The Avifauna of the Sierra del Carmen of Coahuila, Mexico

In the desert of northern Coahuila, Mexico, lies a rugged mountain system collectively known as the Sierra de1 Carmen.The high northern part of this sierra is about 30 miles in extent along a north-northwest axis and it supports conifer and pine-oak vegetation that is well isolated from other such ecologic formations of significant area1 extent.The Sierra consists principally of an elevated limestone plateau, deeply dissected, and with steep escarpments, especially to the west.The top of the plateau in most places is about 8000 feet altitude.The northern end of the Sierra is less than 50 miles southeast of the higher parts of the Chisos Mountains in the Big Bend National Park of Texas.The two mountain areas are part of the same system of uplifts, although of course they are separated by the Rio Grande Valley and are composed of different types of rock.The upper levels of the Sierra de1 Carmen have seldom been penetrated by naturalists and no extensive investigation of the bird life of the area has previously been undertaken.The birds of the lower Chisos Mountains have been well studied (Van Tyne and Sutton, 1937) and considerable data are available on the birds of the mountains of extreme southern Coahuila at the northern end of the Sierra Madre Oriental (Burleigh and Lowery, 1942).In the summer of 1936 Ernest G. Marsh, Jr., botanist, was commissioned by the United States National Park Service to make a biological survey of the Sierra de1 Carmen.Incidental to his general objectives, observations on birds were made and forty-four specimens were deposited in the United States National Museum.Through the courtesy of Herbert Friedmann and Victor H. Cahalane, permission has been granted to report specimens taken by Marsh and to draw on his notes related to them.All Marsh' s specific localities, unless otherwise mentioned, lie along the northwest edge of the Sierra within a five-mile radius of the high northern point known as El Centinela.A few of Marsh' s records were reported shortly after his trip (Marsh and Stevenson, 1938).The Sierra de1 Carmen was visited by A. Starker Leopold, Ward C. Russell and myself in April of 1953 through support by the Associates in Tropical Biogeography of the University of California.Our purpose was to study game populations as part of a broad investigation of this subject in Mexico by Leopold and to determine the extent and relationships of the avifauna of the area.Penetration of the upper levels of the Sierra was possible through the extreme helpfulness of Ramon D. Bosquez whose lumbering interests embrace a large part of the mountains.Many courtesies were extended our party, and it is a pleasure to record the aid received also from Ramon D.