November is the month to observe a variety and abundance of dabbling and diving ducks in Colorado. There’s more to see than the ubiquitous mallard these days. So grab your bird guide, a good pair of binoculars, and some warm clothing and head to your nearest river or reservoir.
The vast majority of ducks that winter in Colorado are arriving from the north-central U.S. and southern Canada. Look for mergansers, diving ducks with long, slender, serrated bills and crested heads on rivers and reservoirs in the eastern portion of the state, in western valleys, and mountain parks. They winter here to dive for small or medium-sized fishes, their primary source of food. The male common merganser has a greenish-black head, black back, and a pinkish-white breast and underside; the red-breasted merganser drake has a crested, glossy-green head, white neck, red breast, and black upper surface with white margins. The females of both are very similar, with crested chestnut heads, white underside, and grey backs.
Hooded mergansers are not really related to the other two species. They are smaller and have a fluffy, fan-shaped crest. Males have a large white patch in the black crest. They are frequently seen on shallow waters along with wood ducks, which also winter here in small numbers. Male wood ducks have an iridescent green and purple crested head marked with white stripes. The female is grayish-brown with a small crest and a white spot around the eye. Another diving duck with a striking yellow eye—the Barrows goldeneye, will reside here through March.
It’s a fact: 85 percent of North America's blue-winged teal, 33 percent of its redheads and shovelers, 25 percent of its American wigeons, 20 percent of its green-winged teal, and 15 percent of its pintails head to Mexico each year. Many pass through Colorado, offering an excellent opportunity for wildlife viewers.
Redhead and canvasback ducks are similar in appearance and sometimes difficult to distinguish. Both are black and white with reddish heads. Canvasback ducks are less common, have a smaller head and a sloped bill. Waves of wigeon and pintails can be found in large numbers on reservoirs and filling the air with their soft whistling calls. Pairs of cinnamon teal may be seen passing overhead and in the region’s waters.
When some migrating ducks and geese arrive, water is plentiful, and that keeps many of the birds here through the winter. Although many will continue the journey south, some shovelers, gadwalls, ringneck, lesser scaup, bufflehead and ruddy ducks will stay. The best places to look are in western valleys and eastern plains, particularly along the South Platte and Arkansas River drainages and in the San Luis Valley.
(Take a look at the Colorado Wildlife Viewing Guide, Second Edition, Revised. Containing information about more than 200 wildlife viewing sites, use it to find locations nearby where you can enjoy watching ducks! The guide is available at many bookstores, through our online store, or through the Colorado Wildlife Heritage Foundation.)