USFWS
Genetic Monitoring for Managers
Alaska

 

Type of GEM

Category 1a GeM Project Example: Impacts of Translocated Animals on Population Viability

The genetic rescue of the Florida panther

Pimm et al. 2006

The Florida panther (Puma concolor coryi) is a critically endangered (CITES Appendix I) subspecies of cougar. Florida's official state animal, the panther has been protected from legal hunting since 1958. In

type fate fig 2
The Florida panther is considered (by some) as one of over 30 proposed subspecies of Puma concolor.

1967 it was listed as endangered by the U.S. Fish and Wildlife Service, and was added to the state's endangered species list in 1973. As one of the most endangered felids in the world, and due to its range including lands under extreme development pressure, panther management has been contentious (see Beier et al. 2006 and Conroy et al. 2006 for reviews).

Panther habitat has been reduced to roughly 5% of historical levels. With each breeding unit, consisting of one male and several females, requiring about 200 square miles (500 km2), habitat loss and degradation due to encroaching human development remains the primary threat to this population. Direct human-caused mortality, primarily collisions with cars, and effects of inbreeding also serve to reduce the likelihood of persistence for the panther.

Panthers have been isolated in southern Florida since the early 1900s. Evidence of severe inbreeding were well publicized. Due to low population numbers and perceived threats of inbreeding, a study in 1992 estimated that the subspecies would go extinct within a few decades (Seal 1992).

The U.S. Fish and Wildlife Service, based on the results of three workshops convened specifically to address the fate of the Florida panther, translocated eight female panthers from Texas, the most closely related population, to Florida in the mid 1900s (USFWS 1995). Five of these females produced kittens, which were subsequently monitored as part of a program to assess success of the program.

type fate fig 3
Monthly mortality rates for purebred and hybrid panthers.

From 1992 onwards, researchers marked 118 purebred and 54 hybrid kittens. Of these, 13 purebreds and 20 hybrids survived to adulthood. Survival to adulthood was significantly higher, greater than three-fold on average, in hybrid kittens compared to purebreds (Chi-squared test, p<0.001). Further, adult female hybrids have lower mortality rates than purebreds. However, the data suggest that hybrid females do not produce more young, at a younger age, or at shorter intervals than do purebreds, and adult male hybrids have higher mortality rates than purebreds.

Since the augmentation effort and likely because of it, panther numbers have rebounded from a low of 20-30 cats, to nearly 100 today, and their range has expanded.

 

Genetic monitoring of this population has provided insights into the realized benefits to an inbred population post-augmentation. The ability to track the fates of individuals in conjunction with knowlege of their genetic composition (i.e., hybrid status) demonstrates the value of long term genetic monitoring.