We’ve often heard that elephants never forget a slight. But it seems our feathered friends also have impressive memories. A new study reveals that crows can hold a grudge for up to 17 years against those who have angered or wronged them. These birds, already recognized as some of the smartest in the animal kingdom, have demonstrated remarkable facial recognition skills. What did researchers uncover?
In the initial phase of the study back in 2006, lead researcher Professor John Marzluff from the University of Washington donned a scary mask and trapped seven crows in a net. Before releasing them unharmed, he attached identification bands to their legs. Professor Marzluff shared that in the following years, he and his assistants occasionally wore the same mask while walking around campus, feeding the local crows, and observing their reactions. On one occasion, he was met with aggressive, “cursing” caws from 47 out of 53 crows he encountered during a research walk. The number of outraged crows was significantly higher than at the start of the experiment. Professor Marzluff speculated that the crows had somehow taught their peers to recognize threatening individuals in masks.
After peaking in 2013, the number of aggressive caws directed at “dangerous” individuals began to decline, and by September 2023, not a single hostile squawk was recorded during one of the walks. This means that 17 years had passed since the beginning of the experiment. During the study, researchers also used a neutral mask. Those wearing it fed the crows without causing them any harm and subsequently did not face any harassment. When the team trapped crows in the outskirts of Seattle for the second part of the experiment, they employed a different set of masks. The scientists then asked volunteers to wear masks without informing them which ones the crows associated with danger and which ones were considered neutral. One volunteer who wore the “dangerous” mask reported, “The birds were very noisy, constantly squawking, and it was clear they weren’t upset about something in general. They were upset with me.”
Meanwhile, residents of the upscale Dalwich neighborhood in southeast London reported a series of dive-bombing attacks by crows this year. Local resident Alison Frean, 60, told the Daily Mail, “Last year, I was attacked three times just trying to get out of my car. It was quite traumatic… Eventually, I tried going out in a bicycle helmet.” Previous studies have shown that due to their remarkable intelligence, crows are capable of making tools and even counting up to four.