Genetic introgression and the survival of Florida panther kittens

Abstract

Estimates of survival for the young of a species are critical for population models. These models can often be improved by determining the effects of management actions and population abundance on this demographic parameter. We used multiple sources of data collected during 1982-2008 and a live recapture-dead recovery modeling framework to estimate and model survival of Florida panther (Puma concolor coryi) kittens (age 0 -1 year). Overall, annual survival of Florida panther kittens was 0.323 ± 0.071 (SE), which was lower than estimates used in previous population models. In 1995, female pumas from Texas (P. c. stanleyana) were released into occupied panther range as part of an intentional introgression program to restore genetic variability. We found that kitten survival generally increased with degree of admixture: F 1 admixed and backcrossed to Texas kittens survived better than canonical Florida panther and backcrossed to canonical kittens. Average heterozygosity positively influenced kitten and older panther survival, whereas index of panther abundance negatively influenced kitten survival. Our results provide strong evidence for the positive populationlevel impact of genetic introgression on Florida panthers. Our approach to integrate data from multiple sources was effective at improving robustness as well as precision of estimates of Florida panther kitten survival, and can be useful in estimating vital rates for other elusive species with sparse data.

Interactions between demography, genetics, and landscape connectivity increase extinction probability for a small population of large carnivores in a major metropolitan area

“…The SMM mountain lion population is currently demographically vigorous with no indication of inbreeding depression as evidenced by estimated survival and reproductive rates that were mostly similar or slightly higher than other unhunted mountain lion populations across North America [22,23,28,33]. The lone exception was subadult survival, which was rspb.royalsocietypublishing.org Proc.…”

“…We simulated inbreeding depression by running population projections with input parameters reduced to reflect proportional changes in age and sex-specific survival rates consistent with differences documented between Florida panthers experiencing inbreeding depression and outbred panthers following the genetic restoration programme [14,22,23]. These adjusted input parameters are provided in electronic supplementary material, table S3.…”

“…This population exhibited low genetic diversity and poor demographic performance resulting from inbreeding depression [14]. Detailed research on the near-extinction and subsequent genetic restoration of panthers provided quantitative predictions for (i) levels of genetic diversity at which inbreeding depression may occur in mountain lion populations and (ii) demographic consequences of inbreeding depression for this species [14,22,23]. Mountain lion populations isolated by habitat fragmentation and major freeways in the greater Los Angeles area have the lowest levels of genetic diversity documented for this species aside from Florida panthers [20,21], causing concern regarding inbreeding depression.…”

Does genetic introgression improve female reproductive performance? A test on the endangered Florida panther

“…We estimated the heterozygosity and genetic ancestry of individuals from genetic samples using techniques detailed elsewhere (Benson et al 2011;Hostetler et al 2010;Johnson et al 2010). We used results from the genetic ancestry analysis along with pedigree information and field evidence to assign panthers to three groups that reflect the genetic makeup of the current Florida panther population (pre-introgression type panthers, F 1 admixed panthers, and other admixed panthers; Benson et al 2011).…”

“…Since this genetic introgression, the population has increased (McBride et al 2008), although the processes that led to this increase continue to be debated (Creel 2006;Maehr et al 2006;Pimm et al 2006). The influence of genetic introgression on age-specific survival of Florida panthers has been explored (Benson et al 2011;Hostetler et al 2010;Johnson et al 2010), but the potential effect of introgression on the panther's reproductive performance remains unclear (but see Pimm et al 2006 for a qualitative comparison). Furthermore, the Scientific Review Team, commissioned by the US Fish and Wildlife Service and the Florida Fish and Wildlife Conservation Commission (FWC) partly in order to make recommendations for continuing Florida panther research, recommended a reanalysis of existing data to rigorously estimate reproductive parameters and an evaluation of the potential influence of introgression on demographic variables (Beier et al 2003).…”