New Records for Coahuila from a Riparian Bird Community in Northern Mexico (Notes‪)‬

Riparian woodlands cover 1% of the arid landscape in western North America, but are particularly important for conservation because they shelter more species of breeding birds than surrounding habitats (Knopf et al., 1988). The Rio Sabinas (130 km in length) is in northeastern Coahuila, flowing from the Sierra Santa Rosa in the municipality of Melchor Muzquiz to the Venustiano Carranza Dam in the municipality of Juarez. The avifauna of this area is poorly known although it is a Priority Terrestrial Region for Conservation in Mexico (RTP-152; Arriaga et al., 2000). The main threat facing this region is open-pit coal mining, which desiccates underground water deposits and causes loss of vegetation. The riparian tree stratum is dominated by Montezuma bald cypresses (Taxodium mucronatum, hereafter bald-cypress), but pecan (Carya illinoinensis), sycamore (Platanus occidentalis), sugar hackberry (Celtis laevigata), and Mexican ash (Fraxinus berlanderiana) also are present. Its shrub stratum is characterized by spiny hackberry (Celtis pallida), huisache (Acacia farnesiana), catclaw (A. greggii), blackbrush (A. rigidula), honey mesquite (Prosopis glandulosa), Texas persimmon (Diospyros texana), and Mexican mulberry (Morus celtidifolia). The herbaceous layer is composed principally of straggler daisy (Calyptocarpus vialis). We conducted surveys during December 2004-August 2006 along the Rio Sabinas, in the municipalities of Melchor Muzquiz, San Juan de Sabinas, and Sabinas. We sampled monthly during the first year, December 2004-November 2005, and during a second winter (December 2005-January 2006) and breeding season (May-August 2006). We conducted a total of 275 randomly selected point counts/year (10 min, 20-m radius), covering ca. 34.5 ha and 64 km along the Rio Sabinas. During sampling, we documented 17 new records (eight breeding, nine non-breeding) and eight rare records for Coahuila. We also recorded the Rio Sabinas as a potential new breeding site for five species and we suggest three potential new breeding records for the state that require additional confirmation.