Coastal BC Insects: Mourning Cloak Butterfly

Mourning Cloak Butterfly

The Mourning Cloak butterfly (Nymphalis antiopa) is common throughout the United States and here in British Columbia. It emerges early in the spring when temperatures reach about 10° C. When Wayne and I were out riding our quads in early April, there were everywhere, leading the way along logging roads and trails. The Mourning Cloak is easy to identify because of its large size and dark maroon-brown wings fringed in yellow and a band of bright blue spots.

The Mourning Cloak feeds on flowering plants, but it chooses willows, poplars, and similar woody plants to lay its eggs. That way, when the larvae emerge they have their food of choice.

After hibernating through the winter, Mourning Cloak butterflies emerge to mate and lay their eggs. At this point, they are about a year old, having overwintered in sheltered locations under logs or forest debris. With the mating ritual complete, their wings become tattered and they die. To me, the life cycle is reminiscent of salmon going upstream to spawn just before their bodies give out.

New butterflies emerge from the larva stage in late July and spend a week or more feeding before going into a dormant stage. They emerge again in the fall for another feeding frenzy. It’s probably this lifestyle that allows them to live longer than most other butterflies.

One of the guidebooks I use regularly at the cabin in Insects of the Pacific Northwest by Peter Haggard and Judy Haggard (Timber Press, Inc., 2006). Each entry includes photographs by Peter Haggard who holds a BS in wildlife management and worked as an agricultural inspector in California. Judy Haggard has a MA in biology and works as a wildlife biologist. I especially like this guide because of the photographs. They make identification easier and more precise, especially when I can get a photograph of my own to compare. -- Margy