The common yellowthroat is a small, chunky, rounded warbler with a short bill. Adult male upperparts are dark olive, with a black mask over the forehead, eyes, and cheeks; above the black mask is a white or grayish border. Underparts are yellow, with varying amounts of white on the belly and some buff on the sides. The female lacks the black mask and has an eye ring and pale eye line; the upperparts are olive brown, including the cheek. The throat usually has a yellow cast. The female of this species is frequently an identification problem. The song is a repeated series of three whistled notes, often described as witchity-witchity-witchity, although it varies considerably. Call is a tcheg, often resembling the call of a marsh wren.
Similar species: The female Wilson’s warbler often resembles the browner female common yellowthroat; note that the olive cheek on the Wilson’s makes its yellow eye ring stand out. The yellow-throated warbler has a confusingly similar name. It has gray (not olive) upperparts, a white eyebrow line, and a white patch on the side of the head, plus black streaks on the sides of the white underparts. The yellow-throated vireo also has a confusingly similar name. Its upperparts are lighter olive, it has yellow “spectacles,” never has a black mask, and, being a vireo, has a thickish, slightly hooked bill.
Length: 5 inches.
Habitat and Conservation
Look for common yellowthroats amid low, thick vegetation in moist, open areas such as marshes, wet prairies, moist grasslands, and similar, sometimes dryer, habitats with low tangles and thickets. To see this species, first learn the distinctive song and call. Then, go to a likely habitat and in spring or summer and listen. Once you hear the voice, scan low shrubs with binoculars — look for the quick, darting movements of this small yellow and olive bird.
Forages low to the ground for insects, spiders, and small seeds.
Common summer resident. Rare in mild winters in cattail marshes and wetland areas.
The female builds a bulky cup nest out of grasses and other materials in a low shrub amid thickets of grasses, sedges, cattails, and other plants. A clutch comprises 1–6 eggs, which are incubated for 12 days. The young are able to leave the nest 12 days after hatching. Males devote themselves to a single mate, vigorously defending their territory, while females sometimes secretly mate with more than one male. There are 1 or 2 broods a year. Yellowthroats are present in Missouri in mid-April through mid-October. They breed across the United States and far into Canada, and they overwinter in Central America, Mexico, the Caribbean, and the southern fringes of our nation.
Common yellowthroats, being wetland birds, suffer when wetlands are drained, converted to housing, businesses, or agriculture, or are otherwise degraded. Also, warblers are insectivores, so pesticides damage their populations. When humans work together to protect wetlands, they protect water quality and many species — including this one.
Birds that nest low to the ground are especially vulnerable to a host of predators eager to eat the eggs and young. Like the yellow warbler, the common yellowthroat has developed behaviors that help it cope with the brood parasitism of brown-headed cowbirds. A yellowthroat is usually able to detect when a cowbird has laid an egg in its nest, so it either abandons the parasitized nest or else, like yellow warblers, builds a new nest (or nests, if necessary) on top of the old one.
About 350 species of birds are likely to be seen in Missouri, though nearly 400 have been recorded within our borders. Most people know a bird when they see one — it has feathers, wings, and a bill. Birds are warm-blooded, and most species can fly. Many migrate hundreds or thousands of miles. Birds lay hard-shelled eggs (often in a nest), and the parents care for the young. Many communicate with songs and calls.