Winter is not typically a season that we associate with bird migration. However, plenty of movement occurs during these cold, dark months, in particular irruptive and facultative movements. Although few irruptive species moved south this year (almost none, other than Snowy Owls), the winter of 2013-2014 has seen a parade of arctic systems move across North America, bringing cold temperatures well outside of recent averages. These have triggered facultative movements as species are literally frozen out of the north and eBirders are contributing greatly to our understanding of the species and patterns involved. In mid-January 2014, it became apparent that White-winged Scoter and Red-necked Grebe were on the move, popping up at lakes, rivers, and ponds in most of the eastern U.S. Some coastal areas also have seen a noticeable increase and it seems clear that the movements of these birds are directly connected to the higher-than-normal ice cover on the Great Lakes. To explore these movements more and better understand the connection to ice cover on the Great Lakes, please visit BirdCast.
White-winged Scoter occurrence in January 2013 (upper; blue dots) and January 2014 (lower; mostly red dots) from eBird. Note that not only are there many more turning up inland, but also that even on the coast (especially south of Cape Hatteras) the species seems to be more widespread. See BirdCast for more on this phenomenon.