Lead author Patt Finnerty in the field.
“So, we created artificial odours that mimicked the smell of plant species they naturally avoid, and this gently nudged problematic herbivores away from areas we didn’t want them to be.
“Given that many herbivores use plant odour as their primary sense to forage, this method provides a new approach that could be used to help protect valued plants globally, either in conservation work or protecting agricultural crops.”
The experiment, conducted in Ku-ring-gai Chase National Park in Sydney, used the swamp wallaby as model herbivore. The researchers selected an unpalatable shrub in the citrus family, Boronia pinnata, and a palatable canopy species, Eucalyptus punctata, to test the concept.
The study compared using the B. pinnata odour mimic and the real plant and found both were equally successful at protecting eucalypt seedlings from being eaten by wallabies.
As part of his doctoral research, Mr Finnerty has also tested the method successfully with African elephants, but that fieldwork does not form part of this research paper.
Previous attempts to use repellent substances, such as chilli oil or motor oil, to control animal consumption of plants have inherent limitations, Mr Finnerty said.
“Animals tend to habituate to these unnatural cues and so deterrent effects are only temporary,” he said.
“By contrast, by mimicking the smell of plants herbivore naturally encounter, and avoid in day-to-day foraging, our approach works with the natural motivators of these animals, with herbivores less likely to habituate to these smells.”