The risk of inter‐specific competition in Australian short‐necked turtles

Abstract

AbstractFreshwater turtles are threatened globally; however, short‐necked turtles in Eastern Australia have been particularly successful in exploiting natural and man‐made permanent water bodies. The catchments of eastern Australia offer a unique opportunity to compare the diets of species in habitats where both genera co‐exist, but only one genus is usually locally dominant. We compared the diets of species ofEmyduraandMyuchelysandFlaviemysin inland and coastal catchments in eastern Australia to determine the breadth of diets. We also conducted a more in depth study of the ecology and habitat preferences of the Bellinger River Emydura (Emydura macquarii macquarii) andMyuchelys georgesi.We found that diets of short‐necked turtles on the east coast of Australia are separated by water conditions, and largely independent of species and location. Species ofMyuchelysandEmyduraare omnivorous. A high proportion of their food is from benthic macro‐invertebrate communities in clear water. Terrestrial invertebrates and filamentous algae are present more in the diets of species inhabiting turbid water. Competition between species ofEmyduraandMyuchelys/Flaviemysis likely to occur when in sympatry, because species ofEmyduracan adapt their diets to various habitats and water quality.Myuchelys georgesiis restricted to, but common in, the Bellinger River. Interspecific competition may occur betweenE. m. macquariiandM. georgesibecause of similar habitat preferences, diets and life histories.Emydura m. macquariiis not unique to the Bellinger River and hybridization with the endemicM. georgesiis a threatening process.