Chris Lee a.k.a chrislio023 was stalking Black-naped Terns (Sterna sumatrana) sometime in April 2009 when he came across a pair that was about to copulate. The male (assuming it was a male) was mounting the female (again, assuming it was a female) when another tern came up from behind and after some noisy confrontation, successfully chased off the amorous bird.
Birds usually pair off after a short courtship. Now how come a third party was involved? An ex? A jealous bird?
This post is a cooperative effort between NaturePixels.org and BESG to bring the study of bird behaviour through photography to a wider audience.