Every now and again someone asks me if nonhuman animals (animals) commit suicide. This past weekend I gave two lectures as part of the Collegiate Peaks Forum Series in Buena Vista, Colorado and after I talked about grief and mourning in a wide variety of species (see also) someone in the audience asked me this question. My answer was that there are some good observations of animals seemingly taking their own lives in situations when one might expect a human to take his or her own life. For example, it's been suggested that whales intentionally beach themselves to end their lives, highly stressed elephants step on their trunks or jump over a cliff to end prolonged pain (see also), and cats stressed out by earthquakes kill themselves.
Opinions vary from "yes they do" to "perhaps they do" to "no they don't" (see also). Some say animals don't have the same concept of death that we have and don't know that their lives will end when they do something to stop breathing.
After one of my talks in Buena Vista one of the women in the audience, Cathy Manning, told me a very simple but compelling story about a burro who seemed to kill herself. Cathy knew a female burro who gave birth to a baby with a harelip. The infant couldn't be revived and Cathy watched the mother walk into a lake and drown. It's known that various equines including horses and donkeys grieve the loss of others (see and and) so I didn't find this story to be inconsistent with what is known about these highly emotional beings.
I think it's too early to make any definite statements about whether animals commit suicide but this does not mean they don't grieve and mourn the loss of family and friends. What they're thinking when they're deeply saddened when another animal dies isn't clear but it's obvious that a wide variety of animals suffer the loss of family and friends. Cathy's story made me rethink the question if animals commit suicide and I hope this brief story opens the door for some good discussion about thie intriguing possibility. As some of my colleagues and I have stressed, we must pay attention to stories and hope they will stimulate more research in a given area.