Influence of prairie dogs (Cynomys ludovicianus) on habitat heterogeneity and mammalian diversity in Mexico

Prairie dogs are considered to be both a keystone species and an ecosystem engineer in grasslands. To partially test these hypotheses we evaluated burrow densities, soil removal, and mammal (i.e. rodents and carnivores) species composition, richness, diversity, and abundance in grasslands with and without prairie dogs (Cynomys ludovicianus) in north-western Mexico. We measured habitat heterogeneity as a function of burrow density. As predicted, density of burrows was much higher in areas with prairie dogs. Soil mix was also much higher in prairie dog colonies. Grasslands with and without prairie dogs differed in small mammal species composition, richness, density, and diversity; four species were exclusively found in areas with prairie dogs. Interestingly, carnivore communities were similar in areas with and without prairie dogs. Our results support the hypothesis that prairie dogs and their activities enhance regional species diversity, and thus are an important component of the grassland ecosystem (C) 1999 Academic Press.