The red fox (Vulpes vulpes) is the dominant predator of lizard models in a semi-arid landscape, and predation risk is reduced by vegetation cover

Abstract

Vegetation structure affects predation risk in ecosystems around the world. Spinifex (Triodia spp.) is a foundation species in fire-prone grasslands and woodlands that cover more than a third of Australia's land surface. Spinifex habitats are known for their high reptile diversity, and it has long been hypothesized that the spiky structure of spinifex dissuades predators, thereby providing a haven for prey. We investigated predation risk to small lizards in semi-arid Australia by identifying teeth marks on replica model plasticine lizards, in combination with remote camera surveillance, to quantify and verify predation risk across several microhabitats, including spinifex. The introduced red fox (Vulpes vulpes) was identified as the main predator of lizard models, constituting 43.9% of all predation attempts. Lizard models placed at the base of spinifex plants (Triodia scariosa) were significantly less likely to be attacked than all other microhabitat types (bare ground, leaf litter, burrows), confirming the hypothesis that spinifex reduces predation risk. Our results support recent work that has highlighted foxes as a significant predator of Australian reptiles. Given that fire is a driver of spinifex cover in arid ecosystems, our findings have implications for interactions between fire and invasive predators in Australian ecosystems.