We’ve all heard that elephants never forget, but it seems that some of our feathered friends have long memories too.
New research suggests that crows can hold grudges for up to 17 years against those who anger or threaten them.
The birds, long considered among the most intelligent bird species, also turned out to be very good at recognizing faces.
The study 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 put identification rings on their paws.
Professor Marzluff told the New York Times that he and his assistants would occasionally wear the mask in subsequent years as they walked around campus feeding the resident crows and recording their reaction.
New research suggests crows can hold grudges for up to 17 years against those who anger or threaten them (file photo)
The study began in 2006 when Professor John Marzluff, an environmental scientist at the University of Washington, put on a scary mask and captured seven crows in a net (file image of a man in a scary mask).
On one occasion, Professor Marzluff recalled, he was subjected to aggressive “reprimand” caws from 47 of the 53 crows he encountered.
He said that since the number of crows was much larger than the original group that were captured, the crows somehow learn to recognize threatening humans from their parents and relatives.
After peaking in 2013, the number of aggressive squawks began to decline until no scolding calls were recorded during a walk in September 2023, 17 years after the experiment began.
As part of the study, members of the research team also wore a “neutral” mask that resembled Dick Cheney, then vice president of the United States.
Those wearing the Cheney mask fed the crows without subjecting them to any trauma and were not subsequently subjected to abuse by the birds.
In another part of the experiment, students wore a different set of masks while trapping crows in Seattle.
The volunteers were then asked to wear the masks without knowing which ones were considered “dangerous” or “neutral” by the crows.
Bill Pochmerski, a volunteer who donned a “dangerous” mask, said: “The birds were very loud, screaming persistently and it was clear that they were not bothered by anything in general.” They were upset with me.’
As part of the study, members of the research team also wore a “neutral” mask that resembled Dick Cheney (pictured), then US vice president.
On one occasion, Professor Marzluff recalled, he was subjected to the aggressive “reprimand” caws of 47 of the 53 crows he encountered (file photo)
Separately, people living in Townley and Beauval Roads in upmarket Dulwich, south-east London, have reported a series of dive bomb attacks by crows this year.
Local resident Alison Frean, 60, told Mail Online: “I was attacked three times last year when I was trying to get out of my car. It was quite traumatic… I tried to get out again with my helmet on.
“Children on small scooters are dive-bombed and people stay in their homes, looking outside.”
Previous studies show that crows’ remarkable intelligence includes the ability to make tools and even count to four.