Photo: Prairie Warbler, Matt Felperin
Evelyn Novins
It’s that time of year again. The warblers will be migrating through our area from their winter habitats in the far south to reach their breeding grounds in North America, making spring an exciting time for birdwatchers. There are more than 50 species to see and hear at this time of year. Most migrants pass through, but the Prairie Warbler, Setophaga discolor, breeds in northern Virginia.
Unfortunately, the Prairie Warbler faces challenges. It is one of the five species of birds that breed in our area that the U.S. Northern American Bird Initiative has designated as at the “tipping point,” that is, a bird that has lost two-thirds of its population in the past 50 years and is on track to lose another 50 percent in the next 50 years.
Prairie Warbler at Occoquan Bay NWR, Matt Felperin
Prairie Warbler at Occoquan Bay NWR, Matt Felperin
Like most warblers, it’s a beautiful little bird. The male Prairie Warbler is a bright yellow with black streaking on his sides. The defining features are the black eyeline and black semicircle under the eye, along with a chestnut patch on its back. The unique face pattern with the semi-circle of black, differentiates it from other warblers although it takes good skill with binoculars to spot this! The female’s streaks are blurry on the side and the face pattern is gray with the signature semi-circle under the eye a darker gray.
Of course, with many warblers it is often their songs that alert us to their presence. The Prairie Warbler does not disappoint. The male has two songs, one for the female and one for his territory. The first is a rising series of buzzy notes from low to high. The second generally consists of several long, clear notes followed by several harsh, raspy notes. In either instance the male appears to love to perch at the highest tree top while singing. He also makes a chek contact call and a tsip alarm call. You can hear Prairie Warbler calls on Cornell’s All About Birds site.
The Prairie Warbler’s habitat here is generally in second growth forests such as overgrown pastures, regenerating woodlands or power line cuts. It thrives in brushy areas growing up after clearing or fires. As the forest matures, the Prairie Warbler disappears. Because the habitat can be temporary, its breeding site can change from year to year. The Florida paludicola subspecies lives in the mangrove forests.
Migrating birds need supportive habitat all through their annual life cycle which includes their breeding grounds, stopovers during migration, and the overwintering area. They are insectivores, so each habitat must be rich in insects to supply these tiny birds with food for themselves and their young, as well as fuel for their long journeys. They eat large quantities of caterpillars, moths, beetles, ants, and flies, as well as spiders, millipedes and mollusks. They forage near the ground, grabbing prey from leaves and branches while moving through the underbrush, pumping their tails all the while.
Prairie Warbler at Piney Grove Preserve, Matt Felperin
In northern Virginia, Prairie Warbler decline generally is attributed to the loss of habitat and a diminishing food supply from use of insecticides. Urbanization is not, however, always the culprit in habitat loss. Good forest management is necessary to combat habitat loss. For example, the Virginia Department of Wildlife Resources (DWR) actively collaborates with many organizations to promote forest management that allows for a range of forest habitats, including both old growth and early successional habitat areas with young and regrowing vegetation that benefit species like the Prairie Warbler. You can read about DWR’s efforts here.
Conservation initiatives also can benefit several struggling species at the same time. Projects to support the Golden-winged Warbler also benefit Prairie Warblers, because they rely on similar habitat. Nature Conservancy’s maintenance of habitat to benefit the Red-cockaded Woodpecker in Piney Grove Preserve in southern Virginia also benefits Prairie Warblers. Conservation initiatives that support grassland birds also can benefit Prairie Warblers because they encourage a diversity of land types, including shrublands bordering grasslands and meadowlands. A good example is the Virginia Grassland Bird Initiative, a collaboration of Smithsonian’s Virginia Working Landscapes, Piedmont Environmental Council, American Farmland Trust, and Quail Forever. The organizations worked with the American Bird Conservancy to designate the Northern Virginia Piedmont and Shenandoah Valley BirdScape as a conservation area.
In our area, you can see the Prairie Warbler at Occoquan Bay National Wildlife Refuge, the Laurel Hill Equestrian Center, Sulley Woodlands and Huntley Meadows as early as April and May. Remember to first listen for its song before searching the brush for that spot of yellow!