Video and text by Brian Rudnick

Naturalists at the Wissahickon Environmental Center Treehouse are raising and launching monarch butterflies. In the Andorra meadow a short distance above the Treehouse, Philadelphia Parks and Recreation staffers Christina Moresi and Maris Harmon harvest milk weed leaves on which monarch butterflies have laid their small white eggs. They bring the leaves down to the Treehouse where the eggs hatch into caterpillars. They demand an abundant supply of milkweed leaves to munch on and grow. Moresi has filmed the whole metamorphosis. The grown caterpillars will climb to the top of a screen mesh and spin into milky green colored pupae. As the pupae mature, their casings become translucent and the butterflies' distinctive orange markings become visible. Finally the encapsulated butterflies emerge out of the bottom and pump blood to stretch out their new wings.

The naturalists place a small round tag on each newborn's wing and register it in an online database so if it is found in Mexico or en route, it can be identified. Moresi (right in photo) explains that the butterflies which lay their eggs in the Andorra are the fourth generation of butterflies migrating from hibernation in Mexico. Before they are released, the young monarchs are fed a rich diet of nectar and become flight worthy in a tall netted enclosure. The Center announces when they are about to release a group of monarchs. They are bound for Mexico, an extraordinary 2000-mile journey.