Genotypic and phenotypic consequences of reintroduction history in the black-footed ferret (Mustela nigripes)

Abstract

Population augmentation with translocated individuals has been shown to alleviate the effects of bottlenecks and drift. The first step to determine whether restoration for genetic considerations is warranted is to genetically monitor reintroduced populations and compare results to those from the source. To assess the need for genetic restoration, we evaluated genetic diversity and structure of reintroduced (n = 3) and captive populations of the endangered black-footed ferret (Mustela nigripes). We measured genotypic changes among populations using seven microsatellite markers and compared phenotypic changes with eight morphometric characters. Results indicated that for the population which rapidly grew postreintroduction, genetic diversity was equivalent to the captive, source population. When growth languished, only the population that was augmented yearly maintained diversity. Without augmentation, allelic diversity declined precipitously and phenotypic changes were apparent. Ferrets from the genetically depaupertate population had smaller limbs and smaller overall body size than ferrets from the two populations with greater diversity. Population divergence (F ST = 0.10 ± 0.01) was surprisingly high given the common source of populations. Thus, it appears that 5-10 years of isolation resulted in both genotypic divergence and phenotypic changes to populations. We recommend translocation of 30-40 captive individuals per annum to reintroduction sites which have not become established quickly. This approach will maximize the retention of genetic diversity, yet maintain the beneficial effects of local adaptation without being swamped by immigration.

No inbreeding effects on body size in two captive endangered gazelles

“…body size, cranial size) have been shown to be useful features for unveiling the effects of inbreeding depression in mammalian species (Leamy et al, 2001;Fredrickson and Hedrick, 2002;Pertoldi et al, 2006;Wisely et al, 2008). For example, in highly inbred captive wolf females, mean body size was significantly smaller than females with little or no inbreeding (Fredrickson and Hedrick, 2002).…”

“…In a study of in situ populations of the endangered Iberian lynx, divergent morphological traits were found in isolated populations, and reduced cranial size was found in a highly inbred population (Pertoldi et al, 2006). Loss of genetic variation can lead to decreased fitness traits, which in the long term can decrease the evolutionary potential of species, increasing their risk of extinction in the face of a changing environment (Franklin, 1980;Wisely et al, 2008).…”

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

“…Translocations are becoming increasingly popular as a management strategy for the genetic restoration of endangered species populations (Tallmon et al 2004;Pimm et al 2006;Wisely et al 2007). The utility of translocations has been mainly based on evidence of their immediate beneficial effects on fitness.…”

Effects of prey metapopulation structure on the viability of black‐footed ferrets in plague‐impacted landscapes: a metamodelling approach

“…This site was plague‐free until 2008 and displayed growing or stable population dynamics of prairie dogs and black‐footed ferrets from the date of first release (1996) to the date of plague arrival (Livieri ; Wisely et al . ). With regional black‐tailed prairie dog densities measured as high as 30 to 50 per hectare (Biggins et al .…”

“…500 km 2 ) began in 1996, resulting in a self‐sustaining ferret population of 335 animals by 2007 (Livieri ; Wisely et al . ). To assess the prey base for ferrets, black‐tailed prairie dog Cynomys ludovicianus colonies across southwestern South Dakota (hereafter, Conata/Badlands region, covering c .…”