Trade-offs of nest relocation in hawksbill turtles: effects on hatching success and hatchling performance

Nest relocation is widely used to safeguard sea turtle clutches from inundation, predation, and human disturbance, yet the consequences for hatchling quality remain uncertain, particularly under extreme thermal regimes such as those of the Arabian Gulf. The present study evaluated whether incubation method influences both hatching success and hatchling morphological and locomotor traits in hawksbill turtles (Eretmochelys imbricata) nesting in Qatar by comparing three strategies: in situ, ex situ (relocated to protected hatcheries), and split-clutch (relocated and divided evenly between two nests), without direct measurement or experimental control of nest temperatures. Ex situ relocation significantly increased hatching success relative to in situ nests, while split-clutch achieved the highest success overall. However, ex situ hatchlings showed reduced physical performance and smaller flipper width compared to in situ hatchlings, suggesting potential performance trade-offs associated with full relocation. In contrast, split-clutch hatchlings performed comparably to in situ hatchlings across performance traits, suggesting that this strategy may reduce some performance trade-offs associated with ex situ incubation, although these findings should be interpreted cautiously given the limited split-clutch sample size. Our results highlight a management trade-off where ex situ relocation boosts output but may depress early-life performance metrics, whereas split-clutch incubation can deliver high hatching success while maintaining hatchling quality. These findings suggest that split-clutch incubation warrants further evaluation as a targeted, site-specific management tool, coupled with continued monitoring of nest thermal profiles and post-emergence performance. These findings provide useful insights for coastal managers seeking to optimize reproductive output and hatchling viability under intensifying climate and human pressures.