Department of Zoology, Wildlife Conservation Research Unit (WildCRU), The Recanati-Kaplan Centre, University of Oxford, Tubney, UK.
J Anim Ecol. 2018 Jul;87(4):1080-1090. doi: 10.1111/1365-2656.12832. Epub 2018 Apr 30.
Climate is known to influence breeding phenology and reproductive success in temperate-zone bats, but long-term population level studies and interspecific comparisons are rare. Investigating the extent to which intrinsic (i.e. age), and extrinsic (i.e. spring weather conditions), factors influence such key demographic parameters as the proportion of females becoming pregnant, or completing lactation, each breeding season, is vital to understanding of bat population ecology and life-history traits. Using data from 12 breeding seasons (2006-2017), encompassing the reproductive histories of 623 Myotis daubentonii and 436 Myotis nattereri adult females, we compare rates of recruitment to the breeding population and show that these species differ in their relative sensitivity to environmental conditions and climatic variation, affecting annual reproductive success at the population level. We demonstrate that (1) spring weather conditions influence breeding phenology, with warm, dry and calm conditions leading to earlier parturition dates and advanced juvenile development, whilst cold, wet and windy weather delays birth timing and juvenile growth; (2) reproductive rates in first-year females are influenced by spring weather conditions in that breeding season and in the preceding breeding season when each cohort was born. Pregnancy and lactation rates were both higher when favourable spring foraging conditions were more prevalent; (3) reproductive success increases with age in both species, but at different rates; (4) reproductive rates were consistently higher, and showed less interannual variation, in second-year and older M. daubentonii (mean 91.55% ± 0.05 SD) than M. nattereri (mean 72.74% ± 0.15 SD); (5) estimates of reproductive success at the population level were highly correlated with the size of the juvenile cohort recorded each breeding season. Improving understanding of the influence of environmental conditions, especially extreme climatic fluctuations, and the identification of critical periods (i.e. spring for reproductive female bats in temperate zones), which have disproportionate and lasting impacts on breeding phenology and reproductive success at a population level, is critical for improving predictions of the likely impact of climate change on bat populations.
气候已知会影响温带蝙蝠的繁殖物候和繁殖成功率，但长期的种群水平研究和种间比较很少见。调查内在（即年龄）和外在（即春季天气条件）因素对关键人口参数的影响程度，如每个繁殖季节怀孕或完成哺乳期的雌性比例，对于了解蝙蝠种群生态学和生活史特征至关重要。使用 12 个繁殖季节（2006-2017 年）的数据，涵盖了 623 只 Myotis daubentonii 和 436 只 Myotis nattereri 成年雌性的繁殖历史，我们比较了繁殖种群的补充率，并表明这些物种对环境条件和气候变化的相对敏感性不同，影响了种群水平的年度繁殖成功率。我们证明了：（1）春季天气条件影响繁殖物候，温暖、干燥和平静的条件导致更早的分娩日期和幼体发育提前，而寒冷、潮湿和多风的天气则延迟出生时间和幼体生长；（2）当年雌性的繁殖率受到该繁殖季节和前一年每个批次出生时春季天气条件的影响。当有利的春季觅食条件更为普遍时，怀孕和哺乳期的比例都更高；（3）两种物种的生殖成功率都随年龄的增长而增加，但增长速度不同；（4）在第二年及以上的 M. daubentonii 中，繁殖率始终较高，且年际间变化较小（平均值为 91.55%±0.05 SD），而在 M. nattereri 中（平均值为 72.74%±0.15 SD）繁殖率则较低且年际间变化较大；（5）每个繁殖季节记录的幼体数量与种群水平的繁殖成功率高度相关。提高对环境条件（特别是极端气候波动）的影响的理解，并确定关键时期（即温带繁殖雌性蝙蝠的春季），对于改善对气候变化对蝙蝠种群可能产生的影响的预测至关重要，因为这些时期对繁殖物候和繁殖成功率有不成比例和持久的影响。
