© Gerry Dewaghe
A Tennessee Warbler is a small songbird. It is gray in color with a yellowish-green back and wings, white belly, and a thin white line over each eye. Females tend to have greener heads and bellies than males. Juvenile birds have more of a yellow color overall.
An average Tennessee Warbler measures 4.75 inches (12 cm) in length with a wingspan of 7.75 inches (19.7 cm) and weighs 0.35 ounces (10 g).
The Tennessee Warbler has a thin bill which is well-shaped for probing in foliage to get food.
In the wild, Tennessee Warblers eat insects, nectar, and some fruit. At Cosley Zoo, the songbirds receive fruits and vegetables, sunflower seeds, mealworms, crickets, and a processed insectivore (insect-eater) diet.
Tennessee Warblers build cup-shaped nests made of leaves, grasses, and twigs. Nests are built on the ground, often at the base of a tree. The female lays 3-8 speckled eggs per clutch (group of eggs). The eggs need to be incubated for 7-12 days before they hatch, and the young fledge (leave the nest) 11-12 days after hatching. Tennessee Warblers typically raise just one brood per year, although they may make a second attempt to raise young if the first nest fails.
Shelter and Space Needs
Tennessee Warblers are migratory, spending their summers in Canadian forests and winters in Central and northern South America, often frequenting coffee farms. In Illinois, they can be spotted during migration as they move through the state, stopping to rest in forest edges and shrubby areas.
Relationship With Man
Tennessee Warblers specialize in eating spruce budworms, insect pests which attack balsam fir trees and other conifers. According to the Minnesota DNR, one paper written by Canadian scientists estimated that a pair of Tennessee Warblers was equivalent to $4,720 per month in pesticide applications. Because this species winters on shade-grown coffee plantations, consumers can help to protect the Tennessee Warbler's habitat by purchasing shade-grown coffee.
- Although the Tennessee Warbler is named for the state of Tennessee, it does not actually reside there during any part of the year. This bird was given its name by someone who first encountered the species in Tennessee during its migration.
- Ornithologists (people who study birds) have said that Tennessee Warblers should be called "Coffee Warblers" because they are commonly found on Central and South American coffee plantations in the winter months.