Effects Of Nest Site Selection Niche On Breeding Dominance In Four Secondary Cavity-nesting Birds

Secondary cavity-nesting birds were important contents of bird community. Probing into nest site resource competition on breeding dominance within community is helpful to understand the intrinsic mechanism of community dynamic. We conducted study on the topic at Zuojia Nature Reserve during March to July in 2013 and 2014 in Jilin province. The Object of study was Great Tit(Parus major), Eurasian Nuthatch(Sitta europaea), Yellow-rumped Flycatcher(Ficedula zanthopygia) and Marsh Tit(Parus palustris).There’re 88 nests of Great Tit, 87 nests of Eurasian Nuthatch, 65 nests of Yellow-rumped Flycatcher and 27 nests of Marsh Tit breeding in natural holes and artificial nest boxes recorded in the study. The highest breeding dominance is Great Tit(0.330), and then followed by Eurasian Nuthatch(0.326), Yellow-rumped Flycatcher(0.243) and Marsh Tit(0.101).We researched the nest site selection of the four secondary cavity-nesting birds. The result suggested, the entrance holes area, cavity height above ground, the diameter at breast height and nest types were the key impact factors of nest holes selection; while the crown covers, shrub covers and shrub height were the key impact factors of nest-site selection.A phenomenon was found in niche overlap among the factors of nest hole, nest sites and the holes types in four secondary cavity-nesting birds. The result indicated the niche overlap values of the six factors(except nest types) above which between Great Tit and Eurasian Nuthatch, Yellow-rumped Flycatcher were high(The values were larger than 0.6); While the values of the factors between Eurasian Nuthatch and Yellow-rumped Flycatcher were high(The values were larger than 0.6). Between Marsh Tit and Great Tit, Eurasian Nuthatch, Yellow-rumped Flycatcher the niche overlap values of the entrance holes area, diameter at breast height and shrub height were high(The values were larger than 0.6), but them of cavity height above ground, breadth of the nest tree cover and shrub cover were low(The values were lower than 0.6). Between Great Tit and Eurasian Nuthatch, Yellow-rumped Flycatcher, the niche overlap value of using of nest hole type was high(The values were larger than 0.5), so was it between Eurasian Nuthatch and Yellow-rumped Flycatcher. However, these value between Marsh Tit and Great Tit, Eurasian Nuthatch, Yellow-rumped Flycatcher was low(The values were larger than 0.4). All above show that there is a drastic competition among the four secondary cavity-nesting birds on the selection and using of nest holes and nest sites.Among the four secondary cavity-nesting birds, the Great Tit was the one whose the niche breadth widest in the 7 kinds factors(except shrub cover and shrub height), then was Marsh Tit, Eurasian Nuthatch, Yellow-rumped Flycatcher. To analyze the niche breadth and the breeding dominance of 4 kinds of secondary cavity-nesting birds by correlation analysis, we found that, the niche breadth of the 6 factors was positively correlated with the breeding dominance of these birds(p<0.05); Whereby, the niche breadth of the nest tree diameter at breast height was significantly positive correlation with the breeding dominance of these birds(p<0.01). So during the reproduction period of the four secondary cavity-nesting birds, the wider one’s niche breadth, the higher it’s breeding dominance.