横断山区Fulvetta属鸟类的种群分化与生活史对策

The Hengduan Mountains, located in the southeastern margin of Qinghai-Tibet Plateau, is characterized as its richness of avian biodiversity and endemism. This region is also considered as Quaternary refuge and thereafter as diversification center for many avian groups. The formation and maintenance of its biodiversity draws much attention of ornithologists and evolutionary biologists. However, the process of population divergence and the acting mechanism of phylogeographic breaks in this area remain unclear in most ongoing avian studies. We select the Fulvetta species as the study group, because 1) most Fulvetta species distribute into Hengduan Mountains; 2) all species are residents and have fine distribution displacement vertically; 3) our former study detected gene introgression might exist between some Fulvetta species. By using the methods of Bayesian, NCA, PCA, character cluster, and niche modeling, an integrative study strategy will be implemented to investigate the evolutionary history of Fulvetta species, geographic population divergence, and ecological adaptations to its own altitude. Data from molecular, morphology and songs will be combined to illustrate the genetic structure, morphological and acoustic variation between populations. We are aiming at answering the 3 key questions: 1) Which hypothesis best explains the fulvetta’s formation in Hengduan Mountains, in-situ diversification or immigration? 2) Which geographical barrier is the main cause to the population divergence, high mountain ridge or deep valley? 3) From the view of genetics, morphology and behavior, do the fulvetta’s populations respond to the barriers consistently?

横断山区是中国鸟类的分布中心和特有种中心，鸟类多样性成因复杂，南北走向的高山和河谷对鸟类产生的阻隔效应明显。Fulvetta属鸟类是主要分布于横断山区的小型莺鹛科鸟类，各个物种在繁殖季节呈海拔替代分布，前期研究发现该属鸟类在横断山区的种群可能存在遗传渐渗的现象。本项目拟结合分子生物学、形态学、行为学和生态学研究方法，从种群遗传结构、形态地理变异、鸣声地理变异、生态位分化和生活史对策等角度，阐述Fulvetta属鸟类在横断山区的物种形成、种群分化和生态适应。重点解决3个科学问题：1）Fulvetta属鸟类物种分化支持就地分化假说或是迁入假说？2）哪种隔离因子（山脉或是河谷）对Fulvetta属鸟类的地理分布格局起主导性的作用？3）地理隔离对Fulvetta属鸟类的种群分化在遗传、形态、鸣声是否具有一致性？

横断山区是中国鸟类的分布中心和特有种中心，鸟类多样性成因复杂，南北走向的高山和河谷对鸟类产生的阻隔效应明显。Fulvetta属鸟类是主要分布于横断山区的小型莺鹛科鸟类，各个物种在繁殖季节呈海拔替代分布。本项目综合分子生物学、形态学、行为学和生态学研究方法，从种群遗传、形态地理变异、鸣声地理变异和生活史对策等角度，阐述Fulvetta属鸟类在横断山区的种群分化和生态适应。取得的主要结果包括：1）河谷隔离在白眉雀鹛的遗传结构、鸣声、形态分化上产生了不同的效应，种群遗传结构受隔离作用最为明显，形态特征主要受环境气候的影响，鸣声地理变异主要受空间距离的影响；2）褐头雀鹛和白眉雀鹛鸣唱相似程度更高、回放彼此均有反应；棕头雀鹛与前2种鸣唱差异较大、回放无反应；3）棕头雀鹛繁殖期为3 - 6月，巢呈球状，巢距地面高度为0.99±0.40 m (n=16)，窝卵数为2.73±0.45枚 (n=11)。卵为椭圆形，卵的底色为白色，钝端分布黑色斑点，卵重1.28±0.13 g，两性共同参与繁殖，孵卵期13.67±0.47 d (n=3)，育雏期为13.00 ±0.71 d (n=4)；4）白眉雀鹛同样为双亲共同参与繁殖，筑巢期、孵卵期和育雏期分别为10、17和14 d(n=1)；窝卵数为2.64±0.93枚(1-4枚，n=14)，卵重1.47±0.13g (n=14)；在孵卵期，亲鸟每次孵卵时间为32.07±14.72 min，亲鸟喂食间隔16.11±14.14min，繁殖期高黎贡山的大风和降水对白眉雀鹛繁殖影响较大。