中文摘要：

对吉林省左家自然保护区内的4种次级洞巢鸟巢资源竞争与其在群落中的优势度进行了研究。结果表明：大山雀（Parus major）各巢洞因子的生态位最宽、优势度最大，其后依次为普通鹤（Sitta europaea）、白眉姬鹋（Ficedula zanthopygia）以及沼泽山雀（Parus palustris）。4种次级洞巢鸟的优势度与巢洞因子的生态位宽度显著相关，说明其对巢资源的竞争可能影响次级洞巢鸟在群落中的繁殖优势度。

英文摘要：

We studied the effects of nest resource competition on breeding dominance in four secondary cavity-nesting birds at Zuojia Nature Reserve in Jilin Province. The niche breadth of nest cavity factors in Great Tit （Parus major） were the widest, followed by Eurasian Nuthatch （ Sirra europaea） , Yellow-rumped Flycatcher （ Ficedula zanthopygia） and Marsh Tit （ P. palustris）. Breeding dominance of Great Tit was the highest, followed by Eurasian Nuthatch, Yellow-rumped Flycatcher and Marsh Tit. The breeding dominance was correlated positively with niche breadth of nest cavity factors in four secondary cavity-nesting birds. The nest resource competition could influence breeding dominance of secondary cavity-nesting birds within community.