Zeng Qing, Zhang Yamian, Sun Gongqi, Duo Hairui, Wen Li, Lei Guangchun
School of Nature Conservation, Beijing Forestry University, Beijing, China.
School of Nature Conservation, Beijing Forestry University, Beijing, China; Office of Environment and Heritage, Sydney, Australia.
PLoS One. 2015 Feb 3;10(2):e0117307. doi: 10.1371/journal.pone.0117307. eCollection 2015.
Scaly-sided Merganser is a globally endangered species restricted to eastern Asia. Estimating its population is difficult and considerable gap exists between populations at its breeding grounds and wintering sites. In this study, we built a species distribution model (SDM) using Maxent with presence-only data to predict the potential wintering habitat for Scaly-sided Merganser in China. Area under the receiver operating characteristic curve (AUC) method suggests high predictive power of the model (training and testing AUC were 0.97 and 0.96 respectively). The most significant environmental variables included annual mean temperature, mean temperature of coldest quarter, minimum temperature of coldest month and precipitation of driest quarter. Suitable conditions for Scaly-sided Merganser are predicted in the middle and lower reaches of the Yangtze River, especially in Jiangxi, Hunan and Hubei Provinces. The predicted suitable habitat embraces 6,984 km of river. Based on survey results from three consecutive winters (2010-2012) and previous studies, we estimated that the entire wintering population of Scaly-sided Merganser in China to be 3,561 ± 478 individuals, which is consistent with estimate in its breeding ground.
中华秋沙鸭是一种全球濒危物种，仅分布于东亚地区。估计其种群数量具有一定难度，且其繁殖地和越冬地的种群数量存在相当大的差距。在本研究中，我们使用最大熵模型（Maxent）并仅依据出现数据构建了物种分布模型（SDM），以预测中华秋沙鸭在中国的潜在越冬栖息地。接收器操作特征曲线（AUC）下的面积法表明该模型具有较高的预测能力（训练集和测试集的AUC分别为0.97和0.96）。最显著的环境变量包括年平均温度、最冷月平均温度、最冷月最低温度以及最干季度降水量。预测长江中下游地区，特别是江西、湖南和湖北省，适合中华秋沙鸭生存。预测的适宜栖息地涵盖6984千米的河流区域。基于连续三个冬季（2010 - 2012年）的调查结果以及以往研究，我们估计中国中华秋沙鸭的整个越冬种群数量为3561 ± 478只，这与在其繁殖地的估计结果一致。
