A cat's tale: the impact of genetic restoration on Florida panther population dynamics and persistence

Genetic restoration has been suggested as a management tool for mitigating detrimental effects of inbreeding depression in small, inbred populations, but the demographic mechanisms underlying population-level responses to genetic restoration remain poorly understood. We studied the dynamics and persistence of the endangered Florida panther Puma concolor coryi population and evaluated the potential influence of genetic restoration on population growth and persistence parameters. As part of the genetic restoration programme, eight female Texas pumas P. c. stanleyana were released into Florida panther habitat in southern Florida in 1995. The overall asymptotic population growth rate () was 1 center dot 04 (5th and 95th percentiles: 0 center dot 951 center dot 14), suggesting an increase in the panther population of approximately 4% per year. Considering the effects of environmental and demographic stochasticities and density-dependence, the probability that the population will fall below 10 panthers within 100years was 0 center dot 072 (00 center dot 606). Our results suggest that the population would have declined at 5% per year (=0 center dot 95; 0 center dot 831 center dot 08) in the absence of genetic restoration. Retrospective life table response experiment analysis revealed that the positive effect of genetic restoration on survival of kittens was primarily responsible for the substantial growth of the panther population that would otherwise have been declining. For comparative purposes, we also estimated probability of quasi-extinction under two scenarios implementation of genetic restoration and no genetic restoration initiative using the estimated abundance of panthers in 1995, the year genetic restoration was initiated. Assuming no density-dependence, the probability that the panther population would fall below 10 panthers by 2010 was 0 center dot 098 (0 center dot 0020 center dot 332) for the restoration scenario and 0 center dot 445 (0 center dot 0320 center dot 944) for the no restoration scenario, providing further evidence that the panther population would have faced a substantially higher risk of extinction if the genetic restoration initiative had not been implemented. Our results, along with those reporting increases in population size and improvements in biomedical correlates of inbreeding depression, provide strong evidence that genetic restoration substantially contributed to the observed increases in the Florida panther population.