Endangered New Jersey: The Incredible Journey of Monarch Butterflies

Every spring, blue skies in Michoacán, Mexico, turn orange as millions of monarch butterflies gather in the same ancient forests.

They are traveling from as far away as Maine, New Jersey, and Canada - up to 3000 miles. They weigh just a fifth of a penny. The millions of flapping wings are said to sound like falling rain.

Right now, the monarchs are leaving these forests, mating along the way.

This summer, four generations will be born and die, each living about a month before a "super generation" arrives. They will live seven months and, though they have never been to Mexico, they will somehow find their way, back to those same forests.

Watch a good video introduction to monarchs.

There are an estimated 250 million monarchs that winter in the Mexican preserve. The number is impressive, but 15 years ago, the number was nearly one billion. One problem is that the giant fir trees where monarchs huddle for warmth are being cut down.

Without cover, millions of butterflies often freeze to death. In typical years, about 15 percent will freeze, but this past winter's bad weather killed more than 50 percent.

Despite 140,000 acres being set aside by the Mexican government as a preserve for the monarch butterflies, more than 100,000 trees are cut down each year within this zone. Much of this is by residents who use the wood for fuel, building and to clear for crops.

Mexico recently lost nearly 7 percent of its forests. That is an area twice the size of New Jersey. A majority of that loss is from illegal logging.

The deforestation also destroys watersheds which can cause dangerous mudslides.

Ecolife Foundation is one organization working to replant trees and educate residents in the area by supplying them with efficient stoves to reduce their use of wood as fuel. Ecolife is pledging to plant a million new trees over the next three years.

The fall monarch butterfly migration.can be observed in New Jersey. Cape May County is a prime location to watch this phenomenon, Stone Harbor Point being an active spot.