Black-throated Green Warbler

With its green back, bright yellow face, and black throat, the male Black-throated Green Warbler is one of the more easily identifiable warblers to occur in New Hampshire. Females have less black in the throat, and immatures and fall adults even less, but the species keeps the yellow face which remains an important identification feature. Also distinctive is the song, which varies less than that of many other warblers and is often rendered as a buzzy “zee see zee zoo zee” that rises slightly at the end.

Black-throated Green Warblers are also one of the most widespread forest warblers in the state. They are most common in the spruce-fir and hemlock forests in the north and west but occur in smaller numbers almost everywhere else. The only regions where they are rare in summer are the immediate coast and the developed areas south of Manchester, and even there they likely appear in scattered forest pockets. Away from their core population, find forest stands that contain a mix of hardwoods and hemlocks and listen for their song.

The Black-throated Green Warbler’s foraging behavior has been extensively studied in comparison to co-occurring warblers. These studies have shown that it preferentially gathers insects from the upper surfaces of small branches rather than twigs, larger branches, or foliage. Other species use different parts of trees, and these divergent strategies are believed to allow multiple species to co-exist in the same habitat. In the same vein, other research demonstrated that foraging behavior is flexible, and will shift if one or more of these competing species is not present in the study area.