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Difference between revisions of "Spotted Owl" - BirdForum Opus

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[[Image:Spotted_Owl.jpg|thumb|550px|right|''Strix occidentalis caurina''<br />Photo by {{user|blubird|blubird}}<br />Near Olema, Marin County, [[California]], March 2003]]
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;Strix occidentalis
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;[[:Category:Strix|Strix]] occidentalis
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[[Image:Spotted_Owl.jpg|thumb|550px|right|Photo by blubird]]
 
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==Identification==
 
==Identification==
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43cm.  Cross-shaped markings on the underparts.  Head and upper parts brown irregularly spotted with white. Under parts buff with brown and white ovals or barring.  Large rounded facial disc that is pale brown with indistinct concentric rings of darker brown encircling the eyes. The facial rim or border is dark brown; lacks ear tufts; the bill is yellowish-green to straw coloured; iris dark brown; claws blackish-brown; feet feathered.  
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Length 40–48 cm (16-19 in), wingspan 100-110 cm, weight (male) 520-700 g, (female) 550-760 g
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*Cross-shaped markings on underparts
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*Head and upper parts brown irregularly spotted with white
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*Under parts buff with brown and white ovals or barring
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*Large rounded facial disc
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:*Pale brown: indistinct concentric rings of darker brown encircling the eyes
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:*Dark brown facial rim or border
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*No ear tufts
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*Yellowish-green to straw coloured bill
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*Dark brown iris
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*Blackish-brown claws
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*Feathered feet
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====Similar species====
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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==
 
==Distribution==
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Western [[North America]].
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Western [[North America|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).
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==Taxonomy==
 
==Taxonomy==
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''S.o. caurina'' is the northern most race. It ranges along the West Coast from SW British Columbia to San Francisco in the coastal ranges.
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====Subspecies====
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''S.o. occidentalis'' is found both along the west slope of the Sierras in California and in the coastal ranges from San Francisco to San Diego.
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[[Image:Owl-Mexican-Spotted-AZ-Miller-DSCN1523 copy 2.jpg|thumb|350px|right|Juveniles, subspecies ''S. o. lucida''<br />Photo by {{user|Brian+Hubbs|Brian Hubbs}}<br />Southeast [[Arizona]], July 2016]]
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''S.o. lucida'' ranges from S. Utah south through Arizona, New Mexico, and W. Texas down into Central Mexico.  
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There are 3 or 4 subspecies<sup>[[#References|[1]]]</sup><sup>[[#References|[2]]]</sup>
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*''S. o. caurina'': '''Northern Spotted Owl''':
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:*Temperate rainforests from southwestern [[British Columbia]] to northern [[California]] (to Marin County)
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*''S. o. occidentalis'': '''California Spotted Owl''':
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:*West side of the Sierra Nevada in [[California]], and from Monterey County south to San Diego County; formerly also northern Baja California (Sierra San Pedro Mártir, now extirpated)
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*''S. o. lucida'': '''Mexican Spotted Owl''':
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:*Mountains of southwestern [[US]] to central [[Mexico]] (Michoacán and Guanajuato)
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*''S. o. juanaphillipsae'': '''Southern Mexican Spotted Owl''':
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:*Mountains of south-central Mexico (treated as distinct by IOC<sup>[[#References|[2]]]</sup>; included in ''S. o. lucida'' by other authorities)
  
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The last 1(-2) subspecies may be better treated as a separate species ''S. lucida''<sup>[[#References|[3]]]</sup>, though this has not yet been done by any of the standard lists.
 
==Habitat==
 
==Habitat==
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Forests.
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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<sup>[[#References|[3]]]</sup>. A further problem is hybridisation between the two species<sup>[[#References|[3]]]</sup>.
 
==Behaviour==
 
==Behaviour==
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It nests in tree holes, old bird of prey nests, or rock crevices.  2 white smooth eggs are laid and are incubated by the female for 28-32 days, who also cares for the young.  The male brings food.
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====Breeding====
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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.
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It is strictly nocturnal and the diet includes small mammals and birds, flying squirrels, wood rats, hares, and/or rabbits, mice and moles.
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====Diet====
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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.)<sup>[[#References|[3]]]</sup>.
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==References==
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#{{Ref-Clements6thOct22}}#{{Ref-GillDonskerRasmussen22V12.2}}#König, C., Weick, F., & Becking, J-H. (2008). ''Owls of the World''. Helm.
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#Avibase
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#owling.com
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#Birdforum Member observations
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{{ref}}
 
==External Links==
 
==External Links==
 
{{GSearch|Strix+occidentalis}}
 
{{GSearch|Strix+occidentalis}}
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[[Category:Birds]][[Category:Strix]]
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[[Category:Birds]]
 

Latest revision as of 02:34, 29 January 2023

Strix occidentalis caurina
Photo by blubird
Near Olema, Marin County, California, March 2003
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

Juveniles, subspecies S. o. lucida
Photo by Brian Hubbs
Southeast Arizona, July 2016

There are 3 or 4 subspecies[1][2]

  • S. o. caurina: Northern Spotted Owl:
  • S. o. occidentalis: California Spotted Owl:
  • West side of the Sierra Nevada in California, and from Monterey County south to San Diego County; formerly also northern Baja California (Sierra San Pedro Mártir, now extirpated)
  • S. o. lucida: Mexican Spotted Owl:
  • Mountains of southwestern US to central Mexico (Michoacán and Guanajuato)
  • 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

  1. Clements, J. F., T. S. Schulenberg, M. J. Iliff, T. A. Fredericks, J. A. Gerbracht, D. Lepage, S. M. Billerman, B. L. Sullivan, and C. L. Wood. 2022. The eBird/Clements checklist of Birds of the World: v2022. Downloaded from https://www.birds.cornell.edu/clementschecklist/download/
  2. Gill, F, D Donsker, and P Rasmussen (Eds). 2022. IOC World Bird List (v 12.2) DRAFT. Doi 10.14344/IOC.ML.12.2. http://www.worldbirdnames.org/
  3. König, C., Weick, F., & Becking, J-H. (2008). Owls of the World. Helm.
  4. Avibase
  5. owling.com
  6. Birdforum Member observations

Recommended Citation

External Links

Retrieved from ‘https://www.birdforum.net/wiki/index.php?title=Spotted_Owl&oldid=262459’
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