Red Admiral Butterflies at Camping Chez Rambaud

Vanessa atalanta

Geographic Range

The range of Red Admirals extends around the Northern Hemisphere, from northern Canada to Guatemala in the western hemisphere, and from Scandinavia and northern Russia south to North Africa and China in the east. It is established on Bermuda, the Azores, and the Canary Islands in the Atlantic, and the Hawaiian islands in the Pacific. It has been introduced to and breeds in New Zealand as well.

Habitat

Red Admirals tend to be found in moist environments such as marshes, woods, fields, and well-watered gardens. These butterflies cannot stand extreme winter cold and are forced to migrate southward during the winter months to warmer climates. During this migration they can be found in habitats ranging from subtropics to tundras. The caterpillars of this species live on the plants they feed on.

Physical Description

The characteristic coloration of the Red Admiral Butterfly is a black hindwing with a red-orange marginal band; the dorsal forewing is also black with white markings near the apex. The wing span of the Red Admiral ranges between 1.75 and 3 inches. These butterflies tend to have a brighter coloration and a larger body mass during the summer months than during the winter. The legs and eyes of the Red Admiral tend to be hairy and the head is moderately large. A mature caterpillar of the larvae stage is cylindrical in shape and has branching spines arranged in rows lengthwise.

Reproduction

Male Red Admirals are territorial butterflies that patrol their areas in order to find female mates. The males typically perch upon sunlit spots, in the mid-afternoon, to wait for females to fly by. Once fertilized, female Red Admirals will lay their eggs on the upper surface of host plant leaves. The majority of Red Admiral butterflies are double-brooded (two generations grow a year); however, in Canada and the northern part of the United States they are single-brooded (one generation a year), and in the southern United States they are triple-brooded (three generations a year).

The general life cycle of the Red Admiral butterfly goes from an egg, to a caterpillar (pupate in a chrysalis), that emerges as an adult. The adult then mates, oviposits, and starts the cycle again.

Behavior

Red Admirals are considered to be people-friendly butterflies that will approach and perch on human beings. In regard to other butterflies of their species, however, the male butterflies are known to be territorial in order to find a mate. Male Red Admirals generally claim an elliptically shaped area ranging between 4-13 m wide and 8-24 m long. To protect this area, the males will patrol their territorial boundaries up to thirty times an hour. If an intruder enters their area, they attempt to drive them away by out-flying and out-maneuvering the intruding butterfly. Red Admirals tend to be fidgety and swift insects that rapidly change direction throughout the course of their flight. The species appears to be most active throughout the spring and fall months, its flight time lasts from March until November. Adult Red Admirals will hibernate throughout the winter months.

Food Habits

Mature Red Admirals tend to feed on fermenting fruits, bird droppings, and sap from trees. Adult Red Admirals are fond of nectaring at composite flowers, such as milkweed, aster, and alfalfa. The food sources for the larva include nettles from the genus Urtica, pellitory from the genus Parietoria, and hops from the genus Humulus.