Scientific Name: Vermivora pinus
Nest Type: Cup
Nest Location: Ground, vine tangle; 5-10'
Clutch Size: 4-7; avg. 5
Food: Insects
Foraging Guild: Foliage gleaner
The Blue-winged Warbler is a locally common wood warbler of the eastern United States. The center of abundance was formerly in southern Ohio, Indiana, Illinois,
northern Kentucky, northern Missouri, and southern Iowa (Bent 1953). During the past century, however, the Blue-winged Warbler has extended its range
northward and eastward, and is now reported breeding from southern New England, west to southern Michigan, southern Wisconsin, and southeastern Minnesota
(Peterson 1980). The species first appeared in southeastern Minnesota about 1940 (Gill 1980), and has since extended its range as far north as the Twin Cities. An
interesting aspect of the breeding biology of the Blue-winged Warbler is its tendency to hybridize with the closely related Golden-winged Warbler wherever the
ranges overlap. There seems to be a close temporal relationship between the establishment of Blue-winged Warbler populations and the local extinction of
Golden-winged Warblers over the past 50 years (Gill 1980). The Golden-winged Warbler formerly bred in the southeastern portion of Minnesota, but has
disappeared from that area since the arrival of the Blue-winged Warbler (Janssen 1987).
The Blue-winged Warbler is a long distance migrant wintering from central Mexico south to Honduras and Panama (Ehrlich et al. 1988). It generally arrives on its
breeding grounds in Minnesota during the first week in May. The fall migration period extends from late July through September (Janssen 1987).
Confer and Knapp 1981) describe the Blue-winged Warbler as a habitat generalist relative to the Golden-winged Warbler. In a study conducted in Tompkins
County, New York, they found Blue-winged Warblers nesting in habitat ranging from abandoned pastures in early successional stages to areas 60-70 years into
secondary succession with a nearly unbroken tree canopy (Confer and Knapp 1981). Ficken and Ficken (1968) described Blue-winged Warbler habitat as
overgrown fields with trees < 6 m tall and bordered by taller trees. At Murphy-Hanrehan Park Reserve in northern Scott County, Minnesota, where a substantial
breeding population exists, this species nests primarily along the edges of cross-country ski trails within mature second-growth forest. It can also be found nesting
on edges between second-growth forest and abandoned pasture or cropland in this Park Reserve.
The Blue-winged Warbler is insectivorous. It forages by gleaning insects from leaves near the tops of shrubs and trees, and by probing buds, leaf clusters, and
occasionally flowers (Ficken and Ficken 1968). This species usually nests in loose aggregations or colonies (Confer and Knapp 1981). Its nest is placed on the
ground, attached to the upright stems of weeds, and remarkedly well-concealed within the rank growth of forbs and grasses at the woodland edge. Four or five
eggs are laid and one brood is raised per season. This species is heavily parasitized by the Brown-headed Cowbird in some areas.
Data collected in the USFWS Breeding Bird Survey indicate an increase in numbers of Blue-winged Warblers across the continent (Robbins et al. 1986). Given the
wide range of habitats acceptable to Blue-winged Warblers, it seems unlikely that increased timber harvest or forest fragmentation will negatively affect this species.
