Captive-raised juvenile hawksbill ( Eretmochelys imbricata ) turtles display naturalistic behaviours upon ocean release

Some conservation programs keep turtles temporarily under human care with the intention of releasing them later to strengthen wild populations. Historically, researchers have questioned whether key survival behaviours might be lost during captive-raising, potentially reducing post-release survivability. Yet no published studies have examined the in-water behaviour of captive-raised turtles in a way that allows comparison with wild conspecifics – an important gap for the critically endangered hawksbill turtle (Eretmochelys imbricata). In this study, eleven hawksbill hatchlings collected from the wild (−11.167, 143.017) were raised for approximately two years in a purpose-built research facility before being released into the Great Barrier Reef (−18.633, 147.067). Following release, turtles were filmed in-water for up to 25 min, and their behaviours were described, categorised, and analysed using Fisher’s exact and Kruskal – Wallis tests. Nine behaviours relevant to survival were observed, including swimming, escape responses, resting, and investigative actions. Locomotive behaviours accounted for 60.1% of observation time, comparable with published data for wild turtles (33.4–78.9%). All turtles were able to dive and surface effectively, demonstrating appropriate buoyancy control and dive profiles consistent with free-living hawksbills. These findings suggest that captive-raised juvenile hawksbill turtles can retain naturalistic behaviours essential for immediate post-release survival.