Mitigating Fox Predation on Freshwater Turtle Nests: Comparing Effectiveness of Three In Situ Protection Methods.

Abstract

Freshwater turtles in the Murray-Darling Basin (MDB), Australia, have declined since the 1970s. Intense nest predation by introduced foxes likely contributes to these declines, disrupting juvenile recruitment needed to sustain populations. Traditional lethal control methods, such as baiting and shooting, have proven inadequate, highlighting the need for innovative conservation strategies. We tested three nest protection methods-fenced nesting beaches, artificial floating islands (artificial nesting habitat), and individual mesh covers-for reducing fox predation. Using artificial turtle nests across protected and unprotected plots, we monitored nest predation with remote cameras and confirmed nest status through excavation. On average, nest predation was lowest on artificial islands (17%), followed by fences (37%) and mesh (40%). All protection methods significantly reduced depredation compared to unprotected controls (85% destroyed). Unprotected nests were almost exclusively depredated by foxes, while protected nests saw more predation from native animals. Native predator species did not differ among protection treatments. Our findings underscore the potential for artificial floating islands as a valuable conservation tool. Further research into optimizing nest protection and understanding ecological impacts is critical for improving recruitment and reversing declines of freshwater turtle species.