Tracking Tiny Turtles—Movement, Survival, and Habitat Use of Hatchling Western Saw-Shelled Turtles (Myuchelys bellii) During Their First Two Weeks in the Wild

Abstract

Turtles are among the world's most endangered vertebrates, with habitat destruction and predation as major contributors to population declines. Hatchling release programmes are increasingly implemented to enhance juvenile recruitment in threatened populations, but limited understanding of hatchling ecology impedes evidence-based management. To address this, we tracked western saw-shelled turtle (Myuchelys bellii) hatchlings using VHF micro-transmitters to quantify movement, habitat preferences, and survival during their first 2 weeks in the wild. We also compared soft-release and hard-release methods. Hatchlings moved an average of 47–62 m daily, dispersing both up- and downstream. Movement was influenced by water temperature and level, with higher water levels prompting increased downstream movements. The maximum cumulative distance moved by an individual hatchling was 2008 m over 13 days of tracking. Strong diurnal movement patterns were observed. Hatchlings predominantly used vegetation along the water's edge (99% of observations). They preferred shoals over steeply descending underwater banks and selected sedge-dominated areas more often than expected, avoiding phragmites-dominated areas, bare banks, and open water. Hatchling survival rates exceeded 90% during the tracking period. A comparison between soft- and hard-release methods revealed no advantage for soft-release animals. Our findings suggest that releasing M. bellii hatchlings into preferred microhabitats could enhance conservation outcomes. Furthermore, we highlight the crucial role of vegetative cover along stream edges in providing shelter for hatchlings.