The overarching objective of this research project is to assess competitive interactions among carnivores theirabundance and population dynamics and their associated effects on prey populations

IT is often implied thatcarnivores are important determinants of ungulate population dynamics but empirical data supporting this claimis limited. Furthermore the competitive interactions between carnivores may influence ungulate populations andthis topic is not well studied. This lack of knowledge was the impetus for this research and will help improvemanagement of both predators and their prey in oregon and elsewhere. We will use information gained from this study in conjunction with other ongoing research to identify factorsinfluencing declining mule deer populations. Our primary objective of this research is to determine carnivoredensities diets and competitive interactions at the starkey experimental forest and range and to estimatecarnivore densities and abundance at two study areas in central and southern oregon. Through this and othercomplementary research we will determine the role of predation in influencing population dynamics and habitatuse of mule deer. We will conduct fieldwork during the current project period to develop an empirical data setto meet project objectives. Information gained from this project will be useful in improving management ofcarnivores and their prey in oregon and other portions of western north america. This research will also assessthe response of carnivores to a substantial decline in available prey biomass primarily ELK at the starkeyexperimental forest and range as part of a controlled experiment. Changes in diet space and habitat use anddensity will be monitored as part of the experimental reduction of the ELK herd. Documenting changes in predatorresponses to prey reductions are important to understanding how predators are likely to affect their preypopulations. We are also conducting work in other portions of eastern oregon in the blue mountains and southern oregon cascade range to document abundance and diet of cougars black bears and coyotes. This work will be used to determine spatial differences in abundance and how habitat may influence density. This knowledge will then be used to identify primary predators of mule deer via presence in scat and also provide accurate information on densities that could be used to alter harvest rates of the species. Additionally data collected as part of this projectwill be used to determine if variation in predator abundance effects mule deer survival.