Does recognized genetic management in supportive breeding prevent genetic changes in life-history traits?

Rémi Chargé,Loïc Lesobre,Frédéric Lacroix,Gabriele Sorci,Michel Saint Jalme,Yves Hingrat,Céline Teplitsky

doi:10.1111/eva.12150

Abstract

Supportive breeding is one of the last resort conservation strategies to avoid species extinction. Management of captive populations is challenging because several harmful genetic processes need to be avoided. Several recommendations have been proposed to limit these deleterious effects, but empirical assessments of these strategies remain scarce. We investigated the outcome of a genetic management in a supportive breeding for the Houbara Bustard. At the phenotypic level, we found an increase over generations in the mean values of gamete production, body mass and courtship display rate. Using an animal model, we found that phenotypic changes reflected genetic changes as evidenced by an increase in breeding values for all traits. These changes resulted from selection acting on gamete production and to a lesser extent on courtship display. Selection decreased over years for female gametes, emphasizing the effort of managers to increase the contribution of poor breeders to offspring recruited in the captive breeding. Our results shed light on very fast genetic changes in an exemplary captive programme that follows worldwide used recommendations and emphasizes the need of more empirical evidence of the effects of genetic guidelines on the prevention of genetic changes in supportive breeding.

Highlights

Because of human activities leading to habitat loss, overexploitation, climate changes and spread of invasive species, we are currently facing a so-called sixth extinction (Barnosky et al 2011), with current species loss being 100 to 1000 times faster than previous mass extinctions (Pimm et al 1995)
We investigated the efficiency of a breeding programme that has used genetic dumping strategy and regular integration of new founders to the captive flock of breeders by analysing data from a captive population of Houbara Bustard (Chlamydotis undulata) (Lesobre 2008)
Despite the concerns about genetic changes in captive breeding, most of, if not all, empirical studies have assessed genetic changes in captive populations not submitted to carefully planned genetic management

Summary

Introduction

Because of human activities leading to habitat loss, overexploitation, climate changes and spread of invasive species, we are currently facing a so-called sixth extinction (Barnosky et al 2011), with current species loss being 100 to 1000 times faster than previous mass extinctions (Pimm et al 1995). Threats are sometimes difficult or even impossible to remove (e.g. habitat loss and climate change), leading to implement ex-situ conservation policies to mitigate species loss. Among these ex-situ programmes, supportive breeding is used when the species habitat is still available, but wild populations cannot sustain themselves (e.g. because of overexploitation). The goal of supportive breeding programmes is to increase the effective size of wild populations through release of captive-born individuals (Wang and Ryman 2001; Duschesne and Bernatchez 2002; Wedekind 2002; Blanchet et al 2008), which should substantially decrease extinction risk. Captive breeding is a widely used tool to restore populations of threatened species (Allendorf and Luikart 2007; Frankham 2008)

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