Effects Of Changing Nest Site Resources On Birds Community Structure Formation In The Secondary Forest

From March to July during 2013- 2014, through providing two sizes of artificial nest boxes to change the amount of nest site resources of experimental plots, we investigated that the variation of nest site resources impacted on the birds community structure in Zuojia Nature Reserve of Jilin Province. The birds community structure were surveyed by counting the number of nest site resources which were utilized by cavity-nesting birds or raptors. We recorded 287 breeding pairs during two years, which belonging to 5 orders, 10 families, 11 generas, 15 species. Secondary cavity-nesting birds used tree-hole nest sites, small artificial nest boxes, large artificial nest boxes and magpie nest sites to breed. Raptors used magpie nest sites, tree-hole nest sites, large artificial nest boxes and old eagle nest sites to breed. The total number of nest site resources had a extremely significant positive effect on species and quantities of secondary cavity-nesting birds or breeding raptors. Both secondary cavity-nesting birds and raptors had interspecific differences for the selection of different nest site resources. Such as Great tit(Parus major), Eurasian Nuthatch(Sitta europaea) and Yellow-rumped Flycatcher(Ficedula zanthopygia) used small artificial nest boxes and tree-hole nest sites to propagate. Coal Tit(Parus ater), Eurasian Hoopoe(Upupa epops) and Marsh Tit(Parus palustris) just used tree-hole nest sites to reproduce. Long-eared Owl(Asio otus) utilized tree-hole nest sites and big artificial boxes. Common Kestrel(Falco tinnunculus) used magpie nest sites and big artificial boxes to breed. Amur Falcon(Falco amurensis) only used magpie nest sites to propagate. Grey-faced Buzzard(Butastur indicus) just used old eagle nest sites to breed. Adding small artifficial nest boxes in the experimental plots, which increased the dominance index of Great tit, Yellow-rumped Flycatcher and Eurasian Nuthatch. Hanging large artifficial nest boxes in experimental plots, which leaded the dominance index of Mandarin Duck(Aix galericulata), Dollardird(Eurystomus orientalis) and Common Kestrel to increase obviously. There are species-specific divergences among birds for selecting nest site resources. The birds that have more choosen for nest sites, which could respond flexibly to the changes in nest site resources and enhanced their dominance. Adding artificial nest boxes to replenish nest site resources, which can alleviate the fact that the shortage of natural nest site resources limited secondary cavity-nesting birds community structure. The quantities of nest site resources changed, which affected the propagation characteristics of cavity-nesting birds or raptors community structure. Both diversity or species richness of birds community were enhanced with the amount of nest site resources increasing.