Oral Presentation AFSS/NZFSS Joint Conference 2019

Effects of urbanisation and hydrological change on a freshwater turtle (#77)

Anthony Santoro 1
  1. Harry Butler Institute, Murdoch University, Perth, Western Australia, Australia

Land use modification, climate drying, and invasive species threaten the south-western snake-necked turtle (Chelodina colliei) in Perth, Western Australia. The extent of impact of these stressors on C. colliei is not known but likely includes increased wildlife-vehicle incidents and predation, and reduced availability and quality of nesting and aquatic habitat. To investigate how these stressors may be altering the turtle's ecology, I used radio-telemetry over two annual cycles to track 50 female turtles in urban wetlands experiencing a continuum of water regimes and a variety of surrounding terrestrial land use modification. Nest predation and turtle corpses were also recorded. It was hypothesised that: the species would move seasonally among the wetlands to maximise access to inundated habitats;  nesting ecology would vary based on available habitat; and predation and vehicle related mortality would increase in modified habitats. The study revealed limited movement between wetlands with turtles aestivating rather than migrating, suggesting that continued climate drying will have implications for population viabilities if individuals do not migrate to more suitable wetlands as hydrology changes. Land use modification is placing pressure on the populations through considerable mortality due to vehicle strikes, mostly of nesting females. Feral animal predation was also a major issue affecting both adults and embryos, significantly reducing the populations reproductive potential. The presence of the European red fox (Vulpes vulpes) was confirmed using wildlife cameras. These results indicate that urgent management of turtle populations based on a detailed understanding of their ecology and interactions is needed for these urban ecosystems.