Butterfly battles — Life in a Southern Forest

Butterflies are usually associated with happiness and serenity. Think of all the children's books, decorations and toys that feature the pretty wings of butterflies in delicate and peaceful scenes. Yet butterflies can be surprisingly aggressive.

This Summer we are seeing large numbers of Jalmenus evagoras (Imperial Hairstreak). The species is widespread and common, but patchily distributed. The colonies here now have been with us for a couple of seasons, but may not be here next year.

The larvae feed on various Acacia species in well-described associations with ants. In fact, this is a very well-studied butterfly. Much is known about the mating behaviour, ecology and even the genetics of this species.

Paul has described the life cycles of these butterflies in previous posts.

Yet despite having watched them extensively, and read quite a bit about them, the butterflies still managed to surprise me this morning.

In clusters of two or three, butterflies were fluttering and interacting in a way I've not noticed before. They were not on their host plants, so this was not egg-laying or typical mating behaviour.

And the more I watched, the more convinced I became that this was simply competition. Presumable these were males ... it is difficult to tell with this species ... and presumably they were battling for territory and mating rights. Whatever the basis, it was quite really quite a sight. Who would have thought that a butterfly could appear so very menacing!

The images below show two butterflies battling. The butterfly on the right seemed keen to defend his prime perch on a bracken frond, shaping up to incoming challengers. These still images show the posturing and head-to-head battles, but fail to show the speed of the wing fluttering involved.