Understanding how the genetic structure of Gouldian populations varies can give important insights in the levels of movement between different areas and the impact of various selection pressures on the species in the wild and in captivity.
In July 2017 at the 6th International Finch Convention in Brisbane, Peri Bolton from Macquarie University presented some interim results from the “Feathers for Science” project, which explored the genetic diversity of Gouldian finches in avicultural collections across Australia. Using two types of genetic information, the results show that genetic diversity is lower in the domesticated birds than in the wild. There is evidence for genetic differences between breeders, towns and states, which exceed those differences found between distant sampling sites in the wild. Similarly, there is evidence for genetic differences between red and black morphs in the domesticated population, and the frequency of genotypes underlying head-colour has changed significantly in the domesticated population.
Dr Bolton has now completed her PhD and STGF has invested funds to cover further DNA sequencing of samples from domesticated and wild Gouldian finches in order to explore how domestication and artificial selection has changed the genome of this species. The work is being conducted in the USA and uses advanced whole genome resequencing techniques in collaboration with global experts in bird genomics at the Cornell Laboratory of Ornithology (http://www.birds.cornell.edu/), Ithaca, New York. Peri has now received full sequence data for a number of individual Gouldians and she will then commence a full comparative analysis.
This information will help to further clarify findings from Peri’s PhD which show:
• There is no clear population genetic structuring of the wild populations across northern Australia, suggesting a reasonably high level of movement and interchange across the range
• there is no indication of the genetic incompatibility (between red and black birds) in the wild populations that we earlier observed previously in the captive population
• There has been a significant reduction in the level of genetic diversity of the current wild population compared to that revealed by historical skins in the museum collections (from before 1920)
Obviously much more to be revealed.