Gossamer Tapestry

Reflections on conservation, butterflies, and ecology in the nation's heartland

Sunday, April 22, 2012

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.



At 20:05, Blogger Randy Emmitt said...

It's been a long whil;e since I saw lots of Red Admirals like that. I recall in WV seeing thistles with 1-2 admirals on every bloom. I'd say you have a male Orange Sulphur there judging from the black margins in the forewing.

At 10:50, Blogger Doug Taron said...

Hi Randy,

You are correct, both in the identification and that the text was confusing in this regard. I have edited for clarity. Thanks.

At 18:24, Blogger Kathie Brown said...

Wow! How exciting! I will keep my eyes open for you here on the east coast and let you know if I see any!

At 22:49, Blogger Ur-spo said...

I did not follow if this is a 'good sign' or a 'bad sign' or merely a normal cycle for these butterflies.

At 22:49, Blogger Ur-spo said...

I did not follow if this is a 'good sign' or a 'bad sign' or merely a normal cycle for these butterflies.

At 09:44, Blogger Doug Taron said...

Ur-spo. I'm getting that question a lot. I don't think that it's necessarily either good or bad. Just noteworthy.

At 11:47, Anonymous Anonymous said...

Hey Doug...The Admirals swept thru the Madison area on Monday the 23rd. First a pair on my balcony, then, 3 pairs in the adjacent tree. It felt so early for butterflies that I took my dog for a walk and a look around. Amazing. Every 4 or 5 houses and the next largish sunlit tree had multiple pairs. For blocks and blocks. Friends from all over town reported the same.


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