Genetic impacts of conservation management actions in a critically endangered parrot species

Abstract

Establishing populations of endangered species in captivity is becoming an increasingly common component of species recovery programs for insurance against extinction, and/or for reintroductions. It is important for the success of these efforts that captive populations are genetically representative of wild source populations, and that genetic diversity is maintained over time. Our study presents SNP data from wild and captive populations of the critically endangered Australian orange-bellied parrot (Neophema chrysogaster). We examine the genetic effects of a decision made in the 2010/2011 breeding season to recruit half of the juvenile cohort (n = 21), from a wild population in decline, to supplement an existing captive program. We report that heterozygosity among wild birds decreased in the years after this action. Following multiple releases of captive-reared birds back into the wild (occurring annually since 2013), captive and wild populations have attained similar overall levels of heterozygosity, and genetic differentiation between these populations is low. Parentage analyses confirm that captive-bred released individuals have successfully paired with wild birds and produced offspring. Our study suggests that translocation of wild individuals into captivity, from wild populations in decline, can potentially have deleterious lasting impacts on genetic diversity levels in these populations. However, our data also confirm that in captivity, founder diversity can be successfully preserved over time, and addition of wild founders can improve captive population health. The genetic diversity retained in captive populations can also be reintroduced to wild populations at a later date, provided that captive-release individuals are able to reproductively contribute to their recipient population.