Nymphalis antiopa

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Geographic Range

The Mourning Cloak occupies an area in North America defined by the tundra line in Canada and Alaska in the north and the region of central Mexico in the south. Its range may extend further southward to northern South America, but it is not native to subtropical locales. Thus, it is usually not found in the southern regions of the states of Texas, Florida, and Louisiana. The Mourning Cloak also inhabits northern Eurasia, where some individuals may wander to England, and the temperate zones of Asia, even as far as Japan (Moucha, 1963; Pyle, 1981; Tveten and Tveten, 1996).

Habitat

The Mourning Cloak occupies "watercourses, sunny glades, forest borders, parks, gardens, open woodlands, and groves" (Pyle, 1981). During hibernation, it may be found "under the eaves of houses, in cellars, crevices and hollows" (Moucha, 1963).

Physical Description

The Mourning Cloak has a wing span of 2.875 to 3.375 in. Its dark maroon wings are characterized by a ragged creamy yellow margin that is lined on the interior by bright blue iridescent spots. When viewed closely, the wings appear to be iridescent as they reflect purple highlights. A rare variation in the appearance of the dorsal side of the wings, in which the margin is wider than normal and the blue spots may be absent, sometimes occurs. This aberration is a result of the pupa's being exposed to unusually cold temperatures. The ventral surface of the Mourning Cloak is a striated pattern of gray-black outlined by a yellow wing margin similar to that found on its dorsal surface (Holland, 1910; Pyle, 1981; Tveten and Tveten, 1996).

Reproduction

Butterflies undergo complete metamorphosis. The first stage of this process is represented by the egg. The Mourning Cloak lays its eggs in clusters of rings around twigs. The pale colored egg is 0.9 x 0.7 mm and becomes black prior to hatching; this event reveals the second stage of the process, the caterpillar. The caterpillar can grow up to 2 in long and is velvety black with raised white dots and a row of red spots on its mid-dorsal region. The caterpillar's legs are the color of rust, and several long black spines line its body. It associates in groups. The caterpillar undergoes four ecdyses, instances in which the caterpillar sheds its skin. Each ecdysis is called an instar. A fully grown caterpillar has gone through five instars. The latitude and altitude of the population's geographic location determines the number of broods, usually two or three. The next stage is the chrysalis. The chrysalis of the Mourning Cloak hangs upside down from grass stems; the tip of its abdomen is adjoined to the leaf by a silk pad produced by the caterpillar. It may grow up to 28 mm long and its color ranges from tan to gray. It has two head horns, a "beak," and tubercles that run the length of its body. The final stage is the adult butterfly (Feltwell, 1986; Klots, 1951; Moucha, 1963; Pyle, 1981; Tveten and Tveten, 1996).

Behavior

The Mourning Cloak is in flight throughout the entire year, mostly in the spring, the latter part of the summer, and the early fall. It hibernates in the winter, during which time it may emerge ocassionally. It often emerges from hibernation before the snows of winter have melted, making it the first butterfly to take wing in the spring throughout most of its range. The Mourning Cloak breeds during this season. It is evidently more active in the summer as it frequents slightly higher altitudes, such as the top branches of trees. It then enters estivation and remains dormant until autumn when it emerges to replenish its fat supplies.

The species does not characteristically undergo significant changes in population numbers.

It rests on dark bark where it enjoys excellent camouflage. Individuals also choose their favorite spots in the direct sunlight, such as leaves or tree trunks, in their particular habitat. This behavior, along with its dark wing color, enables the Mourning Cloak to absorb as much heat as possible. This is important to individuals living in colder, mountainous areas.

It is a non-migratory species, but wandering individuals do exist.

Male Mourning Cloaks exhibit territorial behavior, defending areas that average more than 300 sq meters in area. They ward off other butterflies and birds by flying towards them in a menacing manner. They defend their territory from designated perches, which they eventually alternate with other perches to defend the entire area.

As a mechanism of defense, larvae and pupae twitch together in response to a disturbance (Feltwell, 1986; Klots, 1951; Pyle, 1981; Tveten and Tveten, 1996).

Food Habits

The caterpillar of the Mourning Cloak feeds in groups on the leaves of deciduous trees, including the willow, elm, hackberry, cottonwood, poplar, rose, birch, and mulberry trees. The adult butterfly feeds on tree sap by landing above the flow of sap on a tree and bending its head downward to siphon it. It also feeds on rotting fruit. It very rarely feeds on flowers, but, in the summer, the butterfly may feed on the nectar of scabious and knapweed (Klots, 1951; Pyle, 1981; Tveten and Tveten, 1996).

Economic Importance for Humans: Positive

While the Mourning Cloak's function as a pollinator is minimal because the Mourning Cloak does not usually feed on flowers, it is still existent.

Economic Importance for Humans: Negative

Canada has designated the caterpillar of the Mourning Cloak as a pest that attacks deciduous trees (Moucha, 1963).

Conservation Status

The Mourning Cloak enjoys legislative protection in Austria and Switzerland (Feltwell, 1986).

Other Comments

Upon the approach of a predator, the Mourning Cloak makes a "click" sound when flying away from rest (Pyle, 1981).

The first specimens of Nymphalis antiopa ever recorded in England were taken in 1748 in Cool Arbour Lane near Camberwell, giving the butterfly one of its two common names, the "Camberwell Beauty" (Moucha, 1963).

Its scientific name, Nymphalis antiopa, is derived from Greek mythology. Antiope was the leader of the Amazons (Tveten and Tveten, 1996).

The Mourning Cloak enjoys a long life span of ten to eleven months (Tveten and Tveten, 1996).

Contributors

Vanessa Fonseca (author), Southwestern University, Stephanie Fabritius (editor), Southwestern University.

Glossary

bilateral symmetry

having body symmetry such that the animal can be divided in one plane into two mirror-image halves. Animals with bilateral symmetry have dorsal and ventral sides, as well as anterior and posterior ends. Synapomorphy of the Bilateria.

ectothermic

animals which must use heat acquired from the environment and behavioral adaptations to regulate body temperature

References

Feltwell, J. 1986. The Natural History of Butterflies. New York: Facts on File.

Holland, W. 1910. The Butterfly Book. New York: Doubleday.

Klots, A. 1951. A Field Guide to the Butterflies of North America, East of the Great Plains. Boston: Houghton Mifflin.

Moucha, J. 1963. Beautiful Butterflies. London: Westbook House.

Pyle, R. 1981. The Audubon Society Field Guide to North American Butterflies. New York: Alfred A. Knopf.

Tveten, J. 1996. Butterflies of Houston and Southeast Texas. Austin: University of Texas Press.