94 Mountain Lions of the Black Hills
document prey carcasses at those sites to determine what was being killed and how
often lions were making kills (Smith 2014). For this work we concentrated our efforts
on capturing adult males and females that had established home ranges (usually ani-
mals over 2.5 years of age), because of the cost of the technology (we used global po-
sitioning system [GPS] radio collars in place of traditional VHF radio collars) and
because we were interested only in what lions that were resident to the Black Hills
were consuming (fig. 6.10). Fortunately, the GPS technology was available, but unfor-
tunately, the first collars we purchased had high failure rates, in part from damage
that occurred when lions were capturing prey, fighting with other lions, mating, and
engaging in other activities associated with general lion be hav ior. Later GPS collars
(manufactured by Advance Telemetry Systems) were more robust relative to surviving
normal mountain lion activities. We continued to experience failures, but not near the
rate of the failures with previous collars. We also noted that most of the work con-
ducted on feeding habits of mountain lions using GPS collars involved visiting loca-
tions that were called cluster sites (where clusters of GPS points [≥2 points within
200 m] indicated a potential kill at the site) after a considerable amount of time had
elapsed between the kill and the site visit and where the programmed collars collected
figure 6.10. A mountain lion fitted with a global positioning system radio collar
(manufactured by North Star LLC) in the Black Hills. Courtesy of B. Jansen.