Cougar Kill Rate and Prey Composition in a Multiprey System

• Published in: The Journal of Wildlife Management
• Main Authors: KNOPFF, KYLE H., KNOPFF, ALIAH ADAMS, KORTELLO, ANDREA, BOYCE, MARK S.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Wiley 2010
• Subjects: Canada; Alces alces
• Online Access: http://dx.doi.org/10.1111/j.1937-2817.2010.tb01270.x; https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1111%2Fj.1937-2817.2010.tb01270.x; http://onlinelibrary.wiley.com/wol1/doi/10.1111/j.1937-2817.2010.tb01270.x/fullpdf

Abstract: Assessing the impact of large carnivores on ungulate prey has been challenging in part because even basic components of predation are difficult to measure. For cougars ( Puma concolor ), limited field data are available concerning fundamental aspects of predation, such as kill rate, or the influence of season, cougar demography, or prey vulnerability on predation, leading to uncertainty over how best to predict or interpret cougar‐ungulate dynamics. Global Positioning System (GPS) telemetry used to locate predation events in the field is an efficient way to monitor large numbers of cougars over long periods in all seasons. We applied GPS telemetry techniques combined with occasional snow‐tracking to locate 1,509 predation events for 53 marked and an unknown number of unmarked cougars and amassed 9,543 days of continuous predation monitoring for a subset of 42 GPS‐collared cougars in west‐central Alberta, Canada. Cougars killed ungulates at rates near the upper end of the previously recorded range, and demography substantially influenced annual kill rate in terms of both number of ungulates (subad F [SAF] = 24, subad M [SAM] = 31, ad M = 35, ad F = 42, ad F with kittens <6 months = 47, ad F with kittens <6 months = 67) and kg of prey (SAF = 1,441, SAM = 2,051, ad M = 4,708, ad F = 2,423, ad F with kittens <6 months = 2,794, ad F with kittens >6 months = 4,280). Demography also influenced prey composition; adult females subsisted primarily on deer ( Odocoileus spp.), whereas adult males killed more large ungulates (e.g., moose [ Alces alces ]), and subadults incorporated the highest proportion of nonungulate prey. Predation patterns varied by season and cougars killed ungulates 1.5 times more frequently in summer when juveniles dominated the diet. Higher kill rate in summer appeared to be driven primarily by greater vulnerability of juvenile prey and secondarily by reduced handling time for smaller prey. Moreover, in accordance with predictions of the reproductive vulnerability hypothesis, ...