升金湖越冬白头鹤集群变化及领域行为

白头鹤是长江中下游的大型越冬水鸟,安徽升金湖是其在国内主要的越冬地之一。近年来,由于生境退化,越冬种群的数量在萎缩,种群的越冬生态研究十分必要。2007年10月～2008年4月,我们在升金湖对白头鹤的主要分布地点进行了调查,并对集群情况进行了观察。升金湖白头鹤觅食地主要分布于湖区外围的稻田,夜栖于上湖核心区内。整个越冬期,白头鹤大部分以5只以上的群类型觅食,以家庭集群活动仅占越冬集群数的29.14%。随着越冬期的变化,集群大小发生改变：越冬前期,越冬鹤以家族群活动频率最高,占集群的35.64%,30～49只集群频率最低,仅为6.38%;越冬中期,家庭集群及5～9只集群频率相对于越冬前期减少,10只以上集群频率增加;越冬后期,以≥50只以上集群频率最高,占28.77%。此外,我们还观察到1对成年鹤占有一定面积的稻田并积极保护,表现领域行为。

Assemblage Dynamics and Territorial Behavior of Hooded Crane in Winter on Shengjin Lake

Assemblage of hooded crane（Grus monocha） in winter on Shengjin lake,one of main wintering habitats of the bird,was surveyed from October,2007 to April,2008.Results indicated that in daytime,the bird foraged in paddy field outside the lake and rested in the core region of the upper lake at night.During the winter period,most cranes assembled in groups of more than five indi- viduals to forage,but only 29.14%of groups were composed of families,yet the group condition varied with the wintering stage;at the beginning,the percentage of family assemblage accounted to 35.64%and groups of 30～49 individuals only occupied 6.38%; in the middle stage,family assemblage and groups of 5～9 individuals decreased in number,while number of groups of more than 10 individuals increased.At the later stage,number of large groups of more than 50 individuals increased to 28.77%.The territorial behavior was observed：an adult pair of the crane occupied a certain area in the paddy field and defended the territory throughout the winter.