Photographed by Bette Jackson



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Hi, I'm Dr. Jerry Jackson, out with the wild things. Purple martins nest throughout the United States and into southern Canada. Their numbers decline to the north and west, and in the west, few martins nest in housing provided by humans. Instead, they depend on long-dead trees with multiple abandoned woodpecker holes for their colonies. At the end of the nesting season, however, all martins abandon their nesting site and gather in roosts close to prime feeding areas, usually in a forested wetland where flying insects abound. At first, adults and young from a single colony may roost together. They may use a roost for a week or more, then begin a gradual movement southward. Birds from other colonies join the nightly roosts along the way; there's safety in numbers and the birds are in a new territory. There may also be sharing of information about local food supplies. The farther south the birds get, the larger nightly roosts become as more and more birds converge on traditional migration routes and the prime feeding habitats of swamp lands and forested rivers of the southeast. The largest martin roosts in North America occur along the Gulf Coast from Florida to Louisiana, where martins remain to feed for a few weeks before crossing the Gulf of Mexico to their winter home.