The Snow bunting is appropriately named, being a bird of the Arctic and snowy winter fields. The mostly white feathers of a flock of buntings brings to mind the idea of a snowstorm even on a day that is warm. They are sometimes called "snowflakes," and flocks of them seem like snowflakes, swirling through the air and settling on winter fields. Snow buntings south of the Arctic are strictly winter birds, which arrive in late fall, usually departing at the start of spring. They spend summer in the barren northern tundra. In certain high Arctic communities they nest in birdhouses that people put out for them.
Snow buntings breed in the high Arctic, in Scandinavia, Iceland, northern Scotland, Russia, Siberia, Alaska, Canada and Greenland. Usually these birds migrate south for winter, those in North America going to southern Canada, to the southern and western coasts of Alaska, and to the USA's Great Plains. Birds outside of North America winter in southern Scandinavia, Western Europe, and through central Asia. This species breeds on rocky open tundra, on sea cliffs and sometimes in human settlements, preferring areas with boulder fields and rocky outcrops, and usually avoiding the wet tundra. In winter, they are found in open lowland country, such as stubble fields, steppes, short grass prairies, farmland, grassy sand dunes, lake shores and beaches.
Snow buntings are diurnal and social birds. They migrate in big flocks which look as though they are in constant motion, as birds at the back fly over birds in front, a constant cycle. There is a clear hierarchy in these flocks, adult birds being dominant over birds experiencing their first winter, and males dominant over females. The flocks in winter usually are made up only of Snow buntings. In other seasons they may include pipits, Lapland longspurs and horned larks. To cope with -40 degrees Fahrenheit temperatures and stay warm, snow buntings burrow deep down into the snow. They enjoy bathing in snow. These birds forage either on the ground or within low vegetation by hopping, walking or running. They also catch flying insects and burrow into the snow for food. Their call is used mainly when mating.
Snow buntings are omnivores, they mainly eat seeds, the buds of leaves, and insects. The young are fed arthropods only, both insects and arachnids. Those birds that nest on the sea coast also eat crustaceans.
Snow buntings are monogamous which means that one male mates with only one female. Competition for mates between males is extreme. Pairs form from mid-May to early June, depending on weather conditions. 3-6 weeks before the females, males will return to the breeding grounds, to claim and defend their territory. They often come back to the same territory each year. Once the females arrive, the males sing to attract them. If a female approaches, the male pursues her. He will also perform a flight display, flying high up in the air and then gliding down with his wings in a V-shape, singing at the same time. The breeding season is in summer, from late May until September. A nest is built in a protected place such as a hole in the ground or a deep rock crevice. The female collects the material to build the nest. 2-8 eggs are laid, pale blue-green to whitish, with brown spots on their larger end. The female incubates them on her own for 12-14 days, during which time she is often fed by the male. Spending more time on her eggs is very important in cold northern climates. Both parents feed the chicks, which fledge at 10-17 days old.
The Snow bunting is a widespread and common species. However, evidence suggests that this species is in significant decline in North America. Reasons for this may be due to their distribution resulting from climate change. Another possible threat is the use of pesticides for crops, since these birds often feed heavily in winter at agricultural fields.
According to the IUCN Red List, the total Snow bunting population size is more than 40 million individuals, with national population sizes estimated at fewer than 1,000 wintering individuals, with fewer than 50 individuals and 10,000-100,000 breeding pairs migrating in Japan, around 1,000-10,000 birds on migration and 50-1,000 individuals wintering in Russia. Overall, currently Snow buntings are classified as Least Concern (LC), but their numbers today are decreasing.
The Snow buntings have an important role as eaters of arthropods, seeds, and leaf buds. They also serve as prey for arctic foxes and snowy owls, their natural predators.