«

»

May 08 2011

Print this Post

Snow Bunting (Plectrophenax nivalis)

Snow Bunting

[order] PASSERIFORMES | [family] Calcariidae | [latin] Plectrophenax nivalis | [UK] Snow Bunting | [FR] Bruant des neiges | [DE] Schneeammer | [ES] Escribano Nival | [NL] Sneeuwgors

Subspecies

Genus Species subspecies Breeding Range Breeding Range 2 Non Breeding Range
Plectrophenax nivalis NA, EU n Mediterranean, s USA
Plectrophenax nivalis insulae
Plectrophenax nivalis nivalis
Plectrophenax nivalis townsendi
Plectrophenax nivalis vlasowae

Physical charateristics

Snow Buntings are unmistakable medium sized sparrows, with white underparts and striking black-and-white wings. The slightly larger males are entirely black and white in breeding plumage with a white head and nape. The back and rump are black; the rump is mottled with white. Wings are mostly white with the primary feathers forming large black wingtips, and there is a black spot at the wrist. The tail is black with black-tipped white outer tail feathers. The bill and feet are black.

The summer female looks much like the male, except that the black areas of the body are duller and grayish brown rather than pure black and streaked with white, and the crown and ear coverts are buffy with black streaks. The white of the wings is reduced to a patch on the inner wing.

In winter, both male and female Snow Buntings resemble the breeding female. White areas are washed with pale brown, especially about the crown, sides of the head, and breast. The black feathers of the back are edged with brown and the bill becomes yellowish orange. As with breeding plumage, males show much more white in the wings. The rusty brown feather edges of the winter plumage gradually wear away to reveal the breeding plumage.
Across their range, flocks can reach the thousands and are often in the hundreds, although in Washington, flocks are usually much smaller. These flocks move around a lot from place to place, so their winter distribution can be spotty and ever changing. As they move through a field, birds at the back of the flock fly over the rest of the group to move to the front, making it appear that the flock is rolling. Ground-foragers, Snow Buntings are found in flocks outside of the breeding season

Listen to the sound of Snow Bunting

[audio:http://www.aviflevoland.nl/sounddb/S/Snow Bunting.mp3]

Copyright remark: Most sounds derived from xeno-canto

wingspan min.: 30 cm wingspan max.: 33 cm
size min.: 14 cm size max.: 16 cm
incubation min.: 12 days incubation max.: 13 days
fledging min.: 12 days fledging max.: 13 days
broods: 2   eggs min.: 3  
      eggs max.: 7  

Range

North America, Eurasia : North

Habitat

Breeding habitat is barren tundra with rock piles, boulder fields, and other rocky outcroppings that are used as nesting sites. In winter, Snow Buntings inhabit a variety of open lands, including short-grass prairie, farmland, beaches, and roadsides.

Reproduction

The preferred nest site of Snow Buntings is a crevice or cavity among exposed rocks or boulders on the tundra. Competition for sites is intense, and males-especially older, more experienced males-arrive three to six weeks ahead of females to claim suitable territories. They defend these territories and attract mates with finchlike warbled songs heard only on the breeding range. Nests built of moss and grass and lined with feathers and fur are hidden deep within rock piles or under boulders to avoid discovery by predators. Males feed nest-bound incubating females so that the eggs may be kept constantly warm in these cool shaded nest sites. The young are fed a diet of insects and arachnids.
She incubates 3 to 9 eggs for 10 to 16 days. Rock crevices in this harsh environment can be cold places, and the male feeds the female while she is on the nest so she doesn’t often need to leave the nest during incubation. Both parents help feed the young, which leave the nest at 10 to 17 days. The parents continue to feed the young for 8 to 12 days after they leave the nest, although the young start catching some of their own food within 3 to 5 days. Snow Buntings typically only raise one brood a year.
Snow Buntings breed throughout the tundra regions in the northern hemisphere. They range across northern Russia and Scandinavia, and in North America, across the Canadian high Arctic from the coastal lowlands of Greenland to Alaska and as far south as the southern limits of permafrost, and in the alpine tundra of the Canadian Rocky Mountains. In mid to late September flocks begin to migrate south, arriving in the northern parts of the winter range about the third week of October and the southern areas about a month later.

Feeding habits

Seeds are part of the Snow Bunting’s diet year round, but especially in winter. During summer, they eat more insects and spiders, and the young are fed almost entirely an invertebrate diet. Birds in coastal areas may also eat tiny crustaceans.

Conservation

This species has an extremely large range, and hence does not approach the thresholds for Vulnerable under the range size criterion (Extent of Occurrence <20,000 km2 combined with a declining or fluctuating range size, habitat extent/quality, or population size and a small number of locations or severe fragmentation). Despite the fact that the population trend appears to be decreasing, the decline is not believed to be sufficiently rapid to approach the thresholds for Vulnerable under the population trend criterion (>30% decline over ten years or three generations). The population size is extremely large, and hence does not approach the thresholds for Vulnerable under the population size criterion (<10,000 mature individuals with a continuing decline estimated to be >10% in ten years or three generations, or with a specified population structure). For these reasons the species is evaluated as Least Concern.
Snow Bunting status Least Concern

Migration

Partially migratory to migratory, many birds wintering far south of circumpolar breeding range; northernmost areas are vacated. In Europe, winters mostly in coastal areas and on inland plains. Numbers vary greatly from year to year, and also fluctuate over long periods. Present in Iceland all year, by far the commonest wintering passerine.
Autumn movement prolonged, September-December, with most passage records October-November. Spring movement northward begins early or mid-February. Leaves southern France February-March; latest record 28 February in Rumania, and rare by March in Hungary. Passage peaks end of February to early or mid-March in Denmark, north-east Germany, and Poland. Reaches southern Norway mid- or late March to April, and northern Norway at beginning of May. In north-east Scotland, spring departure rapid; most birds leave in March, a few still present in 1st half of April; males depart c. 9 days before females on average.
Snow Buntings migrate in small, loose flocks. Males arrive on their Arctic breeding grounds in early April. Females follow in May, and both leave in the fall, arriving in and passing through Washington in mid-October. They winter throughout the open country of the northern United States and temperate Canada.

Distribution map

Snow Bunting distribution range map

About the author

admin

Permanent link to this article: http://www.planetofbirds.com/passeriformes-calcariidae-snow-bunting-plectrophenax-nivalis

Leave a Reply