55 5 Turtles of Cooper Creek – life in the slow lane Arthur Georges and Fiorenzo Guarino Introduction Cooper Creek in central Australia is one of the least likely places to be home to freshwater turtles. When it flows, it flows into one of the largest inland salt lakes in the world, Kati Thanda-Lake Eyre, and on the way fills waterholes, channels and floodplains in the semi- arid and arid regions, with median annual rainfall less than 200 mm/year (Kotwicki 1986). Yet turtles not only survive but thrive in the waterholes and billabongs along Cooper Creek. Freshwater turtles in Australia are not only faced with a scarcity of water, compared to turtles in North America and Asia, but also the variability of when this water is available, given the considerable unpredictability in rainfall and resultant timing and magnitude of river flow and floodplain inundation. Turtles such as the Cooper Creek turtle (Emydura macquarii emmottii Fig. 5.1), which survives in the driest part of our continent, cope in different ways with periodic drying and unpredictability, timing and duration of floods and dry periods. Fig. 5.1. The endemic Cooper Creek turtle is a giant of freshwater turtles and a top predator living mainly in the large waterholes of the Cooper Creek catchment (photo, A. Emmott).