From that fount of responsible
journalism:
Crows' excellent memory helps them tell
human friend from foe
By Mail Foreign
Service
Last updated at 12:05 AM on 29th June
2011
They
may not crow about it, but if you get on the wrong side of them, they’re not
going to forget it in a hurry.
Crows
have an excellent memory for human faces, a study has
revealed.
They can tell the
difference between a friendly face and a dangerous one, and can warn each other
which is which.
And the birds –
which are said to be as intelligent as chimpanzees – will remember the face of
someone who poses a threat to them for at least five
years.
Dr
John Marzluff, of the University of Washington, said: ‘Our findings add to the
evolving view of large-brained, social and long-lived birds like crows being on
a cognitive par with our closest relatives.’
A team of
scientists from the university exposed crows in Seattle to a ‘dangerous face’ by
wearing a mask while trapping, banding and releasing birds at five
sites.
Over a
five-year period after the trapping had stopped, they found that the mask
received an increasingly hostile response from birds in the area – suggesting
that the captured birds had been able to warn others.
Dr
Marzluff added: ‘Because human actions often threaten animals, learning socially
about individual people’s habits would be
advantageous.
‘The
number of crows scolding the dangerous mask continued to increase for five years
after trapping, as expected if social learning or social stimulation were
present.
‘As we
conducted trials, walking with the dangerous mask along the route, our actions
presented opportunities for crows to observe or be stimulated by
scolding.
‘The number of
crows encountered was consistent across trials, but the number that scolded the
dangerous mask increased steadily.’
Read more: http://www.dailymail.co.uk/sciencetech/article-2009278/Crows-excellent-memory-helps-tell-human-friend-foe.html#ixzz1Qe65wSRx