Readying for the Monarch Migration

Butterfly Sanctuary tags Monarch butterflies for autumn release

Labor Day weekend, for Mari Gruber - the Butterfly Lady at the Bear Mountain Butterfly Sanctuary in Penn Forest Township, is the start of the Monarch butterfly migration season. From mid-August through mid-September, a generation of Monarchs are maturing in readiness for a flight of over 2,000-miles to north-central Mexico.

At the sanctuary, you can interact with the Monarchs in their various stages of growth: eggs, caterpillars, chrysalises, and adult butterflies in their indoor flight room. Their are videos, crafts and demonstrations about butterflies—and you can even take home Monarch caterpillars, watch them grow to butterflies, and bring them back to the sanctuary to have them tagged and released.

Monarch butterflies are orange, black and white with a wingspan of four to five inches. Most Monarchs live two to three weeks—but as the daylight begins to lessen towards the first day of fall, this newest generation of Monarchs prepare to live a life quite different from their parents, grandparents, great grandparents, and great, great grandparents.

They will live for five to seven months. During this uber-lifetime, they migrate from the impending frost of the northeast to the more moderate climate of Michoacan Mexico, where millions upon millions of the Monarchs converge on the southern side of a cliff at 10,000 feet elevation at the Santuario de la Mariposa Monarca El Rosario—sanctuary of the monarch butterfly of the rosary.

The Monarchs leave the northeast—flying at high altitudes to catch favorable winds, pass through Texas, converging on El Rosario at the end of October—where they will rest and mate, returning in a northward migration, the following March. During this migration, they typically fly two to three days, landing in Texas to refuel on nectar from flowering plants.

As it begins to become hot in Mexico, the Monarchs begin their migration northward, stopping in Texas to lay their eggs on milkweed plants.The milkweed is the only food the Monarch caterpillars eat. The adult butterflies who migrated from Mexico die.

Thirty days later, a new generation of Monarchs have grown from egg to butterfly, and continue the migration north to Canada, before settling, locally in the Pocono Mountains, where several generations will feed as caterpillars on milkweed leaves, and as butterflies on flower nectar, before the shortening of the days triggers the next migration. Monarchs are the only insect known to migrate.

If you are along the route of the Monarch migration, don't be surprised if one day in early autumn you see a cloud of orange, black and white butterflies. At the Sanctuary, they tag the Monarchs on a wing with ultra-thin strips marked with a reference number. All over the country and for many years, Monarchs have been tagged. When the butterflies are found, their tags are forwarded to researchers at the University of Kansas—who produce an on-line migration map.

On the west coast of the U.S. the Monarchs migrate to Baja and the northwestern portion of Mexico.

The Monarch migration satisfies two needs for the butterflies:food and shelter. They migrate to the north in the spring to places where the milkweed is plentiful, and they migrate to the south in the fall when temperatures are dropping, and these cold blooded insects become lethargic at temperatures below 50 F and will die at freezing temperatures.

At the Sanctuary, visitors have a hands-on experience at the Indoor Flight Exhibit where hundreds, of five varieties of butterflies, fly free, and may land on your shoulder. You can use a foam covered stick dipped in a sweet beverage to attract the butterflies and hold them up for examination. Visitors are cautioned not to touch the Monarchs because, since as caterpillars they dieted on the toxic milkweed plant. "It is really cool," said Gruber. "Being up-close and personal with these amazing creatures."

On Fridays through Sundays in September, the Sanctuary will present videos on the Monarch overwinter sites in Mexico; raising, tagging and releasing Monarchs; sending caterpillars and chrysalides home with kids to raise; and having special Monarch-themed crafts on site for kids to make and take home.

In October, the Carbon County Environmental Education Center will offer two programs at the Sanctuary. On Sun. Oct. 8 at 1:00 p.m., the CCEEC presents Radical Reptiles. On Saturday Oct. 13 at 1:00 p.m., the CCEEC presents Hunters of the Sky/Birds of Prey—free with admission to the Sanctuary.

Bear Mountain Butterfly Sanctuary is located on Rt. 903, 8 miles east of Jim Thorpe, near Pocono Whitewater. Its entrance is on Church Road. It will be open through October on Fri., Sat. and Sun, and open on Mondays on holiday weekends. For information call:(570) 325-4848, or see: www.bearmountainbutterflies.com