Golden-winged Warbler (Vermivora chrysoptera)

By, Maryanne Brown, Wild South Intern

The majority of us cannot decipher one bird song from another, nor can we distinguish many birds as they zoom past. Even so, we can appreciate a unique bird when we see it. The Golden-winged Warbler (Vermivora chrysoptera) is a distinct yellow songbird that makes its home in our Southern Appalachian region.

Both the male and female Golden-winged Warbler display bright yellow patches on their crowns and wings and sport distinctive black markings on their throats and mouths. The rest of the body is grayish, with the lower body being slightly lighter. The bird's plumage color changes minimally with aging and season, however its long bill changes color during the non-breeding season. As with most songbirds, the colors on the male bird are more showy.

The Golden-winged Warbler has narrow breeding grounds, which include the Great Lakes region and much of the Appalachians. After pairs form, the female normally prepares a nest on the ground. After the birth of three to six hatchlings, both the male and female work to feed the helpless young. They forage in the upper area of trees and shrubs, seeking insects and spiders and using their bills to open curled leaves. In the winter, it migrates to Central American and northern South America.

This bird is very selective about its habitat and breeding grounds, found only in small isolated populations. The Golden-winged Warbler prefers habitats with young growth of shrubbery, such as abandoned farmlands, powerline rights-of-way, and fields. These habitats are generally referred to as "early successional habitats," which benefit numerous species. While these habitats are critical for species like the Golden-winged Warbler, they do not persist long. The warbler is drawn to forest edge or a patchy shrub area to breed, but after a few years these habitats become overgrown, so the bird moves on to find another shrubby niche. Natural disturbances perpetuate early successional habitats, however, humans have interrupted many of the natural disturbances that affect forest habitats. Large scale industrial logging and an era of fire suppression have disrupted regular ecological disturbance and have left many ecosystems out of balance.

Extinction Pressure
Today there is less habitat available to the Golden-winged Warbler due to development and a lack of disturbance. With a limited forest land base, managers are trying to understand the appropriate scale and context at which to develop early successional habitats and sustain populations of the Golden-winged Warbler. Managers must also consider whether or not the creation of early successional habitat may reduce habitat for other species equally threatened and in need of protection.

To add to its troubles, the Golden-winged Warbler is out-competed by a closely related species, the Blue-winged Warbler. Although these two different birds sometimes interbreed and create two hybrids, the more common "Brewster's Warbler" and the "Lawrence's Warbler," it is unclear how this will effect the Golden-winged Warbler's future.

The combination of habitat loss and the replacement by the Blue-winged Warbler is further assisted by the nest parasitism by the Brown-headed Cowbird. The Cowbird places its eggs into the nests of Golden-winged Warblers. Unaware of the switch, the warbler then proceeds to raise the Cowbird hatchling alongside their own. This intruder often outcompetes the young warblers and will even force unhatched eggs out of the nest. It is estimated that about one-third of all Golden-winged Warbler nests are infected.

Conservation Status
Because of its dramatic decline in the Appalachian part of the United States, the Golden-winged Warbler is now listed as a Federal Species of Special Concern. But there is hope that with thoughtful management and restoration practices, we can maintain the habitats Golden-winged Warblers need to recover. The control of Blue-winged Warblers and Cowbirds is unlikely. Stabilizing and restoring the Golden-winged Warbler populations will help them resist competition and predation. For this to occur, land managers and Wild South need to continue to document the presence of Golden-winged Warblers and work to assess the needs of the species. Wild South will continue to seek ways to promote habitats for this warbler and work to examine the appropriate context, scale, and methods for creating or maintaining early successional habitats.

The restoration of forest ecosystems will increase the diversity of habitats and will serve to provide desired niches for all native species. For example, habitat for the Golden-winged Warbler could be created and maintained through prescribed burning.