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Mourning Cloak Butterflies Emerging from Hibernation

4-11-13 mourning cloak IMG_2827

A male mourning cloak butterfly basks in the sun on an eastern hemlock while its dark wings act as solar collectors, warming the hemolymph (a circulatory fluid analogous to blood) in the wing veins and returning the warmed fluid to the butterfly’s body until it reaches a temperature sufficient for flight. This butterfly has just emerged from hibernating in a sheltered spot, such as behind loose bark. Because they overwinter as adults, mourning cloaks are one of the first butterflies to be seen in the spring.  The adults mate and lay eggs, and the caterpillars that hatch from the eggs will metamorphose into adults in June or July.  After feeding for a short time, the adults become dormant (estivate) until fall, when they re-emerge to feed and store energy for hibernation.

12 responses

  1. Dianne and Ed

    Hurrah……….I’m hoping to see one………..what a beauty…………what a marvel of nature……… Dianne

    April 11, 2013 at 12:19 pm

  2. Here on Martha’s Vineyard, our two recent 60’s degree days brought out the mourning cloaks. And, (grrrr) a cabbage butterfly, which I hope some hungry bird ate.

    April 11, 2013 at 1:02 pm

  3. Emmylou

    I didn’t know that a butterfly was out so early in the spring!

    April 11, 2013 at 8:09 pm

  4. Just curious … why are moths and butterflies so different physiologically? What is different about moths that makes it possible for them to be active at temps close to freezing, while butterflies need much warmer temps to fly?

    April 11, 2013 at 11:04 pm

    • Hi Cheryl,
      What a good question. I will have to do some research, but offhand my guess is that perhaps, like many invertebrates, some moths are able to produce a kind of glucose that allows them to tolerate very cold temperatures.

      April 12, 2013 at 1:27 pm

  5. nancy weaver

    hi emily,are you familiar with mary holland’s blog – its good!and someone may ask us saturday what is that butterfly?and now we know more than just what…nancy psi don’t usually check this personal e-mail address during the day

    Date: Thu, 11 Apr 2013 12:09:50 +0000 To:

    April 12, 2013 at 2:24 am

  6. Rich Benton

    What is the lifespan of this butterfly?

    April 12, 2013 at 12:59 pm

    • Hi Rich,
      The mourning cloak butterfly lives up to 10 months — considerably longer than most butterflies!

      April 12, 2013 at 1:22 pm

  7. Judy

    Now I understand why I would see so many of these in the woods on trail rides. They seemed to like the horse’s droppings, too.

    April 12, 2013 at 1:19 pm

  8. Muffin

    Just saw a mourning cloak while walking up a dirt road in Sunapee, New Hampshire. Thanks for the post, as I did not know what it was and was very surprised to see it.

    April 13, 2013 at 12:03 pm

    • Muffin

      This was before the snow and sleet we got on Friday!

      April 13, 2013 at 12:04 pm

      • Definitely, Muffin!

        April 15, 2013 at 12:06 pm

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