Birds from Coahuila, Mexico

by Emil K. Urban

The size of the testes (9×5 mm.) of No. 31446 and an enlarged oviduct and an ovum (4 mm. in diameter) of No. 31447 indicate breeding by the Poor-will in Coahuila.

**Chordeiles minor howelli Oberholser.—Specimen examined: one, ♂ 31443, from 3 mi. N, 4 mi. E San Francisco (=25 mi. N Ocampo), 4850 ft., May 16, 1954.

Van Hoose (1955:302) wrote that nighthawks were heard and seen frequently 3 mi. N and 4 mi. E San Francisco. Blake (1953:227) said that the Common Nighthawk breeds in Sonora, Chihuahua, Tamaulipas, and Durango; the size of the testes (7×4.5 mm.) of No. 31443 indicates the possibility of breeding by this species in the State.

*Chordeiles acutipennis texensis Lawrence.—Specimens examined: total 4: ♂ 32044 and ♀ 32045 from 2 mi. W Jiménez, 850 ft., June 20, 1952; ♀ 31442 from 5 mi. N, 13 mi. E Ocampo, May 6, 1954; and ♂ 32046 from 2 mi. N, 1 mi. W Ocampo, 4050 ft., July 6, 1952.

Specimens of the Lesser Nighthawk, subspecies C. a. texensis, have been recorded in the literature from representative localities throughout most of Coahuila. Burleigh and Lowery (1942:190-191) obtained, on April 18, at "a small pond at the edge of Saltillo," one male that was exceedingly fat; they (loc. cit.) suggested that their specimen was a migrant. Goldman (1951:377, 389) stated that C. a. texensis occupied the Lower and Upper Sonoran and Upper Austral life-zones of Coahuila. Dickerman saw Lesser Nighthawks at San Marcos (=20 mi. S Cuatro Ciénegas) on May 4, 1954. Van Tyne and Sutton (1937:41) reported that the Lesser Nighthawk was common throughout the lower parts of the Big Bend in Texas. This is probably true for northwestern Coahuila as well.

The presence of an egg in the oviduct of No. 32045 and the dates (May 6, June 20, and July 6) on which Nos. 31442, and 32044-32046 were obtained indicate breeding by this species in Coahuila.

**Aëronautes saxatalis saxatalis (Woodhouse).—Specimen examined: one, ♂ 31672, from Pico de Jimulco, 5600 ft., April 5, 1953, weight, 35 gms.

Burleigh and Lowery (1942:191) found the White-throated Swift to be common at "the summit of Diamante Pass and on the nearby ridges." Miller (1955a:164) saw the species from 4800 feet up to the crest of the Sierra del Carmen. Several White-throated Swifts were seen flying overhead at Pico de Jimulco on April 5.

No specimens of A. s. sclateri from México are known. Miller (1955a:165) listed one specimen with dimensions (wing, 145 mm.) that approaches sclateri. The measurements of No. 31672 (wing, 143 mm.; tail, 58 mm.) also approach the dimensions of specimens of sclateri but are best referred to A. s. saxatalis.

**Calothorax lucifer (Swainson).—Burleigh and Lowery (1942:191) obtained a male Lucifer Hummingbird at the Chorro del Agua on April 19. Van Tyne and Sutton (1937:43) reported a male from the Río Grande (=3 mi. W Boquillas, Texas).