A dainty warbler of the Canadian boreal forest, the Tennessee
Warbler specializes in eating the spruce budworm. Consequently
its population goes up and down with fluctuations in the
populations of the budworm.
Cool Facts
- The Tennessee Warbler breeds no closer to the state of
Tennessee than northern Michigan, over 1,000 km (620 mi)
away, and it winters over 2,000 km (1,440 mi) away in
southern Mexico and southward. It was given its name in 1832
by Alexander Wilson who first encountered the bird in
Tennessee during its migration.
- Males of most other warblers in the genus Vermivora
have small, concealed patches of red or orange feathers on
the tops of their heads. The Tennessee Warbler usually does
not, but a very few males have a few reddish feathers there.
- The Tennessee Warbler is a common nectar "thief" on its
wintering grounds in tropical forests. Instead of probing a
flower from the front to get the nectar, and spreading
pollen on its face in the process, the warbler pierces the
flower tube at its base and gets the reward without
performing any pollination.
Description
- Size: 10-13 cm (4-5 in)
- Wingspan: 20 cm (8 in)
- Weight: 8-13 g (0.28-0.46 ounces)
- Small songbird.
- Drably colored with few distinct field marks.
- Back green.
- Underparts whitish.
- Crown and nape gray.
- Thin white line over eyes.
- Thin blackish eyestripe.
- Underparts may be tinged yellow.
- Tail greenish and without spots.
- May show faint wingbar.
- Bill gray with darker top edge.
- Eyes dark brown.
- Legs dark gray, soles of feet yellowish.
Sex Differences
Sexes similar, but female duller, with less gray on head and
more yellow on chest.
Male
Breeding (Alternate) Plumage: Forehead,
crown and nape pale bluish gray. Sides of face and neck pale
gray. White eyestripe above a dark line through eyes. Back,
wings, and rump bright olive-green. Dull whitish from chin to
undertail. May have slight yellowish wash across breast or on
flanks. Wing feathers and tail dark gray.
Nonbreeding (Basic) Plumage: Plumage duller,
with head and nape gray-green, similar to rest of upperparts.
Variable yellowish wash on throat and breast. Belly and
undertail whitish.
Female
Breeding (Alternate) Plumage: Forehead,
crown, and nape olive-gray. Sides of face and eyestripe grayish
white tinged with yellow. Dusky line through eyes. Back, wings,
and rump olive-green. Dull whitish from chin to undertail, with
variable yellowish wash across breast and flanks. Wing feathers
and tail dark gray.
Nonbreeding(Basic) Plumage: Plumage duller,
with more yellow on underparts, especially belly and flanks.
Immature
Juvenile similar to nonbreeding female, but duller and darker
green, with only indistinct pale eyeline and dusky eyestripe.
Underparts pale yellow, darker on upper belly and flanks. Two
faint wingbars on each wing.
Similar Species
- Orange-crowned Warbler can be very
similar to juvenile or fall female, but is duller green on
the back, has yellow undertail, faint blurred streaks on the
sides of the breast, and a thin, split eyering.
- Vireos are slightly larger, more
robustly built, have more distinct eyelines, duller green
backs, thicker and less pointed bills, and are less active
foragers.
Sound
Song a loud, spitting three- or two-part series of trills,
with the middle series composed of two-note syllables and the
third part faster, higher, and louder.
Range
Range Map
Summer Range
Breeds across Canada and the very northern United States.
Winter Range
Winters from southern Mexico to northwestern South America.
Habitat
Breeds in boreal forest, in open areas containing grasses,
dense shrubs, and young deciduous trees. Winters in open second
growth forests and agricultural habitats, such as shade coffee
plantations
Food
Invertebrates, especially moth caterpillars, fruit, and
nectar.
Behavior
Foraging
Gleans insects from outer foliage of trees and shrubs. Pecks
base of flowers to get nectar.
Reproduction
Nest Type
Open cup of dead grass, weed stems, dried leaves, twigs, or
bark strips, lined with fine grass, moss, rootlets, or hair.
Placed on ground, often hidden in hummock of sphagnum moss or at
base of small shrub or tree.
Egg Description
White, speckled with reddish brown.
Clutch Size
3-8 eggs.
Condition at Hatching
Helpless.
Conservation Status
No evidence of population declines. Populations fluctuate
widely, depending on spruce budworm outbreaks.
Other Names
Paruline obscure, la fauvette obscure (French)
Chipe peregrino, Reinita verdilla (Spanish)
