Thursday, December 15, 2011

River Refuge

Following a period of exceptionally cold weather along the Colorado Front Range, most of our lakes and ponds have frozen over, sending waterfowl to the South Platte River for vital nourishment. This annual phenomenon, earlier than usual this winter, concentrates the varied species of waterfowl as well as their natural predators. For birders and naturalists, this seasonal river refuge offers an opportunity to see a wide variety of species on a relatively short hike.

Yesterday morning, under clearing skies and amidst the warming air of a gentle chinook, I took a walk along the river through South Platte Park, in Littleton. As expected, ducks were abundant, including mallards, gadwalls, green-winged teal, buffleheads, common goldeneyes, common mergansers and a few ruddy ducks; hooded mergansers were unusually common, including one flock of a dozen birds. Belted kingfishers, great blue herons, ring-billed gulls, Canada geese, killdeer, black-billed magpies and the usual mix of winter songbirds were also drawn to the open water. A young coyote bolted from the riverside brush as I approached but other predators, including red fox, bald eagles and peregrine falcons were not encountered on my morning stroll.

The South Platte River is certainly not unique in its winter role as a waterfowl refuge. Most rivers throughout colder regions of our planet. providing open water amidst a frozen landscape, offer such seasonal spectacles. Indeed, birding along some of our larger rivers (the Upper Mississippi, Missouri and Ohio) is often very productive in winter as large, mixed flocks of waterfowl, gulls and bald eagles gather on and along their icy channels.