Date of Award:


Document Type:


Degree Name:

Master of Science (MS)


Wildland Resources

Committee Chair(s)

Eric M. Gese


Eric M. Gese


Daniel R. MacNulty


Daniel J. Thompson


Determining the abundance or density of wildlife populations is needed for informed decision-making by wildlife biologists. Cougars (Puma concolor), however, are a highly secretive species occurring at very low densities across the landscape, and thus their populations are difficult for biologists to accurately assess. The conventional, and most trusted, method entails physically trapping and radio-collaring as many cougars as possible in a population, and then performing a simple count to determine a minimum population size. While accurate, this method is prohibitively expensive, logistically challenging, and behaviorally disruptive to the study animal. Many noninvasive surveying techniques, such as camera trapping, have been proposed as alternatives for cougar populations, with the goal of providing accurate estimates of population size at a lower cost and with less impact on the study animal. These methods use detections of individual cougars in a mark-recapture framework, as opposed to a simple count, and have the benefit of being true, statistically rigorous estimates with confidence intervals. However, little research has been done to empirically verify the accuracy of these methods, or to determine their comparative cost-effectiveness. We compared the accuracy and cost-effectiveness of three types of noninvasive surveys applied on a population of cougars in Northwest Wyoming. Between 2011 and 2014, we applied two surveys each of remote camera trapping, winter snow tracking, and scat detection dogs. To evaluate these methods, we estimated the density of the same cougar population using the conventional “capture-collar-count” method, and then used that estimate as a reference. Our research indicated that: 1) on a cost-per-detection basis, scat detection dog surveys were almost an order of magnitude less expensive the other methods; and 2) remote camera trapping may not be applicable to cougars due to the difficulty of distinguishing individual cougars in photographs. Our research should be valuable to research biologists, wildlife managers, or conservation entities responsible for monitoring cougar populations.