After two Arctic blasts scoured the Front Range, most small lakes and ponds have frozen over. Some of the larger lakes and reservoirs retain pools of open water and the South Platte River continues to flow past its icy banks.
Waterfowl that winter along the Front Range thus concentrate on these open waters, producing a congregation of species that, before the storms, were scattered throughout the valley. This morning, at South Platte Park, relatively small pools harbored gadwall, coot, hooded mergansers, redheads, common goldeneyes, buffleheads and northern shovelers; mallards, as usual, favored the river, joined in some areas by Canada geese and small flocks of other wintering ducks.
For birders, these winter congregations offer convenient viewing and allow close comparison of the various species. For natural predators, such as bald eagles and peregrine falcons, the ice concentrates their prey, making hunts more efficient and effective. Our current warm spell (60 degrees F today) may open more water surface but the next winter storm is expected by Christmas Eve.