Wednesday, May 27, 2009

Nature Guide: Early Spring Butterflies

By this time in spring most of the migratory birds have passed through our area, leaving behind the population that we see throughout the summer. Our Nature Guide Jon Latimer begins a three-part report on another population of colorful species in our area now: butterflies.

"One of the earliest butterflies to appear in spring is a medium-sized white butterfly seen wandering lazily across open fields or patrolling along the edges of wooded areas. These are usually members of the Cabbage White species (about 1.5 in.) which was introduced from Europe in the 1860s. It has adapted well and become the most common butterfly in North America. Its caterpillars are considered pests in fields of leafy vegetables such as cabbage, giving it its name. Adult butterflies can be seen in our area from early spring to late summer.

"A larger species that also appears early in spring is the Mourning Cloak (3 in.). It is brown with a distinctive yellow-white border and a row of shimmering blue spots on it wings. It is unusual because it hibernates through winter as an adult, hiding in a woodpile or behind loose bark. Most other butterflies spend winter as an egg, caterpillar or chrysalis. When temperatures reach around 60 degrees, Mourning Cloaks take flight, but they are most likely to be seen in shady areas where it 's cooler.

"Another early spring species is the tiny Spring Azure (1 in.), which is a pale blue. They are most active in the afternoon, flying about 3 feet above the ground. They often drink nectar from the flowers of viburnum or dogwood trees and sometimes gather around wet soil on roads or near streams. Their caterpillars produce a sweet liquid known as honeydew. Ants feed on the honeydew and protect the caterpillars from predators, a kind of natural system of bribery.

"We'll talk about more spring butterflies in our next report."

NPS Photo by Sally King