Data from: A 20-year investigation of declining leatherback hatching success: implications of climate variation

Unprecedented increases in air temperature and erratic precipitation patterns are predicted throughout the 21st century as a result of climate change. A recent global analysis of leatherback turtle hatchling output predicts that the nesting site at Sandy Point National Wildlife Refuge (SPNWR) will experience the most significant regional climate alterations. We aimed to identify how local air temperatures and precipitation patterns influenced within nest mortality and overall hatchling output at this site between 1990 – 2010. We show that while the greatest mortality occurred during the latest stages of development (stage three), the rate of embryo mortality was highest during the initial stages (stage zero) of development (~3.8 embryos/day/clutch). Increased mortality at stage three was associated with decreased precipitation and increased temperature during this developmental period, whereas precipitation prior to, and during stage zero had the greatest influence on early mortality. There was a significant decline in overall hatching success (falling from 74% to 55%) and emergence rate (calculated from the number of hatchlings that emerged from the nest as a percentage of hatched eggs) which fell from 96% to 91%, However, there was no trend observed in local temperature or precipitation during this timeframe, and neither variable was related to hatching success or emergence rate. In conclusion, our findings suggest that despite influencing within-nest mortality, climatic variability does not account for the overall decline in hatchling output at SPNWR from 1990 – 2010. Further research is therefore needed to elicit the reasons for this decline.受气候变化影响，预计整个21世纪全球气温将出现前所未有的升高，降水模式也将变得异常不稳定。近期一项针对棱皮龟（leatherback turtle）幼龟孵化产出的全球分析预测，位于桑迪角国家野生动物保护区（Sandy Point National Wildlife Refuge, SPNWR）的筑巢地将遭遇该区域最显著的气候变化。本研究旨在明确1990年至2010年间，该保护区内的局地气温与降水模式如何影响巢内死亡率及整体幼龟孵化产出量。研究结果显示，尽管最高死亡率出现在发育晚期（第三阶段），但胚胎死亡率的峰值却出现在发育初期（零阶段），约为3.8枚胚胎/天/窝。第三阶段的死亡率升高与该发育阶段内降水量减少、气温升高相关；而零阶段之前及零阶段期间的降水则对早期死亡率影响最为显著。整体孵化成功率（hatching success）从74%降至55%，出巢率（emergence rate，以巢内成功出巢的幼龟数量占已孵化卵总数的百分比计算）从96%降至91%，均出现了显著下降。然而在此研究时段内，局地气温与降水均未呈现出明显的变化趋势，且这两个变量均与孵化成功率及出巢率无显著关联。综上，本研究结果表明，尽管气候变率（climatic variability）会影响巢内死亡率，但并不能解释1990年至2010年间桑迪角国家野生动物保护区幼龟孵化产出量的整体下降趋势。因此，仍需开展进一步研究以探明该下降现象的成因。