19 April 2006

A comma in the afternoon sun


I have discovered a nearby wooded hill where these butterflies, Eastern Comma (Polygonia comma), are common in the afternoons before sunset. They frequently land on trees and let me approach them to take close-up pictures. Now is the best time of the year to photograph them in natural light, because in another week, all the trees will be covered with leaves and it will be difficult to take pictures without resorting to a flash.

comma2I have noticed that these butterflies always land on trees with their heads facing either down or sideways, but never up. This results from the way they approach a tree: they always come from above even when they are landing high above the ground.

I can think of one survival advantage in their preferred position. Since a predatory bird is most likely to come from above, a butterfly facing down or sideways will take off away from the bird, whereas a butterfly facing up will have no choice but to fly up and will be more likely to get caught.

Next time I am on that hill, I have to pay closer attention to the flight directions of these butterflies when they are taking off from trees.


Katie said...


Cindy said...

Hi. I found your blog while googling for info. on snails. Lots of interesting stuff here. I liked the shots of the carpenter bees. (and your alternate title cracked me up!) I'll be back.

Nuthatch said...

Or in cool weather does this maximize surface area exposed to the sun? If they really were trying to avoid predators, they'd sit with their wings closed, then they are nearly invisible. Let us also not forget the brown creeper, which spirals up the trunk of a tree from the bottom.


Nuthatch, what does the surface area have to do with the orientation of the butterfly on the trunk?

But, yes, they are probably keeping their wings open to keep warm, although it was a warm afternoon.