Data from: Pedigree analysis reveals a generational decline in reproductive success of captive Tasmanian devil (Sarcophilus harrisii): implications for captive management of threatened species

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 utilise 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.