Elephant behaviour
In the natural cycle species mate with their own to ensure the survival of the species - this is the way of the wilderness - but as in most things there are exceptions to the rule. In today's world man has interfered so much in the natural scheme of things that more and more 'unnatural' behaviour is noted in animals - some stranger than than others.
All images © Gary Webber
You seem to argue that man has caused this perversion, but could this not be linked to natural explanations. the same way your lions 'killing for survival' article argues that it might be natural behaviour for lions to simply kill for fun, perhaps the elephants odd sexual behaviour is a natural one - is perversion just a part of nature? the same way it's unexplainable why male dolphins gang rape females, or even observations of homosexual behaviour in animals. Is this all to do with hormones? are we changing these by affecting the environment and habitats of animals, or have these oddities existed in animals since the beginning of time?
AWG: The dolphin example you use and the reference to homosexuality in animals refers to interaction with members of the same species whereas in the essay the elephant is attempting to mate with a rhino. It has been noted in studies in parts of Africa that elephants that have grown up without the supervision of adults exhibit unusual behaviour. Attempting to mount rhino is one of the most recorded forms of unusual behaviour and it has been argued that due to the number of incidents of this behaviour the phenomenon should be researched further and not rejected out of hand as unusual. The fact is that all recorded incidents of this have occurred after human interference.