Often described as “tiny,” “dainty,” or “delicate,” the Northern Parula (pronounced PAR-a-la or PAR-ya-la) is one of North America's smallest wood-warblers. Originally named Finch Creeper by Mark Catesby and Blue Yellow Back Warbler by J. J. Audubon and Alexander Wilson, this handsome blue-gray, yellow, and white bird can be found breeding throughout the eastern half of the United States and in southern Canada from Manitoba to the Maritime Provinces. It winters primarily in eastern Mexico and on islands of the West Indies.

An active bird of the mid- and upper tree canopy, where it gleans for insects and spiders, the Northern Parula (“little titmouse”) seems to prefer riparian vegetation. In the northern part of its breeding range, it is found in moist deciduous, coniferous, or mixed woodlands where it builds its nest in beard moss (Usnea lichen). Southern populations nest in the pendulous Spanish moss (Tillandsia) which is abundant in hardwood bottomlands along rivers and swamps. Other nesting sites and materials are used where neither lichen nor moss are found.

Breeding males sing two types of primary songs: Type A is an ascending trill with a separated terminal note; Type B consists of a series of buzzy notes. Intriguing patterns of covariation in the Type A song and morphology suggest possible divergence into eastern and western populations of this species.

Key studies of this species have focused on habitat and song. Gaps in our knowledge of the Northern Parula lie in migration and wintering ecology, as well as in population dynamics.