山地次生林冬季鸟类集群的初步研究

通过山地次生林两冬季鸟类集群的研究表明，集群的鸟类主要是由大山雀、沼泽山雀和普通Ｓｈｉ组成；每群个体数为７．４１－１０．６３只；据群的行为（单种群、多种集群和单独个体）分析，大多数种类是单独个体活动，冬季鸟类集群大小和组成有空间的变化。气候因子影响群的形成和行为。

ON BIRD FLOCKING IN SECONDARY FOREST OF MOUNTAINOUS DISTRICT IN WINTER

The size and species composition of birds flocking in secondary forest of the Zuo Jia Nature Protection Region were nearly indentical in over two winters. The Great tit (Parus major), Marsh tit(Parus palustris)and Nuthatch(Sitta europaea)showed lower number of individuals per flock,but the highest number occurred in two winters in all flocks-75. 4% and 66. 7%; 66. 2%and 63.4% ;80%and 65. 6%respectively. Most species always contitued mono-specific flock or solitary foragers,although they occurred more often mixed-species flock. The flock size was significantly greater in early winter than that in middle and late winetr. The flock size was apparently influenced by weather condition. With regard to flock size and species-composition,that the flocks which were observed in secondary forest varied depending upon the time and space indecatied that many factors that were responsible for birds to join a flock,varied in space and time too.