This grosbeak breeds in open forest, forest edge, woods and tall second growth. The regular breeding distribution is from Northwest Territories and Alberta, south and east to the Great Lakes to southern Quebec; in the south from Oklahoma to North Carolina, and south in the mountains to north Georgia [AOU 1998]. Nests are on outer deciduous tree branches at a height of 2-8 m, with one or two broods. Food is gleaned from tree canopies and includes invertebrates, seeds, buds and some fruit [Stokes and Stokes 1996]. Rose-breasted Grosbeaks winter in coniferous, mixed and gallery forest, feeding on fruit and insects [Rappole et al. 1983]. They feed singly or in flocks, often with other species [Howell and Webb 1995]. The winter distribution is from both coasts of central Mexico, south through Central America to central Peru and northwest Venezuela [AOU 1998].
Migration is nocturnal, and a wide variety of wooded habitats are used. Spring migrants frequently follow the east Mexican coast, spreading out east of the Rocky Mts. and furthest east along the U.S. Gulf coast. Some migrants cross the Gulf, particularly in fall, and are irregular on Bermuda, the Bahama Is. and the Greater Antilles [AOU 1998}. Spring migrants leave South America in early April [Paynter 1995], pass through eastern Mexico in April-May [Howell and Webb 1995], reaching Massachusetts in mid to late May [Veit and Petersen 1993]. Fall migration in the northeast is generally throughout September, passing south through Mexico by October-November [Howell and Webb 1995].
The Breeding Bird Survey showed stable populations since 1966, but from 1980-2000 there were significant declines in the northeast at -1.9% per year [Sauer et al. 2001]. Rose-breasted Grosbeaks are common hosts of Brown-headed Cowbirds [DeGraaf and Rappole 1995] and are adversely affected by loss of forest throughout the breeding and wintering ranges. Rose-breasted and Black-headed Grosbeaks (Pheucticus melanocephalus) hybridize where their ranges overlap in the Great Plains, but are currently considered separate species [AOU 1998].
|
