|Ward Jr, James|
|Block, William - US FOREST SERVICE|
|Van Horne, Beatrice - US FOREST SERVICE|
Submitted to: The Wildlife Society
Publication Type: Abstract Only
Publication Acceptance Date: September 1, 2007
Publication Date: September 22, 2007
Citation: Ward Jr, J.P., Block, W.M., Van Horne, B. 2007. Trends, ecological covariates, and some conservation implications of rodent abundance in a montane island of southern New Mexico [abstact]. 14th Annual Conference of the Wildlife Society, September 22-26, 2007, Tucson, Arizona. p. 97. Technical Abstract: Rodents provide food for a number of species that are targeted for management in southwestern forests. The Mexican spotted owl (Strix occidentalis lucida) and northern goshawk (Accipiter gentiles) are two examples of predators that shape management of several thousands of montane acres in this region. There are a number of ecological factors that effect rodent populations, which in turn, influence population numbers and distribution of focal predators. Some factors like habitat condition can be readily manipulated, while other factors like precipitation cannot. Population dynamics of five rodent species commonly consumed by Mexican spotted owls in the Sacramento Mountains are influenced by interactions among habitat, weather, and fauna. Over a six-year period (1991-1996), we found that population numbers of two species of deermice (Peromyscus maniculatus and P. boylii) and voles (Microtus mogollonensis and M. longicaudus) exhibited dynamic patterns of fluctuation, particularly relative to the less fluctuating numbers of the larger woodrat species Neotoma mexicana. Using envirograms and an information-theoretic approach to model selection, we found only slight similarity in ecological predictor variables for each species. We surmised that populations of the two vole species would be the most feasible to increase through habitat management, followed by populations of the Mexican woodrat, and lastly the two species of deermice. By providing values of rodent abundance expected for specific values of key habitat variables and other prominent covariates that influence habitat-abundance relationships, our results can be used to assess and design management experiments intended to enhance food resources for at least one focal predator in upper montane forests of the Southwest.