Warbling Vireo

The Warbling Vireo is well-named, since unlike its relatives in New Hampshire it utters a far more complex song. Rather than the repetitive short phrases of our other species it sings a long warbling tune similar to that of the House Finch. Sometimes described as “squeeze me and squeeze me and squeeze me until I squeak,” this song typically rises and falls throughout to end on a rising note. Both sexes sing, although the female does so rarely, and males frequently sing from the nest. Studies of song in this wide-ranging species suggest that there may be two species, one each east and west of the Great Plains.

Throughout its range, the Warbling Vireo is a bird of deciduous forests, including wetland and riparian edges and early successional forests. As a result, it is most common in the lowlands of New Hampshire, being largely absent from the higher parts of the White Mountains and much of the North Country away from river valleys. It generally nests lower than other vireos, perhaps because the trees in its preferred habitat are often shorter. It also shows considerable variation in the amount of understory in breeding areas, ranging from dense tangled shrubs in some floodplains to open spaces such as parks and even orchards.

Warbling Vireos are nondescript, being largely grayish brown with a faint eye-line. In the fall they can have a distinct yellowish tinge to the underparts, leading to potential confusion with the rarer Philadelphia Vireo. The latter tends to have a more distinct gray cap and always has a dark area between the bill and eye. Warbling Vireo also leaves the state roughly a month earlier than Philadelphia, with the latter far more likely in October. By this time Warbling Vireos are well on their way to their wintering grounds in southern Mexico and northern Central America.