Colorado is a vast state and diverse landscapes are home to a wide range of wildlife species, including several species of owls. These magnificent birds of prey have fascinated humans for centuries with their unique features and hunting prowess.
Owls are nocturnal creatures that are adapted to live in different habitats, from dense forests to arid grasslands, making Colorado a perfect habitat for them.
In this article, I will go through the different species of owls found in Colorado, their unique characteristics, nesting behaviours, and diets. Together, we will also delve into the challenges faced by these birds and the efforts being made to protect their habitats.
From the tiny Northern Pygmy Owl to the majestic Great Horned Owl, Colorado’s owl population is diverse and fascinating. Join us as we take a closer look at these remarkable birds and learn more about their importance to the Colorado ecosystem.
1. Eastern Screech-Owl
- Scientific name: Megascops asio
- Life span: 8 to 10 years
- Size: 16 to 25 cm (6.5 to 10 in)
- Weight: 121 to 244 g (4.25 to 8.5 oz)
- Wingspan: 46 to 61 cm (18 to 24 in)
- Status: Least Concern
The Eastern Screech-Owl is a bird known for its remarkable adaptability, often spotted in various areas of Eastern North America, including Mexico. It appears to be unfazed by human activity and can even thrive in urbanized landscapes.
This species is divided into two separate colourations, reddish hues in southern populations and greyish tones in the north. Researchers theorize that such variations are influenced by the colours of their natural woodland habitats.
The Eastern Screech-Owl is recognized for its solitary nature, typically forming pairs during the breeding season in April. The owls engage in bonding rituals during courtship to establish a lifelong connection.
Following mating, they build nests in the dark, dense forests’ hollow tree trunks. While the Eastern Screech-Owl is most often monogamous, some males have been observed mating with multiple different females during the same breeding season, resulting in the eviction of the first female and the laying of a new clutch of eggs.
As an adaptable predator, the Eastern Screech-Owl hunts a diverse range of prey depending on its surroundings. The species mostly hunt small mammals like voles, mice, shrews, and rats in Colorado, but also feeds on significant amounts of insects such as beetles, moths, and other invertebrates like spiders, worms, and snails, especially during times when mammal populations are low or in decline.
Additionally, it feeds on small reptiles, birds, and amphibians and occasionally consumes fruits and berries. The owl is primarily a nocturnal hunter, using its hearing to locate prey. After consuming its prey whole, it regurgitates the indigestible parts, like fur, feathers, and bones, in the form of pellets.
The Eastern Screech-Owl is not currently considered endangered, but like many other owl species, it is vulnerable to poisoning from its prey and habitat disruption or destruction. The International Union for Conservation of Nature’s Red List classifies the Eastern Screech-Owl as “Least Concern.”
2. Great Horned Owl
- Scientific name: Bubo virginianus
- Life span: 25 – 50 years
- Size: 43 to 64 cm (17 to 25 in)
- Weight: 1200 to 1600 g (2.64 to 3.52 lbs)
- Wingspan: 91 to 153 cm (3ft 0in to 5ft 0in)
- Status: Least Concern
With its brown-speckled feathers, the Great Horned Owl is a versatile bird that flourishes in a diverse range of habitats, including deserts, wetlands, grasslands, urban areas, and forests. These creatures are nocturnal and can camouflage themselves in their environment.
They are not limited to North America, as they are also found as far south as Brazil. The owl’s distinctive “horns” are actually feathers known as plumicorns, which may serve as visual markers or a means of communication with other birds, though their precise purpose remains unclear.
The Great Horned Owl is an early breeder in North America, with the selection process starting as early as January. Male owls usually take the lead in finding the ideal nesting spot and wooing potential mates by performing elaborate aerial displays and stomping on the chosen site.
Instead of building their own nests, they prefer to use abandoned nests left by other large birds such as eagles or hawks. Their nesting sites are diverse and can range from caves and cliffs to cacti.
These owls are opportunistic predators with a diverse diet and a reputation for adaptability in hunting. In Colorado, their diet varies with the seasons and prey availability, with small mammals like voles, mice, and rabbits being the primary food source.
However, they are not limited to small mammals and also eat a wide range of other animal groups, including birds, reptiles, amphibians and insects. They rely heavily on their sharp talons and beaks to capture prey and are mainly nocturnal hunters.
Although not categorized as a threatened species, the Great Horned Owl population in North America has significantly declined over the past four decades and is most likely due to human activities. 65% of owl fatalities are caused by human activities, including shootings, trapping, car collisions, power line electrocution, and rat poison poisoning.
Unfortunately, in the past, farmers and hunters have viewed these owls as pests due to their predation on domestic chickens and small game, leading to their hunting and killing for centuries and, even to this day, by illegal poachers.
3. American Barn Owl
- Scientific name: Tyto furcata
- Life span: 10 years
- Size: 34 to 38 cm (13 to 15 in)
- Weight: 400 to 600 g (0.88 to 1.3 lbs)
- Wingspan: 29 to 36 cm (11 to 14 in)
- Status: Least Concern
The American Barn Owl is a remarkable and mysterious bird that is notable for its stunning and ethereal appearance. This nocturnal creature typically spends its daylight hours concealed within dense foliage or hollow tree trunks, only emerging at nightfall to search for prey.
The American Barn Owl belongs to a subspecies group that includes the Western and Eastern Barn Owls and is recognized for its striking physical attributes. The bird’s upper body and wings exhibit a pale brown colouration, while its face, chest, and belly are a creamy white hue.
The American Barn Owl’s unique facial features have inspired numerous tales and legends, often portraying the owl as a mystical or celestial entity.
The American Barn Owl is a stunning and mysterious nocturnal bird that spends its days hiding in trees or vegetation and hunts only at night. Between March and June, American Barn Owls form monogamous pairs for life during the nesting season.
The male owl diligently searches for an ideal nesting spot such as a tree cavity or cliff and establishes his territory by energetically flying around the area. Courtship behaviour as chasing and sweeping is exhibited toward the female before breeding.
American Barn Owls feed mainly on small mammals like voles, shrews, and mice in Colorado. Their ears are asymmetrically placed, which enables them to locate prey through sound, and they can hunt in complete darkness.
These birds require a greater amount of food than other owls of their size due to their higher metabolic rate. While they may also consume small birds and insects, their diet mainly consists of small rodents found in Colorado’s agricultural landscape.
Although not globally threatened, the population of American Barn Owls in North America has decreased due to increased pesticide and rodenticide use. These chemicals can contaminate their food sources and lead to significant fatalities. Despite this setback, the species has shown resilience and has the ability to recover from these losses in the short term.
4. Barred Owl
- Scientific name: Strix varia
- Life span: 8 years
- Size: 40 to 63 cm (15 to 25 in)
- Weight: 610 to 1,150 g (1.34 to 2.54 lb)
- Wingspan: 96 to 125 cm (38 to 49 in)
- Status: Least Concern
A thorough analysis conducted on a sample of 158 marked Barred Owls revealed that these birds tend to have small, non-migratory territories, covering a distance of no more than 6 miles from their original location. Nevertheless, Barred Owls are commonly found throughout most of the eastern regions of the United States and southern parts of Canada.
They are recognized by their remarkable brownish-grey feathers, which are complemented by dark stripes on their underparts.
Barred Owls, similar to American Barn Owls, have a tendency to form lifelong monogamous pairs during mating. During courtship, the male spreads its wings and waits for the female’s acceptance, which generally occurs in February. They create their nests within hollow tree trunks located in dense forests.
Barred Owls’ diet mainly consists of small mammals like mice and voles, as well as smaller types of birds, reptiles, and insects. On occasion, they will consume larger prey like rabbits and squirrels. These opportunistic predators use their acute hearing to locate prey around forest rivers and wetlands and will even scavenge for carrion if available.
With an estimated worldwide population of 3 million, Barred Owls are considered widespread in North America and are globally classified as “Least Concern” on the IUCN Red List. However, similar to other owl species on this list, they face threats like prey contamination and habitat destruction or disturbance in deep, dark forests.
5. Short-eared Owl
- Scientific name: Asio flammeus
- Life span: 12 years
- Size: 34 to 43 cm (13 to 17 in)
- Weight: 206 to 475 g (7.3 to 16.8 oz)
- Wingspan: 85 to 110 cm (33 to 43 in)
- Status: Least Concern
The Short-Eared Owl is a widely distributed and common bird that inhabits different environments across the world. It can be identified by its black small beak, spotted brown body, and impressive wings and tail with distinctive brown bars.
A peculiar feature about the Short-Eared Owl is that different from other owls it prefers to hunt during the daytime, rather than at night
The Short-Eared Owl is a widely distributed species that inhabits various ecosystems across the globe. This bird has a small black beak and a brown-spotted body with striking wings and a tail marked with bold brown bars. Unique among owl species, the Short-Eared Owl hunts primarily during daylight hours.
During the breeding season, which starts in March, Short-Eared Owls mate serially for a single season and live together in flocks. Dissimilar to many other species of owl, they construct their nests on the ground in low-vegetated areas like prairies, meadows, and tundras.
Short-Eared Owls feed mostly on small mammals such as voles, shrews, and rodents, as well as other animal groups such as reptiles, amphibians, insects, and birds like sparrows and larks. These opportunistic hunters fly low to the ground during daylight hours to capture prey in grasslands, meadows, and other open habitats.
The Short-Eared Owl population has decreased due to habitat destruction and collisions with vehicles. However, the species is currently expanding its range globally and is thus currently listed as “Least Concern” on the IUCN Red List.
6. Long-eared Owl
- Scientific name: Asio otus
- Life span: 10 to 27 years
- Size: 31 to 40 cm (12 to 16 in)
- Weight: 160 to 435 g (5.6 to 15.3 oz)
- Wingspan: 86 to 102 cm (2ft 10in to 3ft 4in)
- Status: Least Concern
The Long-eared Owl has a remarkable ability to blend into the thick foliage of pine trees due to its intricate camouflaging of brown and black feathers.
This globally distributed species is known for being abundant and its haunting calls can carry up to a mile in dense forests, making it a unique and easily recognizable sound for those visiting its habitats.
The Long-Eared Owl is a skilled predator known for its camouflaging of brown and black feathers, resembling pine trees, which helps it blend into the thick foliage. This globally abundant species is often recognized by its haunting calls that can be heard up to a mile away in dense forests.
Males of this species establish their territory through distinctive singing and wing-flapping patterns during the breeding season, which usually starts in March. Unlike many other owl species, Long-Eared Owls do not build their own nests, instead, they occupy available hawk nests or tree trunks with cavities.
Like most other owls the Long-Eared Owl’s diet mainly consists of small mammals such as mice, voles, shrews, and rodents, along with other groups of animals such as insects and small birds. They are skilled hunters who can patiently wait for prey to come within range while perching or flying low to search for food on the ground.
The Long-Eared Owl population is decreasing due to habitat destruction and vehicle collisions, but the species is still expanding its range globally. Despite these challenges, the IUCN’s Red List currently classifies the Long-Eared Owl as “Least Concern.”
These owls are known for their exceptional camouflage and haunting calls, which make them a familiar presence in wooded areas.
7. Northern Saw-whet Owl
- Scientific name: Aegolius acadicus
- Life span: 7 to 17 years
- Size: 17 to 22 cm (6.7 to 8.7 in)
- Weight: 54 to 151 g (1.9 to 5.3 oz)
- Wingspan: 42 to 56.3 cm (16.5 to 22.2 in)
- Status: Least Concern
The Northern Saw-Whet Owl is a diminutive owl species commonly found throughout North America, including the state of Colorado, that is known for its elusive nature. The owl has a unique appearance, featuring a circular cream-coloured face patterned with brown streaks, a sharp dark beak, and striking yellow eyes.
The bird’s underbelly is a light white hue adorned with delicate brown markings, while its back and wings are a deep brown colour with bright white spots. The Northern Saw-Whet Owl’s name is thought to have been derived from its distinct call, which sounds a lot like the sound of a saw being sharpened on a whetstone.
The Northern Saw-Whet Owl is a small bird species that form monogamous pairs during the breeding season, which usually starts in March. However, males may mate with multiple females when there is abundant prey available. They typically nest in pre-existing holes such as those made by woodpeckers or in man-made nest boxes.
In Colorado, the Northern Saw-Whet Owl mainly feeds on small mammals such as voles, mice, and shrews, along with insects, birds, and other small creatures. They are skilled hunters and use their sharp talons and beaks to capture prey, even in confined spaces, and can even take down prey larger than themselves.
Although widespread, the Northern Saw-Whet Owl is threatened by habitat loss and competition for nesting sites from other birds and squirrels. They’re also prey for many larger birds due to their small size. Nonetheless, the species is still considered “Least Concern” by the IUCN Red List.
8. Burrowing Owl
- Scientific name: Athene cunicularia
- Life span: 6-8 years
- Size: 8-11 inches (20-28 cm)
- Weight: 5.3-8.5 oz (150-240 g)
- Wingspan: 20-24 inches (51-61 cm)
- Status: Least Concern
The Burrowing Owl is a unique and charismatic species found throughout North and South America. They are often recognized by their long legs and small size and are commonly known to inhabit burrows dug by prairie dogs or other burrowing mammals. These owls are active both night and day, making them an interesting sight for birdwatchers.
One fun fact about the Burrowing Owl is that they often decorate their burrows with manure and animal dung to attract insects, which they then catch and eat.
The Burrowing Owl is a fascinating bird species found in Colorado. These owls have a unique nesting behaviour as they excavate their burrows in the ground or use abandoned burrows of prairie dogs and other rodents. These burrows offer protection to the owls from predators and harsh weather conditions.
Burrowing owls feed on a varied diet that includes insects, small mammals, and reptiles. These birds are known for their piercing yellow eyes, striking white eyebrows, and unique vocalizations that resemble a dog’s bark.
The Burrowing Owl has faced numerous conservation challenges over the years. In Colorado, human development and the destruction of their natural habitat have led to a decline in their population. However, there have been significant conservation efforts to restore their habitats. Conservation organizations have created artificial burrows and nesting sites for these birds, helping to provide them with a safe and suitable environment.
In terms of their conservation history, Burrowing Owls were once classified as a threatened species in Colorado. However, due to significant conservation efforts, their population has stabilized, and they are no longer classified as threatened. Despite this progress, the Burrowing Owl still faces numerous conservation challenges, and their continued survival remains a priority for wildlife advocates. They are classified by the IUCNs Red List as “Least Concern” on a global level.
9. Flammulated Owl
- Scientific name: Psiloscops flammeolus
- Life span: 6-8 years
- Size: 6-7 inches (15-18 cm)
- Weight: 1.1-2.2 oz (31-62 g)
- Wingspan: 14-17 inches (36-43 cm)
- Status: Least Concern
The Flammulated Owl is a small and inconspicuous bird, found in the dense forests of North America. With their reddish-brown feathers and dark eyes, they blend seamlessly into their surroundings, making them difficult to spot, as seen in the picture below.
Their name comes from the Latin word “flammula,” which means “little flame,” a reference to the small flame-like markings on their feathers. Despite their small size and unassuming appearance, Flammulated Owls have a distinctive vocalization, with a series of hoots that sound like a bouncing ball.
During the breeding season, these owls are monogamous and nest in tree cavities, sometimes using old woodpecker holes. The female lays a clutch of 2-4 eggs, which is incubated by both parents for about a month. The young are fed by both parents until they fledge at about four weeks of age.
The Flammulated Owl feeds mainly on insects, including moths, beetles, and grasshoppers, but they have also been known to eat small rodents and birds. They hunt mainly at night and rely on their excellent eyesight and hearing to catch their prey.
Flammulated Owl populations have declined in Colorado due to habitat loss and fragmentation, and they are now considered a species of concern in the state.
Conservation efforts, such as habitat restoration and nest box installation, have been implemented to help protect these unique and valuable birds. However, they’re still perceived as “Least Concern” according to the IUCN red list.
10. Northern Pygmy Owl
- Scientific name: Glaucidium gnoma
- Life span: 7-10 years
- Size: 6-7 inches (15-18 cm)
- Weight: 2.1-2.5 oz (60-70 g)
- Wingspan: 14-16 inches (36-41 cm)
- Status: Least Concern
The Northern Pygmy Owl, a small and charismatic owl, is found throughout North America, from Alaska to Mexico. They have a distinct appearance, with a round head, yellow eyes, and a contrasting dark bill.
The plumage of the Northern Pygmy Owl varies depending on their habitat, ranging from grey to brown and white. These owls are known for their fierce hunting skills and have been observed preying on birds much larger than themselves, including quails and jays.
These owls usually nest in natural cavities or abandoned woodpecker nests, and sometimes in nest boxes. They lay 3-7 eggs and incubate them for about a month. Once hatched, the young owls remain in the nest for about four weeks before fledging.
The Northern Pygmy Owl in Colorado feeds on a variety of prey, including small birds, mammals, and insects. Like the Short-Eared owl, these birds are also keen to hunt during the day and night, giving them an advantage over their prey.
The Northern Pygmy Owl is a threatened species in Colorado due to habitat loss and fragmentation caused by human activities, as well as climate change. Despite conservation efforts, the population of Northern Pygmy Owls in Colorado remains low, and continued efforts are needed to ensure their survival. They are, however, on a global level, seen as “Least Concern” by IUCN.
11. Western Screech Owl
- Scientific name: Megascops kennicottii
- Life span: 6-8 years
- Size: 8-10 inches (20-25 cm)
- Weight: 4.3-8.6 oz (122-244 g)
- Wingspan: 18-24 inches (46-61 cm)
- Status: Least Concern
The Western Screech Owl is a small, stocky owl found throughout the western regions of North America, from Mexico to Canada. With their distinctive ear tufts, piercing yellow eyes, and mottled brown and grey feathers, these owls are a fascinating sight to behold.
Despite being the smallest owl in North America they have a mighty call that can be heard from a distance! A fun fact about Western Screech Owls is that they have a unique call that sounds like a bouncing ball or a muffled whistle.
Western Screech Owls are cavity nesters and they usually nest in natural tree cavities or abandoned woodpecker holes. They are also known to use man-made nest boxes.
Breeding season begins in late winter or early spring, and the female typically lays 2-4 eggs. Both parents take turns incubating the eggs, which hatch after about 30 days. The young owls fledge after around 30-35 days.
Western Screech Owls in Colorado feed on a variety of prey, including insects, small mammals, birds, and reptiles. Their diet also includes spiders and scorpions. They are opportunistic hunters and will eat whatever is available in their habitat.
Western Screech Owls have experienced a decline in population in Colorado due to habitat loss and degradation. The use of pesticides has also had a negative impact on their population. Conservation efforts include the protection and restoration of their habitat and the installation of nest boxes. Western Screech Owls are also protected by state and federal laws.
On a global level they’re not threatened, however, and are on the IUCN red list as “Least Concern”
12. Snowy Owl
- Scientific name: Bubo scandiacus
- Life span: 9-10 years
- Size: 20-28 inches (52-71 cm)
- Weight: 3.5-6.5 lb (1600-2950 g)
- Wingspan: 4.2-4.8 ft (130-150 cm)
- Status: Vulnerable
The Snowy Owl is a majestic and iconic bird of the Arctic tundra, with a striking appearance that includes pure white feathers and piercing yellow eyes. These birds can be found in the northern regions of North America, Europe, and Asia.
Unlike many other owls, Snowy Owls have feathers on their legs and feet, which help them to regulate their body temperature and protect their extremities from the cold. These magnificent creatures are also known for their incredible hearing, which allows them to detect prey even under thick layers of snow.
Snowy Owls nest on the ground, often on tiny mounds deep in the tundra. They will sometimes use natural depressions in the ground, but more commonly they will use the abandoned nests of other birds, such as those of Arctic Terns or other shorebirds. Snowy Owls are monogamous and will often return to the same nesting site year after year.
These majestic birds primarily feast on lemmings, although they have been known to indulge in other prey such as rodents, birds, and fish. They are however opportunistic hunters, and can easily adapt to their environment and take advantage of whatever food source is available.
Sadly, Snowy Owls have been listed as “Vulnerable” by the IUCN due to declining populations in some areas. The primary culprits are habitat loss and climate change, which have caused significant disruptions in their natural habitats. In the past, these beautiful creatures were also hunted for their feathers, which were prized for clothing and other decorative items.
13. Boreal Owl
- Scientific name: Aegolius funereus
- Life span: 8-10 years
- Size: 8-10 inches (22-27 cm)
- Weight: 3.5-7.5 oz (100-210 g)
- Wingspan: 20-24 inches (51-61 cm)
- Status: Least Concern
The Boreal Owl, also known as Tengmalm’s Owl, is a small and mysterious species found in the boreal forests of North America and Eurasia. These nocturnal birds have striking yellow eyes and a round head with a unique facial disk that helps them locate their prey in the dark.
Boreal Owls have an extraordinary sense of hearing, with one ear higher on their head than the other, allowing them to locate prey with incredible accuracy.
Boreal Owls are cavity nesters, which means they rely on tree cavities or nests created by other birds. In Colorado, they have been found nesting in abandoned woodpecker holes, which are usually found in mature forests with a mix of coniferous and deciduous trees.
They typically lay 4-6 eggs and incubate them for around 28 days.
The Boreal Owl’s diet consists mostly of small rodents, such as voles and mice, but they have also been known to prey on shrews, birds, and insects. They hunt by flying low over the ground, listening for sounds made by their prey. Once they locate their prey, they will dive to pierce the unsuspecting prey with its sharp talons.
Boreal Owls are considered a species of concern in Colorado due to habitat loss and fragmentation. Logging, wildfires, and climate change have all contributed to the decline of mature forests, which are crucial for Boreal Owl nesting and foraging.
In Colorado, they are protected under the federal Migratory Bird Treaty Act, which makes it illegal to harm or harass them without a permit. Efforts are being made to protect and restore their habitat in the state, including through forest management practices that prioritize the conservation of old-growth forests. Globally, the Boreal Owl is seen as “Least Concern” by IUCN.
Where to look for Owls in Colorado
Owls can be found in a variety of habitats throughout Colorado, including forests, mountains, prairies, and wetlands. The best time to look for owls is when they are most active at dusk or dawn. Owls are notoriously difficult to spot, so it’s important to be patient and observant when searching for them.
One of the best ways to find owls is by listening for their calls. Each species of owl has a distinct call that can help you identify it. If you hear an owl hooting, use a flashlight to scan the trees and look for their silhouette.
Owls are most active during the breeding season, which is typically from late winter to early spring, so this is a great time to look for them.
Four good areas to find owls in Colorado are:
- Rocky Mountain National Park: This park is home to several species of owls, including the Great Horned Owl and the Northern Pygmy Owl.
- Pawnee National Grassland: This grassland is a great place to look for owls like the Burrowing Owl and the Short-eared Owl.
- San Juan National Forest: This forest is home to the Flammulated Owl and the Northern Saw-whet Owl.
- Chatfield State Park: This park is a good place to look for the Eastern Screech-Owl and the Great Horned Owl.
When searching for owls, it’s important to respect their habitat and not disturb them. If you want to see them up close, you should use binoculars or a camera with a telephoto lens.
With a little patience and perseverance, you may be lucky enough to catch a glimpse of these elusive birds in their natural habitat.
Conclusion
For those who love owls and birdwatching, Colorado is an absolute haven. Its varied terrain, encompassing everything from forests and swamps to grasslands and meadows, is host to a wide array of owl species, each with its own individual quirks and behaviours.
The thrill of hearing or catching a glimpse of an owl while wandering through the woods is an unforgettable experience that further enhances the feeling of being one with nature.
Colorado’s owls come in all shapes and sizes, from the tiny and elusive Northern Saw-Whet Owl to the magnificent and imposing Great Horned Owl. These fascinating birds never fail to impress, with their unique calls and majestic flights.
