Measuring the Meltdown: Drivers of Global Amphibian Extinction and Decline

Habitat loss, climate change, over-exploitation, disease and other factors have been hypothesised in the global decline of amphibian biodiversity. However, the relative importance of and synergies among different drivers are still poorly understood. We present the largest global analysis of roughly 45% of known amphibians (2,583 species) to quantify the influences of life history, climate, human density and habitat loss on declines and extinction risk. Multi-model Bayesian inference reveals that large amphibian species with small geographic range and pronounced seasonality in temperature and precipitation are most likely to be Red-Listed by IUCN. Elevated habitat loss and human densities are also correlated with high threat risk. Range size, habitat loss and more extreme seasonality in precipitation contributed to decline risk in the 2,454 species that declined between 1980 and 2004, compared to species that were stable (n = 1,545) or had increased (n = 28). These empirical results show that amphibian species with restricted ranges should be urgently targeted for conservation.栖息地丧失、气候变化、过度开发、疫病及其他多种因素，均被推测为全球两栖动物生物多样性下降的潜在驱动因素。然而，学界对各类驱动因子的相对重要性及其协同作用仍知之甚少。本研究开展了迄今规模最大的全球尺度分析，覆盖约45%的已知两栖动物类群（共计2583个物种），以量化生活史特征、气候条件、人类活动密度以及栖息地丧失对两栖动物种群衰退与灭绝风险的影响。多模型贝叶斯推断结果显示：地理分布范围狭窄的大型两栖动物，以及温度与降水季节波动显著的类群，最有可能被国际自然保护联盟（IUCN）列入红色名录。栖息地丧失程度加剧与人类活动密度升高，同样与较高的物种受威胁风险呈显著相关。相较于种群保持稳定（n=1545）或种群数量增长（n=28）的物种，1980年至2004年间出现种群衰退的2454个物种，其衰退风险与分布范围大小、栖息地丧失程度以及降水极端季节波动幅度显著相关。本研究的实证结果表明，地理分布范围狭窄的两栖动物类群亟需被纳入优先保护序列。