During the height of summer, colorful flights of butterflies may be seen throughtout Alaska. Though more southerly states can claim more than 50 species, at least 78 species flit around the Alaska countryside. Anywhere flowering plants are found, butterflies may appear. The nectar of blooms is their sustenance, all that is necessary to keep them flitting among the flowers for the course of their adult lives.
Summer’s coolness rather than winter’s cold limits the number of butterflies in the Arctic and subarctic. Butterflies’ bodies do not have their own source of heat; they must gain it from their environment through solar energy and they need a certain minimum body temperature in order to fly. By making use of solar heat, they are capable of raising their body temperature as much as 30 degrees Fahrenheit above the ambient temperature. That is why you may sometimes see butterflies sitting on a rock with their wings spread open: they are collecting heat from the warm stone.
In the North, some species of butterflies tend to be darker than their southern relatives so they can absorb more heat. Also, northern butterflies tend to be smaller in response to the stress of a cold environment. This is an interesting contrast to northern mammals, which are bigger than their southern relatives. Mammals generate their own heat, so there is an advantage to being large.
In winter butterflies are inactive. Some species overwinter in the adult stage and avoid freezing damage to their body by making a sort of antifreeze in the fall. Other species will overwinter in the larval stage.
Butterflies are insects in the order of Lepidoptera. Like all insects, they have three main body regions (head, thorax, and abdomen), three pairs of jointed legs and one pair of antenna. Most have two pair of wings. Lepidoptera, which also includes moths, is the largest order of insects next to Coleoptera, the beetles. Its not always easy to tell the difference between butterflies and moths, but typically, butterflies fly during the day and most moths are nocturnal. Also, all butterflies have knoblike clubs at the tips of their antennae while moths do not. Butterflies develop through complete metamorphosis. After mating, females lay eggs on a blade of grass or leaf, most often on a plant that will serve as food for the larva or caterpillars, which the eggs hatch into. Following the caterpillar stage, a winged adult emerges. The full life cycle of some butterfly species may take years to complete.
A number of resident species are familiar to many of us. The delicate little “blues,” with a wingspan of about an inch are seen flying close to the ground and found mostly at lower elevations in fields or forest clearings. In contrast to the blues are the “sulphurs,” strong flyers also known by their coloration and found flying high above the ground in high winds. And there are the “coppers,” which feed on the tundra rose.
Scientists have found that the large group of fritillary butterflies take more than two winters of hibernation as larva before pupating into caterpiillar and shortly afterward into an adult. Alpine fritillaries, recognized by the orange and black pattern on the upper part of their wing, have been found on rocky slopes as high as 9,000 feet elevation. The dingy arctic fritillary solves the high tundra wind and low solar energy problems by simply walking where it needs to go, crawling over tundra plants, fulfilling its important butterfly role as plant pollinator.
These winged creatures are all amazing, with a variety of adaptations that stretch the imagination. Yet, some species have gone extinct and many are threatened or endangered. Entomologists have found that monarch butterflies, the species that annually migrates the incredible distance between Canada and Mexico, are threatened by the pollen from corn which has been genetically engineered to protect itself from pests. We must take careful measures to make sure what we humans do does not alter the little things in this world which make our surroundings magical.