Rape, a sexual form of aggression, was observed in some animals. Biologists have noted forcible rape in orangutans, dolphins, bighorn sheep, seals, wild horses, and some birds. In Arizona, an attempted rape was noticed in coatimundis (long-nosed raccoon-like animals). A big male bounded out of the bushes into a group of females and juveniles, mounted a young female and tried to mate with her. She squealed and right away three adult females ran snarling at the male, drove him away, and chased after him for fifty yards down the canyon. In none of these species does rape come out tobe the norm, but in several it does happen regularly. For example, although white-fronted bee-eaters (tunnel-nesting African birds) form mated pairs, female bee-eaters getting out of the nest need to dodge males who try to force them to the ground and rape them. The males preferably attack females who are laying eggs and thus may lay an egg fertilized by the rapist, instead of the mate.
Among waterfowl such as mallards, teal and pintail, an unwilling female is at times pursued by one or more males, which can cause her death by drowning when numerous males try to pile on. She would fight back and flee, and her mate would try to drive away the aggressors, but their efforts at defense don't always succeed. Additionally, the male of a pair of mallards will sometimes try to mate with the female immediately after a rape attempt
At one marine park, where recently captured dolphins would be given a companion who was used to captivity, bottle-nosed dolphins could not be used as companions since they would torment and sometimes rape the newcomer, if it was of different species. In the wild, bottle-nosed dolphins, in spite of their saintly popular image, have been seen to form male gangs to seize and rape females of their own species.
Hans Kruuk saw a male spotted hyena trying to mate with a female, who drove him off every time. Her ten-month-old cub was nearby, and the male hyena repeatedly mounted it and ejaculated on it. According to Kruuk, the cub occasionally ignored this and sometimes struggled "a bit as if in play." The mother didn't interfere. Yet such behavior appears to be rare in animals and accounts are hard to find.