Spring's First Butterfly

Photo: commons.wikimedia.org

In April before the native trees leaf out, a butterfly called the Mourning Cloak emerges from hibernation. The Mourning Cloak is a fairly large butterfly with nearly a three-inch wingspan. Its Latin name is Nymphalis antiopa.

The velvety brown coloration of the topside of its wings allows it to absorb the warmth of the sun's rays even on cool days. Being cold-blooded, the insect depends on external sources of heat to warm up its muscles.

The border of the wings is golden with an inner pattern of oval blue scales. The underside of the wings are camouflaged with bark-like striations and edged in tan instead of gold. Butterflies rest with their wings folded above them to avoid detection by predators.

The Mourning Cloak is in the Brushfoot family whose defining characteristic is a pair of front legs that are reduced to hairy stubs.

The habitat for these butterflies is in moist temperate forests. The females lay their eggs on native trees like willow, elm, cottonwood, and birches. The caterpillars are black with bristles and red spots down the back. They go through metamorphosis during the summer and the adult emerges to feed on ripe fruit or tree sap in autumn.

Unlike other Lepidoptera families, the Mourning Cloak hibernates as an adult after building up a reservoir of nutrients to be used when overwintering.

Mourning Cloaks are best spotted at rest on the leaf litter in early spring enjoying those fleeting moments of sunshine when the forest is first awakening.

—Mary Gillick, Program Director

Sources:

"Creating a Butterfly Friendly Environment" by David Bouton (2002)

"North American Butterflies" by Jeffrey Glassberg