Order
Passeriformes
Family
Corvidae
Genus
Corvus
 
Neotropical Birds logo
Version 1.0

This is a historic version of this account.  Current version

SPECIES

Sinaloa Crow Corvus sinaloae

Claudia I. Rodríguez-Flores, Carlos A. Soberanes-González, Marîa del Coro Arizmendi, Guy M. Kirwan, and Thomas S. Schulenberg
Version: 1.0 — Published November 15, 2013

Appearance

Distinguishing Characteristics

Crows (Corvus) are large, black passerines with stout tarsi and strong bills; they also have bristle-like feathers that cover the nares. Sinaloa Crow is a small Corvus. The plumage is entirely glossy black; the head and upperparts have a purplish sheen, whereas the underparts are glossed with bluish to bluish purple. The sexes are similar; the juvenile is undescribed, but presumably is duller and sootier.

Similar Species

Sinaloa Crow is very similar to Tamaulipas Crow (Corvus imparatus) of northeastern Mexico, but these two species are completely allopatric. Sinaloa and Tamaulipas crows also have different vocalizations, and the tail of Sinaloa Crow averages slightly longer (especially in males). Chihuahuan Raven (Corvus cryptoleucus) is much larger than Sinaloa Crow, with a much heavier bill, a longer wedge shaped tail, and different vocalizations. The greater identification challenge is separating Sinaloa Crow from males of Great-tailed Grackle (Quiscalus mexicanus), which are similar in overall length to the crow but are more slender with a longer, graduated, "keeled" tail, and pale irides.

Detailed Description

The following description of the adult is based on Ridgway (1904); Ridgway's description encompasses both Sinaloa Crow and Tamaulipas Crow (Corvus imparatus), but no plumages differences are known between these two species:

Adult: Black, glossed purplish on the upperparts and bluish on the underparts. Crown, nape, wing coverts and secondaries glossy dark violet. Sides of neck, the back, scapulars, rump, uppertail coverts, and primary coverts glossy dark violet blue. Primaries and rectrices dark steel blue, the central rectrices tinged with violet, and the outermost primaries more greenish blue. Sides of head and the underparts dark steel blue or greenish steel blue, becoming more greenish posteriorly.

Juvenile: Apparently undescribed specifically for Sinaloa Crow (Howell and Webb 1995), but presumably is similar to the juvenile of Tamaulipas Crow (Corvus imparatus), which is duller than the adult. The juvenile of Tamaulipas Crow is described by Goodwin (1976) as "duller and less lustrous but with more iridescence than is usual in juvenile crows"; Marzluff (2009), however, describes the juvenile as "duller than adult, with limited sheen".

Molts

Apparently undescribed, but presumably are similar to those of other North American crows and ravens. If so, then Sinaloa Crow follows the Complex Basic molt strategy. There is a preformative molt, which is partial; the outer coverts and the rectrices are retained. Subsequent prebasic molts are complete, and there is no prealternate molt (see Pyle 1997).

Bare Parts

Iris: brown, dark brown

Bill: black

Tarsi and toes: black

Measurements

Total length: 35.5-38 mm (Howell and Webb 1995)

Linear measurements (from Johnston 1961):

male

wing length (chord): mean 253.5 mm SD 7.35 mm, range 242.0-267.0 mm, n = 24

tail length: mean 155.0 mm SD 5.60 mm, range 147.0-164.0 mm, n = 25

bill length (from anterior edge of nostril): mean 29.97 mm SD 1.19 mm, range 27.4-32.5 mm, n = 25

tarsus length: mean 40.37 mm SD 1.72 mm, range 35.9-43.8 mm, n = 25

female

wing length (chord): mean 238.3 mm SD 7.26 mm, range 229.5-262.5 mm, n = 23

tail length: mean 144.0 mm SD 4.62 mm, range 133.5-150.0 mm, n = 22

bill length (from anterior edge of nostril): mean 28.07 mm SD 1.28 mm, range 25.8-31.8 mm, n = 22

tarsus length: mean 40.0 mm, range 37.5-42.3 mm, n = 7

Mass: mean 244 g (range 229-258 g, n = 2, sexes undetermined; Dunning 2008)

Recommended Citation

Rodríguez-Flores, C. I., C. A. Soberanes-González, M. d. C. Arizmendi, G. M. Kirwan, and T. S. Schulenberg (2013). Sinaloa Crow (Corvus sinaloae), version 1.0. In Neotropical Birds Online (T. S. Schulenberg, Editor). Cornell Lab of Ornithology, Ithaca, NY, USA. https://doi.org/10.2173/nb.sincro1.01