Creature Feature: Wood Thrush (Hylocichla mustelina)

The wood thrush (Hylocichla mustelina) is a songbird that is slightly smaller than the well-known robin, with rich reddish-brown feathers and a spotted belly. It has a bold white eye ring around its large eyes. Although it may be hard to see the wood thrush in the forest interior where it prefers to live, you can listen for its melodious song on your next hike.

Words really can’t describe the beautiful song of the wood thrush – some say it is a flute-like “ee-oh-lay.” The famous 19th century naturalist, Henry David Thoreau, wrote in 1853 that the wood thrush “…is the only bird whose note affects me like music. It lifts and exhilarates me. It is inspiring. It changes all hours to an eternal morning.” Males will answer one another’s calls, but instead of singing the same song to each other like other species do, they will almost always sing a new song to their competition. Males can amazingly sing over 50 unique songs!

As a strict forest dweller, this is a bird that won’t be visiting your backyard bird feeder. The wood thrush scratches at the forest floor and searches through leaf-litter for a delicious meal of beetles, caterpillars, ants, spiders and millipedes. It will also supplement its diet with small berries and other fruits growing in the forest. You may hear it at nearby preserves or woodlots, or on a visit to the Refuge! And if you “leave the leaves” this fall, you might just see one foraging in your yard. 

Unfortunately, the wood thrush population is on the decline. One very large contributor to the population decline is habitat fragmentation in breeding and wintering grounds. When forest habitats are fragmented, they are separated into smaller patches by neighborhoods, industrial development, and roads. Many species are negatively impacted by this sporadic distribution of habitat. In the case of the wood thrush, some scientific studies have shown that it can lead to poorer diet and nest predation. The wood thrush is also vulnerable to nest parasitism. Instead of building its own nest, the brown-headed cowbird will lay eggs in other songbird nests for the unsuspecting parents to raise. According to the Cornell Lab of Ornithology, almost every wood thrush nest contains at least one brown-headed cowbird egg in Midwest woodlands. Once hatched, the larger cowbird can outcompete the smaller thrush chicks for food. Although this is a natural interaction, forest fragmentation may lead to more nest parasitism, especially when a wood thrush nest is on the edge of its habitat. Wood thrushes are long distance migrants, spending their winters in Central American lowland tropical forests. Therefore, wide-reaching conservation efforts are imperative for the preservation of this species. Keep an eye and an ear out for wood thrushes as they migrate through Long Island this Fall!

By Cara Fernandes