Home ranges of Fitzroy River turtles ( Rheodytes leukops) overlap riffle zones: potential concerns related to river regulation

Abstract

Ten Fitzroy River Turtles ( Rheodytes leukops) were followed by radio telemetry near the type locality. Robust estimates of female home ranges (for >10 fixes) spanned a range that approximated the average distance from a riffle zone. Home range estimates (for all local fixes) averaged 2.4 ha by the minimum convex polygon method, 4.0 ha by a 90% core-weighted kernel method, and 417 m for the range span. A long distance excursion was recorded for a female that travelled 6.8 km downstream and eventually returned to the riffle zone after six months. Sixty-two percent of locations for females tracked in the 1997 dry season were in depths <1.1 m. Mean movement rate was 20 m/day (95% confidence interval 10–30 m/day, range 0–350 m/day). Mean distance to the closest riffle was 310 m (95% confidence interval 280–340 m, range 0–700 m). The findings raise conservation concern about loss of riffle habitats, which this endemic and vulnerable turtle was associated with throughout the year.