Excerpted from Finding a Safe Place to Rest and Refuel, which first appeared in the Spring 1998 GCBO newsletter.

What types of habitat are most important to migrating songbirds? Where do they occur, and how is their distribution and abundance changing as a result of development and land conversion? The movement of birds across the Gulf of Mexico each spring and fall is a prominent feature of the Nearctic-Neotropical bird migration system. The coastal woodlands and narrow barrier islands that lie scattered along the northern coast of the Gulf of Mexico probably provide important stopover habitat for Neotropical landbird migrants.They represent the last possible stopover before fall migrants make a nonstop flight (18-24 hr) of greaterthan 1,000 km, and the first possible landfall for birds returning north in the spring.

Some of the birds that stop to rest and forage in coastal habitats will avoid predators, find food, replenish fat stores and get on with their northward journey; others will be less successful. Visualize a red-eyed vireo gleaning small caterpillars from the edge of hackberry leaves in the middle of the long, narrow chenier near Johnson's Bayou, Louisiana. Now consider the many "decisions" she must make in response to the problems encountered en route. Besides the energetic cost of transport, she must adjust to unfamiliar surroundings, balance conflicting demands between predator avoidance and food acquisition, compete with other migrants and resident birds for limited resources, cope with unfavorable weather, and correct for orientation errors. How well she solves those problems will determine the success of her migration, while a successful migration is ultimately measured in terms of her survival and reproductive success.

Migrating birds are likely to solve en route problems if they settle in high quality habitat. Coastal woodlands of SE Texas, Louisiana, Mississippi and Alabama are good places to stop over following a trans-Gulf flight. Yet, the northern coast of the Gulf of Mexico, arguably the most important migratory stopover area for songbirds in North America, is expected to see significant human population increases. Between 1960 and 1985, the population living within 50 miles of the US coast increased from 92.7 million people to 125 million people-52 percent of the population in the coterminous United States (US Department of Commerce 1988). The southward migration of industry coupled with changing demographics will increase development pressure on stopover habitats in the decades ahead. As stopover habitat is transformed or degraded, the cost of migration increases and the potential for a successful migration is jeopardized. Some coastal habitats spared from development are threatened by accelerating rates of coastal erosion. The combined effects of coastal subsidence, the disruption of sediment supplies, and sea level rise will add further to the loss of important stopover habitats. As coastal areas are developed, there is a commensurate increase in the value of unaltered habitat to migratory birds, which makes the creation of new habitats to replace those lost to coastal development a major conservation challenge in the next century.

Dr. Frank Moore is an avian biologist at the University of Southern Mississippi, and a member of the GCBO Scientific Advisory Committee