“It’s always interesting when individuals of two different species strike up a relationship. This might be a hunting partnership (raptor species have been reported co-operating to flush prey, as have coyotes and American badgers), an alliance where species warn each other of approaching predators (as in the case of co-operating monkeys and duikers)… or a sexual relationship where individuals engage in bizarre cases of interspecies intercourse. I’m not about to start documenting medical anomalies at Tet Zoo, but I will admit a certain visceral fondness of Kirov et al. (2002), a paper that reports a most remarkable and eye-watering case of zoophilia…”

(via Tetrapod Zoology)