For many of these species, Colorado is their version of wintering in Palm Springs. It's hard to believe this when the thermometer here barely reaches the double-digits, but it's definitely warmer than spending the winter above the Arctic Circle.
Kestrel fluffed up against the cold
The species I look most forward to seeing each winter is the Rough-Legged Hawk (Buteo lagopus). While the plumage on Roughies isn't as variable as that on Red-Tailed Hawks, it does sport two very fetching and distinct color phases, light and dark, with gradations between. And while anecdotal evidence says that these birds tend to stay out on open farm and ranch land far clear of cities, I have regularly seen them soaring over towns and highways here near Boulder.
Juvenile Rough-Legged Hawk hunting near Louisville, CO
Light phase Roughies are quite distinctive both in flight and perched - short beak, feathered legs, and dark "wrist' patches under their wings are giveaways. Very dark belly-bands are typically present on the lighter birds, and hunting from a hover (similar to a kestrel) is another distinctive trait of these raptors.
In some years, winter can bring another beautiful visitor from the far north: Snowy Owls (Bubo scandiacus). A very large, diurnal owl (active during the daylight), Snowies are surprisingly difficult to spot after winter storms have dumped a foot of powder along the Front Range. While again tending to stay in more rural areas, Snowies will go where the food is: namely, small rodents. I have seen Snowies perched on fence posts in an active farm yard, on top of manure piles, garbage dumps, heavy construction machinery, road signs, and on the peaks of barns.
Snowy Owl on a pile of tires
Other raptors that winter in Colorado are more northern populations of hawks, eagles, falcons, and owls.
Bald Eagle at Stearns Lake, Colorado
As with all wild animals, please take care when observing and photographing migrating birds of prey. Truly arctic birds like Rough-Legged Hawks and Snowy Owls come only as far south as they need in order to find food. If the rodent population is good to the north, few of these raptors come south into the lower 48. But if the rodent population has crashed that year, the birds won't have as much prey to eat so hunger will drive them south until they find food. By the time these Arctic birds reach Colorado, they're hungry, sometimes VERY hungry. Take care to disturb them as little as possible because their lives depend on their ability to capture food. On a cold day, too much human activity can cause them to expend a lot of precious energy avoiding us rather than tracking down and catching a much-needed meal.
Juvenile Bald Eagle feasting on a goose, Waneka Lake, CO
All text and photos copyright Nancy Rynes, 2013. You may link to this page, but please do not copy any text or pictures, for any reason, without my written permission.