Migration Patterns of the Prothonotary Warbler
Prothonotary warblers have strong site fidelity. Although they have a large nesting area in the US, individual birds return to the place of their birth. Males stake out a territory and fill cavities with moss, tempting females to use them. But after mating, the female chooses the actual nesting site and constructs the nest, using moss, cypress needles, leaves, and other materials, usually laying 4-6 eggs. At Beidler, researchers band warblers and have documented that some birds use the exact same nesting cavity year after year. The success they have in rearing babies without losing them to snakes, raccoons and other predators appears to strengthen their allegiance to a particular site. Imagine flying thousands of miles to wintering grounds in Central and South America then making a return flight to the exact same hole in a cypress knee the following year.