Genetic data reveal the secret world of one of Australia's more elusive marsupial species.
Trying to catch even a glimpse of some of Australia’s shy marsupial species in the wild can be quite a challenge, let alone observing their behaviour long enough to understand how their populations function. But for a species under threat from introduced predators, and continued loss of habitat, having this information is vital to effective conservation and management.
With our colleagues from the NSW Office of Environment and Heritage and Victorian Department of Environment and Primary Industries, we have been studying the secret life of the threatened, but little studied long-nosed potoroo. A pot-o-what you might ask? Potoroos are small marsupials – the size of a small rabbit- that closely resemble the wallabies and kangaroos they are most related to. They play a significant role in maintaining the health of forest ecosystems and therefore their conservation is pretty important.
To help uncover the dynamics of potoroo populations we have been using patterns in their DNA as a fantastic short-cut to spending hours trying to observe their behaviour in dense undergrowth in the wild. Using these methods we have found potoroos have small neighbourhoods, which results in genetic structuring between populations located as little as 6 km apart within continuous habitat. So, somewhere like a National Park probably contains lots of separate localised potoroo communities.
Why do potoroos stay so close to home? Well, potoroo daughters stick close to their mums, setting up home nearby, often next door. We found females in proximity (~100m) to one another tended to be highly related. Males tended to be the dispersers, moving further than females which reduces the risk of inbreeding within the neighbourhood, but given they don’t have to move too far to do this, gene flow across the larger landscape happens slowly and only over long a period of time.
We can now tell managers that preserving or re-establishing habitat connectivity is essential to potoroo population persistence as even within continuous habitat dispersal is limited. It also means that gene flow between potoroo populations now in isolated patches of bush is likely to be non-existent and so these populations will require special care to ensure their survival.
Dr Greta Frankham
Dr Mark Eldridge
Senior Research Scientist
Frankham GJ, Handasyde KA, Norton M, Murray A, and Eldridge MDB, (2014) Molecular detection of intra-population structure in a threatened potoroid, Potorous tridactylus: conservation management and sampling implications.Conservation Genetics.
Frankham, G. J., Reed, R. L., Eldridge, M. D., & Handasyde, K. A. (2012). The genetic mating system of the long-nosed potoroo (Potorous tridactylus) with notes on male strategies for securing paternity. Australian Journal of Zoology.60(4) 225-234