Of cats and Haruspices^*: genetic intervention in the Florida panther. Response to Pimm et al. (2006)

Abstract

The claim that the Florida panther Puma concolor coryi has been genetically rescued by the introduction of Texas cougars P. c. stanleyana is based on the questionable development and interpretation of a maximum likelihood model, data dredging and a misleading presentation of historical data. In addition, the claim that Florida panther 'hybrids are expanding the known range of habitats panthers occupy and use' is offered in the absence of data or supporting analyses. By (1) ignoring regional differences in habitat quality, (2) ignoring the earlier extinction of the hybrid Everglades population, (3) ignoring the influence of social structure on the relative success of Texas cougars and their offspring, (4) using cursory spatial analyses of panthers before and after intervention and (5) choosing a second-best model, a misleading scenario was presented. Undoubtedly hybrid animals have increased in abundance and distribution on the south Florida landscape, but it is quite possible that current patterns of abundance and distribution would be similar if purebred Florida panthers had been introduced instead of Texas cougars in 1995. This is because all the demographic events that have occurred since genetic intervention in 1995 can be more reasonably explained by factors relating to panther social structure and habitat variability. We are hopeful that the current genetic management effort will contribute to the recovery of this endangered population; however, it is too early to claim that this intervention has succeeded or failed. We suggest a number of ways in which more reliable insight on this issue might be obtained.

Genetic introgression and the survival of Florida panther kittens

“…Genetic introgression has been highly controversial (e.g., Maehr and Caddick 1995; Maehr et al 2006; Pimm et al 2006). Pimm et al (2006) reviewed the arguments for and against genetic introgression in general, and in the Florida panther population in particular.…”

“…Based on this recommendation, 8 female Texas pumas ( P. c. stanleyana ) were released into the Florida panther population in 1995. Although the panther population has experienced an almost fourfold increase since 1995 (McBride et al 2008), the success of the introgression continues to be a topic of debate (Maehr et al 2006; Onorato et al 2010; Pimm et al 2006). There have also been non-management releases of captive pumas into south Florida; some of these (between 1957 and 1967) resulted in a genetic population with partial Central American ancestry in the Everglades (O’Brien et al 1990).…”

Beyond the beneficial effects of translocations as an effective tool for the genetic restoration of isolated populations

“…Although translocation of birds into Illinois from larger and genetically diverse populations resulted in immediate increases in fitness (Westemeier et al 1998a), concerns existed over both the long-term benefit of translocations on population viability and the potential genetic swamping of the Illinois population by the introduction of birds from other locations. Although this and a few other case studies (e.g., Madsen et al 1999;Vilà et al 2003;Arrenda et al 2004;Hogg et al 2006) have documented the beneficial effects of translocations in alleviating the detrimental effects of inbreeding depression in endangered wild populations, there is still a need for well-documented studies on the potential role of translocations in restoring overall genetic diversity to historical levels and increasing population viability (Pimm et al 2006;Maher et al 2006;Beier et al 2006).…”

Microsatellite and mitochondrial DNA variation defines island genetic reservoirs for reintroductions of an endangered Australian marsupial, Perameles bougainville

“…Judging the success of a reintroduction program depends largely on the goals of the reintroduction effort and should be evaluated incorporating criteria across a number of key areas including: demographics, population health and genetic composition of the new population compared with the source population (Hedrick 2005;Hogg et al 2006;Maehr et al 2006). Essentially, ex situ recovery programs fall into two broad categories: supplementation of existing wild populations; and reintroductions into areas following the extinction of the locally adapted natural population (Theodorou and Couvet 2004).…”