Snow bunting (Plectrophenax nivalis)

KingdomAnimalia
PhylumChordata
ClassAves
OrderPasseriformes
FamilyEmberizidae
GenusPlectrophenax (1)
SizeLength: c.15 cm (2)
Wingspan: c.30 cm (3)
Weight30 - 46 g (2) (3)

The snow bunting is classified as Least Concern (LC) on the IUCN Red List (1).

The aptly-named snow bunting (Plectrophenax nivalis) is a hardy, medium-sized songbird of the high Arctic and snowy winter fields. Sometimes known as the ‘snowflake’, its white plumage and dancing flight give its flocks the appearance of swirling snow flurries (3) (4) (5).

During the breeding season, the adult male snow bunting is largely snowy white, except for a contrasting black back, black wing tips and black central tail feathers (2) (3) (5) (6). The wings also have a black spot on the leading edge (3). The male’s legs and feet are dark grey to black, and the beak is dark, becoming more yellowish-orange in autumn, with a black tip (2) (3). The breeding female is white below, with a more greyish head, mottled upperparts, dark leading edges to the wings, a pale reddish-brown wash on the flanks, and a yellowish-orange beak (2) (3) (5) (6).

Outside of the breeding season, the male and female snow bunting are more similar in appearance, both developing more buffy plumage. The feathers of the head are tipped with brown and those of the back and wings are tipped white or reddish-brown, giving a mottled appearance (2) (3) (5) (6). There is also a faint reddish band across the breast (3) (5). Unusually, although the adult male snow bunting’s breeding and non-breeding plumage look very different, the breeding plumage is not attained through a moult into new feathers. Instead, the coloured tips of the feathers wear off in late winter and spring, revealing the pure black or white bases of the feathers beneath (2) (3). Juvenile snow buntings are distinguished from the adult by a greyer body and head, and a dark brownish-black tail and wings (2) (3) (5).

Four subspecies of snow bunting are recognised: Plectrophenax nivalis nivalis, Plectrophenax nivalis vlasowae, Plectrophenax nivalis townsendi and Plectrophenax nivalis insulae (2). Although it is generally quite a distinctive species, the snow bunting can sometimes be confused with McKay’s bunting (Plectrophenax hyperboreus), which has purer white plumage. The two species occasionally hybridise (2) (3).

The song of the male snow bunting, given from a perch or in flight, consists of a rapid, musical trilling or warbling. Snow buntings also use a variety of calls, including a soft, rolling, musical rattle, a loud ‘tsweet’, a sharp ‘chi-tik’, and a mournful-sounding ‘teu’ (2) (3) (5).

The snow bunting breeds in the high Arctic, from Scandinavia, Iceland and parts of northern Scotland, through Russia and Siberia, to Alaska, Canada and Greenland (2) (6) (7). Most populations migrate south for the winter, with those in North America travelling to southern Canada, the western and southern coasts of Alaska, and south to the Great Plains of the USA. Outside of North America, the snow bunting winters from southern Scandinavia and western Europe, eastwards through central Asia (2).

During the breeding season, the snow bunting is found on tundra, typically nesting in rocky areas, boulder fields or on cliffs, near to well-vegetated areas where it can feed (2) (3) (4) (7). It tends to avoid nesting on open, vegetated tundra with few rocky areas, but may use such habitats if artificial nesting sites are available (2). The snow bunting is often found at relatively high altitudes, even in the high Arctic, and is one of the few species to inhabit ‘nunataks’, exposed islands of tundra that protrude above surrounding ice caps (2).

In winter, the snow bunting may be found in coastal regions and around lake and ocean shores, as well as in open fields and on farmland (2) (3) (4) (5) (7).

The snow bunting usually feeds on the ground, on a variety of seeds, buds, insects and other small invertebrates, including small marine crustaceans in coastal areas (2) (3) (4) (6). The young are fed mainly on invertebrates (2) (4). Weed, grass and sedge seeds are commonly eaten, and the snow bunting also feeds on grains such as wheat, oats and barley, as well on young leaves in spring (2) (4). This species may form dense foraging flocks in winter (5).

The first migrant to arrive in the Arctic in spring (2), the male snow bunting returns to its breeding grounds in mid-March to early April, when temperatures can still reach as low as -30 degrees Celsius and snow still covers much of the ground. The males arrive early to establish a territory containing suitable nesting sites. When the females arrive, around four to six weeks later, the males display to attract a mate, flying up high before gliding down again while singing (2) (3) (4).

The snow bunting usually begins nesting around June (2). The nest is built deep in a crack or cavity in rock, and consists of a thick-walled cup of moss and grass, lined with grass, rootlets, fur and feathers (2) (3) (4). In areas where natural nest sites are limited, the snow bunting will also use man-made sites, including buildings, rubble, barrels, boxes and metal cans (2) (4). The female snow bunting builds the nest and incubates the clutch of 2 to 8 eggs, which hatch after about 10 to 15 days. Although rock cavities are usually quite safe from predators, they can be cold for developing eggs. The male may therefore feed the female during the incubation period, allowing the female to remain on the nest and prevent the eggs from chilling (2) (3) (4).

The young snow buntings are cared for by both parents and leave the nest after 12 to 15 days. The chicks are then divided between the male and female, with each adult caring for just one part of the brood. The adult snow buntings continue to feed the young for a further 8 to 12 days (2). Each breeding pair raises only one brood a year in Arctic regions (2) (4), although they can sometimes raise two in more southerly parts of the range (2).

The snow bunting is a common and widespread species (3) (4) (7), and most of its breeding habitat is remote from the effects of human activities (4). However, there is some evidence to suggest that the snow bunting is in serious decline in North America. The reasons for this are unknown, but may be linked to a shift in the species’ distribution as a result of climate change (2).

Other potential threats to the snow bunting include the use of pesticides on crops, since this species often feeds heavily on agricultural fields in winter (2).

There are not known to be any specific conservation measures currently in place for this Arctic songbird. The provision of artificial nest sites could potentially increase the snow bunting population in some areas, and studies are needed into the possible effects of pesticides and other chemicals on its winter habitats and food supplies (2).

The apparent decline of the snow bunting in North America may simply reflect the survey methods used rather than an overall population change, as this species occurs outside of most census areas. Further research is therefore needed to clarify the snow bunting’s population trends and identify the reasons for any declines (2).

Find out more about the snow bunting and its conservation:

This information is awaiting authentication by a species expert, and will be updated as soon as possible. If you are able to help please contact:
arkive@wildscreen.org.uk

  1. IUCN Red List (March, 2011)
    http://www.iucnredlist.org/
  2. Montgomerie, R. and Lyon, B. (2011) Snow bunting (Plectrophenax nivalis). In: Poole, A. (Ed.) The Birds of North America Online. Cornell Lab of Ornithology, Ithaca. Available at:
    http://bna.birds.cornell.edu/bna/species/198/
  3. The Cornell Lab of Ornithology: All About Birds - Snow bunting (March, 2011)
    http://www.allaboutbirds.org/guide/Snow_Bunting/id
  4. Kaufman, K. (2001) Lives of North American Birds. Houghton Mifflin Harcourt, Boston, Massachusetts.
  5. Peterson, R.T., Mountfort, G. and Hollom, P.A.D. (1993) Collins Field Guide: Birds of Britain and Europe. HarperCollins Publishers, London.
  6. RSPB - Snow bunting (March, 2011)
    http://www.rspb.org.uk/wildlife/birdguide/name/s/snowbunting/index.aspx
  7. BirdLife International (March, 2011)
    http://www.birdlife.org/datazone/speciesfactsheet.php?id=8973