News

Postgraduate Excellence Prize awarded for rat-impact research



13 November 2014

Helen Smith has won the 2014 Postgraduate Excellence Prize for her work investigating how natives react to an exotic invader.

Prize winner Helen Smith investigates how native skinks respond to exotic rats.
Prize winner Helen Smith investigates how native skinks respond to exotic rats.

The Postgraduate Excellence Prize was announced late last week with Helen Smith, of the Behavioural Ecology and Conservation Research Group, taking the top prize. The other finalists for the prize were Sebastián Duchêne, Aaron Greenville and Isobel Ronai.

Helen's study investigated the impact of the exotic invader Rattus rattus, by observing the reaction of native animals to a new predator. "Australia is an interesting system to consider the impacts of exotic rodents, since native Rattus species also persist," explained Helen. "Unlike other regions that are evolutionarily rat-free - such as many islands - native wildlife in Australia may respond differently to the arrival of exotic Rattus." The theory being that, for example, native lizards will respond to invading rats as if they were natives, because the lizards have co-evolved with native rats. Native or exotic - the lizards will respond the same.

"I predicted that skinks would show muted responses to the removal of black rats owing to their shared evolutionary history with endemic Rattus species," she said. "I found that while Delicate Skink (Lampropholis delicate) showed substantial increases in numbers, these increases were, nonetheless, smaller than those reported in analogous removal experiments on other exotic predators." So the skinks responded positively to the removal of rats, but not as much as you would expect if the skinks were rat-naïve. "I suggest that Australian skinks may respond appropriately to the predatory behaviour of exotic rats because they coevolved with endemic Rattus species."

"My work raises the thorny issue of how to manage an exotic predator that is arguably functioning as a native predator (of lizards at least) in the Australian system." From a management perspective, this work asks about the usefulness of classifying animals as 'exotic' and the appropriateness of wide sweeping removal of exotics. "We need to move away from classifying species as exotic or native, but rather examine how they function in the environment."

2014 finalists: Sebastián Duchêne, Aaron Greenville and Isobel Ronai, with Head of School Associate Professor Clare McArthur
2014 finalists: Sebastián Duchêne, Aaron Greenville and Isobel Ronai, with Head of School Associate Professor Clare McArthur

When asked about winning the Postgraduate Excellence Prize, Helen said "It certainly makes all the hard work of my PhD feel worth it, but I could not have done it without the fantastic support and enthusiasm of my supervisor Associate Professor Peter Banks."

The other finalists presented on a diverse range of topics including; the timescale of virus evolution (Duchêne); how the web of arid life changes with a changing climate (Greenville) and the mechanism of worker sterility in honey-bee colonies (Ronai). The standard of scientific research and the quality of the presentations was uniformly excellent. Congratulations all!