Common yellowthroats are small songbirds that have olive backs, wings and tails, yellow throats and chests, and white bellies. Adult males have black face masks that stretch from the sides of the neck across the eyes and forehead, which are bordered above with white or gray. Females are similar in appearance, but have paler underparts and lack the black mask. Immature birds are similar in appearance to the adult female. First-year males have a faint black mask which darkens completely by spring.
Common yellowthroats breed in North America, ranging from southern Canada to central Mexico. Northern populations winter in the southern parts of the breeding range, Central America and the West Indies. Southern birds are largely resident. Common yellowthroats inhabit marshes and other wet areas with dense low vegetation, and may also be found in other areas with a dense shrub.
Common yellowthroats are generally solitary but may forage in mixed-species flocks. They are active during the day and spend most of their time hiding in dense thickets while searching for small insects and spiders. At times they may also catch their prey in midair. Common yellowthroats communicate with a soft 'jip' call and their song is a loud 'twichety twichety twichety twich'.
Common yellowthroats are polygynous meaning that one male breeds with more than one female. However, some birds may form serially monogamous pairs that remain together only for one season. Common yellowthroats nest on or near the ground in the grass, reeds, weeds, or low scrubs. Their nest is a bulky cup made with grasses, bark, sedges, rootlets, and even hair. The female constructs the nest in which she then lays 3-5 eggs. Incubation lasts about 12 days and is done by the female only, but both parents feed the young. The chicks hatch helpless and will stay in the nest for about 8-10 days.
Common yellowthroats are very common throughout their range. However, populations have declined in many regions due to habitat loss and climate change. These birds are also frequent victims of collisions with windows and communication towers, especially during their nocturnal migrations.
According to the All About Birds resource the total breeding population size of the Common yellowthroats is 87 million birds. Currently, this species is classified as Least Concern (LC) on the IUCN Red List and its numbers today are stable.