Snow Cover and Winter Bird Movements

Andrew Farnsworth The Cornell Lab Dec 28, 2012

The National Operational Hydrologic Remote Sensing Center produces national snow analysis graphics. As of 28 December, as seen in the graphic below, approximately 64% of the United States is covered in snow! This is a dramatic change from the previous week, when 20% less of the country was covered in snow.

Snow covers approximately 64% of the country as of 28 December 2012. Snow cover on the ground, which has expanded rapidly over the past week, may force many birds that forage on the ground to seek areas free of snow cover and engage in substantial facultative movements in search of open ground.

Such extensive cover may translate into substantial facultative movements of birds, particularly ground-feeding species like Horned Lark, American Pipit, many sparrows, longspurs, and Snow Buntings among others. Birders should be on the look out for such movements to occur, particularly in areas where snow cover may be minimal like shores of open water or even sidewalk or road surfaces near urban parks and in areas to the south of the extent of the snow cover. Additionally, as temperatures drop and open water disappears in more northerly locations, waterfowl and other species associated with open water like loons and grebes will be on the move. As always, please enter your sightings into eBird!