AMERICAN CROW

AMERICAN CROW  Corvus brachyrhynchosCorvus brachyrhynchos

The “caw, caw” of the American Crow is a familiar sound in eastern Texas and the eastern Panhandle, and is the standard for describing the calls of the 4 other members of its genus found in this state. This crow is curious and inquisitive, an omnivorous and opportunistic feeder, and engages in cooperative breeding. The oldest reported wild crow was nearly 15 years of are, but this age may reflect the difficulty of catching corvids more than the actual maximum age (Verbeek and Caffrey 2002).

DISTRIBUTION. During the 1987-1992 field work of the TBBA project, volunteers found confirmed breeding evidence for the American Crow in the Pineywoods, Coastal Prairies, Post Oak Savannah and Blackland Prairies and much of the Rolling Plains regions (see map in Lockwood and Freeman (2004). South of the 32nd parallel and west of the 99th meridian, breeding is essentially absent but breeding occurs throughout the Panhandle.

American Crows breed in at least some parts of all the 48 contiguous United States, southern Canada and northern North American Baja California, Mexico, although densities are lower on the western Great Plains and in the intermountain west and the southwestern deserts (Verbeek and Caffrey 2002, Sauer et al. 2005).

SEASONAL OCCURRENCE. American Crows are permanent residents in Texas in the areas described above. where they breed from early February to June. Eggs have been collected from February 23 to May 15 and young have been found in the nest as late as June 5. In winter the population density and range within this state are increased by the arrival of migrants from the northern parts of the breeding range (Oberholser 1974, Lockwood and Freeman 2004).

In Colorado the breeding season of this species extends at least from March 8 (nest-building) to August 4 (feeding young) based on dates from that state’s Breeding Bird Atlas (Winternitz 1998).

BREEDING HABITAT. In Texas American Crows breed from near sea level to 750 m (2500 ft) in open pine or oak woodlands, cities, towns, farm shelter-belts and other human-altered habitats. In the Panhandle they nest in cottonwoods along streams (Oberholser 1974, Verbeek and Caffrey 2002). In Colorado where nesting habitats have been quantified, breeding occurred in a variety of habitat types, most of which could be classified as rural, urban and coniferous and deciduous woodlands (Winternitz 1998).

The nest is often placed on a horizontal limb of a tree or shrub or on a utility pole crossbar 3-21 m (10-70 ft), usually over 7.5 m (25 ft), above ground. The large, substantial basket of sticks, twigs, bark, vines and some mud is lined with shredded bark fiber, moss, grass, feathers, hair, roots and leaves. Both sexes build the nest in about 12 days. The outside diameter is 56×66 cm (22×26 in), height 23 cm ( 9 in), inside diameter 15×18 cm (6×7 in), and cup depth of 11 cm (4.5 in).

The female commonly lays 5-6 (range 4-7) bluish or grayish green eggs (see Harrison [1979] for photo of markings). These eggs may vary in shape, size, color and markings and are indistinguishable except for the large size from those of Fish Crow (Corvus ossifragus). The female incubates the eggs for 16-18 days.The young may be attended by as many as 9 adults. The nestlings leave the nest after a period averaging 30-38 days after hatching. Crows raise only one clutch per year (Harrison 1979, Verbeek and Caffrey 2002).

STATUS. The TBBA map generally agrees with the breeding locations on Oberholser’s (1974) map. In the Panhandle, the earlier map shows no breeding records and only a few summer records.This contrasts with the TBBA map which shows a number of confirmed breeding records in the eastern Panhandle, decreasing in density from east to west. The TBBA map matches the Breeding Bird Survey (BBS) map of relative abundance which shows 10-30 crows detected per 40 km (25 mi) route in the eastern Panhandle, decreasing to <1 per route in the west (Sauer et al. 2005). Lockwood and Freeman ( 2004) describe the American Crow as a common to abundant resident of the eastern half of Texas west to the central Panhandle. This is consistent with the TBBA and BBS maps.

Trend data from 111 BBS routes in Texas indicate the population of American Crows in this state has increased by an average of 2.2% per year from 1966-2004, considerably larger than the 0.9% annual increase for the total range of the species (Sauer et al. 2005). This adaptable species is apparently a permanent feature of the Texas avifauna.

Text by Robert C. Tweit (2006)

Texas Breeding Bird Atlas map

Literature cited.

Harrison, H. H. 1979. A field guide to western birds’ nests. Houghton Mifflin, Boston, MA.

Lockwood, M. W. and B. Freeman. 2004. The TOS handbook of Texas birds. Texas A&M University Press, College Station.

Oberholser, H. C. 1974. The bird life of Texas. University of Texas Press, Austin.

Sauer, J. R., J. E. Hines, and J. Fallon. 2005. The North American Breeding Bird Survey, results and analysis 1966-2004. Version 2005.1. USGS Patuxent Wildlife Research Center, Laurel MD (Web site, http://www.mbr-pwrc.usgs.gov/bbs).

Verbeek, N. A. M. and C. Caffrey. 2002. American Crow (Corvus brachyrhynchos). In The birds of North America, No. 647 (A. Poole and F. Gill, eds.). The Birds of North America, Inc., Philadelphia, PA.

Winternitz, B. L. 1998. American Crow (Corvus brachyrhynchos). In Colorado breeding bird atlas, pp. 326-3275 (H. E. Kingery, ed.), Colorado Bird Atlas Partnership, Denver.

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