The rakali, Hydromys chrysogaster, also known as the ‘water-rat’, lives in burrows on the banks of water ways and opportunistically feeds on a range of aquatic and terrestrial prey (e.g. aquatic invertebrates and vertebrates, including birds’ eggs and water birds). Rakali are beasts! They can reach up to about 1.2 kg in mass. Individuals are adapted for an aquatic lifestyle with partially webbed hind legs, waterproof fur and streamlined body shape.
Rakali are present on Barrow Island, off the Western Australian coastline, likely stemming from a small population that became isolated from the mainland when sea levels rose around 7,000 years ago. Genetic evidence suggests that the Barrow Island rakali have limited genetic diversity and albinism is common for this population (Bettink, 2016).
There is also a plan to reintroduce Rakali from Barrow Island to the Montebello Islands mid-2021 as the final species for the Montebellos Renewal Plan, and Gorgon Threatened Species Translocation Plan. Decisions after that will be according to findings of this proposed PhD project.
This project will (1) compare monitoring methods to optimise surveys, (2) quantify home range of water rats, (3) undertake genetic analysis to determine population composition (i.e. help to determine the best source populations for the translocation), (4) track and monitor water rats post translocation.
This project involves a range of field-based or lab-based studies around better understanding the biology of the Barrow Island rakali, and careful behavioural studies to understand the movement and survival of the translocated population on the network of islands. This project has direct conservation management outcomes and will therefore suit a student who is interested in developing practical skills in conservation science.
Bettink, K. A., (2016) Shedding light on rakali: Genetic and morphological differentiation in the Australo-Papuan golden-bellied water rat (Hydromys chrysogaster), with notes on the Barrow Island population. PhD thesis, The University of Western Australia.