We’ve all heard that elephants never forget, but it seems some of our feathered friends have long memories too.
New research shows that crows can hold grudges against those who anger or threaten them for up to 17 years.
The birds – long considered the most intelligent bird species – also turned out to be very good at recognizing faces.
The research began in 2006 when Professor John Marzluff, an environmental scientist at the University of Washington, put on a terrifying mask and captured seven crows in a net. Before releasing them unharmed, he placed identification rings on the birds’ legs.
Professor Marzluff told the New York Times that in subsequent years, he and his assistants would occasionally wear the mask as they walked around campus to feed the crows and record their reactions.
New research shows that crows can hold grudges against those who anger or threaten them for up to 17 years (stock photo)
The research began in 2006 when Professor John Marzluff, an environmental scientist at the University of Washington, put on a scary mask and caught seven crows in a net (stock image of a man wearing a scary mask)
Professor Marzluff recalled that on one occasion he was subjected to aggressive ‘scolding’ cries from 47 of the 53 crows he encountered.
He said that since the number of crows was much higher than that of the original group that was captured, the crows somehow learn to recognize threatening people from their parents and relatives.
After a peak in 2013, the number of aggressive shouts began to decline until no swearing sounds were recorded at all during a walk in September 2023 – 17 years after the experiment began.
As part of the study, members of the research team also used a ‘neutral’ mask that resembled Dick Cheney, then US Vice President.
Those wearing the Cheney mask fed the crows without subjecting them to any trauma – and were subsequently not subjected to bird abuse.
In another part of the experiment, students used a different set of masks while capturing crows around Seattle.
Volunteers were then asked to wear the masks without knowing which were considered ‘dangerous’ or ‘neutral’ by the crows.
A volunteer who donned a ‘dangerous’ mask, Bill Pochmerski, said: ‘The birds were very hoarse, shouting incessantly, and it was clear they were not angry about anything in general. They were angry with me.’
As part of the study, members of the research team also used a ‘neutral’ mask that resembled Dick Cheney (pictured), then US Vice President.
Professor Marzluff recalled that on one occasion he was subjected to aggressive ‘scolding’ caws from 47 of the 53 crows he encountered (stock photo)
In addition, people living in Townley and Beauval Roads in upscale Dulwich, south-east London, have reported a series of dive-bombings by crows this year.
Local resident Alison Frean, 60, told Mail Online: ‘Last year I was attacked three times while trying to get out of my car. It was quite traumatizing…. I tried to go out with a bicycle helmet again.
“Kids on small scooters are being bombarded with dives and people are just staying in their houses and looking outside.”
Previous studies show that crows’ remarkable intelligence includes the ability to make tools and even count to four.