Megascops kennicottii
Western screech-owls are a relatively widespread and abundant species in the western regions of North America, found in a range of habitat types from woodlands and suburban parks and gardens with mature tree cover to the arid mesquite landscapes of the Sonoran Desert.
Western Screech-Owl
Immature Western Screech-Owl
Pair of Western Screech-Owls
Western Screech-Owl resting in natural habitat
Among western screech-owl populations in North America, there is considerable variation in plumage color, depending on geographical location.
In the northwest, the predominant coloring is brown or gray-brown, with coastal populations showing a reddish wash. Further south, in the southern desert regions, most western-screech owls are a darker gray.
All variations have pronounced ear tufts, which are visible when in a state of heightened alert. A darker ring surrounds the facial disc, which is paler in comparison to the streaky facial markings of the head and throat.
Their upperparts, either mainly brown or dark gray, are patterned with intricate mottling and lighter and darker streaks, which help them to remain hidden out of sight in their forest habitats. Their underparts are similarly marked, with bold darker vertical streaks across their wings, belly, and flanks.
Western screech-owls have pale yellow eyes and a sharp, curved bill which is black in more southern populations and a lighter shade of gray in northern birds. Legs and feet are bristled with short gray feathers.
Females share the same coloring and patterning as males but are usually noticeably larger in size and weight.
In juvenile western screech-owls, streaks on the belly are horizontal rather than vertical and some feathers are tipped with white. Young birds have lighter bills than adults, but otherwise, the coloring is very similar.
Western Screech-Owl in woodland
A relatively small owl species, the western screech-owl is the same size as its eastern counterpart, the eastern screech owl. Females are larger and heavier than males, and this difference between the sexes is clearly visible when a pair is seen side by side.
Western Screech-Owl with pronounced ear tufts
Despite its name, a western screech-owl doesn’t actually screech, instead making a series of accelerating hoots with an intensifying pace. A loud bark-like call signals distress or alarm, while pairs use a contact call consisting of a short trilled note, followed by a longer trill.
Western Screech-Owl hooting
While they are mainly an insectivorous species, a western screech-owl will feed on anything available, preying on small mammals, including mice, voles, and shrews, as well as small reptiles, birds, and amphibians. Scorpions, earthworms, and spiders are also caught. Insect prey includes crickets, grasshoppers, and caterpillars.
Western screech-owls rely on both sight and sound to hunt, catching prey after swooping from branch perches in trees.
A mix of prey is brought to the nest by the male western screech-owl after their eggs hatch. The prey is delivered to the female who then feeds items to their young. This includes invertebrates (beetles, moths, crickets, and caterpillars), with small mammals introduced several days later, in particular voles and small mice. Birds may also be brought to the nest, particularly fledglings or injured birds which are easier for the adult western screech-owl to capture.
Western Screech-Owl perched in a tree looking for prey
Woodlands and forests are a popular choice of habitat for western screech-owls, with mixed species woodland preferred for the variety of cover, prey, and nesting choices they offer.
Riversides and lakeshore areas with well-established patches of vegetation are also used, as are rocky canyons and caves, with a wealth of nesting possibilities. Wooded canyon bottoms, expanses of desert mesquite, and farmland groves all provide suitable habitats.
Western screech-owls are present from the south coast of Alaska, small regions of southwestern Canada, southwards through the western United States, and throughout western Mexico.
Western screech owls are found across the western United States with established breeding populations present in Washington, Oregon, California, Idaho, Montana, Wyoming, Utah, Colorado, Nevada, New Mexico, and parts of western Texas.
Populations are particularly concentrated across Arizona’s mesquite landscapes. Canada and Mexico also have resident breeding populations and breeding has also occurred in Guatemala, Belize, and Honduras.
The population of western screech-owls in the United States and Mexico is estimated to be around 220,000 individuals. Their nocturnal habits make them more challenging to spot, although some daytime hunting may occur during the nesting period.
Western Screech-Owl peeking out from behind a tree trunk
Redwood State and National Parks in California and Big Bend National Park in Texas offer opportunities for catching sight of western screech-owls in their preferred natural habitats of riverside woodlands.
The range of western screech owls is located mainly south of Canada’s border with the United States, although an estimated 350 to 500 adults are estimated to live in Canada, in southwestern British Columbia, and occasional sightings are recorded in Alberta and Saskatchewan.
Pacific Rim National Park Reserve in British Columbia is as good a location as any to watch out for the species.
Western Screech-Owl sitting in a tree in parkland
The average lifespan of western screech owls in the wild, obtained from banding records, is fairly low: around 1.83 years for males and 1.73 years for females. The longest-living wild western screech-owl lived to the age of 13, while a captive pair reached 19 years. Breeding is thought to occur for the first time at one year old.
Being a relatively small species, western screech-owls are a common target for much larger owls, including great-horned, spotted, and barred owls. Raccoons, skunks, squirrels, crows, and weasels may raid nests for eggs and young, and occasionally gopher snakes have been observed to take a nesting female.
Legislation in the United States (the Migratory Bird Treaty Act) and in Canada (the Migratory Birds Convention Act) protects northern screech-owls against being killed, injured, taken into captivity, or traded for sale. Their eggs, young, and nest sites are also protected.
Some slight declines in the global breeding population are evident, due to habitat loss and land use change, but there are no immediate concerns for their long-term future. Western screech-owls are classified as a species of least concern.
However, locally, on the British Columbia coast, a more worrying fall in numbers has been observed, with a year-on-year decline of 32 percent, thought to be caused by increased predation by barred owls and habitat loss meaning fewer available nest cavities.
Western Screech-Owl perched in a tree
Cavities excavated by northern flickers, gilded flickers, and pileated woodpeckers provide suitable nest sites for western screech-owls.
Natural chambers are also readily used, including hollows that have formed at the site of broken branches or rotting deadwood. Cottonwood and maple are frequently chosen, and in southern Arizona, reusing the nests of flickers in saguaros is common. Nest boxes are also readily used throughout their range.
The breeding season begins early in the year, with pairs forming between January and February, and courtship feeding, a precursor to copulation and egg-laying, is observed between March and April.
Eggs are incubated for between 26 and 34 days, with the female taking sole charge of incubation. Males remain nearby, roosting a short distance from the cavity opening.
Between 2 and 7 smooth white eggs are laid by western screech-owls in a typical clutch. Eggs measure on average 4.2 cm by 3.6 cm (1.6 in by 1.4 in).
It is thought that western screech-owls are monogamous, and form long-lasting pairs once they reach breeding age. Gray and red-brown variations mate with each other. Pairs raise one brood together each season and will look for a replacement mate if a previous one dies.
Western Screech-Owl sitting in nest cavity
Aggressive behavior is frequently shown when defending the nest site, even against much larger threats, including humans. Hissing, swiping and flapping are used as a means of driving off any intruders.
Western screech-owls are nocturnal and find suitable roosting spots in trees to sleep during the day. In the winter and spring, conifers are preferred, with deciduous trees becoming more popular later in the year once leaf cover develops. Spots are usually located close to the trunk, as their plumage offers perfect camouflage against the bark.
Western Screech-Owl sitting on a branch
Western screech-owls are a resident species in the westernmost regions of North America and do not migrate, remaining in the same territories all year round.
Western screech-owls are resident in the westernmost regions of the US all year round, raising their young and wintering in the same territories. The related species, the eastern screech owl, is found to the east, and there is little overlap between the two species.
Western Screech-Owl watching out of a nest cavity
Western screech owls are generally a mottled mixture of dark gray, brown, and white. Coloring varies across their range, with northwestern birds having a reddish wash, while the plumage of those further inland and to the south features more gray tones. They have bright yellow eyes.
Although a strictly nocturnal species, during the breeding season western screech-owls (particularly males) will head out to hunt during daylight if the feeding demands of hungry young owlets mean they may need to seek additional prey during the day.
Western screech owls do eat squirrels although they are not among their primary prey. Normally they hunt smaller mammals, including voles, shrews and mice. However, if the opportunity arises to catch a squirrel, then may well give it their best shot.
Tall trees with existing cavities for nesting offer western screech-owls a ready-made nesting spot. Mounting artificial nest boxes and adding wood chips as a lining may also tempt them to set up a home in your yard.
The best way to attract owls is to provide their natural habitat, with access to fresh water, tree cover, and the opportunity to catch prey, including plants that will encourage different insect species.
Length:
20cm to 25cm
Wingspan:
50cm to 60cm
Weight:
100g to 305g
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