Scientific name: Nymphalis antiopa
(Information in this Species Page was compiled by Jennifer Sensor in Biology 220M, Spring 2005, at Penn State New Kensington)
Typically the mourning cloak (Nymphalis antiopa) is the first butterfly seen in the spring on our Nature Trail. The ability of the adults of this species to hibernate in tree holes, inside unheated buildings, and even under the loose bark of some tree species makes this early spring (mid to late March) adult emergence possible. Often there is still snow on the ground when these beautiful butterflies make their first appearances. The ability to move about in their wooded habitats very early in the season enables this species to consume their favorite food (tree sap) just as it begins its seasonal rise up through the tree’s vascular tissue. Individuals emerging from hibernation rely on vigorous thoracic muscular contractions to generate body heat and also will bask extensively with their dark, dorsal wing sides exposed to the incoming sunlight.
The distributional range of the mourning cloak is expanding into more and more northern regions. Its is thought that this expansion is yet another observation of the biological consequences of human induced global warming.
The mourning cloak’s wings are irregularly notched into a rough, scalloped edge. The dorsum (back) of its wings are dark in color (purple to maroon) and are edged by an inner line of iridescent, blue spots and an outer border of yellow or creamy white. The venter (underside) of the wings is a dark and striated blackish brown with a pale, gray border. The mourning cloak at rest or in hibernation folds its wings together so that only the drab, camouflaging coloration of the ventral wings is exposed to its potential predators. The name mourning cloak comes from the perceived similarity of the rich, dorsal wing colorations to a traditional cloak worn during a period of bereavement and mourning.
A key characteristic of the taxonomic family to which the mourning cloak belong are the small, somewhat coiled front legs which are typically tucked up “underneath the chin” of the individual. This family of butterflies (the Nymphalidae) is called the “brush-footed” butterflies because of this distinctive first leg pair shape.
The caterpillars are voracious eaters and readily consume the leaves of the American elm, aspen, cottonwood, hackberry, paper birch, and several species of willow. The caterpillars grow rapidly and undergo four molts as they move through their larval instars toward the inactive pupal stage. The pupa is encased in a gray chrysalis of silk which hangs from a thread attached to branches or some type of overhanging structure. The metamorphosis into adults takes about 15 days.
The eggs laid in early spring will pupate and emerge as adults by early summer (June or July). These adults may enter a warm-weather inactivity phase (“aestivation”) after which they re-emerge and feed very actively in order to build up hibernational fat reserves. They then hibernate for the winter. An individual experiencing this type of life cycle pattern may live up to 10 months or more! This makes the mourning cloak the longest lived of all butterflies! These June or July emerging adults, though, may also, depending on the climatological conditions or levels of habitat resources, skip the aestivation phase and proceed directly to mating and egg laying. This second brood of eggs, then, hatches into caterpillars which grow, pupate and metamorphose into adults by August or September. This second brood, then, begins to feed and prepare itself for the long winter hibernation. In the northern sections of the mourning cloak’s range one or two of these seasonal broods are common. In the southern sections of the range, however, up to three brood generations are typical.
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This page was last updated on July 16, 2006
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