More migrants are settling in for the winter

Male Snow Bunting in winter

Juncos have arrived. So have White-throated Sparrows. And Pine Siskins. And Great White-fronted Geese. If those weren't enough signs that winter is at our doorstep, add one more to the list: the Snow Bunting.

The Snow Bunting breeds in the high Arctic, where its mostly white plumage resembles the landscape. If you lived anywhere in the swath of land from Alaska to Labrador, you'd see them in the summer hopping through the stunted grass looking for seeds or insects. They breed farther north than almost any other land bird in North America.

These sparrow-sized birds winter as far south as Pennsylvania and coastal Maryland. They are uncommon in the Lehigh Valley area, which is why the report last week of a Snow Bunting at the marina at Lake Nockamixon in Bucks County is such a treat.

Many years will go by without anyone seeing a Snow Bunting in our area. Flocks sometimes will congregate one year, with no birds being seen at all for the next several years running. The last major flock in the Lehigh Valley, consisting of about 410 birds, was reported in December 1998 at Point Phillips in Northampton County, according to Birds of the Lehigh Valley and Vicinity, a must-have reference book published by the Lehigh Valley Audubon Society. 

Snow Buntings favor open fields, especially farm fields where manure has been spread. They also seek seed along roadsides and will even peck in the crevices of parking lots to locate stray grass seeds.

Male Snow Bunting in breeding plumage

During the breeding season in the Arctic, Snow Buntings nest deep in cracks or cavities in the rock. The sites are secure from predators, but they are stone-cold. A thick lining of fur, moss, rootlets and feathers provides some insulation for the eggs and nestlings, but the female must remain with them constantly to provide sufficient warmth. The male brings food. The female typically lays four to six white eggs in a clutch.

The male Snow Bunting uses color to attract a female. Most of the year, the male is brownish with a brown-and-black striped back. The feathers underneath the body are white and the back feathers are pure black. Before breeding season the male will actively rub his feathers against the snow until he becomes immaculately white and jet black.

Currently the Snow Bunting is considered to be common and widespread, with a global population estimated in excess of 30 million. However, their numbers are in steep decline in North America, according to the 2014 State of the Birds Report. Winter flocks are getting smaller. Their nesting populations have decreased by 64 percent over the past four decades, according to the National Audubon Society.

Because Snow Buntings need snow and cold, the increasingly warmer winters are believed to be the species' primary long-term threat. The birds are now getting serious study, with research focusing on the specific reasons behind the population decline.