Habitat use and movements in an upland population of Johnstone River Snapping Turtles, Elseya irwini

Our objectives were to ascertain the patterns of movement and habitat use in upland populations of the regionally restricted Johnstone River Snapping Turtle, Elseya irwini, in tropical Queensland, Australia. Between October 2014 and October 2015, we radio tracked eight (four male and four female) Elseya irwini in the headwaters of the Johnstone River in far north Queensland. Over this time, we made 342 radio fixes for males and 353 for the four females, with fixes varying between 78 and 90 per animal. There was not a significant relationship between the distances a turtle moved from its point of release and the number of days since release, suggesting turtles restrict their movements to a home range. While the movement of males was more variable than females, male movement did not differ significantly from females in linear range span or total linear distance. Linear home range of the eight turtles varied between 387 and 1128 m. Daily displacement distances were small (9–31 m) with the four individuals with the largest and smallest displacement distances being male. Other than one male, which disappeared from the area for a period of six weeks, there was no indication of long-range migratory movements. This species appears to be largely sedentary with small home ranges and short daily movements. Long range movements do occur but appear to be extremely rare. A sedentary lifestyle potentially makes this turtle more susceptible to localized negative impacts such as habitat degradation, disease, and feral animal predation of nests.