The family Tyrannidae includes 46 species found in North America.

Tyrant Flycatchers are most abundant in the Neotropics and include a wide array of ecotypes, including species that are the counterparts of warblers, wrens, vireos, jays, shrikes, pipits, thrushes and certain New World orioles. They range in weight from 4.5 to 80 gm. Plumages tend to be greenish, yellow, brownish and gray with little or no sexual dimorphism. Some have yellow, orange, white or red crests, often concealed until erected. The species that make aerial sorties to capture flying insects tend to have long, narrow wings. Those that take insects from foliage may have short, rounded wings. Tails vary from short and square to long and forked. Legs are long in terrestrial species and short in arboreal species.

Most tyrants are insectivorous, but the methods of foraging include aerial sorties from a perch, gleaning from foliage, dropping to the ground from a perch and walking on the ground. Some of the large species take fish, frogs, lizards, mice and bird's eggs, as well as large insects. Many tropical species also eat fruit. The Piratic Flycatcher and some species of Elaenia are mainly frugivorous when fruits are available.

In most species both sexes build a cup nest placed in the fork of a branch. Others build globular nests of grass and twigs. The species of Myiarchus nest in cavities and line the nest with soft animal material, usually including pieces of shed snake skin. The Piratic Flycatcher takes over the nest of some other species, often throwing out the eggs or young of its victim. Eggs vary from plain white to gray, brownish or buffy, often with spots or blotches of reddish, brown or lilac. Clutch sizes usually 3-5 in temperate areas, 2-3 in the tropics. Incubation takes 14-20 days, only by females. Young remain in the nest for 14-23 days, brooded only by the female but fed by both sexes which bring insects in the bill, not by regurgitation. Young of tropical species may remain with the parents in a family group for nearly a year. Age at first breeding is probably 1-2 years in most species.