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

Population Status
A vital prerequisite for managing most wildlife species is a credibly accurate assessment
of population size (Caughley and Sinclair 1994). As biologists, we understand the
predicament agencies are faced with when estimating cougar populations; this species is
among the most demanding to study. It is recognized that a reliable and accurate method
for enumerating cougar populations is lacking (Lindzey 1987, Ross et al.1996).
Nonetheless, population estimation is the foundation used to create management-guiding
documents and formulate scientifically credible decisions. Agencies with insufficient
data may continually be criticized. Our survey revealed that although most agencies were
using more than one source of information for deriving population estimates, evaluation
of hunting harvest data was the most commonly used method. While harvest data is a
constant and useful source of information, it should be evaluated with scrutiny because it
is not reflective of population status (Anderson and Lindzey 2005) and snowfall may
influence harvest significantly. Only half the agencies were incorporating field research
or GIS analysis in developing population estimates; many agencies relied on modeling,
using densities reported in the literature multiplied by the amount of available habitat.
Because population estimates are a parameter that influences all aspects of cougar
management protocols, agencies may want to scientifically evaluate their own cougar
management programs and address population estimation in a more scientificallydefensible
manner.
Cougar database management
Almost all agencies had a mandatory reporting system for recording cougar mortalities
(except TX and Mexico [MX]), and agencies collected a considerable amount of data
from kills for their databases (Table 10). While the data collected was important,
agencies may want to collect some additional biologically important data while the
carcass is readily available. For instance, while most agencies collected a tooth to age
cougar kills using cementum annuli, less than 1/3 of agencies collected measurements on
gum-line recession. It has been reported that aging cougars based solely on cementum
annuli may not be precise (Trainer and Mattson 1988). Since many agencies rely on
population reconstruction using harvest data, agencies may want to use multiple aging
techniques for accurate modeling (Anderson and Lindzey 2005). Collecting gum-line
recession measurement has showed promise in being more accurate for aging live cougar
(Laundré et al. 2000) but some standardization for measuring is necessary when
numerous personnel are involved and training may be needed to enhance consistency and
accuracy. Also, little is known how the gum-line recesses after death (Laundré et al.
2000) and agencies could add knowledge to this science by collecting this data.
Agencies may also want to consider collecting the lactation status on female mortalities;
this data could be valuable for population modeling and recording kitten mortality (Ruth
et al. 2003). It may also help accurately age cougars that get classified as 2-3 year-old
cougars with an error rate of ±1 year using cementum annuli (Anderson and Lindzey
2005).
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