Acadia National Park

Description  ADULT MALE Has mainly orange face and underparts with black back, nape, crown, eyestripe, and narrow line on throat. Black wings have white edges to flight feathers and broad white patch on coverts. Rump is orange and orange tail is marked with an inverted black "T." ADULT AND IMMATURE FEMALES Have an olive-gray back, pale yellow hood and breast, and otherwise mostly whitish underparts. Wings are blackish with white edges to flight feathers and two white wing bars. Rump and tail are yellowish. IMMATURE MALE Recalls adult male in terms of plumage pattern overall, but orange elements of plumage are yellow (very pale on belly), back is streaked olivegray, and crown is grayish yellow.

Dimensions  Length: 7-8 1/2" (18-22 cm)

Habitat  Common and widespread summer visitor (mainly May-Aug) to open woodland, especially waterside habitats where cottonwoods and willows flourish; winters mostly in Mexico.

Observation Tips  Although not unduly shy, surprisingly easy to overlook when foraging unobtrusively in dappled foliage.

Range  California, Rocky Mountains, Southwest, Plains, Texas, Northwest

Voice  Song is a brisk, whistled tch-t'tch-pe'wee-tu-wee-weep; call is a dry tchup.

Discussion  Colorful oriole that is the western counterpart of Baltimore; formerly, both were lumped together as single species, Northern Oriole. Male is unmistakable; confusion is possible between females and immatures of both species, although ranges barely overlap. Identification of dull individuals requires experience and may not be possible in some cases. But overall, immature Bullock's in fall has a brighter yellow face and neck than Baltimore and back is plain gray (Baltimore's back has faint dark streaks). To add to the confusion, hybridization occurs in narrow zone of overlap on Great Plains. Sexes are dissimilar.

Migration Info  This western counterpart to the eastern Baltimore Oriole moves rapidly up the west coast, often reaching the California-Oregon border by mid-April. In the easterly portions of its range, arrivals are up to two weeks later than at the same latitude along the coast. During the winter, this species is most numerous along the Pacific slope of Mexico, where it feeds heavily on nectar. The migratory characteristics of the Bullock's Oriole are poorly understood; the birds are believed to move primarily at night in small flocks. Mature males arrive first, followed by females and first-year males.