Postgraduate Profiles

Aline Gibson Vega

Aline Gibson Vega profile photo

Thesis: Genetic characterisation and behavioural ecology of the western grasswren (Amytornis textilis textilis)

The western grasswren (Amytornis textilis), a small ground-dwelling passerine, has undergone dramatic population decline. In Western Australia it is estimated that it persists in less than 10% of its former range. No formal assessment has been made about the stability of the remaining populations. In addition, the available literature about the ecology of this species is very limited, leading to an overall lack of knowledge in the basic ecology of this highly cryptic species.

Using next generation sequencing, I will look into the population genetics of the remaining subpopulations in Shark Bay, Western Australia, to better understand the importance of landscape heterogeneity on dispersal effects, as well as explore whether the population shows signs of inbreeding depression. I will couple genetic investigation with behavioural experiments to gain valuable insight into multiple facets about the biology of the western grasswren.

Why my research is important

The western grasswren (Amytornis textilis carteri) was once found on Dirk Hartog Island. In the early 1900’s it became extinct due to land degradation as a result of overgrazing from stock. A. t. textilis, the closest living relative to the now extinct island subspecies, is to be translocated to the island under the Dirk Hartog Island Ecological Restoration Project, managed by the Department of Biodiversity, Conservation and Attractions. However, to create a robust translocation strategy, detailed ecological information is required of the species of interest – of which is significantly lacking in the western grasswren. It is unclear how to source the animals based on 1) genetics (no knowledge of population genetics or genetic diversity), 2) founder population size (no knowledge of the impact of genetics on their reproductive output), and 3) song dialect (no knowledge on the effect of song dialect between the two subpopulations). Hence, the data outputs from this project will be used to inform the translocation strategy to be implemented for the western grasswren. By increasing the chance of a successful translocation, not only will the western grasswren species be returned to Dirk Hartog Island, but this new population will serve as an insurance population to the uncertain stability of the mainland populations.

Funding

Female western grasswren. Image credit: Aline Gibson Vega

Feb 2019

Feb 2022