Warblers, sometimes called “wood-warblers”, are a group of tiny, highly vocal and often brightly colored songbirds. Every year in May, they arrive in New York from Central and South America where they overwinter. Some continue north to Canada, but many stay here to raise their young, and then return south again in the fall. Most warblers are insectivorous, at least in spring and into summer. That means they eat mainly insects. So it is no coincidence that their spring migration follows the return of the buggy season. As leaves first appear in the spring and the bees and butterflies and other insects start moving about, keep your eyes and ears open for returning warblers.
Some warblers are pretty uncommon, so you will have to look extra hard to find them. One of these is the Golden-winged Warbler, once plentiful across New York and large areas of the eastern United States, but now quietly disappearing. Intense studies over the past few decades by wildlife scientists have helped to determine the causes of the dramatic declines and what could be done to prevent the loss of this brilliantly colored bird.
Changes in land use are one of the causes for decline. Peak numbers of golden-wings coincided with the rise of agriculture and timber harvest that created an abundance of young forest and shrublands that the birds preferred. As dairy farms dwindled, shifting to extensive croplands or reverting back to forests which continued to mature over the past century, the early successional habitats became less abundant and with it the decline of the golden-wings. More recently, studies also found that competition and hybridization with the closely related Blue-winged Warbler has taken a big toll on the golden-wing populations.
Although Golden-winged Warblers often nest and forage in shrublands, they also utilize forests for a portion of their time to forage, and provide cover for their young. There are many types of forests, but all of them change as they grow older. Mature forests have trees in all shapes and sizes, many of them stretch up high and crowd out the sun from reaching lower levels of the forest. Younger forests have many bushes and smaller trees, all competing to become the big, mature trees someday. Scientists have known for a long time that some forest birds prefer shrubland and young forest while others prefer more mature forest, and some prefer a mix of both. Golden-wings prefer shrubland and young forest with mature forest nearby. Young forests and shrublands, which were once created by natural wildfires, beaver flooding, as well as careful logging, were all growing into old forest habitat in the era of fire prevention, removal of beavers, and a decline of logging. Much of the golden-wing’s habitat was disappearing, and without it the golden-wings had no place to raise their young.
The good news is that habitat loss is something New Yorkers can do something about, giving this brightly colored songbird and other shrubland and young forest species a fighting chance at a future.
To ensure this future, Audubon New York is working with forest owners in certain areas of New York to identify existing areas of young forest and early successional habitats and, where appropriate, to create small patches of young forest, while preserving the older forests nearby. In New York State Parks, biologists are working with Audubon New York and NY Natural Heritage Program biologists in places like Harriman and Sterling Forest State Parks, to restore habitats that naturally support the open structure and mosaic of forest types that Golden-winged Warblers prefer. By surveying where the birds were and identifying the right places to create and maintain habitat for the Golden-winged Warbler, park biologists hope to increase the number of stable populations in the region.
In the future, the partnership hopes to learn more about the interaction and distribution of Golden-winged Warblers and the more abundant and competing Blue-winged Warbler in order to guide conservation needs. In 2016, the Palisades Interstate Parks Commission and Audubon New York partnered to fit individual golden-wings and Blue-winged Warblers with geolocators. These are small devices that measure day length and allow for specific locations of each bird to be calculated when in migration and while on wintering grounds in South America. This will help scientists identify additional conservation actions to save the Golden-winged Warbler.
To learn more about the Golden-winged Warbler, and ongoing conservation efforts visit the Golden- winged Warbler working group website at www.GWWA.org. For more information on what you can do to help conserve the Golden-winged Warbler in New York, visit Audubon New York at http://ny.audubon.org/.
Post by Andy Hinickle, Audubon NY and Julie Lundgren, NY Natural Heritage Program
Dig deeper into Golden-winged Warblers
Confer, J. L., Hartman, P., & Roth, A. (1992). Golden-winged Warbler: Vermivora Chrysoptera. American Ornithologists’ Union.