Western Screech
Owl
(Megascops
kennicottii)
Common names include Kennicott's Owl,
Little Horned Owl, Dusk Owl, Ghost Owl, Mouse Owl, Cat Owl, Little
Cat Owl, Puget Sound Screech Owl, Washington Screech Owl, and
Coastal Screech Owl.
Description: The Western Screech Owl is a small,
nocturnal, woodland Owl of western North America and is one of the
west's more common Owls at lower elevations. They are squat-looking
Owls that sit erect, with their plumage fluffed out, with the feet
and legs obscured, and distinct ear tufts raised. The iris is
bright yellow and the bill is gray to black, with tufts of bristly
feathers around its base. The facial disk is bordered by black. The
toes are yellow. Plumage is either mainly grayish or reddish-brown
variegated dark and light, resembling a furrowed tree bark pattern.
They use the variegated plumage as camouflage. When threatened, the
bird stretches its body and tightens its feathers in order to look
like a branch stub to avoid detection, but will take flight when it
knows it has been detected. They have noticeable light spotting
along the edge of the scapulars. There is much individual variation
within the two colour morphs. In the gray-phase, birds in the dry
southwest are a paler gray, while birds in the humid northwest are
darker and browner. The red-phase is very rare and found only in
the Pacific Northwest.
Adult (gray phase) - Facial disks are dusky white with fine
gray-brown mottling. Overall gray-brown, with gray-brown narrow
vertical stripes, bars, and spots on the underparts, and barred
wings and tail. The legs have fine buff mottling. Adult (red phase)
- Similar pattern to gray phase except dull cinnamon instead of
gray. The face is buff light cinnamon. There is rufous spotting on
the breast with black anchor marks.
The juvenile of both colour phases is similar to the adults, but
the indistinct stripes and bars are more patterned, with many
feathers tipped with white.
The Western Screech Owl is likely to be confused with the
Eastern Screech Owl and Whiskered Screech Owl. These Owls can be
distinguished by bill colour (Eastern Screech Owls have gray-green
bills while Western Screech Owls have gray to black bills) and
their different calls. Western and Eastern Screech Owls only occur
together locally in eastern Colorado and southern Texas. Western
and Whiskered Screech Owls only occur together in southern Arizona
and Mexico.
During direct flight, the Western Screech Owl flies fairly
rapidly with a steady wing beat of about 5 strokes/second. It
rarely glides or hovers, but may fly bat-like with erratic
movements, when manoeuvring through wooded areas. Wings are broad
and the head is held tucked in giving a flying bird a stubby
appearance.
Size: Female average Length: 23cm (9.2") Wingspan 56cm
(22") Male average Length: 21cm (8.2") Wingspan 54cm (21") Weights
of different subspecies vary widely. In general, weights decrease
from north to south, from an average of 186g (6.5oz) for females
and 152g (5.3oz) for males in a northern population to 123g (4.3oz)
for females and 111g (3.9oz) for males in a southern
population.
Habits: Nocturnal, with activity generally begining 20-30
minutes after sunset. Flight is noisless with soft wingbeats and
gliding. Will become motionless if disturbed at roost, and can
sometimes be cought by hand in this state. This owl is very
aggressive when defending a nest site, and may attack humans.
Voice: The male's most common call is a mellow, muted
trill "hoo-hoo-hoo....", or bouncing ball song, that speeds up at
the end, but maintains a constant pitch. It is given by the male
during the mating and nesting seasons, but also during the autumn
and winter. This call is primarily territorial in nature. A
secondary song is a double trill of rapid bursts. Other calls are a
soft "cr-r-oo-oo-oo-oo" given as a greeting call, and a sharp bark
given when excited.
Mortality: Western Screech Owls can fall prey to Northern
Goshawks, Cooper's Hawks, Great Horned Owls, Barred Owls, Spotted
Owls, Long-eared Owls, Great gray Owls, Short-eared Owls, mink,
weasels, raccoons, skunks, squirrels, snakes, and crows.
Cannibalism by other Screech Owls also occurs.
Western Screech Owls are dependent on deciduous woodlands or open
mixed forests that have suitable nesting sites and sufficient prey
densities. Removal of riparian forest in drier regions will cause
population declines because most densities are highest in riparian
zones. However, this adaptable Owl can survive in wooded suburban
areas and city parks as long as long as they are not directly
persecuted. Populations likely fluctuate more depending on prey
availability. Nest box programs can enhance local populations,
especially in areas short of suitable tree cavities. Silviculture
practices that include removal of dead and dying trees can
eliminate this bird as a breeding species from local areas.
Habitat: Western Screech Owls inhabit a wide variety of
habitats. On the northwest coast, they inhabits humid Douglas-fir,
western hemlock, western red cedar, and Sitka spruce forests along
the edges of clearings, rivers, and lakes. Further inland they
occupy a narrow ecological niche of lowland deciduous forests,
especially riparian woodlands along river bottoms. Southern
populations inhabit lowland riparian forests, oak-filled arroyos,
desert saguaro and cardon cacti stands, Joshua tree and mesquite
groves, and open pine and pinyon-juniper forests. They avoid dense
forests because Great Horned Owls use that habitat, and high
elevation forests. In general, they require open forests, with an
abundance of small mammals and insect prey, and cavities for
nesting. They roost mainly in natural or woodpecker cavities in
large trees, but also in dense foliage of deciduous trees, usually
on a branch next to the trunk, or in dense conifers.
Distribution: Resident from south-coastal and extreme
southeastern Alaska, coastal (excluding Queen Charlotte Islands)
and southern British Columbia, northern Idaho, western Montana,
northwestern Wyoming, Colorado, extreme western Oklahoma, and
western Texas south to Baja California.
Western Screech Owls also occurs northern Sinaloa and across the
Mexican highlands through Chihuahua and Coahuila as far as the
Distrito Federal.
