Testing the regional genetic representativeness of captive koala populations in South-East Queensland
Jennifer M. SeddonA,F, Kristen E. LeeB, Stephen D. JohnstonC, Vere N. NicolsonD, Michael PyneE, Frank N. CarrickB and William A. H. EllisB
ASchool of Veterinary Science, The University of Queensland, Gatton, Qld 4343, Australia.
BKoala Study Program, Centre for Mined Land Rehabilitation, Sustainable Minerals Institute, The University of Queensland, St Lucia, Qld 4072, Australia.
CWildlife Biology Unit, School of Agriculture and Food Science, The University of Queensland, Gatton, Qld 4343, Australia.
DDreamworld, Dreamworld Parkway, Coomera, Qld 4209, Australia.
ECurrumbin Wildlife Sanctuary, 28 Tomewin Street, Currumbin, Qld 4223, Australia.
FCorresponding author. Email
Context Captive breeding for release back to the wild is an important component of ex situ conservation but requires genetic diversity that is representative of the wild population and has the ultimate goal of producing ecologically sustainable and resilient populations. However, deﬁning and testing for representativeness of captive populations is difﬁcult. Koalas (Phascolarctos cinereus) are bred for educational and tourism purposes in zoos and wildlife parks in South-East Queensland, but there are drastic declines evident in some wild koala populations in this region.
Aim We compared genetic diversity at microsatellite loci and mitochondrial DNA in two captive koala populations with that of the local, wild koalas of South-East Queensland, determining the degree to which genetic diversity of neutral loci had been preserved and was represented in the captive populations.
Key results The expected heterozygosity and the allelic richness was signiﬁcantly greater in one captive colony than one wild South-East Queensland population. There was low but signiﬁcant differentiation of the captive from wild populations using FST, with greater differentiation described by Jost’s Dest. In contrast, a newly introduced Kullback–Leibler divergence measure, which assesses similarity of allele frequencies ,showed no signiﬁcant divergence of colony and wild populations. The captive koalas lacked many of the mitochondrial haplotypes identiﬁed from South-East Queensland koalas and possessed seven other haplotypes.
Conclusions Captive colonies of koalas have maintained levels of overall neutral genetic diversity similar to wild populationsatmicrosatellitelociandlowbutsigniﬁcantdifferentiationlikelyresultedfromdriftandfoundereffectsinsmall captive colonies or declining wild populations. Mitochondrial DNA suggests that captive founders were from a wider geographic source or that haplotypes have been lost locally.
Implications Overall, tested captive koalas maintain sufﬁcient microsatellite diversity to act as an in situ reservoir for neutral genetic diversity of regional populations.