In regions where safeguarding valuable plants is imperative for ecological or economic reasons, the impact of local herbivores poses a significant threat. Traditionally, solutions involve lethal measures against these animals; however, ethical and social concerns are pushing towards alternative approaches. Acknowledging this shift, a recent study by a dedicated team has unveiled a groundbreaking method that utilizes herbivores’ reliance on smell to deter them from vulnerable native tree seedlings.
Published in Nature Ecology & Evolution, the study explores the potential of manipulating herbivores’ olfactory senses to guide them away from targeted plants. The research, conducted by the team, reveals a novel strategy involving the creation and deployment of key smells that herbivores actively avoid. By mimicking the scent profile of a shrub detested by herbivores, the team successfully reduced the likelihood of wallabies consuming native tree seedlings.
The study acknowledges the pressing issue of hungry herbivores, which pose challenges for conservationists, farmers, and foresters. These herbivores can wreak havoc on revegetation efforts and post-fire recovery, causing substantial damage to billions of dollars worth of forestry and agriculture each year. Moreover, the long-term survival of threatened plant species is at risk due to the impact of herbivores.
The research takes a pioneering approach, shifting the focus from what herbivores are eating to how they find their food. By exploring the olfactory landscape that herbivores navigate, the study introduces the concept of “olfactory misinformation” or “chemical camouflage.” Similar approaches have proven effective in reducing invasive predators in New Zealand and controlling house mice in Australia.
In this study, the team focused on swamp wallabies foraging in an eucalypt woodland in Australia. Utilizing an innovative method, the researchers identified the key scent compounds of a plant known to be avoided by wallabies, Boronia pinnata. These compounds were then synthesized to create “informative virtual neighbors” that mimicked the scent of the detested plant. Placed strategically around eucalypt seedlings, these virtual neighbors effectively reduced the likelihood of wallabies consuming the targeted plants.
The success of this study offers a promising avenue for herbivore management. By influencing herbivores’ behavior through olfactory manipulation, this non-lethal and cost-effective tool could prove instrumental in protecting valuable plants. The concept of virtual neighbors, as demonstrated in this study, holds potential for broader applications across various herbivores, offering a sustainable and humane approach to mitigate the challenges posed by herbivore-induced damage.