San Diego Natural History Museum--Your Nature ConnectionSDNHM Field Guide

Danaus plexippus

Family: DANAIIDAE (Milkweed Butterflies)


Monarchs are large butterflies, noted for their powerful flight and long migrations. They have a wing span of 3 3/8 – 4 5/8 inches. Males have a black scent patch on the top of the hindwing, and are also a bright orange while the females are a duller orange color with thicker black veins on wings. Caterpillars are ringed with yellow, black and white. Learn more about the lifecycle of the monarch.

Range and Habitat

Habitats include streambeds, high altitude meadows, canyons, foothills, prairies, roadsides and fields. Abundant nectar sources and milkweeds need to be present. Monarchs are the most familiar of all our butterflies, and are summer residents in Canada and throughout the entire continental U.S. They overwinter along the central and southern California coast, as well as high in the mountains of Mexico. Learn more about their migration.

Natural History

The family Danaiidae is a tropical group that is predominantly represented in the lower latitudes. Milkweed and its evolutionary relatives radiated out of the tropics as well. Monarchs can not survive freezing temperatures for very long. They have 4 to 5 broods a year with one generation overwintering as an adult. Members of this species migrate long distances to reach their overwintering habitat.

Monarchs store poisonous compounds called glycosides, which are derived from the milkweed plants that serve as their only food as caterpillars. These compounds make them distasteful to birds that would otherwise prey on them. The Viceroy is an edible species that mimics the Monarch in the western states.


Sites in California and Mexico need to be protected to enhance survival of Monarch populations. Learn more about threats to the Monarch's survival.

Related or Similar Species

Queen, Western Viceroy, Painted Lady

Monarch, photo by Bob Parks

Monarch just emerged from chrysalis, photo by Bob Parks

Text by Margi Dykens and Christian Manion.
Photo by Bob Parks.

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