Bird Watching: Tennessee Warbler

You probably will not find the Tennessee warbler (Vermivora peregrina) anywhere in Tennessee. Granted, the ornithologist Alexander Wilson, who discovered it in 1811, gave it the name; because he first saw it in the state of Tennessee. (He may have noticed it when it was migrating to or from its winter home in the tropics.) To observe this little songbird in its natural habitat, however, you will have to travel further north.

The Tennessee warbler actually lives much further north, primarily in Canada, where it breeds from the Yukon eastward across the country to Labrador and southward into British Columbia and southern Ontario. In the United States, it can be found breeding in Wisconsin and Maine. It spends the winter months in the tropics and is sometimes called the coffee warbler due to its proclivity for wintering in coffee plantations in Latin America.

The Tennessee warbler at 5 inches is about the same size as most other species of warblers. The male has greenish upperparts in the spring during the breeding season with a white throat and white underparts. It has a gray cap with a white line over the eyes and a dusky-colored line through the eyes. In the fall, the coloring changes to olive upperparts and yellowish underparts. The female during the breeding season has olive-gray head and nape with olive-green upperparts and whitish underparts washed in yellow. The wings and tail will be a dark gray. When not breeding, the female's coloring is duller with more yellow on the underparts.

During their breeding season, Tennessee warblers prefer mixed woodland areas. Their main habitat is the boreal forested area of Canada, which is comprised primarily of coniferous trees; e.g., fir, pine, and spruce. When they are migrating, they tend to hang out in young deciduous trees and bushes. They lay 4-6 white eggs with brown spots on the ground hidden under a shrub or in a knoll of moss beneath shrubs. The eggs are incubated for about 7-12 days with the fledglings leaving the nest 11-12 days later.

Tennessee warblers principally dine on insects, such as moths and caterpillars. They also will "steal" the nectar from flowers by pecking at the base of the flower, which means that they do not help in the pollination process. They really like spruce budworms, and their population will fluctuate with the availability of these worms.

If you are ever visiting Canada or the northern part of the United States, look for the little Tennessee warbler. (Remember, you probably will not see it in the state after which it was named.) You can also listen for its staccato di-dit-di-dit-swit-swit-swit-chip-chip-chip-chip-chip song.

References:

Bull, John and John Farrand, Jr. National Audubon Society Field Guide to North American Birds: Eastern Edition. NY, NY: Alfred A. Knopf, Inc., 1994.

Carpenter, Tom. The Gardener's Bird Book. Minnetonka, MN: National Home Gardening Club, 1999.

Cornell Lab of Ornithology: All About Birds. Tennessee Warbler

Smithsonian National Zoological Park. Migratory Bird Center: Tennessee Warbler by Thomas Dietsch