MacGillivray's Warbler

Oporornis tolmiei

Order PASSERIFORMES - Family PARULIDAE

Menu

1. Cool Facts
2. Description
3. Similar Species
4. Sound
5. Range
6. Habitat
7. Food
8. Behavior
9. Reproduction
10. Conservation Status
11. Other Names

A furtive bird of forest edges and thickets, MacGillivray's Warbler breeds across much of the Pacific Northwest and the Rocky Mountains. In appearance, voice, habits, and winter range, it resembles its close relative, the Mourning Warbler, but the breeding ranges of the two species do not overlap.

Cool Facts

• MacGillivray's Warbler and Mourning Warbler are now considered distinct species, but in the recent past, they have been considered to be the same species on the basis of similar plumages and possible cases of hybridization where their ranges overlap. Size disparity (MacGillivray's is smaller), consistent differences in morphology and song, and physical separation of breeding ranges supports the recognition of separate species.
• MacGillivray's Warbler nests from near sea level to as high as 3,000 meters (9842 ft) in elevation.

• MacGillivray's Warbler was named by John James Audubon for his friend and editor, Dr. W. MacGillivray. Audubon coined this name even though John Kirk Townsend had already named the species "Tolmie's Warbler," after Dr. W. T. Tolmie.

Description

• Size: 10-15 cm (4-6 in)
• Wingspan: 19 cm (7 in)
• Weight: 9-13 g (0.32-0.46 ounces)

• Small songbird.
• Slate-gray hood, covering head, nape, and throat.
• White eye-arcs.
• Olive-green back and wings.
• Yellow chest and belly.

• Yellow under tail.
• Dark lores.
• Upper mandible dark, lower pink.
• Eyes black.
• Legs pinkish.

Sex Differences

Female has paler head with less pronounced white eye-arcs and black lores, and lacks male's dark mottling on breast.

Male

Dark gray head, throat, and upper breast. Diffuse black markings on upper breast. Bold white crescents above and below eye. Olive back and wings. Yellow belly and flanks. Pinkish or brownish legs.

Female

Pale gray-olive head, throat and upper breast. Subtle white eye-arcs. Olive upperparts. Yellow underparts.

Immature

Similar to adult female, but may be duller with slightly paler throat.

Similar Species

• Connecticut Warbler is much larger and heavier, with complete white eye ring (not crescents or arcs).
• Mourning Warbler lacks eye-crescents; male Mourning Warbler has a pronounced black patch in the middle of the breast. Some individual Mourning Warblers may show traits of MacGillivray's, including, rarely, white eye-arcs.

Sound

Song is a rolling series of churring syllables, similar to song of Mourning Warbler but more complex, longer, and higher. Call is a harsh chip, or a high, ventriloquial chip.

»listen to songs of this species

Range

Summer Range

Breeds from the Rocky Mountains to the Pacific Ocean, as far northward as the Yukon and as far southward as isolated areas in southern California, Arizona, and New Mexico. Also an isolated population in central Mexico.

Winter Range

Winters in Mexico and Central America, from the interior highlands to the Pacific slope. Winter range not well documented.

Habitat

Clear-cuts in coniferous forest, mixed deciduous forest, and riparian areas and thickets. Requires dense understory.

Food

Insects.

Behavior

Foraging

Feeds at or just above ground level. Usually gleans from low branches.

Reproduction

Nest Type

An open cup of coarse grass and other plant fiber, placed at or near ground level under dense shrub cover.

Egg Description

Creamy white, with variable tints and speckling.

Clutch Size

2-6 eggs.

Condition at Hatching

Helpless and naked.

Conservation Status

Because of its preference for cleared or regenerating land, MacGillivray's Warbler has probably benefited from human land-use practices such as logging and mining.

Other Names

Paruline des buissons (French)
Chipe cabecigiris de Tolmie, Reinita de tupidero, Reinita de MacGillivray, Verderón de Tolmie, Verdin de Tolmie (Spanish)

Sources used to construct this page:

Pitochelli, J. 1995. MacGillivray's Warbler (Oporornis tolmiei). In The Birds of North America, No. 159 (A. Poole and F. Gill, eds.). The Academy of Natural Sciences, Philadelphia, PA, and the American Ornithologists' Union, Washington, D.C.