One of the more enjoyable birding ventures to pursue each year is to go out in search of winter raptors.  Here in Colorado, we have some raptors that are only around in the summer, and they then migrate farther south for the winter: Turkey Vulture, Osprey, Mississippi Kite, Swainson’s Hawk, and Peregrine Falcon.   We also have a few species whose numbers remain relatively constant throughout the year: Sharp-shinned Hawk, Cooper’s Hawk, Northern Goshawk, and American Kestrel.  However, there are a number of species that not only breed in Colorado, but their numbers actually increase during the winter due to the arrival of migrants that bred farther north but choose Colorado as the place to spend the winter:  Northern Harrier, Bald Eagle, Red-tailed Hawk, Ferruginous Hawk, Golden Eagle, and Prairie Falcon.  And, furthermore, there are a couple of species that are only found here in the winter: Rough-legged Hawk and Merlin.  The bottom line – winter is when the raptor watching is best!  And the prized species at that time are Rough-legged Hawk and Merlin!

So, if you’re thinking of becoming a raptor expert, and are saying, “Oh, good, I only have 17 species to learn.”  Hold your horses, Pardner!  First of all there are an additional four or five species that occur rarely in Colorado, e.g. Broad-winged Hawk, Red-shouldered Hawk, Gyrfalcon, and Snowy Owl, then each species has almost a gazillion different looks – male vs female, youngster vs adult, dark-morph birds vs light-morph birds, various subspecies, etc.  Venturing into this ID realm is not for the faint of heart.

Nonetheless, a group of us boldly ventured forth on Saturday to do our best against these odds, visiting the diminishing open country south of Barr Lake and west of DIA which is still one of the best areas close to Denver for seeing a good variety of raptors.  And we didn’t do too badly, getting to see eight species well: Northern Harrier, Bald Eagle, Red-tailed Hawk, Rough-legged Hawk, Ferruginous Hawk, Great Horned Owl, American Kestrel, and Prairie Falcon.  A ninth species was a bit trickier, and for that one I need a new paragraph.

We had no sooner gotten to our first stop of the morning when we had a pair of accipiters cartwheeling, diving, and chasing each other through dense shrubs and small trees.  They would periodically perch, but just for the briefest moment before they were off again, so good looks were not available.  A reminder – we have three accipiters here in Colorado, Sharp-shinned is the smallest, Cooper’s is intermediate, and Goshawk is the largest; they are all designed for diving through dense branches with their proportionally longer tails and shorter wings than Buteos (soaring hawks).  Our birds were, in all likelihood, two territorial males aggressively duking (or taloning) it out.  While they initially seemed fairly small – male Sharpies are only about eleven inches long, the possibility of their being male Coops (fifteen inches long) was also a possibility, and one of them had a rounded tail – a Coop characteristic.

A final note on bird identification.  As much as we want to be able to come up with the correct identification of a bird, relying on our own level of expertise, or relying on whatever field guides we have, or relying perhaps on the perceived capability of someone we construe as being better at this ID game than we are, or relying on an app like Merlin to just give us the right answer right now, we need to be willing to admit the fallibility of all of the above.  Maybe today we don’t get to add another species to our list.  Maybe we just take whatever small lessons we may have learned and wait until a future date to have a bit more confidence that we’ve gotten it right.  I feel that we’re presently seeing too many people on eBird saying that “there were a lot of us” that saw the bird, or that a good birder provided the identification, or that Merlin said it was a such-and-such.  Please, be willing to walk away with your uncertainty, and know that next time you’ll be closer to arriving at the correct identification on your own.

Adams County Raptors
Feb 1, 2025 
23 species (+1 other taxa)
15 participants

Snow Goose 8
Cackling Goose  1400
Canada Goose  1600
Cackling/Canada Goose  4000
Mallard  7
Rock Pigeon (Feral Pigeon)  70
Eurasian Collared-Dove  19
Sharp-shinned/Cooper’s Hawk  2
Northern Harrier  10
Bald Eagle  28
Red-tailed Hawk  17
Rough-legged Hawk  2
Ferruginous Hawk  3
Great Horned Owl  1
American Kestrel  14
Prairie Falcon  1
Blue Jay  3
Black-billed Magpie  14
Horned Lark  75
European Starling  1600
American Robin  40
House Sparrow  4
House Finch  2
White-crowned Sparrow  6
Western Meadowlark  95