Flatbacks and foxes: Using cameras to capture sea turtle nest predation

Flatback turtles (Natator depressus) are marine turtle species endemic to Australia. There is currently insufficient data to allocate a conservation status for this species by the International Union for Conservation of Nature (IUCN). Predation upon turtle nests is recognised as a key threatening process to marine turtle species (Commonwealth of Australia, 2003) along with a number of other key anthropogenic threats. The Pilbara region in north-west Western Australia has a number of regionally significant rookeries including the Mundabullangana (Munda) Rookery located on the mainland. Fox predation is known to occur at the Munda rookery however the predation rate and impact of predators disturbing nests is unknown. Physically observing turtle nests daily for signs of predation is time consuming and requires extensive resources to access remote locations. Camera and non-camera sites were installed at the time of oviposition by flatback turtles to monitor the entire incubation period. Daily observations were undertaken and c² tests were applied to determine effectiveness of camera monitoring as opposed to physical observation and impacts upon nests. Foxes were found to be the primary predator of turtle nests at Munda rookery. The predation rate by foxes was found to be 26% at Munda rookery with 42% of predated nests predated more than once. Foxes were found to be a late term nest predators with 11 out of 19 nests predated in the period of time between post-hatching and pre-emergence. Cameras were found to be significantly better than physically observing turtle nests for incidents of predation. Cameras were also able to provide behavioural data on target species as well as identify avian and other native faunal predators of hatchlings. Predation of nests at Munda were significant and warrant the implementation of fox mitigation strategies and actions to protect nests. Cameras are a useful tool for monitoring turtle nesting beaches for predators, however, the research location, weather conditions and ease of accessibility are factors which need to be considered, as cameras do require more frequent cleaning in beachenvironments than when located in less exposed sites and removal may be necessary during extreme weather events.