As winterís grip tightens, open water shrinks, the smaller bodies first. Great flocks of diving ducks bob on Lake Erie waters, or pass by on the horizon. Puddle ducks may have few recourses—the copious spring-fed water at Castalia in Erie County is a well-known one—and may be supported by spilled grain in agricultural fields until they are compelled to move further south. Some water birds continue gathering in December, like redheads, greater scaups, the scoters, and common mergansers, and their numbers tend to increase. Late in the month Lake Erieís surface—as shallowest of the Great Lakes it is the most prone to this—may begin to freeze extensively, causing equally extensive movements of water birds.
While there are often sought-after surprises, the list of landbirds present shrinks to our familiar residents and a few visitors from the north. Christmas Bird Counts are conducted in sixty-odd circles in the state, and typically find between 145 and 150 species altogether during the period. Species like gray catbird, brown thrasher, eastern phoebe, hermit thrush, towhee, etc., are variably present, more often in the southern part of the state; while they are often called "half-hardy" species, it should be noted that warmer winters do not necessarily mean more of them will be present. Birds of our latitude and north, it must be remembered, are well-adapted to survive in the coldest winters, and when die-offs occur—as has happened with mockingbirds, Carolina wrens, and northern bobwhites in recent hard winters—it is nearly always an inability to reach food (caused by ice or deep snow), and not extended periods of below-zero temperatures, that killed birds. Incursions of species from the north like the "winter finches"—siskins, crossbills, red-breasted nuthatches, grosbeaks, redpolls, etc.—seem not to be correlated at all with harsher winters; they are far more involved with fluctuations of winter seed crops in Canada, which recently have occurred in a fairly regular biennial schedule.