It has an extensive home range, but specific habitat needs. Its mating habits are in some ways the opposite of what one would expect, and its complex adaptations continue to cause argument amongst researchers to this day. The ecology and the home range of the monarch butterfly are closely intertwined, as with most species. The distribution of the monarch is controlled by the distribution of milkweed, it regulates their density in a given area, and it is for this plant that the monarchs migrate for long distances every year. So dependent upon milkweed is the monarch that where one finds the monarch, one will also find milkweed.
Milkweed is the host plant for most of the monarchs life cycle.
Eggs are deposited and hatch on the underside of leaves of the milkweed plant. Upon hatching, the larva will feed upon the fine hairs on the leaves of this plant, and stay on this same plant throughout its five molting stages. After molting, the larva will leave the milkweed and construct its chrysalis somewhere else. The monarchs will spend their summer either in the New England-Great Lakes area, or else in the canyons of the eastern Rocky Mountains. The Great Lakes population will migrate southwest in the fall, and spend the winter in the Sierra Madre mountains of central Mexico.