Introduced red foxes (Vulpes vulpes) driving Australian freshwater turtles to extinction? A critical evaluation of the evidence

It has been asserted that introduced red foxes (Vulpes vulpes) destroy similar to 95% of nests of freshwater turtles in south-eastern Australia, are more efficient predators of freshwater turtle nests than Australian native predators, and are driving Australian freshwater turtle species to extinction. Available information was reviewed and analysed to test these assertions. Nest predation rates for all predators including foxes averaged 70% across Australia and 76% for south-eastern Australia compared to 72% for North America where freshwater turtles co-exist with many native predators, including foxes. Predation rates on Australian freshwater turtle nests did not differ significantly where foxes were included in the identified nest predators and where they were not, but sample sizes were very small. Evidence was lacking of foxes being the primary driver of population declines of Australian freshwater turtles, and some turtle populations are stable or increasing despite exposure to fox predation. Australian native species can be effective nest predators, and their role has probably been usurped by foxes to some degree. Where research shows that increased recruitment is necessary to conserve Australian freshwater turtle populations, strategies such as electric fencing of nesting beaches, nest protection cages and ex situ incubation of turtle eggs will probably be more cost-effective than efforts to reduce fox numbers. Further research is also needed to better understand the biological and environmental factors that regulate nest predation rates.

Automated summary

Introduced red foxes in southeastern Australia are said to destroy nearly 95% of nests of freshwater turtles, but available data shows that predation rates are similar to North America where native predators also exist. Australian native species can be effective nest predators, but their role has likely been taken over by foxes to some extent.