Inbreeding, heterozygosity and fitness in a reintroduced population of endangered African wild dogs (Lycaon pictus)

Abstract

It is crucial to understand the genetic health and implications of inbreeding in wildlife populations, especially of vulnerable species. Using extensive demographic and genetic data, we investigated the relationships among pedigree inbreeding coefficients, metrics of molecular heterozygosity and fitness for a large population of endangered African wild dogs (Lycaon pictus) in South Africa. Molecular metrics based on 19 microsatellite loci were significantly, but modestly correlated to inbreeding coefficients in this population. Inbred wild dogs with inbreeding coefficients of C0.25 and subordinate individuals had shorter lifespans than outbred and dominant contemporaries, suggesting some deleterious effects of inbreeding. However, this trend was confounded by packspecific effects as many inbred individuals originated from a single large pack. Despite wild dogs being endangered and existing in small populations, findings within our sample population indicated that molecular metrics were not robust predictors in models of fitness based on breeding pack formation, dominance, reproductive success or lifespan of individuals. Nonetheless, our approach has generated a vital database for future comparative studies to examine these relationships over longer periods of time. Such detailed assessments are essential given knowledge that wild canids can be highly vulnerable to inbreeding effects over a few short generations.

Genetic diversity and spatial genetic structure of African wild dogs (Lycaon pictus) in the Greater Limpopo transfrontier conservation area

“…Nonetheless, previous studies similarly suggest that genetic diversity in adaptive markers also decreased in African wild dogs (Girman et al 1997;2001;Spiering 2011;Leigh et al 2012;Marsden et al 2012). …”

“…In the case of an isolated and genetically depleted population of grey wolves in Scandinavia, the arrival of one immigrant led to selective outbreeding, which caused an increase in heterozygosity, the introduction of new alleles, and an exponential population growth (Vilà et al 2003). For African wild dogs, the loss of heterozygosity is likely to be mitigated due to their natural behaviour of avoiding inbreeding within a pack (Girman et al 1997;Spiering 2011). …”

“…Nevertheless, inbreeding has been confirmed in a semi-natural meta-population in KwaZulu-Natal, South Africa, with reduced longevity for inbred individuals (Spiering et al 2011). This would suggest that inbreeding avoidance can be compromised if natural dispersal and outbreeding are restricted (Spiering et al 2011;Leigh et al 2012).…”

“…This would suggest that inbreeding avoidance can be compromised if natural dispersal and outbreeding are restricted (Spiering et al 2011;Leigh et al 2012).…”

Inbreeding and inbreeding depression of early life traits in a cooperative mammal

“…Although a growing body of work is now revealing inbreeding and inbreeding depression in wild animal systems (Keller & Waller 2002), comparatively few studies have focused on cooperative species (but see Brown & Brown 1998;Daniels & Walters 2000;Hoogland 1992; Keane et al 1996;McRae 1996;Richardson et al 2004;Spiering et al 2011). As cooperative species tend to live in family groups with close relatives of the opposite sex in near proximity the potential for inbreeding is high (Koenig & Haydock 2004).…”