A still from the video of a marmoset exhibiting behavior that resembles human grieving.
The pair had been the dominant male and female since observations began. When the female fell out of the tree, her partner engaged in a number of behaviors, including embracing her, sniffing at her, chasing other monkeys away, sitting by her, and trying to copulate with her. He also emitted alarm calls normally used when a predator is near. And several months after her death, the male disappeared from the marmoset group, never to be seen again.
More: Do Monkeys Grieve for Fallen Mates? | Science/AAAS. Here's the study, in the journal Primates. There's video, too. [via Ed Yong]
