Source: BBC

Crows are known to behave strangely around their dead: they gather around and squawk loudly nearby.

The idea that it is part of some sort of ritual funeral has often been proposed.

But what they are actually doing has largely remained a mystery, as scientists had little to rely on except anecdotal evidence of such behaviour.

A team has now set out to unpick just why crows act so attentively around their fallen brethren.

To do so, they set up an innovative experiment, capitalising on the knowledge that crows do not forget a threatening face.

This was discovered from earlier research. A series of studies led by John Marzluff of the University of Washington in Seattle, US, revealed that crows will remember an apparently dangerous individual.

They then teach others to scold loudly at the dubious face in question, meaning a whole community of other crows also scold at that face several years later.

To prevent any real life harassment from crows, the face they used was not a real one but a rather realistic latex mask covering their real face.

Crows recognise individual human faces (Design Pics Inc/Alamy)

Using a similar disguise, researchers introduced a lone mask-clad individual to an area where the crows knew to expect a tasty treat from the experimenter, Kaeli Swift, also of the University of Washington.

They would be holding a dead crow, palms outstretched like you might hold a plate of hors d’oeuvre.

By bringing treats, she played good cop. But the masked individual played bad cop, arriving on the scene holding up a dead crow. This sinister individual would remain in place for 30 minutes.

“I was always the friendly feeder, which was nice, I never made any crow enemies,” says Swift. “I would put my food out, then this second person would show up.

“They would be holding a dead crow, not violently, not reenacting a death scene, just holding it like they were picking it up to throw it in rubbish, palms outstretched like you might hold a plate of hors d’oeuvre.”

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