Differentiating nest sites characteristics of four sympatric cavity-nesting birds

Abstract

Diverse group of cavity-nesting birds inhabit secondary forests of northeastern China, accounting for about one-third of breeding avian species. We examined differences in nest-site characteristics among four cavity-nesting birds, including two cavity excavators (i.e., great spotted woodpecker [Dendrocopos major] and grey-headed woodpecker [Picus canus]) and two secondary cavity-nesters (i.e., yellow-rumped flycatcher [Ficedula zanthopygia] and Eurasian nuthatch [Sitta europaea]) in Dagang Forestry Farm, Jilin Province, China. We detected total 160 active hole nests in the breeding season of 2008, including 58 nests of cavity excavators and 102 of secondary cavity-nesters. Secondary cavity-nesters tend to prefer Salix pierotii for nestingtrees, but the excavators not. Picus canus used south-facing cavities, which may have been due to thermal advantages. Nest tree and nest-site quadrat characteristics were different between the two excavator species. Specifically, there were significant differences in the entrance diameter and cavity inner diameter between the nest sites of Dendrocopos major and Picus canus, and the entrance length and canopy height of nest tree between Ficedula zanthopygia and Sitta europaea. The characteristics at the scale of nest tree were 第 6期 周春发等: 四种同域分布洞巢鸟的巢址特征比较 717 important for distinguishing nest sites for cavity excavators as well as secondary cavity-nesters. Discriminant analyses illustrated that Ficedula zanthopygia and Sitta europaea used cavities excavated by Dendrocopos major and Picus canus, respectively. Differences in size of nesting holes excavated by different woodpeckers could affect the usage of nest sites by secondary cavity-nesters, which may have an impact on avian community structure in secondary forests.