HABITS

The monarch butterfly is found throughout North and South America wherever the milkweed plant grows. The monarch larvae feed on various types of milkweed, which thrives in open spaces, as well as beside roads, along woodland edges, on empty lots, and in overgrazed pastures. Monarchs will thrive wherever milkweed grows.

 

Milkweed Plants

Genus: Asclepias Species: Syriaca

Need milkweed seeds? Visit Butterfly Encounters or Monarch Watch

 

"Butterfly Encounters is encouraging everyone to plant Milkweed in their garden because it is the only plant that the Monarch butterfly can lay their eggs on. With all the development that occurs in the United States the Monarch has lost much of its habitat. By planting Milkweed seeds it helps to replenish habitat that has been lost."

 

MIGRATION

Despite it's paper-thin wings, the monarch butterfly is a powerful flyer with uncanny endurance, It is best known for it's annual migration, sometimes as far as 3,000 miles, through North America to California and Mexico. Monarch butterflies that breed in temperate parts of North America migrate so that their eggs and caterpillars will not be killed by prolonged winter frost. For this reason, the autumn Monarch broods are more likely to migrate than those that are hatched during the warm spring weather. The five million monarch butterflies from western North America head for a small number of sites scattered along the coast of California. The 100 million butterflies from the eastern part of the continent head south to Michoacan, in central Mexico.

During the last 200 years, the monarch butterfly has also succeeded in colonizing places as far away as Hawaii, Fiji, Australia, and New Zealand. These tropical monarch butterflies tend to be less mobile than their relatives in the temperate zones, seldom needing to travel far from their warm habitat.

Flight:  Successive broods; April - June migrating northward, July - August resident in North, September - October migrating southward, rest of year in overwintering locals. Year-round resident in S. California and Hawaii.

Habitat:  On migration, anywhere from alpine summits to cities; when breeding, habitats with milkweeds, especially meadows, weedy fields and watercourses. Overwinters in coastal Monterey pine, Monterey cypress, eucalyptus groves in California, and fir forests in Mexican Mountains.

Range: Nearly all of North America from south of Hudson Bay through South America, absent from Alaska and Pacific Northwest Coast. Established in the Hawaiian Islands and Australia.

One of the best known butterflies, the Monarch is the only butterfly that annually migrates both north and south as birds do, on a regular basis. But no single individual makes the entire round-trip journey. In the fall, Monarchs in the North begin to congregate and to move southward. Midwestern and eastern Monarchs continue south all the way to the Sierra Madre of middle Mexico, where they spend the winter among fir forests at high altitudes. Far western and Sierra Nevada Monarchs fly to the central and southern coast of California, where they cluster in groves of pine, cypress, and eucalyptus in Pacific Grove and elsewhere. Winter butterflies are sluggish and do not reproduce; they venture out to take nectar on warm days. In spring they head north, breed along the way, and their offspring return to the starting point. Both Mexican and international efforts are underway to protect the millions of Monarchs that come to Mexico. In California, nearly all of the roosting sites face threatening development.

 

HIBERNATION

The crowded winter roosts of the monarch butterfly are one of the natural wonders of the world. In Mexico, the roosting sites of the eastern monarch butterfly consist of a small area of pine forest. As many as 15 million orange and black butterflies cover the trees at one time. The temperature of the roost should be just above freezing. If it is too cold, the butterflies will die; if it is too warm, they will awaken from hibernation and expend valuable energy.