Fake turtle nests measure the effect of fox baiting

NRM NEWS - FEBRUARY 2021 - AQUATIC SYSTEMS

By Jamie Hearn
Senior Land Services Officer - Central Murray Ramsar project
P: 03 5881 9925 | M: 0447 420 789 | jamie.hearn@lls.nsw.gov.au

The Murray region is home to three different turtle species. The broad-shelled turtle (Chelodina expansa), the eastern long-necked/ snake-necked turtle (Chelodina longicollis), and the Murray/ Macquarie turtle (Emydura macquarii ssp. macquarii).

Research has shown a 60 - 90% decline in numbers across the Murray-Darling Basin.  This decline is primarily due to predation by foxes which can destroy up to 95% of turtle nests at a site. We know that 1080 baiting reduces fox numbers, but we don't know if it results in increased turtle hatchling survival as one fox can still destroy many nests in one night.

Working with Saunders Spraying (baiting contractor), La Trobe Uni, Barratta Station, and Yarkuwa Indigenous Knowledge Centre, the Ramsar Project has recently completed a 20 week, intensive fox baiting program around two known turtle nesting sites.

Four unbaited control sites and the two baited sites had fake turtle nests (buried chicken eggs) installed. The program aims to get through the nesting season with the buried chicken eggs remaining intact and the nest undisturbed by foxes.

The results between the baited and unbaited sites were significant, with most nests at the unbaited sites being destroyed in the first few days while several nests in the baited areas lasted up to 10 weeks.

This information has led to a changed approach to next year's baiting program and the plan to create a baiting 'buffer' out from the lagoons to reduce pressure on the nest sites further.

Unfortunately, we won't know precisely how effective the baiting program is for a few years. This is when any surviving turtles will be large enough to be caught in the sites' annual trapping program. Still, with another two nesting seasons of baiting planned, we hope to have enough information to undertake future targeted baiting projects with the confidence we are positively impacting turtle numbers.

Left to right: Tracy Hamilton, Yarkuwa; Liticia Ross, Yarkuwa; Tim Saunders, Saunders Spraying; Jamie Hearn, Murray LLS; and James Van Dyke, La Trobe University.

This project is supported by Murray Local Land Services, through funding from the Australian Government’s National Landcare Program.