Johann Schumacher The dark maroon wings of the mourning cloak butterfly match the vast and subtle browns of the early spring woods. Velvety and saturated with color, the wings are bordered with a warm yellow band and dotted with a row of unexpected iridescent blue spots. This butterfly is both handsome and cryptic; while resting or feeding, it folds its wings to create a gray, ragged-edged silhouette â€" the perfect imitation of a dead leaf.
These dark colors are more than simply elegant; they help absorb the warming rays of the sun. This butterfly (Nymphalis antiopa) is a strong flier and is frequently encountered while it scouts the woods for sunny patches on which to land. When it finds a good spot, the butterfly opens its dark wings and may spend long minutes positioning and repositioning itself while following the sun’s rays, looking a bit like a model posing for the camera.
One of only a few adult butterfly species that survive the winter, the mourning cloak is also one of the earliest butterflies to be seen gracing the spring woods. But having survived months of harsh weather, hibernating under loose bark or in a tree cavity, the adults awaken to enjoy only a few short weeks of warmer weather. They emerge to mate and then deposit their eggs on black willow, birch and hackberry trees. Though very few adults persist past spring, by then each has survived for 10 or 11 months, making the species one of North America’s longest-lived butterflies.
Mourning cloak eggs develop into dramatic black, spiny, red-spotted caterpillars. These caterpillars feed and grow quickly on a diet of fresh spring leaves. By June, they pupate, and in midsummer they return to the woods as newly minted adults.
Male mourning cloaks aggressively defend a territory and can often be observed chasing other butterflies away. Their ambitions often involve creatures far greater than mere butterflies; mourning cloaks will attack much larger animals.
Indeed, the first encounter most people have with a mourning cloak occurs after unknowingly trespassing into a male’s territory. The butterfly immediately flies up and actively circles, often flying head-on at intruders, attempting to bully them out of the area. You haven’t lived until you’ve been attacked by a butterfly. Be prepared, when you travel in mourning cloak country.
Emerging well before most wildflowers, early-season mourning cloaks feed primarily on the sap dripping from wounds or abrasions in tree trunks and branches. I have also seen them actively feeding on the fluids dripping from sun-warmed road kill, rotting fruit, animal scat and mud puddles.
Even when wildflowers are available, mourning cloaks rarely seek them. This is hardly the carefree image we have of butterflies, but then, life is tough in the city. Mourning cloaks can be found in all five of New York City’s boroughs, wherever a park of decent size harbors tall trees and enough open space for them to call home.
A version of this article appears in print on 05/04/2014, on page MB4 of the NewYork edition with the headline: Winter Survivor, Sunbathing.