Admiral Invasion

Depending on where you live, you may or may not be experiencing a huge invasion of Red Admiral butterflies.  I have gotten reports from friends and colleagues in Iowa, Wisconsin, Michigan, upstate New York and Ontario confirming the influx.  On the other hand, I was in eastern Massachusetts just a week ago and saw none, so it hadn't made it that far east.  They are migrating up from their wintering grounds in the deep South.  The mild winter and warm spring are probably responsible for their early arrival, and may or may not be responsible for the huge numbers.  This species is well known to undergo occasional population booms. 

Yesterday I went out to Bluff Spring Fen.  With temperatures hovering around 60, it was on the cool side for butterfly activity.  Bright sunshine, however, allowed them to warm up via basking and the admiral invasion was much in evidence.

Nettles (Urtica dioica) at Bluff Spring Fen

There were scores of butterflies in this open area. 

Red admiral caterpillars eat plants in the nettle family.  We have several large patches of stinging nettles at the Fen.  There were dozens and dozens of admirals flying in the patches.  I saw numerous females laying eggs.

Given the cool temperatures and abundance of individual butterflies, I thought that I maght have an especially easy time with photography. My hopes that the butterflies would be more sluggish and approachable were not to be realized.  I got photos of butterflies on bad backgrounds.

I got shots of bad specimens.

I did manage to get a couple of photos that I was reasonably happy with.  I saw a couple of other species out and about yesterday, as well.  There were a bunch of clouded and orange sulphurs.

The real story continues to be the admirals.  I don't know how long it will last, but I've never this species undergo such a huge population explosion.