The observer, Kees Moeliker , suggested that "when one died the other one just went for it and didn't get any negative feedback—well, didn't get any feedback. Studies of the brain have proven that pleasure and displeasure are an important component in the lives of animals. Lions are known to engage in sex to create bonds and interact with each other. David Linden , professor of neuroscience at Johns Hopkins University , remarks that:. Although procreation continues to be the primary explanation for sexual behavior in animals , recent observations on animal behavior has given alternative reasons for the engagement in sexual activities by animals. As of , the scientific literature contained reports of homosexual behavior in at least wild species. However, the practice might have been a consequence of homosexual rearing, as the male orangutan in this dyad had had extensive same—sex experience.
International Journal of Primatology. A review of the literature found 44 species pairs that had been observed attempting interspecies mating, and 46 species pairs that had completed interspecies matings, not counting cases that had resulted in hybridization.
Non-reproductive sexual behavior in animals
Applied Animal Behaviour Science. The mother did not intervene. I am informed by a gentleman who is a recognized authority on goats, that they sometimes take the penis into the mouth and produce actual orgasm, thus practicing auto-fellatio. Autoeroticism in female mammals , as well as heterosexual and homosexual intercourse especially in primates , often involves direct or indirect stimulation of the clitoris Genital rubbing has been observed once among male orangutans  and several times in a small group of lar gibbons , where two males thrust their genitals together, sometimes resulting in ejaculation in one of the partners. The success of reproduction for each individual lion is dependent on the number of male lions found in their social group. Male stoats Mustela erminea will sometimes mate with infant females of their species.