Spatial scaling of pocket gopher (Geomyidae) density

Pocket gophers have been considered as both serious pests to management of natural resources and critically important to the function of ecosystems. A ssessments of their positive and negative impacts have relied largely on po pulation density and behavior. However, 100 reported estimates of pocket go pher density from 32 published studies varied 415-fold from low to high den sity, and much of this variation can be explained by the 1,000-fold range i n spatial extent of study area. Unlike mammalian carnivores, however, body mass explained a significant portion of the variation in density, even afte r adjusting density by size of the study area. Nearly all variation in dens ity can be explained by study area and female body mass estimated at the co rresponding study site. Residual variation in density differed significantl y but not substantially among categories of dominant vegetation and land us e, and among species. Pocket gopher density is spatially dependent, and the refore should not be compared among species, populations, or localities wit hout defining the estimate to spatial scale. Further research across large areas and a range of conditions will be required to fully understand the fa ctors that influence distribution and abundance of gophers.