Debate Guide: Nonhuman relatives
Our animal relatives do not only engage in masturbation and casual homosexual behaviours, but sexually induct their young in ways that would often be described as incestuous by human standards. Yet, no harm is done. Indeed, such complex behaviours appear to be evolutionarily adaptive in these species. So why should the innate 'pedophile impulse' be any different for us? Animals, it seems, have no reason to limit child sex play to the nursery, i.e. they lack a restrictive moral structure. To them, it feels good and helps you get on.
So, using our own terms, who in the animal kingdom does what? Various primates engage in behaviours including incestuous matings with juveniles (both sexes, sometimes for reproductive purposes), intense relationships involving pederastic fondling, oral sex between younger and older males, fellatio, motherly sex play, masturbation and mounting with infants, child - child and child - parent faux - mountings, adult - pubescent lesbian relationships, adult male - infant female babysitting that involves masturbation and thrusting, adolescent anal sex (to ejaculation), sexualised greetings as normal interactions, studly, penetrative behaviour in very young infant males, multipositional homosexual mounting and masturbation during juvenile / adolescent wrestling games, infant initiation of intercourse and fatherly acceptance of mother - son cunnilinguis. Our research page explains the issue in more detail.
Of course, one could employ a fallacious argument by saying that other animals can behave in savage and unethical ways (sometimes in combination with the rape of infants). But that's beside the point; animals do not see or suffer these child love experiences as 'sex abuse', which is an entirely human construct, not far from a negative equivalent to the way that humans justify their own behaviour as being more civil and ethical than other animals; civility and ethics being human standards, anyway!