Living Olfactory Barrier Trials Using Ribes odoratum for Threatened Fauna Nest Protection in Southern Australia

Abstract

Rooting and digging by invasive feral mammals—principally feral pigs ( Sus scrofa ), feral deer, and rabbits—causes severe direct predation of eggs and nest destruction across critically threatened Australian fauna, including the vulnerable malleefowl ( Leipoa ocellata ), the endangered Eastern Ground Parrot ( Pezoporus wallicus ), and multiple freshwater turtle species protected under the Environment Protection and Biodiversity Conservation Act. Current management relies on physical exclusion fencing, baiting, and lethal culling—methods that are costly and difficult to sustain at landscape scale. Here, we present a research proposal for in situ trials of Ribes odoratum Pursh (clove currant/buffalo currant; Grossulariaceae ) as a living olfactory barrier planting around threatened fauna nesting sites in three geographically distinct Australian regions. The proposal draws on the established hypothesis that the genus Ribes L. produces a continuously emitted suite of monoterpene and sesquiterpene volatile organic compounds from glandular trichomes across all above-ground plant tissues—documented to include 19 monoterpenes and 20 sesquiterpenes in bud essential oil [1] —that may act as olfactory deterrents disrupting ground-level scent-tracking in rooting mammals. Ribes odoratum is selected over R. nigrum L. for its lower winter chilling requirement and tolerance of hot, semi-arid conditions across the priority trial sites. Three case study sites are proposed: 1) malleefowl mound complexes in the Grampians-Little Desert-Mallee corridor, targeting feral deer and feral pig mound disturbance; 2) Eastern Ground Parrot heathland nesting sites in coastal southeastern Victoria and eastern South Australia, targeting feral pig rooting; and 3) freshwater turtle nesting banks in southeastern Queensland and northeastern New South Wales, targeting feral pig egg predation. Experimental design, volatile organic compound sampling methodology, and measurable outcomes are outlined for each site. This proposal represents the first systematic investigation of Ribes volatile organic compound emissions as a non-lethal, habitat-integrated deterrent in a conservation context.