In the book The Human Zoo, Desmond Morris states that you see very little masturbation or other weird sex in wild animals, but you often see it in zoos and othe

In the book The Human Zoo, Desmond Morris states that you see very little masturbation or other weird sex in wild animals, but you often see it in zoos and other captive/domesticated animals. He puts it down to dealing with being in an unnatural environment and makes parallels with people living in cities.