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

Survival
We asked whether puma mortality differed between the developed and undeveloped
zones. We documented survival or mortality of each puma during the period of
monitoring, beginning at capture and ending with the puma’s last documented location.
When collars transmitted mortality signals, we located the collar and investigated the
cause of puma death or collar detachment. We calculated percent mortality during the
study for all collared pumas as well as for pumas by zone, sex, and age class. We
conducted two-sample independent Student’s t-tests in JMP 5 ® statistical software (SAS
Institute, Cary, N.C.) to determine whether pumas in each zone, sex, and age class were
monitored for similar periods of time, allowing valid comparisons of mortality rates.
We used Pearson’s chi-square tests to determine whether the proportion of pumas known
to have died to pumas alive at the end of monitoring differed between puma zone, sex, or
age classes. We recorded mortality and cause of death for pumas after collar drop-off
through spring 2007, in the case that ear tag numbers on carcasses were reported to
CDFG. We did not include puma deaths occurring after the expected date of collar
retrieval in analyses, because developed-zone pumas often died due to depredation. These
deaths were more likely to become known to us post-collar drop-off than were
undeveloped-zone puma mortalities, which were less likely to result from depredation.
To facilitate comparison of survival with other studies, we also calculated 12-month
mortality rates, including only pumas that were monitored for at least one year, or died
within their first 12 months of being monitored.
Dispersal
We analyzed subadult dispersal patterns in combination with survival, to determine
whether the population conformed to a habitat-limited structure, a source-sink structure,
or an unfragmented population structure. We expected that a large proportion of
subadults in a habitat-limited environment, such as that of the Florida panther (Maehr
2002), would disperse long summed distances or durations compared to other
populations, possibly at relatively young ages, but fail to establish independent home
ranges. We expected relatively short Euclidean dispersal distances for those animals
successfully establishing home ranges, indicating a lack of available habitat elsewhere.
This pattern could be represented by “frustrated dispersal” (Lidicker 1975), in which
animals disperse long total distances, fail to find suitable habitat for a home range, and
frequently return to their natal regions. In a source-sink population structure, we expected
a large proportion of subadults to disperse and establish independent home ranges, but to
experience high mortality or low chance of reproductive success in their new home
ranges (Pulliam 1988). In an unfragmented structure, we expected dispersal frequency,
establishment of independent home ranges, and survival rates to be similar to other puma
populations in relatively undisturbed areas that were not heavily hunted.
We documented dispersal parameters for collared subadult animals that gained
independence from their mothers during the study period. We used GPS collar locations
from downloaded collars, as well as capture and mortality locations taken with handheld
Proceedings of the Ninth Mountain Lion Workshop
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