Colorado’s varied topography, ranging from eastern plains to the towering peaks of the Rocky Mountains, creates diverse habitats that support numerous raptor species. Owls maintain a distinct presence across the state’s ecosystems. Their unique adaptations as nocturnal and sometimes diurnal hunters allow them to thrive in virtually every corner of Colorado. This article explores the common owls found at lower elevations and the specialized species restricted to higher mountain forests.
Identifying Widespread Colorado Owls
The Great Horned Owl ( Bubo virginianus ) is the most commonly encountered species, found across every habitat in Colorado, from dense forests to urban parks. This large raptor is easily identified by its prominent ear tufts (plumicorns) and its deep, resonant hooting call, often heard year-round. The species’ adaptability allows it to prey on a wide range of animals, including skunks, rabbits, and other birds of prey.
The Barn Owl ( Tyto alba ) is recognizable by its pale, heart-shaped facial disk and its raspy, hissing screech, as it lacks a classic hoot. These non-migratory owls prefer open grasslands, agricultural fields, and riparian areas in the eastern plains and lower valleys. They often nest in barns, silos, or cliff cavities. Their diet concentrates on small rodents, such as voles, which they hunt nocturnally by flying silently over fields.
The Western Screech-Owl (Megascops kennicottii) is a smaller, stocky owl that resides in diverse wooded areas across the western and southwestern parts of the state. It possesses small ear tufts and mottled gray or brown plumage that provides excellent camouflage against tree bark. Unlike its name suggests, this owl does not screech, communicating instead with a series of soft, accelerating whistles or trills. Western Screech-Owls are cavity nesters, often utilizing old woodpecker holes in trees within canyons and riparian zones.
Specialized Owls of Mountain and High-Altitude Zones
The Flammulated Owl (Psiloscops flammeolus) is found in higher-elevation coniferous forests, often above 8,000 feet. It is the smallest owl in the state, measuring six to seven inches long, and is primarily an insectivore, feeding largely on moths and beetles. This migratory species arrives in Colorado in May and is found in forests dominated by ponderosa pine and Douglas-fir, where it nests in abandoned woodpecker holes.
The Boreal Owl (Aegolius funereus) is a dense-forest specialist found in subalpine spruce-fir forests, typically above 9,500 feet. This highly nocturnal species is rarely seen due to its remote habitat. Its presence is sometimes detected by its distinctive, tremulous, repetitive territorial call given in late winter and early spring. Boreal Owls are non-migratory but primarily hunt small mammals, such as voles, often in meadows adjacent to their forest cover.
The Northern Pygmy-Owl (Glaucidium gnoma) is a small owl, about seven inches in length, unique for hunting during the daytime. This raptor is often found in the foothills and montane zones, favoring a mix of conifer and aspen forests. A distinguishing feature is the pair of dark, deceptive eye spots located on the back of its head, believed to confuse potential predators. It preys heavily on small birds and mammals, using its diurnal habit to its advantage.
Finding Owls Distribution and Seasonal Activity
Owls are year-round residents in almost all of Colorado’s ecosystems, with the exception of the alpine tundra. Distribution is closely linked to habitat type and elevation; for example, the Flammulated Owl is a seasonal visitor, present only during the spring and summer breeding months before migrating south. The best time to detect species is during the late winter and early spring (February through May), when males are most vocal in establishing territories and attracting mates. Most owls are strictly nocturnal, but the Northern Pygmy-Owl and the Short-eared Owl (Asio flammeus) are notable exceptions that hunt during the day or at twilight, respectively.