A rare event these days, a native US songbird, the Swainson's warbler, is increasing in numbers. A research review that complied data from twenty years of field studies suggest the warbler will be able to survive in short rotation pine plantations to the end of the 21st century. It was thought that the rare bird was restricted to dense forest in the southeastern US and its wintering range in the Carribean, but the studies show that it is found in a wide range of habitats including loblolly pine plantations used as managed source of wood. Researchers think that there is a period of seven to eight years when these artificial forests are dense enough to suppor the warbler. When these forests are harvested, the warbler is able to move to adjacent forested areas. The Swainson's is now considered a success story in a habitat once believed to be barren from a biological standpoint. About 90,000 breeding individuals are sparsely distributed across fifteen states. The small, olive brown bird with pale underparts is secretive, but has a loud and distinctive song. Male Swainson's defend large territories for a small bird, ranging in size from 7 to 44 acres.