Ex situ conservation genetics: a review of molecular studies on the genetic consequences of captive breeding programmes for endangered animal species

Abstract

Captive breeding has become an important tool in species conservation programmes. Current management strategies for ex situ populations are based on theoretical models, which have mainly been tested in model species or assessed using studbook data. During recent years an increasing number of molecular genetic studies have been published on captive populations of several endangered species. However, a comprehensive analysis of these studies is still outstanding. Here, we present a review of the published literature on ex situ conservation genetics with a focus on molecular studies. We analysed 188 publications which either presented empirical studies using molecular markers (105), studbook analyses (26), theoretical work (38), or tested the genetic effects of management strategies using model species (19). The results show that inbreeding can be minimized by a thorough management of captive populations. There seems to be a minimum number of founders (15) and a minimum size of a captive population (100) necessary in order to minimize a loss of genetic diversity. Optimally, the founders should be unrelated and new founders should be integrated into the captive population successively. We recommend that genetic analyses should generally precede and accompany ex situ conservation projects in order to avoid inbreeding and outbreeding depression. Furthermore, many of the published studies do not provide all the relevant parameters (founder size, captive population size, H o , H e , inbreeding coefficients). We, therefore, propose that a general standard for the presentation of genetic studies should be established, which would allow integration of the data into a global database.

A suite of microsatellite markers for genetic management of captive cracids (Aves, Galliformes)

“…This increases the risks that deleterious alleles become homozygous and lead to inbreeding depression, threatening the success of both captive breeding and reintroductions (Witzenberger and Hochkirch, 2011). The traditional approach to avoid inbreeding is minimizing the mating between closely related individuals following studbook data (Ballou and Foose, 1995).…”

“…However, pedigree recordings are not available for the current captive cracid populations, although most of them were founded at least 2 decades ago. In these cases, molecular genetic analyses can provide accurate genetic pedigrees, as well as information on population genetic structure and variability (Witzenberger and Hochkirch, 2011). Thus, there is an urgent interest in implementing genetic monitoring programs for captive cracid populations that are intended to supply individuals for the ongoing and future reintroduction programs.…”

Maximising evolutionary potential in functional proxies for extinct species: a conservation genetic perspective on de‐extinction

“…It should be noted, however, that survival among Attwater's prairie-chickens, particularly chick survival post-hatch, may be indirectly influenced by an introduced non-native invasive species, the red imported fire ant (Solenopsis invicta) by reducing invertebrate biomass available for food (Morrow et al 2015) further complicating efforts to produce a self-sustaining population in the long-term. (Witzenberger & Hochkirch 2011). Genetic diversity may be further eroded by genetic drift in captivity if founder representation is not equalised and monitored regularly (e.g.…”

Utility of several microsatellite markers for the genetic characterisation of three ex situ populations of threatened caprine taxa (<i>Capra aegagrus</i>, <i>C. cylindricornis</i> and <i>C. falconeri</i>)

“…Witzenberger and Hochkirch, 2011). Although many microsatellite markers have been developed for wild and domestic caprines Bhebhe et al, 1994;Bishop et al, 1994;Crawford et al, 1995;Kemp et al, 1995;Kogi et al, 1995;Ma et al, 1996;Vaiman et al, 1996;Luikart et al, 1999Luikart et al, , 2006Maudet et al, 2001Maudet et al, , 2002Maudet et al, , 2004Kumar et al, 2009), they remain uninvestigated in respect of their utility for some taxa.…”