Habitat
Golden-winged Warblers breed in tangled, shrubby habitats such as regenerating clearcuts, wet thickets, tamarack bogs, and aspen or willow stands. They tend to occur in wetland habitats more often than the closely related (and competitive) Blue-winged Warbler. Recent radio-tracking studies have discovered that Golden-winged Warblers move into mature forests immediately after fledging. This means that mosaics of shrubby, open areas (for nesting) and mature forest habitats (which offer cover for fledglings from like predators like hawks) are important landscape features. Historically periodic natural disturbances would create this patchy habitat—wildfires or flooding from beaver dams created a patchwork of shrubby openings amid a largely forested landscape. The early 20th century was good to Golden-winged Warblers, as settlers cleared forest openings for settlement and farming. But as the century progressed, many of those cleared areas grew back into forests, and humans prevented natural disturbances from opening up new pockets of nesting areas. Since the 1960s, Golden-winged Warbler habitat has decreased by an estimated 22 percent in the Great Lakes region and 43 percent in the northern Appalachians. On their wintering grounds, Golden-winged Warblers live in semiopen woodlands, as well as bird-friendly coffee farms under a forest canopy.Back to top
Food
Food items include caterpillars, moths and other insects, and spiders. Leafroller caterpillars appear to be an important food source. Golden-winged Warblers feed among the foliage by probing with their sharp bills into rolled-up leaves to find hidden prey. They only rarely catch insects on the wing.Back to top
Nesting
Nest Placement
Females probably select the nest site, which is typically on the ground in a grassy opening or along the shaded edge of a field near a forest border. The nest is typically well concealed by overhead grasses and leafy material.
Nest Description
The female builds the nest, usually on the ground, over the course of 1–3 days. She often places the nest at the base of a plant such as goldenrod or blackberry, using the a tall, thick plant stem as a support (adults often land on this when arriving at the nest). She makes a base from up to 30 leaves and then adds grapevine or arrowwood bark and other long strips of plant material. Finished nests measure about 3.5 to 6 inches across and 1 to 2.5 inches deep. Females are very sensitive to disturbance and may abandon nests even after the first eggs have been laid.
Nesting Facts
Clutch Size: | 3-6 eggs |
Number of Broods: | 1 brood |
Egg Length: | 0.6-0.8 in (1.4-1.9 cm) |
Egg Width: | 0.4-0.6 in (1.1-1.4 cm) |
Incubation Period: | 10-12 days |
Nestling Period: | 8-9 days |
Egg Description: | Pale pink or pale cream, with fine streaks or small blotches |
Condition at Hatching: | Helpless and mostly naked; juvenile flight feathers begin to emerge on sixth day. |
Behavior
Golden-winged Warblers often forage among brushy and shrubby areas, where they hop along branches, carefully inspecting the leaves for prey, and sometimes dangling off the edges of branches like a chickadee. Male golden-wings are extremely bold and vocal during the 3 to 4 weeks at the start of their breeding season, prone to prolonged and exuberant bouts of singing. They also engage in a variety of postures and behavior in order to demarcate their territory, including chasing and flying past rival males, spreading their tails in face-offs, and sometimes actually physically fighting. Males also chase after females during courtship, raise their crowns and flick their tails when approaching a potential mate, and perform flight displays with slow, deep wingbeats. But after territories are established and mates are selected, they become very secretive during nesting and raising young. Golden-wing males are mostly monogamous, though there are a few reports of them having multiple mates.Back to top
Conservation
Golden-winged Warblers have declined sharply and now have one of the smallest populations of any bird not on the endangered species list. The North American Breeding Bird Survey estimates a decline of almost 2.5% per year between 1966 and 2014—amounting to an overall decline of 68%. Partners in Flight estimates the global breeding population at 410,000, with 84% spending some part of the year in the U.S., 2% in Mexico, and 16% breeding in Canada. They rate a 15 out of 20 on the Continental Concern Score and are on the 2014 State of the Birds Watch List, which lists bird species that are at risk of becoming threatened or endangered without conservation action. They are also listed as a Tri-National Concern species. In 2012, the U.S. Fish and Wildlife Service took the species under consideration for listing as an endangered species. As numbers have fallen, the species’ range has also shifted northwest. The breeding range is now largely split into two distinct regions, with 95% of the population in the Upper Great Lakes (mostly Wisconsin, Minnesota, and Manitoba) and the other 5% in the Appalachians from New York to Georgia. Minnesota now has the highest remaining density of Golden-winged Warblers, with about half the global population. The Appalachian mountains population has nearly been extirpated (down 98 percent). Causes of the bird’s decline include habitat loss and hybridization and competition with the closely related Blue-winged Warbler (in which the Golden-winged tends to lose out). Wetland habitats seem to be a stronghold for Golden-winged Warblers, but invasive Phragmites is making the birds’ preferred tussock-sedge nesting sites harder to find. Clearcutting, burning, and grazing can improve habitat for Golden-winged Warblers, although new evidence points to the importance of keeping mature forest nearby. Loss of open forests on the wintering grounds is also a problem, and bird-friendly or shade-grown coffee and cacao plantations can help retain habitat for the species. The Golden-winged Warbler Working Group, a consortium including the Cornell Lab of Ornithology and 38 other universities, agencies, and conservation groups, has released a conservation plan to improve the species’ prospects by 2050.Back to top
Credits
Confer, John L., Patricia Hartman and Amber Roth. (2011). Golden-winged Warbler (Vermivora chrysoptera), version 2.0. In The Birds of North America (P. G. Rodewald, editor). Cornell Lab of Ornithology, Ithaca, New York, USA.
Lutmerding, J. A. and A. S. Love. (2020). Longevity records of North American birds. Version 2020. Patuxent Wildlife Research Center, Bird Banding Laboratory 2020.
North American Bird Conservation Initiative. (2014). The State of the Birds 2014 Report. US Department of Interior, Washington, DC, USA.
Partners in Flight (2017). Avian Conservation Assessment Database. 2017.
Sauer, J. R., J. E. Hines, J. E. Fallon, K. L. Pardieck, Jr. Ziolkowski, D. J. and W. A. Link. The North American Breeding Bird Survey, results and analysis 1966-2013 (Version 1.30.15). USGS Patuxent Wildlife Research Center (2014b). Available from http://www.mbr-pwrc.usgs.gov/bbs/.
Sibley, D. A. (2014). The Sibley Guide to Birds, second edition. Alfred A. Knopf, New York, NY, USA.
Stephenson, T. and S. Whittle (2013). The Warbler Guide. Princeton University Press, New Jersey, USA.