干旱区生态环境知识资源中心

The lack of ecological knowledge of-the Mexican Tamaulipan Province encouraged us to determine the composition, diversity, and density of the rodent community in a desert schrub habitat in Northeastern Mexico. During 1997, small mammals were captured with Sherman traps. We selected two study sites, one fenced with deer proof mesh. Density was calculated using NOREMARK software. Diversity was estimated using the inverse of Simpson's index (N2). We used two quadrants with one replica to-quantify the community structure. To date we have recorded 8 species: Chaetodipus hispidus, Dipodomys merriami, Perognathus flavus, Neotoma albigula, Onychomys leucogaster, Peromyscus eremicus, Sigmodon hispidus, and Spermophilus mexicanus. The dominant species were Sigmodon hispidus (13 ind/ha), Dipodomys merriami (11 ind/ha), and Peromyscus sp. (9.9 ind/ha). Rare species were Neotoma albigula (1.81 ind/ha) and Spermophilus mexicanus (1.43 ind/ha). Seven species were nocturnal, one diurnal (S. mexicanus) and one active through day and night (Sigmodon hispidus). Overall diversity was higher for the dry season (N2=6.60) than the wet one (N2=5.28). Density for most species (n=7) is increased during the wet season, only Sigmodon hispidus shows variation along the year.