviour gave us the word "cuckoldry", is an example of a "brood parasite"—birds, insects or fish that trick others into raising their young.

This is often at the expense of the foster parents' own offspring.

To avoid getting caught—which will lead to the imposter egg being kicked out of the nest—the cuckoo has developed some nifty tricks, including matching its egg colouring to that of its target, for camouflage.

The bird has also adopted "remarkable secrecy and speed" in depositing its egg, said the team.

For this reason, scientists have battled to understand why the cuckoo would risk exposure by "chuckling" so soon after committing its crime.




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