Snow may still be on the ground in spring when the adult mourning cloak butterfly emerges from its winter hibernation. Because of this hibernation, mourning cloaks are the longest-lived butterfly in North America at 10-11 months old.

Why is it called a "mourning cloak butterfly"?
The butterfly's common name comes from the adult's dark wings, which resemble the traditional woolen cloak worn in the 1800s. The dark capes were often worn to funerals, hence the "mourning" part of the name. Its scientific name, Nymphalis antiopa, comes from Nymphalis meaning "pertaining to a fountain" and antiopa, which honored the queen of the Amazons. Unfortunately, the derivation of the scientific name is not clear. In England, this butterfly is called the Camberwell beauty or grand surprise.

Description
The dark brownish-purple wings are 3-5 inches wide. They have a light creamy-yellow border, which contrasts to an inner row of bluish spots. The outer edge of the wings has a series of irregular scallops. There are also two short projections on the hind wings. The dark mottled undersides of the wings help make the butterfly cryptic when perched on tree bark.

Range
Mourning cloaks may be found throughout much of North America, except south Texas, southern Louisiana, and peninsular Florida. They range into Europe and temperature Asia, as well. These butterflies may be found in many different habitats, from forests to backyards.

Stages of Life
Female mourning cloak butterflies lay bunches of pale yellow eggs, up to several hundred, on twigs of elms, hackberries, aspens, birches, willows, and cottonwoods. The eggs hatch into young caterpillars that feed in groups on their host's leaves. The blackish caterpillars are colored with white and reddish spots and are covered with bristles (to make them appear inedible). They will go through four growth stages or instars until they are about 2 inches long. At this point, the caterpillars are ready for their last instar—the pupa stage.

Caterpillars that are ready to pupate hang upside down from a branch or under the eaves of a house. Resembling the letter J, they anchor themselves with a pad of silk and transform into a grayish-tan, spiky chrysalis. In this resting stage, the caterpillars change or metamorphose into an adult butterfly in about 10-15 days.

For the rest of the summer, the adults feed on tree sap, fruit, carrion, nectar, or animal droppings until cold weather hits. Some adults go into a resting stage called aestivation if it becomes too hot or dry. Then they emerge and feed again before winter. (A second generation of eggs may be laid in July).

Adults hibernate beneath loose boards, old shingles, tree bark, or hollow logs.
If winter temperatures are mild, the adults may emerge to feed. If not, they wait until late March or early April. At this time these older individuals will emerge. The light creamy-yellow border on their wings has faded white. They will seek a mate and start another generation of mourning cloak butterflies.

Class Project
Mourning cloaks are easy to raise indoors. Place caterpillars in a clear container like an unused aquarium or fishbowl. Use cheesecloth, wire mesh, or an old nylon stocking to cover the top. Keep the cover in place with a big rubber band. You can also use an 18-gallon plastic tub with a lid. Have an adult punch the lid with a screwdriver to make air holes.

Place a clean yogurt or soda cup filled with some water in the large container. Add stems that have leaves from the caterpillar's host plant to the small container. Cover the small container with a lid that has holes in it for the stems to emerge. The lid keeps the caterpillar from falling into the bottom of the cup. Replenish the leaves often, as the caterpillars need green leaves to eat. Clean up the droppings and keep the container clean. Include some larger sticks in the container for the caterpillars to climb on and eventually to hang from when they go into their chrysalis form. When the adults emerge from the chrysalis, just remove the lid and let them dry their wings. They'll fly when they are ready!

Local sources for mourning cloak caterpillars include backyards, parks, and areas with host trees (cottonwood, elm, willow, poplar, and hackberry), friends who talk about "spiny" caterpillars in their yards, and plant nurseries. If a person has a connection with a nursery, these are great places to obtain caterpillars. Don't forget to buy some host plants from them at the same time! Check the local county extension offices. Locate a local butterfly club or an expert. The Internet also offers ways to communicate with butterfly breeders as to obtaining caterpillars. Two Internet locations to check for mourning cloak caterpillars are:

http://www.butterflybreeders.com
http://www.kevincollison.com

Bibliography
Opler, Paul. A Field Guide to Western Butterflies, 2nd ed. New York: Houghton Mifflin Company, 1999.

Pyle, Robert Michael. National Audubon Society Field Guide to North American Butterflies. New York: Chancellor Press, Inc., 1997.

Internet Resources
http://www.inhs.uiuc.edu/inhsreports/fall-02/mcloak.html
http://www.naturenorth.com/spring/bug/mcloak/mcloak.html
http://www.wildlife.state.nm.us/education/documents/mourningcloakbutterfly.pdf

Damian Fagan is a former National Park Ranger and wildlife biologist, who is now a freelance writer and photographer. He has written several field guides and many magazines articles for children and adults. Damian lives in Bend, Oregon with his wife, daughter and 16-year old dog.

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