Proceedings of the Ninth Mountain Lion Workshop - Carnivore ...

Source-Sink Dynamics and the Recovery of Overexploited Cougar
Populations
David C. Stoner, Department of Wildland Resources, Utah State University, Logan, UT
84322-5230, USA, david.stoner@usu.edu
Michael L. Wolfe, Department of Wildland Resources, Utah State University, Logan, UT
84322-5230, USA, michael.wolfe@usu.edu.
ABSTRACT The cougar (Puma concolor) is a large New World felid that has
demonstrated remarkable resilience to anthropogenic impacts, remaining one of the most
prevalent large carnivores in North American ecosystems. Presently, cougars are
subjected to annual harvests over much of their current range, yet the impacts of
sustained hunting on demographic structure and population persistence are not well
understood. We have been monitoring two cougar populations in Utah, USA, since 1997.
We compared demographic characteristics between an exploited and a protected
population to examine the behavioral mechanisms of population recovery and
productivity. The treatment population had a younger age distribution, low survival,
declining density, and variable fecundity, and generally fit the profile of a sink
population. In contrast, the reference population exhibited the opposite trends in nearly
every parameter and appeared to act as a source. Under these conditions, sustained
exploitation created an ecological trap on the treatment site. Data five years posttreatment
suggests that following the implementation of a constant number of permits,
the sink population recovered in phases and began functioning as a source. We offer
empirical evidence for the occurrence of source-sink dynamics in an exploited cougar
population, and argue that in conjunction with the principles of landscape ecology, the
source-sink model of population regulation holds promise for the conservation of
exploited cougar populations.
Proceedings of the Ninth Mountain Lion Workshop
184