白头鹀冬季种群特征及其食性分析

STUDY ON POPULATION STRUCTURE AND FOOD STRUCTURE OF EMBERIZA LEUCOCEPHALA GMELIN

1987～1989年的10～12月和l～4月间,在山西庞泉沟自然保护区(东径111℃22′～111℃33′,北纬37℃45′～37℃55′),对白头鵐(Emberiza leucocepahala)冬季种群特征进行了初步研究,包括季节迁徙,种群数量,年龄组成,雌雄比例;并对其冬季食物组成等作了初步探讨。最早迁来和最晚迁者成幼鸟比例为1:3.17;迁离最晚者成幼鸟比例为1:0.60,种群密度(只1公顷)三年均值为24.69±3.90。根据腔上囊,头骨化程度和体重,基于404只标本观测,将该鸟划为4个不同的年龄组。共剖检白头鵐404只,其中有成鸟134只,占总数的33.17％;幼鸟270只,占总数的66.83％。成鸟与幼鸟的比例为1:2.02。雄雌性别比例为1:1.61,雌鸟多于雄鸟。

From 1987 to 1989, October to December, January to April, the authors of this paper studied the population structure of Emberiza Leucocephala Gmelin, at pang Quan Ditch. The nature sanctuary of the national level in Shanxi province (111°22′E--111°23′E and 37°45′N- 37°55′N). The reserch content mainly consists of the seasonal movement, number of population, the composition of population age, and the population sex ratio; also about of the food structure in winter. The result shows the ratio between the adult bird arriving earliest and the young bird arriv- ing last is 1: 3. 17; the ratio between the adult leaving last and the young leaving last is 1: 0. 60 the average density of population by hectare during three years is 24. 69± 3. 9. Surveying sample of 404 birds, the birds divided 4 age group, there are 134 adult birds and 270 young birds, the proportions are respectively 33. 17 % and 66. 83 %. The ratio between the adult and the young is 1: 2. 02. The ratio between the male and the female is 1: 1. 61.