Shanaz Masani, PhD candidate at The University of Sydney.

When I moved to Sydney from the UK to begin my PhD at the University of Sydney, I couldn’t wait to explore the unique wildlife that Australia has to offer, something which has always been so alien and intriguing to me. I certainly didn’t expect my research to focus on understanding the behaviour of invasive predators such as the black rat (Rattus rattus) and the European red fox (Vulpes vulpes). Yet the native wildlife which I was so excited to learn about is under threat by these invasive mammalian predators, which were introduced to Australia during the European settlement over 200 years ago. Since then, they have spread across Australia and have had devastating impacts on Australian flora and fauna.

A massive amount of effort and resources have been dedicated to controlling these species and minimising their impacts, such as building predator-proof fences, as well as using lethal control such as toxic baits and shooting. Sadly, these invasive predators continue to persist and, as a result, a range of native species have become extinct or are in decline. For example, Ground-nesting shorebird species such as the little tern (Sternula albifrons) and pied oystercatcher (Haematopus longirostris) are now endangered in New South Wales, with nest predation by foxes being listed as a major threat. Avian population declines are not only an issue in Australia but are a global conservation problem.

As invasive predators continue to persist and native prey populations continue to decline, it’s time to try a new approach – it’s time to start thinking like a predator.

Invasive mammalian predators are olfactory-driven; they use odour to detect and locate prey. Therefore, if you alter the olfactory cues predators experience in their environment, you can make it more difficult for predators to find the prey in the first place. This technique of altering the scent cues which animals experience in their environment is referred to as olfactory misinformation. One form olfactory misinformation is odour pre-exposure.

Any individual moving through their habitat is navigating a sensory-rich environment, being bombarded with a plethora of different sensory cues. When foraging, one must use limited information to identify if these cues are reliable, rewarding and thus worth following, and which are unreliable, unrewarding, and thus worth ignoring. But because there are so many different cues which an individual is experiencing at any given time, it is too cognitively taxing to register and process all of them. An adaptive trait to cope with this information overload is to habituate to non-useful cues. In the context of foraging, if following a scent cue has resulted in failed foraging attempts, an individual would be less motivated to pursue this cue in the future and will habituate to this unrewarding cue so it can focus its limited cognitive energy on more useful cues.

Odour pre-exposure uses this flexible learning of invasive predators. By pre-exposing predators to unrewarding prey odour before prey are present (e.g., before nesting season), this leads them to habituate to it. Once prey appears in the system (e.g., during nesting season), the predators are no longer motivated to follow their odour cues and therefore don’t find the prey as quickly, therefore reducing predation rates. (When explaining this to family and friends this is the point when their eyes light up and they say ‘So clever yet so simple!)

My research aims to improve our understanding of predator responses to odour pre-exposure so it can be rolled out as an effective conservation management tool to reduce nest predation of vulnerable ground-nesting shorebirds during nesting season. Or as I like to put it, I’m exploring how predators use information in their environment so I can trick them ignoring vulnerable prey.

In a time where fake news is so powerful and prevalent in our society, it’s time to use misinformation for good!

Shanaz Masani was awarded a Holsworth Wildlife Research Endowment to support this research.