thumb|Song and call
The common yellowthroat (Geothlypis trichas) is a New World warbler. It is an abundant breeder in North America, ranging from southern Canada to central Mexico. In the northern parts of its range the birds are migratory, wintering in the southern parts of the breeding range, Central America and the West Indies. Southern forms are largely resident. Historically, it has also been known as the "yellow bandit", Maryland yellow-throat, and yellow-breasted warbler.
Taxonomy
The common yellowthroat was formally described in 1766 by the Swedish naturalist Carl Linnaeus in the twelfth edition of his Systema Naturae under the binomial name Turdus trichas. The specific epithet is from Ancient Greek τριχας/trikhas, τριχαδος/trikhados, a type of thrush. Linnaeus based his account on "The Maryland yellow-throat" that had been described and illustrated in 1758 by the English naturalist George Edwards in his book Gleanings of Natural History. Linnaeus specified the locality as North America but this was restricted to the state of Maryland by the American Ornithologists' Union in 1931. The common yellowthroat is now one of 15 species placed in the genus Geothlypis that was introduced in 1847 by the German ornithologist Jean Cabanis. The genus name combines the Ancient Greek γεω-/geō- meaning "ground-" or "earth-" with θλυπις/thlupis, an unknown small bird.
Thirteen subspecies are recognised:
The subspecies mainly differ in the males' facial patterns and the brightness of the yellow underparts. The southwestern subspecies of this bird are the brightest and the yellowest below.
The song is a loud '. Its call is a soft jip.
thumb|upright|Singing male yellowthroat
thumb|Male singing
Measurements: wintering in the southern parts of the breeding range, Central America and the West Indies. Southern forms are largely resident. This species is a very rare vagrant to western Europe.
Routes of migration vary based on the season and location of common yellowthroats. During fall migration, from August to October, common yellowthroats in Canada, Western, Eastern, and Central U.S., and regions outside of the United States all have unique migration routes. When migrating in the fall months, all adults and immature individuals tend to arrive at their migration destinations around the same time. Migration differences in timing and routes are also seen during the spring months from early February to late May in these same groups across the United States, Canada, and other areas. However, males generally arrive at their destination site before the females during the spring migration months. During both fall and spring migration, many birds take time to rest during a stopover period. Some individuals stay at their stopover destinations for several weeks or months while others spend only a few days resting before they continue on in their migration patterns to their final destination.
Migration of common yellowthroats in Florida has also been extensively studied. In Florida, the common yellowthroat can be found more often in the southern peninsular region rather than the northern panhandle region closer to the mainland of the United States. Peak migration times of the birds in this region are during the last week of September through the second week of October. Not as much is known about spring migration in Florida, but the patterns appear similar to that of the autumn migration.
Behaviour and ecology
These birds feed on insects, which are usually captured in dense vegetation, but sometimes caught in midair.
Conservation status
Despite a decline in numbers, this species is still very common.