Vireos and Peppershrikes: Vireonidae

Vireos and peppershrikes are usually solitary but active birds, but sometimes appear as a breeding pair or family group. During the nonbreeding season, they are sometimes found in foraging flocks of many different species of birds. Their song is heard often, even during the hottest parts of the day when most birds are quiet, and it usually is loud and melodic, but seldom is it considered beautiful. The song generally consists of several repeated phrases. Different species range from about ten to more than 100 song types. Males sing most frequently, being vocal especially during foraging. Males commonly sing while sitting on the nest. Northern species of the birds migrate, while southern species do not. The trip may vary from 100 miles (160 kilometers) to 3,000 miles (4,800 kilometers).

After migration is complete, birds pair up soon after arriving in their spring breeding territory. Males defend the territory with their song. Open, cup-shaped nests are woven from spider and silkworm webbing, grass stems, other plant fibers, lichens, mosses, and feathers. In species where both sexes build the nests, males construct a rough bag, and females make the lining. Birds locate the nest at the fork of a tree branch, usually suspended by the rim from the bark. The nests are usually located close to the ground or high in the forest canopy.

Females lay two to five whitish to speckled or spotted eggs of various colors. Both females and males perform incubation and caring for the young. The incubation period (time it takes to sit on and warm the eggs before hatching) is usually twelve to fourteen days, and the nestling period (time necessary to take care of young unable to leave nest) is usually nine to eleven days. Fledglings cannot fly well when first leaving the nest, but are good at running along branches and within shrubs. Both parents feed them for about three weeks after leaving the nest. Migratory species usually have two to three clutches (group of eggs hatched together) each year.