Satellite Tracking Reveals Nesting Patterns, Site Fidelity, and Potential Impacts of Warming on Major Green Turtle Rookeries in the Red Sea

Major aggregations of nesting green turtles (Chelonia mydas) occur in the northern Red Sea, although little is known about the reproductive ecology of this endangered species in the region. To address this issue, we satellite-tracked 30 female green turtles to document their movements and to identify factors driving habitat use at two major rookeries in the Red Sea, Jazirat Mashabah (Mashabah Island) and Ras Al Baridi in Saudi Arabia. Between successive nesting events, turtles displayed high fidelity to nesting beaches and adjacent in-water habitats (inter-nesting habitats). Using generalized linear mixed models, we estimated the mean probability of nesting per beach emergence (nesting success rate) to be 0.628, and the mean duration between a successful nesting event and the successive emergence onto the beach (re-nesting interval) to be 10.8 days at each site. The nesting success rate was relatively high (>0.8) when the preceding daytime land surface temperature (LST) was lower than 37°C but decreased with elevated daytime LST (47°C). Re-nesting interval was longer at lower water temperatures and towards the end of the nesting season of individuals. Our study improves the robustness of abundance estimates from census data (e.g., track counts) and shows that the protection of nesting and inter-nesting habitats during a breeding season would be an effective conservation strategy for the species. We discuss how global warming could increase energy expenditure due to lowered nesting success, ultimately compromising the reproductive fitness of these populations.

红海北部分布有大规模筑巢绿海龟（Chelonia mydas）种群，但目前对这一濒危物种在该区域的繁殖生态学认知仍较为匮乏。为填补这一研究空白，我们对30只雌性绿海龟开展卫星追踪，以记录其活动轨迹，并明确沙特阿拉伯境内红海两处主要筑巢地——马沙巴岛（Jazirat Mashabah）与拉斯阿尔巴里迪（Ras Al Baridi）——的栖息地利用驱动因子。在连续筑巢事件之间，海龟对筑巢海滩及其邻近的巢间生境（inter-nesting habitats）表现出高度的栖息保真度。本研究采用广义线性混合模型（generalized linear mixed models），估算得出两处研究点的单次沙滩登陆筑巢概率（筑巢成功率，nesting success rate）均值为0.628，成功筑巢至下一次登陆沙滩的间隔时长（重筑巢间隔，re-nesting interval）均值为10.8天。当此前日间陆地表面温度（LST）低于37℃时，筑巢成功率相对较高（>0.8）；而随着日间陆地表面温度升高至47℃，筑巢成功率呈下降趋势。重筑巢间隔在水温较低时更长，且随个体筑巢季的推进而延长。本研究提升了基于普查数据（如轨迹计数）的种群数量估算的稳健性，同时表明在繁殖季对筑巢生境与巢间生境实施保护，是针对该物种的有效保育策略。此外，本研究探讨了全球变暖如何因筑巢成功率下降而增加能量消耗，最终损害这些种群的繁殖适配度。