The monarch is the only butterfly known to make a two-way migration as birds do. Unlike other butterflies that can overwinter as larvae, pupae, or even as adults in some species, monarchs cannot survive the cold winters of northern climates.

Monarch butterfly migration is the phenomenon, mainly across North America, where the subspecies Danaus plexippus plexippus migrates each autumn to overwintering sites on the West Coast of California or mountainous sites in Central Mexico. Other populations from around the world perform minor migrations or none at all.

In all the world, no butterflies migrate like the monarchs of North America. They travel much farther than all other tropical butterflies, up to three thousand miles. They are the only butterflies to make such a long, two way migration every year. Amazingly, they fly in masses to the same winter roosts, often to the exact same trees.

2017年10月16日 · Each fall, millions of monarch butterflies leave their summer breeding grounds in the northeastern U.S. and Canada and travel upwards of 3,000 miles to reach overwintering grounds in southwestern...

2021年3月16日 · Every year, the Eastern monarch butterfly flies up to 2,500 miles from its breeding grounds in the US and Canada, all the way down to its hibernation grounds in central Mexico. These tiny creatures have the most highly evolved migratory pattern of any known species of their kind, but this unique phenomenon is under threat.

Most monarch butterflies that emerge after about mid August in the eastern U.S. enter reproductive diapause (do not reproduce) and begin to migrate south in search of the overwintering grounds where they have never been before. From across the eastern U.S. and southern Canada, monarchs funnel toward Mexico.

A monarch butterfly sips nectar from New England aster. Decreasing day length and temperatures, along with aging milkweed and other nectar sources, trigger the birth of the super generation and their epic migration.