Crows Can Hold Grudges for 17 Years

Research led by Professor John Marzluff from the University of Washington has revealed that crows can hold grudges for up to 17 years against individuals they perceive as threats. The study began in 2006 when crows were captured while Marzluff wore a scary mask, and subsequent interactions showed that crows remembered and reacted aggressively to the mask years later. Notably, 47 out of 53 crows scolded Marzluff during one encounter years after the initial event, indicating their long memory and ability to recognize faces. The findings suggest that crows have a brain region similar to the mammalian amygdala, responsible for storing negative associations. Interestingly, the number of aggressive responses from crows began to decline after peaking in 2013, with no scolding calls noted by September 2023, marking the end of the study period. These results contribute to understanding the cognitive abilities of crows, highlighting their intelligence and capacity for social learning.