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https://www.earth.com/news/crows-hold-grudges-for-up-to-17-years/
Birds are more intelligent than most people realize, especially when it comes to recalling those who pose a threat.
Recent research has illuminated this startling dimension of avian behavior, revealing that crows – members of the avian elite – can hold grudges for up to 17 years.
Crows hold grudges for up to 17 years