The Wood Thrush’s high, lilting call is a first sign of springtime in our forests. Even if you don’t know the name of the bird that sings this distinctive song, if you spend much time between April and September in the forests that line the banks of the James and its tributaries you have most likely heard its song.
You are unlikely to find a Wood Thrush at a bird feeder; it prefers to forage for food on the forest floor sifting through decomposing leaves for snails, beetles, spiders and caterpillars. This diminutive forest dweller has a cinnamon brown back, distinctive white eye ring and a white belly with black spots. The Wood Thrushes’ shape and profile appears like a smaller version of an American Robin.
The Wood Thrush spend their winters in the Neotropics of southern Mexico and Central America and then migrate to spend their summers in the Eastern United States nesting and raising their young. These beautiful and melodic birds are just one of over 200 bird species called Neotropical migratory birds. These birds link the natural habitats of the two continents through their behavior, learned and repeated over eons.
Every February in Central America when the weather and angle of the sun begin to signal the end to winter, the Wood Thrush begins the process of practice flocking, sometimes even in mixed species flocks. Then one day when the sun sets in the forest preserves in Sothern Mexico and Central America the flocks ride up into the sky with the evening thermal energy rising off the land and fly all night in the cool, stable nighttime air. They are nocturnal (nighttime) migratory birds, even though they are active during the day for the rest of their lives, they migrate at night. They will continue this nighttime flight pattern and travel between 100 and 200 miles a night for weeks until they reach their final destination for the summer, which can be as far as 3700 miles.
When the travel is done and the male Wood Thrush has found the significant stand of forested land that it wants to call home for the summer, he will call out the borders of his home, defend that territory from other males and attract a mate. Once the male and female Wood Thrush have mated the female will begin to build the nest out of mud and grasses in a shrub or sapling. Once their first brood of eggs hatches the male does most of the feeding of the young while the female works on making a second nest for another brood.
Over the last fifty years there is growing concern of the rapid decline in the Neotropical migrant bird species. The Wood Thrush’s alarming pattern of decline has been an average of 1% a year every year from 1966 to 2009 and their overall population decline is close to 50%. Forest fragmentation and development in both the winter and summer grounds is considered a likely reason for some of the decline. Forest fragmentation opens up the habitat for the Wood Thrush to be susceptible to predators such as jays, raccoons and the brood parasite the Brown Headed Cowbird. The Cowbird lays its eggs in the Wood Thrushes nest and leaves it for the Wood Thrush to take care of. Once hatched, the Cowbird chick is so large it out-competes its Wood Thrush nest mates for food.
Throughout the James River watershed the biggest concern for the Wood Thrush is to conserve and enhance a network of healthy forests. Healthy connected forest corridors and a native diverse understory is critical to the Wood Thrush’s ability to survive. For most of the spring and summer the Wood Thrush needs to consume forest floor invertebrates for the protein and calcium to restore its body weight after the long flight and then use these snails, bugs and caterpillars for strengthening their newly hatched young. In the fall when preparing for their flight back south, they need to add the berries of native trees and shrubs to their diet to give them the energy needed for the long flight.
Better than a Bird Feeder….
Attracting this forest harbinger of spring to your home and community is not about having bird feeders or planting specific flowers but more about the long term maintenance of any areas with tall trees, forest edges or shade gardens in your yard and community. Allowing leaves to collect and decompose on parts of your property will, over several years, build the forest floor ecosystem that the birds need to survive. In addition, the elimination of any pesticides in the maintenance of these areas is critical to the Wood Thrush’s survival.
Large trees such as native red and white oaks, American beech, and American hornbeam will provide the leaves that create the perfect ground layer for the Wood Thrush. In addition, the forest understory species southern arrowwood, smooth blackhaw, spicebush, pepperbush, rhododendron, and blueberry will provide both the leaves and berries that help the Wood Thrush thrive. The bugs and other invertebrates attracted to these decomposing leaves will provide food for birds but do no damage to living garden plants.
Viewing the Wood Thrush
A few public lands offer the opportunity to see the Wood Thrush in the wild. On the lower James River, visit Dutch Gap Conservation Area in Chesterfield, the Harrison Lake National Fish Hatchery in Charles City and Deep Bottom Park in Henrico. In the Central Piedmont area, consider visiting Cumberland State Forest just west of Richmond and both the James River State Park and Wildlife Management Area in Gladstone.
The Wood Thrush’s distinctive song is a sort of duet it sings with itself. It sings pairs of notes simultaneously, one in each branch of its y-shaped voice box . To hear a recording of its song visit Wildlife Migrations (Storypoint 10).
Smithsonian Migratory Bird Center, Neotropical Migratory Bird Basics
Wood Thrush : A "Sing"-ular Sensation, Mary Deinlein
Cornell Lab of Ornithology, All About Birds: Wood Thrush
Written by: Karen Kelly Mullin, Willow Oak Group, LLC.