As Red-winged Blackbirds and other early migrants begin arriving in Vermont, where are the Common Loons that will reappear on our still-frozen lakes next month? March eBird maps show Common Loons are reported along the coast from the Canadian Maritimes to the Gulf of Mexico, with some found inland on areas that are ice free. There are even a few loons on the open waters of southern Lake Champlain.
Recent satellite telemetry studies, as well as sightings of banded birds, reveal that most New England loons winter off the Northeast coast. Generally, breeding loons from further west in Ontario will travel further south to the Chesapeake and the Carolinas, while loons from the Midwest often spend the winters in the Gulf of Mexico. Loons breeding further west in Alberta and British Columbia spend winters along the Pacific coast.
Biodiversity Research Institute and the U.S. Geological Survey, which have spearheaded studies of loon winter ecology, have made some interesting discoveries. Male loons nesting in Maine tended to stay off the Maine coast during winter, while their female counterparts ventured further south, ending up from Cape Cod to Chincoteague, MD. Is this a strategy that enables the earliest possible return by males to their breeding lakes, shortly after ice melt? It is now known that many wintering loons return to the same area year after year, paralleling their strong breeding site fidelity in summer. Most loons occupy a 10-20 square km “home range” area for the duration of the winter. A 2015 paper by Jim Paruk in Condor: Ornithological Applications noted that site-faithful loons likely gain fitness and survivorship advantages via local knowledge of a discrete wintering area.
As winter transforms into spring during the coming weeks, loons will bide their time on open waters, waiting for the right moment return to breeding areas, anticipating ice-free lakes. In years of late ice-out, volunteers have observed flyovers of loons inspecting the lake country, but with no place to land. These birds likely retreat to await another exploratory flight. In early ice-out years, we rarely hear about loons showing up earlier than expected. They have a schedule, an internal clock, an ingrained time table for spring migration.
If you travel to the coast this late winter or early spring, bring binoculars and scan the nearshore waters. You’ll likely find a loon, and you might be lucky enough to hear one call. And be sure to add all of your sightings to eBird.