Some butterflies from Maryland’s Eastern Shore take part in one of nature’s most amazing migrations. Monarch butterflies migrate up to 3,000 miles to reach their southern wintering grounds in the Oyamel fir forests of central Mexico.

In most migratory species, members of one generation complete the yearly migration. Monarchs, however, perform a generational migration with different generations responsible for different legs of the trip.

The last generation of Monarchs, which leaves Maryland in the fall, overwinters in central Mexico. The following spring those same Monarchs will migrate to the Gulf Coast states, where they will lay their eggs and die. The next generation of Monarchs will travel father north and, like their predecessors, will lay their eggs and die. This cycle continues until the third generation reaches southern Canada, the northern limit of the Monarchs’ range. The next generation will continue the life cycle into the early fall. When the fall, or overwintering, generation reaches the butterfly stage, they will not breed. Instead, they focus on feeding to fortify themselves for the migration to Mexico. The arduous cycle then begins anew.

The Monarchs arrive at the wintering grounds en masse and can reach densities of four million butterflies per acre. Overwintering conditions can be very harsh and can be aggravated by forest destruction in Mexico. Illegal logging in the preserves changes the micro-climate that affords protection from the winter weather, causing many butterflies to die.

Habitat loss is not only a problem in Mexico. In the United States, intensive development, farming and poor land management have destroyed Monarch habitat. This loss threatens the very existence of our region’s migratory Monarchs.

On a quest to gather data on the migration patterns of Monarchs, Chesapeake Wildlife Heritage (CWH) has been tagging migrating Monarchs since 1999. This work is part of a larger study conducted by the University of Kansas. In March 2006 one of the Monarchs, tagged by CWH six months earlier at our Barnstable Hill Farm Sanctuary on Kent Island, was recovered in El Rosario Monarch Butterfly Sanctuary near Angangueo, Mexico – a 1,960-mile flight from Chester. Other Monarchs tagged by CWH in Queen Anne’s County have been found to have made similar journeys.

CWH works to restore and protect habitat for a variety of wildlife. Monarchs and many other critters benefit from shallow-water wetlands and native meadows because of the variety of flowering plants, like goldenrod, tickseed and asters. These plants produce nectar for summer generations of Monarchs as well as the crucial nectar needed for migrating Monarchs in the fall. The meadows also produce milkweed (Asclepias sp.), the sole food source for Monarch caterpillars.

By providing a little habitat for Monarchs in your own yard, or on your farm, you can help these amazing creatures complete their miraculous journey.

Chesapeake Wildlife Heritage conducts a free Monarch Workshop every September. The public may join in tagging Monarchs and learning about their life cycle and their plight for survival. The Monarch Workshop for 2017 is Saturday, September 16 at 10 a.m. at the Barnstable Hill Farm Sanctuary on Kent Island. Registration for the workshop is required since the size of the group is limited. Call CWH at 410-822-5100 to register.