title: Pedigree analysis reveals a generational decline in reproductive success of captive Tasmanian devil (Sarcophilus harrisii): implications for captive management of threatened species.
abstract: Captive breeding programs are an increasingly popular tool to augment the conservation of threatened wild populations. Many programs keep detailed pedigrees, which are used to prescribe breeding targets to meet demographic and genetic goals. Annual breeding targets are based on previous productivity, but do not account for changes in reproductive success that may occur over generations in captivity and which may impair the ability of a program to meet its goals. We utilize a large studbook from the Tasmanian devil (Sarcophilus harrisii) captive breeding program to investigate biological, genetic, and environmental factors that affect variation in reproductive success among individuals and over generations of captive breeding. Reproductive success declined with increasing generations in captivity: wild-born females had a 56.5% chance of producing a litter compared to a 2.8% chance for generation 5 captive-born females (N = 182) and when they did, wild-born females produced more offspring (3.1 joeys, 95% CI: 2.76-3.38, compared to 2.7 joeys, 95% CI: 2.55-2.90, in captive-born females [N = 105]). Reproductive success also declined as dam age at first breeding increased. Our results reveal a conflict with the widely cited conservation strategy to limit opportunity for selection by extending generation length through delaying reproduction, as captive breeding programs that delay female breeding with this goal in mind risk reduced productivity. Our data demonstrate the benefit of pedigree analysis to identify biological processes that reveal crucial trade-offs with conservation best-practice.
authors.affiliation: School of Life and Environmental Sciences, Faculty of Science, University of Sydney, NSW 2006, Australia; Zoo and Aquarium Association Australasia, Mosman, NSW 2088, Australia; San Diego Zoo Global, San Diego CA, USA.
authors.forename: Katherine A
authors.initials: KA
authors.lastname: Farquharson
authors.affiliation: School of Life and Environmental Sciences, Faculty of Science, University of Sydney, NSW 2006, Australia; Zoo and Aquarium Association Australasia, Mosman, NSW 2088, Australia; San Diego Zoo Global, San Diego CA, USA.
authors.forename: Carolyn J
authors.initials: CJ
authors.lastname: Hogg
authors.affiliation: School of Life and Environmental Sciences, Faculty of Science, University of Sydney, NSW 2006, Australia; Zoo and Aquarium Association Australasia, Mosman, NSW 2088, Australia; San Diego Zoo Global, San Diego CA, USA.
authors.forename: Catherine E
authors.initials: CE
authors.lastname: Grueber
mesh_terms: D000822:Animal Husbandry / Q000592:standards; D000818:Animals; D000836:Animals, Zoo / Q000502:physiology*; D001947:Breeding; D003247:Conservation of Natural Resources; D056727:Endangered Species; D005260:Female; D056084:Genetic Fitness / Q000502:physiology*; D008394:Marsupialia / Q000502:physiology*; D010375:Pedigree; D012098:Reproduction / Q000502:physiology
keywords: adaptation to captivity; captive breeding; inbreeding; reproduction; senescence