https://www.theatlantic.com/science/archive/2018/07/crow-necrophilia/565442/
What especially caught my attention was these:
Swift, who studies bird behavior at the University of Washington, had previously shown that crows conduct “funerals” by gathering around the corpses of their peers. Now a film crew had come to capture this behavior.
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Sex aside, there are also many documented cases of animals grieving, which the anthropologist Barbara King defines as “some visible response to death that goes beyond curiosity or exploration, to include altered daily routines plus signs of emotional distress.” Elephants, dolphins, and chimpanzees have been noted standing watch over or carrying the bodies of dead babies and companions.