Golden-winged Warbler

Distribution and Abundance

• BBS Map
• Breeding range north-central and northeastern United States; also southern Ontario.
• Breeding range has changed for at least the last 130 years; generally, contracting at the southeast limits while expanding at north and northwest limits (Hands et. al 1989, Confer 1992).
• In Minnesota, expanding into the northeast and north-central portions of the state (Janssen 1987). In Wisconsin, formerly bred throughout the state, now nearly disappeared as a nester in southern areas while remaining fairly common in most other areas (Robbins 1991). In Michigan, well established in the southeast by 1880s. By 1950, established in lower peninsula (Berger 1958). By 1981, still moderately common in lower peninsula, but had declined in southern counties (Will 1986).
• In Ontario, nesting just north of Lake Eric through the 1930s (Peck and James 1987); first noted around Toronto around 1950 (Mills 1987). Northward expansion since then (Godfrey 1986) although density has declined in the southern portion of Ontario during the last 20 years.
• Density varies across the breeding range; highest in parts of Pennsylvania, New Jersey, New York, West Virginia, Maryland, Minnesota and Wisconsin.
• Winters in southern Central America and northern South America.

Habitat

• This warbler's territories typically include dense patches of herbs, shrubs and trees (Confer and Knapp 1981), and usually include some open areas such as patches of sedge or grass, mowed lawns and even secondary roads or exposed dirt (Frech and Confer 1987).
• In Wisconsin, Michigan, and Ontario, territories often include the edge of tamarack bogs. In Minnesota, nests often in wetlands dominated by alders and in young conifer plantations (Pfannmuller 1979). In New York, found in shrubby fields produced by secondary succession following farmland abandonment. In southern New York and adjacent New Jersey, some territories include marshes and their forested edges.
• In Wisconsin, 51% of observations from 1995-2000 were in upland hardwood shrub or upland mixed shrub; the next common habitat type indicated was lowland hardwood shrub, particularly shrub swamp dominated by willows, alder or dogwoods (WSO 2002).
• Nest sites often located along the shaded edge of a forest-field. Edges in small forest openings, paths or trails also used. Nest usually on the ground, often at the base of a cluster of leafy plant material. Nests sometimes built in a tussock of grass or sedge. Most nests include a taller, thicker stem in the supporting material which adults grasp when arriving at the nest.
• On wintering grounds, found in woodland canopy, semi-open or less dense forests and forest borders (Hilty and Brown 1986, Ridgely and Tudor 1989, Stiles and Skutch 1989).

Behavior

• Major food items are moths and their larvae; rarely eats flying insects. Frequently pries open curled leaves in search of larvae.
• Generally not a social species. Territories range from about 0.4 - 0.6 ha. Boundaries often determined by edge or row of tall trees and by interactions with neighboring males. 
• Overlap of territories is normal where Golden-winged and Blue-winged Warblers breed in the same region. Interaction between males of the two species is generally infrequent (Ficken and Ficken 1968, Gill and Murray 1972, Confer and Knapp 1977, Murray and Gill 1976, Will 1986).
• Females readily desert nests disturbed during construction; may build as many as four partial nests. Even nests with incomplete clutches may be abandoned if disturbed.
• Adults at nest engage in decoy behavior; when adults are feeding nestlings and detect a nearby human, the birds may repeatedly carry food down nearby stems as if decoying a potential predator (Bradbury 1991).
• Families with fledged young may join mixed-species flocks in July. Occurs in mixed-species flocks on wintering grounds in Costa Rica (Tramer and Kemp 1980).

Parasitism and Predation

• Brown-headed Cowbird only known brood parasite. As determined by a survey of several hundred nest records, about 30% of nests have at least one cowbird egg (Coker and Confer 1990).
• In Wisconsin, only 1 of 477 confirmed Brown-headed Cowbird observations from 1995-2000 indicated Golden-winged Warbler as host species (WSO 2002).
• In central Michigan, cowbird eggs were found in 4 of 13 nests (Will 1986). In north-central New York from 1990-1991, 8 of 23 nests had cowbird eggs or chicks.

Conservation and Management

• Classified as a species of special concern by the U.S. Fish and Wildlife Service. Five factors may contribute in various degrees to the regional declines of this species: (1) loss of breeding habitat; (2) Brown-headed Cowbird parasitism; (3) interference or competition with Blue-winged Warblers; (4) hybridization with Blue-winged Warblers; and (5) loss of winter habitat.
• All regions where Golden-winged Warblers are extirpated or currently declining have diminished habitat due to extensive reforestation or urban sprawl, as well as numerous Brown-headed Cowbirds and Blue-winged Warblers. In fact, Golden-wings disappeared from many regions within 50 years of the arrival of Blue-winged Warblers (Gill 1980).
• Current trends towards reforestation and urban/suburban expansion necessitate deliberate management to maintain or create suitable habitat. A forty-year cycle of burning 10-20 ha units of habitat has been proposed (Confer 1992).
• BBS trend results from 1966-2000 (Sauer et al. 2001) in the Northern Spruce-Hardwoods region indicate the Golden-winged Warbler population may have increased slightly in this region  (0.9, p=0.60 Trend Graph S28); on the other hand, in the Great Lakes Transition region, this species has been decreasing (-2.0, p=0.14 Trend Graph S20). Survey-wide (US and Canada), this species has significantly decreased (-2.5, p=0.01 Trend Graph SUR).

For more information about the conservation and management of the Golden-winged Warbler, please see the Species Management Abstract, from the Conserve Online public library, maintained by The Nature Conservancy.

References

• Berger, A.J. 1958. The Golden-winged Blue-winged complex in Michigan and the Great Lakes area. Jack-Pine Warbler 36:37-71.
• Bradbury, R.C. 1991. Decoy behavior of Golden-winged Warblers at nest. Bird Observer 19:306.
• Coker, D.R. and J.L. Confer. 1990. Brown-headed Cowbird parasitism on Golden-winged and Blue-winged warblers. Wilson Bull. 102:550-552.
• Confer, J.L. 1992. Golden-winged Warbler, pp. 369-383 in Migratory nongame birds of management concern in the Northeast, (K.J. Schneider and D.M. Pence, eds.). U.S. Fish & Wildlife Service, Newton Corner, MA.
• Confer, J.L. and K. Knapp. 1977. Hybridization and interactions between Blue-winged and Golden-winged Warblers. Kingbird 27:181-190.
• Confer, J.L. and K. Knapp. 1981. Golden-winged Warblers and Blue-winged Warblers: the relative success of a habitat specialist and a generalist. Auk 98:108-114.
• Ficken, M.S. and R.W. Ficken. 1968. Territorial relationships of Blue-winged Warblers, Golden-winged Warblers and their hybrids. Wilson Bull. 80:442-451.
• Frech, M.H. and J.L. Confer. 1987. The Golden-winged Warbler: competition with the Blue-winged Warbler and habitat selection in portions of southern, central and northern New York. Kingbird 17:65-71.
• Gill, F.B. 1980. Historical aspects of hybridization between Blue-winged and Golden-winged warblers. Auk 97:1-18.
• Gill, F.B. and B.G. Murray. 1972. Discrimination behavior and hybridization of the Blue-winged and Golden-winged warblers. Evolution 26:289-293.
• Godfrey, W.E. 1986. The birds of Canada. Rev. ed. Natl. Mus. Nat. Sci., Ottawa, Canada.
• Hands, H.M., R.D. Drobney and M.R. Ryan. 1989. Status of the Golden-winged Warbler in the north-central United States. U.S. Fish Wildl. Serv.
• Hilty, S.L. and W.L. Brown. 1986. Guide to the birds in Colombia. Princeton Univ. Press, Princeton, NJ.
• Janssen, R.B. 1987. Birds in Minnesota. Univ. Minnesota Press, Minneapolis, MN.
• Mills, A. 1987. Golden-winged Warbler, pp. 358-359 in Atlas of the Breeding Birds of Ontario, (M.D. Cadman, P.F.J. Eagles and F.M. Helleiner, eds.). Univ. of Waterloo Press, Waterloo, Ontario.
• Murray, B.G. Jr. and F.B. Gill 1976. Behavioral interactions of Blue-winged and golden-winged warblers. Genetics 89:583-590.
• Peck, G. and R. James. 1987. Breeding birds of Ontario: nidiology and distribution. Vol. 2-Passerines. Misc. Publ. Roy. Ont. Mus., Toronto.
• Pfannmuller, L.A. 1979. Bird communities of the regional copper-nickel study area. M.S. Thesis, Univ. Minnesota, Minneapolis, MN.
• Ridgely, R.S. and G. Tudor. 1989. The birds of South America, Vol. 1. Univ. Texas Press, Austin, TX.
• Robbins, S.D. Jr. 1991. Wisconsin birdlife: population and distribution past and present. Univ. Wisconsin Press, Madison, WI.
• Sauer, J.R., J.E. Hines and J. Fallon. 2001. The North American Breeding Bird Survey, Results and Analysis 1966-2000. Version 2001.2, USGS Patuxent Wildlife Research Center, Laurel, MD.
• Stiles, F.G. and A.F. Skutch. 1989. A guide to the birds of Costa Rica. Cornell Univ. Press, Ithaca, NY.
• Tramer, E.J. and T.R. Kemp. 1980. Foraging ecology of migrant and resident warblers and vireos in the highlands of Costa Rica, pp. 285-297 in Migrant birds in the Neotropics: ecology, behavior, distribution and conservation, (A. Keast and E.S. Morton, eds.). Smithson. Inst. Press, Washington, D.C.
• Will, T.C. 1986. The behavioral ecology of species replacement: Blue-winged and golden-winged warblers in Michigan. Ph.D. diss., Univ. Michigan, Ann Arbor, MI.
• Wisconsin Society for Ornithology. 2002. Wisconsin Breeding Bird Atlas.