- Strix occidentalis
Identification
Length 40–48 cm (16-19 in), wingspan 100-110 cm, weight (male) 520-700 g, (female) 550-760 g
- Cross-shaped markings on underparts
- Head and upper parts brown irregularly spotted with white
- Under parts buff with brown and white ovals or barring
- Large rounded facial disc
- Pale brown: indistinct concentric rings of darker brown encircling the eyes
- Dark brown facial rim or border
- No ear tufts
- Yellowish-green to straw coloured bill
- Dark brown iris
- Blackish-brown claws
- Feathered feet
Similar species
The closely related Barred Owl is slightly larger, with barred upper breast and streaked lower breast, rather than spotted, and with a more orangey-yellow bill.
Distribution
Western North and Central America: found in Canada (southwestern British Columbia), the USA (Arizona, California, Colorado, New Mexico, Oregon, Texas, Utah, Washington), and Mexico (mountain forests in the Sierra Madre Occidental and Sierra Madre Oriental).
Taxonomy
Subspecies
There are 3 or 4 subspecies[1][2]
- S. o. caurina: Northern Spotted Owl:
- Temperate rainforests from southwestern British Columbia to northern California
- S. o. occidentalis: California Spotted Owl:
- Mountains of southern California to northern Baja (San Pedro Mártir)
- S. o. lucida: Mexican Spotted Owl:
- S. o. juanaphillipsae: Southern Mexican Spotted Owl:
- Mountains of south-central Mexico (treated as distinct by IOC[2]; included in S. o. lucida by other authorities)
The last 1(-2) subspecies may be better treated as a separate species S. lucida[3], though this has not yet been done by any of the standard lists.
Habitat
Mixed forests of Redwood, Spruce, Douglas-fir, Oak, etc. Wooded mountain canyons. The two northwestern subspecies are restricted to extensive old-growth forests, and are now endangered as a result of forest clearance allowing the larger and more aggressive Barred Owl (which is more tolerant of disturbed habitats) to colonise and displace them from much of their range[3]. A further problem is hybridisation between the two species[3].
Behaviour
Breeding
They nest in tree holes, old bird of prey nests, or rock crevices. The 2 white smooth eggs are incubated by the female for 28-32 days, who also cares for the young. The male brings food.
Diet
They are strictly nocturnal and the diet consists of small mammals and birds, flying squirrels, wood rats, hares, rabbits, mice and voles. The northwestern subspecies catch most of their prey in trees, taking relatively little ground-dwelling prey; the southeastern subspecies takes much more ground-dwelling prey, particularly woodrats (Neotoma spp.)[3].
References
- Clements, J. F., T. S. Schulenberg, M. J. Iliff, D. Roberson, T. A. Fredericks, B. L. Sullivan, and C. L. Wood. 2016. The eBird/Clements checklist of birds of the world: v2016, with updates to August 2016. Downloaded from http://www.birds.cornell.edu/clementschecklist/download/
- Gill, F and D Donsker (Eds). 2016. IOC World Bird Names (version 6.3). Available at http://www.worldbirdnames.org/.
- König, C., Weick, F., & Becking, J-H. (2008). Owls of the World. Helm.
- Avibase
- owling.com
- BF Member observations
Recommended Citation
- BirdForum Opus contributors. (2021) Spotted Owl. In: BirdForum, the forum for wild birds and birding. Retrieved 29 April 2021 from https://www.birdforum.net/wiki/Spotted_Owl
