The Birth of a Monarch

Teddy went out looking for monarch caterpillars feeding on milkweed leaves and bought six of them back to the trailer so that we could observe them metamorphose into adult butterflies. The Monarch is a common poisonous butterfly that eats poisonous milkweed in its larval stage and lays its eggs on the milkweed plant. Animals that eat a Monarch get very sick and vomit (but generally do not die). These animals remember that this brightly-colored butterfly made them very sick and will avoid all Monarchs in the future. The monarch gets its poison (cardenolide glycosides) when it is a caterpillar, from eating the poisonous milkweed plant (genus Asclepias) while in its larval (caterpillar) stage. The poisonous Monarch is mimicked by the non-poisonous North American Viceroy butterfly (Limenitis archippus), which has a similar shape, coloration and patterns. Predators who have learned to avoid the Monarch will also avoid the similar-looking Viceroy.
Some groups of Monarchs migrate for over 2,000 miles during August-October, flying from Canada and the USA to overwinter in coastal southern California to the transvolcanic mountains of central Mexico; this was determined by the Canadian scientist Dr. Fred A. Urquhart in 1975. Females lay their eggs along the migratory route. This migration takes up to three generations of Monarchs to complete.
Other Monarchs stay in one area their entire lives. The life span of the adult Monarch varies, depending on the season in which it emerged from the pupa and whether or not it belongs to a migratory group of Monarchs. Adults that emerged in early summer have the shortest life spans and live for about two to five weeks. Those that emerged in late summer survive over the winter months. The migratory Monarchs, which emerge from the pupa in late summer and then migrate south, live a much longer life, about 8-9 months.

I took this series of photographs of the metamorphic process.

(click on picture for a larger image)

CLASSIFICATION
Order: Lepidoptera (butterflies and moths)
Family: Nymphalidae (over 5,000 species of butterflies with dwarfed front legs)
Subfamily: Danaidae (milkweed butterflies)
Genus and species: Danaus plexippus