E-Fauna BC: Electronic Atlas of the Wildlife of British Columbia

Plectrophenax hyperboreus Ridgway, 1884
Mckay's Bunting
Family: Calcariidae

Species account author: Jamie Fenneman
Photo of species

© Mike Yip  Email the photographer   (Photo ID #11777)


Distribution of Plectrophenax hyperboreus in British Columbia.
(Click on the map to view a larger version.)
Source: Distribution map provided by Jamie Fenneman for E-Fauna BC

Introduction


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Species Information

Breeding male
This unmistakable plumage is held between March and August and is unlikely to be encountered in B.C. The plumage is almost entirely pure-white, with the exception of black tips to the central tail feathers, black tips to the primaries, and black tertials; most birds also show variable amounts of black on the scapulars. The iris is dark, the short, conical bill is black, and the legs and feet are black.

Non-breeding male
This plumage is held between August and March. It is overall similar to the plumage of the breeding male, but the head and upperparts are faintly washed with rusty-buff or brownish-buff (darkest and most prominent on the crown, ear coverts, and sides of the breast). The bill is yellowish, but bare part colouration is otherwise similar to that of the breeding plumage.

Breeding female
This plumage is held between March and August and, like in the male, is unlikely to be encountered in British Columbia. The plumage is similar to that of the breeding male, but the back and scapulars are variably streaked with black, the tail and wings show more extensive black (white patch on wings largely restricted to the upper secondary coverts, secondaries, and bases of the inner primaries), and the forehead, crown, and ear coverts show variable amounts of fine, blackish speckling. In addition, there is sometimes a very faint buffy or brownish tinge on the head, upperparts, and upperwings (although many birds lack this and appear more or less black and white). Bare part colouration is similar to the breeding male.

Non-breeding female
This plumage is held between August and March. Non-breeding females resemble breeding-plumaged females, but have less noticeable black streaking on the upperparts (largely obscured by extensive whitish feather edges), a brownish tinge to the black areas of the plumage, a yellow bill, and a stronger buffy or rusty-buff wash on the head and upperparts which, like the male, is darkest and most prominent on the crown, ear coverts, and sides of the breast.

First-winter immature
Immature plumage is held throughout the first winter, being lost during the early spring (March-April) of the second year. This plumage of both sexes is similar to the non-breeding female, but shows considerably more buffy or rusty-buff on the head and upperparts (especially on the crown, ear coverts, sides of the breast, scapulars, and tertial fringes), often with a buffy wash over the rump. The white areas of the wings and tail are slightly less extensive than in the adult female, particularly in the immature female (immature male approaches adult female in this characteristic).

Measurements
Total Length: 16.5-17 cm
Mass: 42-44 g

Source: Lyon and Montgomerie (1995b); Sibley (2000)

Biology

Identification

The only species with which the McKay’s Bunting is likely to be confused is the closely-related Snow Bunting. Adult male McKay’s are largely white throughout the year (even during the winter, although the plumage becomes washed with areas of buff) and are extremely unlikely to be mistaken. Female and immature McKay’s Buntings, however, approach similarly-plumaged Snow Bunting and be considerably less straightforward to identify, particularly given the extremely rare potential for a Snow x McKay’s Bunting hybrid to occur in the region. All of these plumages nonetheless average significantly whiter than the corresponding plumage of Snow Bunting, with less extensive dark streaking on the paler buffy-white back and scapulars, a prominent white rump (generally buffy or brown on Snow Bunting), more extensive white in the wings and tail, and less extensive buffy wash on the the whiter head and underparts.
Vocalizations

The song and calls of the McKay’s Bunting are apparently identical to those of the closely-related Snow Bunting. Common calls include a soft, husky, rattled dididididi and a clear, descending tew or cheew.

Source: Sibley (2000)

Breeding Ecology

This species is a vagrant to British Columbia and does not breed in the province.
Foraging Ecology

All foraging behaviours and food habits are identical to Snow Bunting. During the non-breeding season this species feeds almost exclusively on small weed and grass seeds which it attains by foraging directly on the ground. The few vagrants that have occurred along the Pacific coast of North America (including in B.C.) have generally been associated with flocks of Snow Buntings which forage in rolling, sandpiper-like fashion over open habitats.

Source: Lyon and Montgomerie (1995a, 1995b)

Habitat


Wintering birds are almost entirely restricted to coastal habitats in Alaska, including beaches, estuaries, and coastal marshes. Vagrants south along the Pacific coast are found in similar coastal habitats, with the few vagrants in B.C. being recorded from sandy beaches, dunes, and coastal rock jetties; the single inland record from B.C. (Harrison Lake) was from a sandy lakeshore. This species could potentially occur in any such habitat along the coast, particularly where Snow Buntings are known to occur.

Source: Lyon and Montgomerie (1995b)

Distribution

Global Range

This is one of the rarest and most localized breeding bird species in North America. It breeds only on the islands of the Bering Sea off western Alaska, with most breeding birds occurring on Hall Island and St.Matthew Island, with small numbers on the Pribilof Islands and St.Lawrence Island. It winters almost entirely along the Bering Sea coast of Alaska (from Kotzebue south to the Alaska Peninsula), although small numbers are occasionally seen along the southern coast of Alaska east to Homer. It is strictly casual farther south along the Pacific coast in fall and winter, with a handful of records strecthing as far south as Oregon.
BC Distribution

Vagrancy
Accidental in late fall and casual in winter/early spring on the south coast (Vancouver Island, Lower Mainland), but could potentially occur as a vagrant anywhere along the coast. Records in British Columbia span the period from to mid-November to early March, concurrent with peak numbers of Snow Buntings on the south coast.

The British Columbia records (all of which are photo-documented) are as follows. Note that Record #3 includes two separate individuals at the same location that arrived and departed on different dates:

1.(1) adult; February 12, 1980; Wickaninnish Bay, Pacific Rim National Park
2.(1) adult female; November 19-20, 2004; Harrison Lake
3.(1) adult male; December 4-29, 2004; Iona Island, Vancouver
(1) adult female; December 8, 2004-March 7, 2005; Iona Island, Vancouver

Conservation

Population and Conservation Status

The total world population of this species, which breeds exclusively in Alaska has been estimated only 2,800-6,000 individuals, and thus it is considered one of the rarest breeding birds in North America. It’s occurrence south of remote areas of western Alaska is extremely rare, and it is a species that causes considerable excitement when such an event occurs. It is considered an accidental vagrant in B.C. (and Canada) and is not tracked as a species of concern at either the provincial (B.C. Conservation Data Centre) or federal (COSEWIC [Committee on the Status of Endangered Wildlife in Canada]) level.

Source: Lyon and Montgomerie (1995b)

Taxonomy


This species is monotypic, with no recognized subspecies. It is very closely related to the Snow Bunting, and has been considered conspecific by some authors; these two species hybridize sporadically on the Bering Sea Islands, but this is a considerably infrequent event given the scarcity of Snow Buntings within the normal breeding range of this species.

The Plectrophenax buntings (Snow, McKay’s), along with the four longspur species, were formerly included in the family Emberizidae along with the sparrows and Old World buntings. Recent genetic evidence, however, indicates that these species are not particularly closely related to the rest of the family Emberizidae and, as a result, were moved to a separate family by the American Ornithologists’ Union (AOU) in 2010.

Source: Lyon and Montgomerie (1995b); Chesser et al. (2010)

Status Information

Origin StatusProvincial StatusBC List
(Red Blue List)
COSEWIC
NativeSNAAccidentalNot Listed
BC Ministry of Environment: BC Species and Ecosystems Explorer--the authoritative source for conservation information in British Columbia.

Additional Range and Status Information Links

Additional Photo Sources

General References


Recommended citation: Author, Date. Page title. In Klinkenberg, Brian. (Editor) 2021. E-Fauna BC: Electronic Atlas of the Fauna of British Columbia [efauna.bc.ca]. Lab for Advanced Spatial Analysis, Department of Geography, University of British Columbia, Vancouver. [Accessed: 2024-05-30 6:48:14 AM]
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