云南纳帕海自然保护区灰背伯劳的巢址选择

Nest Site Selection of Lanius tephronotus in Napahai Nature Reserve,Yunnan,China

2013年5—6月,在云南省纳帕海自然保护区对灰背伯劳Lanius tephronotus的巢址选择进行了研究。结果显示,灰背伯劳对树种具有极强的偏好性,有78.48%(n=62)的巢位于火棘Pyracantha sp.灌丛中,枝条具刺是影响灰背伯劳选择筑巢树的首要因素。主成分分析表明,影响灰背伯劳巢址选择的因素有5类:距离因子(巢距道路距离、距居民点距离)、安全性因子(刺数量、刺长度)、觅食生境因子(耕地占比)、隐蔽度因子(树冠幅、树高)以及巢生境因子(灌木占比)。总之,灰背伯劳喜好营巢于距离居民点较近、巢周围耕地面积较大的多刺灌丛。房屋和道路修建对灌丛的侵占是威胁灰背伯劳生存的主要因素。

The nest site selection of the grey-backed shrike（ Lanius tephronotus） in Napahai Nature Reserve（ 99°38＇E,27°51＇N） were studied from May to June in 2013. We found that L. tephronotus perferred to nesting in thorny bushes,because 78. 48% of the nests（ n = 62） were found to locate in firethorn（ Pyracantha sp.） bushes. Whether the branches had thorns was the primary factor that determined the selection of nesting tree for grey-backed shrikes. The result of principal component analysis demonstrated that 5 types of factors,including distance（ distance to roads,distance to settlements）,safety（ number and length of thorns）,feeding habitat（ % of the farmland）,concealment（ crown width and height of nesting bushes） and nesting habitat（ % of the bushes）,can influence the nest site selection of L. tephronotus. Our results suggest that L. tephronotus prefer to nesting in thorny bushes that are close to the settlement,and the settlement are normally surrounded by large area of farmland. The encroachment of human house and road construction on the bushes is the main factor that threatens the survival of L. tephronotus.