Birds from Coahuila, Mexico

by Emil K. Urban

The subspecies potosinus has been recorded from several localities in Coahuila. Davis (1951:70) listed the following localities in the State from which P. f. potosinus has been collected: Muralla, San Lázaro Mountains, 50 mi. S Monclova, 2850 ft., Saltillo; Saltillo (Chorro de Agua); 19 mi. W Saltillo; Cresta Blanca, 12 mi. W Saltillo, 5500 ft.; Diamante Pass, 11 mi. S Saltillo, 6000-8000 ft.; and Carneros. Miller, Friedmann, Griscom, and Moore (1957:358) recorded a "small juvenile" from El Diamante on July 5. Sutton and Burleigh (1939a:45) recorded P. f. texanus from Diamante Pass on March 6. I suspect that Davis (op. cit.) reidentified the specimen concerned from Diamante Pass as P. f. potosinus. Burleigh and Lowery (1942:207) indicated that P. f. potosinus "was fairly common and of general distribution in the area, occurring both on the arid plateau about Saltillo and on the mountain sides up to an elevation of about 8,000 feet." Nos. 32155, 31676, and 29560 are typical for P. f. potosinus. The size of the testes (14×7 mm.) of No. 32155 suggests breeding by the Brown Towhee in southeastern Coahuila.

*Pipilo fuscus texanus van Rossem.—Specimen examined: one, ♀ 31103, from 10 mi. S, 5 mi. E Boquillas, 1500 ft., March 5, 1952, weight, 46.9 gms.

This subspecies of the Brown Towhee occurs in northwestern Coahuila south through the Sierra del Carmen. Miller (1955a:176) reported that his series of Brown Towhees from the Sierra del Carmen agreed satisfactorily with texanus although revealing some sign of intergradation with potosinus. Davis (1951:70) thought that P. f. potosinus is present in northern as well as southern Coahuila. Miller (1955a:176), however, remarked that P. f. texanus is more characteristic of the population of Brown Towhees of northwestern Coahuila. He indicated that a single juvenile taken by Marsh on August 28 from Jardín del Sur and allocated to P. f. potosinus by Davis probably is P. f. texanus.

Calamospiza melanocorys Stejneger.—Specimen examined: one, ♂ 30239, from 10 mi. E Torreón, 3700 ft., January 9, 1951.

The Lark Bunting is an uncommon winter visitant in Coahuila. Other than the present specimen, the only record of the Lark Bunting in Coahuila is that of Burleigh and Lowery (1942:207), who reported a small flock of this species from which several specimens were collected "on April 20 in a field on the edge of Saltillo."

Passerculus sandwichensis oblitus Peters and Griscom.—Miller, Friedmann, Griscom, and Moore (1957:364) recorded P. s. oblitus from Sabinas on February 25 and March 18 and 24. These records represent sparse winter visitants to Coahuila.

Passerculus sandwichensis brooksi Bishop.—Burleigh and Lowery (1942:208) recorded P. s. brooksi from Diamante Pass in April; Miller, Friedmann, Griscom, and Moore (1957:363) remarked that this specimen is perhaps best regarded as a variant of one of the races normally wintering in this area.

Passerculus sandwichensis anthinus Bonaparte.—Specimens examined: total 3: ♂ 31104 from 10 mi. E Hacienda La Mariposa, 2000 ft., March 30, 1952, weight 15 gms.; ♀ 31105 from 8 mi. N, 4 mi. W Múzquiz, 1800 ft., April 1, 1952, weight, 19.0 gms.; and ♀ 31594 from 17 mi. S Ocampo, 5300 ft., April 7, 1954, weight, 16 gms.

Burleigh and Lowery (1942:208) recorded P. s. anthinus from Diamante Pass. This subspecies is not uncommon in Coahuila. The University of Kansas specimens showed no indication of breeding.

Passerculus sandwichensis nevadensis Grinnell.—This subspecies of the Savannah Sparrow is uncommon in Coahuila; Hellmayr (1938:490) listed one specimen from Sabinas.