Colorado’s dramatic landscape, ranging from the windswept Eastern Plains to the rugged peaks of the Rockies, creates a perfect sanctuary for birds of prey. Among these raptors, falcons hold a special place.
Built for speed and aerial precision, they are often seen slicing through the high-altitude air or stooping at incredible velocities to catch their prey. If you are birding in the Centennial State, knowing the different types of falcons in Colorado will add a thrilling dimension to your outdoor adventures.
While hawks often soar on thermals with broad wings, falcons are defined by their tapered, pointed wings and rapid, powered flight. In Colorado, you have the unique opportunity to see species that thrive in arid deserts, high-alpine tundras, and even downtown Denver.
Whether you are a seasoned birder or a casual observer, learning to distinguish the resident American Kestrel from the rare, wintering Gyrfalcon requires patience and a keen eye for detail.
American Kestrel
The most familiar and widespread falcon you will encounter is the American Kestrel (Falco sparverius). Roughly the size of a Mourning Dove, this small raptor packs a tremendous amount of personality into a compact frame. They are common residents across much of Colorado, though many migrate to lower elevations or further south during the harsh winter months. You are most likely to spot them perched on telephone wires along rural roads, scanning the ground for grasshoppers, voles, and lizards.
One of the best ways to identify a Kestrel is by its hunting behavior. Unlike other raptors that perch and wait, the Kestrel frequently hovers in place, facing into the wind with rapid wingbeats before dropping onto its prey. This “kiting” behavior is distinct and can be spotted from a moving car.
Visual Identification Guide:
- Facial Markings: Look for two bold, vertical black stripes on a white face (often called “mustache” and “sideburn” marks).
- Male Plumage: Slate-blue wings contrasting with a rusty-red back and tail.
- Female Plumage: Reddish-brown overall with black barring on the back and wings.
- Flight Profile: Buoyant and erratic flight, often with pointed wings swept back.
Pro Tip: Kestrels are cavity nesters. In areas where old trees with hollows are scarce, such as the open plains, they readily take to nest boxes. Installing a box on your property near open fields is a fantastic way to support their population and observe their family life.
Merlin
As the aspen leaves turn gold and the first snows dust the foothills, the Merlin (Falco columbarius) arrives in Colorado. These stocky, powerful falcons breed in the boreal forests to the north and spend their winters here, patrolling open woodlands, parks, and suburban neighborhoods. Unlike the delicate hover of the Kestrel, the Merlin is a bullet in the sky, known for flying low and fast to ambush small birds.
Merlins are generally darker and heavier-bodied than Kestrels. They lack the bright reds and blues, sporting instead a streaky brown or slate-grey appearance. Their hunting style is aggressive; they will chase prey in high-speed pursuits, often twisting and turning through trees or between houses. They are frequently seen harassing larger birds, including Magpies and Crows, driving them away from their territory with surprising ferocity.
Comparison: American Kestrel vs. Merlin
| Feature | American Kestrel | Merlin |
| Seasonality | Year-round / Summer Resident | Winter Resident / Migrant |
| Body Shape | Slender, small head | Stocky, broad-chested, blocky head |
| Flight Style | Buoyant, hovers frequently | Powerful, direct, continuous flapping |
| Primary Diet | Insects, small mammals | Small birds (caught in mid-air) |
| Temperament | Cautious, observant | Aggressive, bold |
Prairie Falcon
The Prairie Falcon (Falco mexicanus) is the spirit of the American West. Perfectly adapted to the arid landscapes of Colorado, this raptor is found in the open grasslands, sagebrush steppes, and canyonlands. They are similar in size to the Peregrine Falcon but are paler and sandier in color, allowing them to blend seamlessly into the sandstone cliffs where they nest.
Identifying a Prairie Falcon can be a challenge because they look so much like a Peregrine at first glance. However, their behavior and habitat often give them away. While Peregrines might be found near water or in cities, Prairie Falcons stick to the dry, open country. They are fierce hunters of ground squirrels and medium-sized birds, often hunting from a high soar or a low, contour-hugging flight.
The “Armpit” Identification Trick:
If you see a large, sandy-colored falcon soaring overhead, wait for it to pass directly above you. The most diagnostic field mark for a Prairie Falcon is the dark triangular patch of feathers in the “armpit” (axillaries) and underwing coverts. This dark triangle contrasts sharply with the otherwise pale underwing, distinguishing it from the uniformly patterned underwing of a Peregrine.
Habitat Preferences:
- Pawnee National Grassland: An excellent spot to scan power poles for perching birds.
- Colorado National Monument: Look for them nesting on vertical cliff faces.
- San Luis Valley: Wintering populations often hunt in the agricultural fields here.
Peregrine Falcon
The Peregrine Falcon (Falco peregrinus) is a legend of the avian world, renowned as the fastest animal on the planet. During a hunting dive, or “stoop,” they can reach speeds exceeding 200 mph. In Colorado, Peregrines were once threatened by pesticide use but have made a remarkable recovery. They typically nest on high cliff ledges in the mountains, but they have also adapted to the “artificial cliffs” of urban environments.
In downtown Denver, it is not uncommon to see Peregrines perched on skyscrapers, scanning the city streets for pigeons. These urban dwellers are often resident year-round, while mountain-dwelling birds may migrate or move to lower elevations in winter.
Key Field Marks:
- The “Helmet”: A broad, dark black “hood” or helmet that covers the head and cheeks, contrasting with a white throat.
- Structure: Heavy-bodied with broad, pointed wings that look like an anchor in flight.
- Wingbeats: Stiff, shallow, and powerful, unlike the deep, fluid wingbeats of a raven or gull.
Key Insight: The Royal Gorge Bridge area is a fantastic place to observe Peregrines in their natural habitat. The steep canyon walls provide ideal nesting sites, and the thermals rising from the Arkansas River give them the lift they need to soar effortlessly while hunting.
Gyrfalcon (Rare Winter Visitor)
The final and most elusive bird on our list is the Gyrfalcon (Falco rusticolus). This is the largest falcon in the world, a true ghost of the Arctic. They breed on the tundra far to the north and are considered a rare, irregular winter visitor to Colorado. Seeing one is a “red letter day” for any birder and usually draws crowds of enthusiasts with spotting scopes.
Gyrfalcons are bulky and powerful, often described as having a barrel-shaped chest. They come in three color morphs: white, grey, and dark. In Colorado, the grey morph is the most common, though white birds are occasionally seen. They prefer wide-open spaces that mimic their tundra home, so look for them in the vast agricultural fields of the Eastern Plains or open mountain parks in winter.
How to Distinguish a Gyrfalcon:
- Size: Noticeably larger and bulkier than a Peregrine or Prairie Falcon.
- Flight: Their wingbeats are slower and deeper than other falcons, appearing almost deceptively slow despite their speed.
- Location: They are almost exclusively found in wide-open, treeless areas, often perched on the ground or fence posts rather than high trees.
Conclusion
Whether you are scanning the high plains for a white Gyrfalcon in January or watching a Kestrel hover over a wildflower meadow in June, searching for the types of falcons in Colorado connects you to the wild, rugged heart of the state. These birds represent the pinnacle of aerial evolution, each adapted to a specific niche within Colorado’s diverse ecosystems.
By understanding the seasonal rhythms—knowing that Merlins bring the winter chill and Prairie Falcons rule the dry canyons—you can target your birdwatching efforts more effectively. So grab your binoculars, head out to the open country, and keep your eyes on the sky. You never know when one of these speedsters will make an appearance.
