Northwestern Crow (Corvus caurinus)

Northwestern Crow

[order] PASSERIFORMES | [family] Corvidae | [latin] Corvus caurinus | [UK] Northwestern Crow | [FR] Corneille d’Alaska | [DE] Sundkrahe | [ES] Cuervo de Alaska | [NL] Bairds Kraai

Subspecies

Monotypic species

Physical charateristics

This small beachcombing crow of the Northwest is smaller than the American Crow and has a quicker wingbeat. It replaces the American Crow on the narrow northwestern coast strip. There is apparently some integration with the American Crow in the Puget Soun
d area, hence some believe they may be conspecific.

Listen to the sound of Northwestern Crow

[audio:http://www.aviflevoland.nl/sounddb/N/Northwestern Crow.mp3]

Copyright remark: Most sounds derived from xeno-canto

wingspan min.: 75 cm wingspan max.: 79 cm
size min.: 38 cm size max.: 43 cm
incubation min.: 17 days incubation max.: 20 days
fledging min.: 29 days fledging max.: 35 days
broods: 1   eggs min.: 3  
      eggs max.: 6  

Range

North America : Northwest

Habitat

Near tidewater, shores. Generally found close to the immediate coastline. Often along open beaches, roc
ky shores, tidal estuaries, coastal ponds, inshore islands. Also forages in woods and fields close to shore. Only occasionally moves to fields several miles inland.

Reproduction

Usually solitary in nesting, not in colonies. Offspring from previous year may remain on nesting territory of adult pair; these “helpers” assist in mobbing predators, may or may not assist with feeding the nestlings.
Nest: Site is usually in fork of tree or shrub; sometimes placed on the ground (sheltered by rocks) on islands
. Nest (built by both sexes) is a bulky platform of sticks, bark, plant fibers, and mud, lined with softer material such as grass, animal fur, and rootlets.
Eggs: 4-5. Dull blue-green to gray-green, blotched with brown and gray. Incubation is by female only, about 18 days.
Young: Fed by both parents, and sometimes by one-year-old “helpers.” Age when young leave the nest not well known, probably close to 4 weeks.

Feeding habits

Omnivorous.
Seems to feed on anything it can find in its habitat, including fish, crabs, shellfish, carrion, garbage, various insects, berries, nuts, seeds, and birds’ eggs (especially in seabird colonies).
Behavior: Forages mostly while walking on ground or in very shallow water; also sometimes forages in trees. May concentrate
at salmon runs along with other birds. Flies up into the air carrying mussels, and drops them on rocks to break them open. May store food on territory and retrieve it later.

Conservation

This species has a very large range, and hence does not approach the thresholds for Vulnerable under the range size criterion (Extent of Occurrence <20,000 km2 combined with a declining or fluctuating range size, habitat extent/quality, or population size and a small number of locations or severe fragmentation). The population trend appears to be increasing, and hence the species does not approach the thresholds for Vulnerable under the population trend criterion (>30% decline over ten years or three generations). The population size is extremely large, and hence does not approach the thresholds for Vulnerable under the population size criterion (<10,000 mature individuals with a continuing decline estimated to be >10% in ten years or three generations, or with a specified population structure). For these reasons the species is evaluated as Least Concern.
Northwestern Crow status Least Concern

Migration

Northwest coast. Migration:
Permanent resident. Smaller crows sometimes seen along Oregon coast in winter may or may not be this form.

Distribution map

Northwestern Crow distribution range map

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