Papilio glaucus

The eastern tiger swallowtail ranges from Alaska and the Hudsonian zone of Canada to the southern United States, east of the Rocky Mountains.

This species occurs in nearly every area where deciduous woods are present, including towns and cities. It is most numerous along streams and river, and in wooded swamps.

The forewing spans 4 to 7.6 cm. The males are yellow, with black tiger stripes. A large black border surrounds the edges of the wings. In Georgia, the coloring has more of an orange hint. The subspecies australis has been applied to these southeastern tiger swallowtails. Females are dimorphic. Some female swallowtails have the same color pattern as the males, while some are completely black. A variety of patterns between completely black, and yellow with black stripes can be seen in female swallowtails. These two extreme female colorings are thought to coexist because they both have equally beneficial effects. While the tiger striping causes a distracts predators, the dark coloring imitates the unpalatable blue swallowtail.

As with most butterflies, Eastern tiger swallowtails tend to be solitary. Males "patrol" for a mate, flying from place to place actively searching for females. "Patrolling" male tiger swallowtails can recognize areas of high moisture absorbtion by the sodium ion concentration of the area. It is believed that the moisture found by these males helps cool them by initiating an active-transport pump. Both male and female tiger swallowtails are known to be high fliers. Groups of fifty butterflies have been spotted in Maryland flying 50 meters high, around the tops of tulip trees.

Larvae are polyphagous, meaning they feed externally on the leaves of various woody plants. Foodplants include a variety of poplars, mountain ash, birch, cherry, tulip tree, ash, basswood, apple, maple, willow, magnolia, and occasionally sassafras.

The eastern tiger swallowtails are not yet threatened by human impact on their ecosystem.

The tiger swallowtail is thought of as the American insect, in much the same way as the Bald Eagle is thought of as the American bird. It was the first American insect pictured in Europe; a drawing was sent to England from Sir Walter Raleighs' third expedition to Virginia.