Evolution in aviculture: genetic diversity and divergence head-colour morph frequencies in the domesticated Gouldian finch

2020-05-13T06:42:06Z (GMT) by Peri Bolton Simon Griffith
ABSTRACT: Aviculturists are enthusiastic to be included in conservation efforts by providing expertise or genetic stock to support captive-breeding or reintroduction programs, but little work has explored these possibilities. Bringing organisms into captivity can have rapid and profound effects on behaviour, physiology and population genetic diversity, which can have important consequences for viability of reintroduction and the extrapolation captive experiments to wild counterparts. The Gouldian finch (Erythrura gouldiae) is a popular avicultural species that is endangered in the wild, and potential flagship for such reintroduction efforts. Experiments on domesticated birds have shown natural head-colour morphs are correlated with ecologically relevant traits, and subject to high offspring mortality when interbred. Here we use genetic methods to explore the reintroduction potential of avicultural genetic stock from a neutral and a functional perspective. We used microsatellite and mitochondrial markers to characterise genetic diversity within and among breeders in the broader population of domesticated Gouldian finches in Australia, and with respect to natural head-colour morphs and artificially selected plumage variation. Domesticated Gouldian finches have lost 31-48% of genetic diversity compared to current wild populations and exhibit hierarchical genetic structure. Head-colour genotype frequencies were substantially different from the wild, and showed strong evidence of selection, or non-random mating. Given the previously established relationship between head-colour and functional traits, and possible adaptation to captivity, we suggest caution before introducing domesticated stock into the wild.