青海湖棕头鸥(Larus brunnicephalus)夏秋季活动区研究

2006年4～9月,采用无线电遥测技术对青海湖重要繁殖水鸟棕头鸥(Larus brunnicephalus)在不同繁殖阶段的活动性,以及与人和鸟的关系进行了研究.对6只棕头鸥个体的遥测结果表明,繁殖初期棕头鸥的活动区较大,进入繁殖中期,活动区明显变小;随后繁殖后期的活动区面积有所增加,到了迁徙前期,活动区面积已接近繁殖初期.不同阶段活动区核心面积(50%Fixed Kernel)与活动区变化趋势基本一致.繁殖初期、中期、后期和迁徙前期活动区面积分别为(15.48 km2±4.54 km2)、(1.61 km2±0.41 km2)、(3.53 km2±2.63 km2)和(11.61 km2±9.36 km2).棕头鸥在不同繁殖阶段的日活动区大小有显著差异.繁殖初期,棕头鸥经常活动于鸬鹚岛、蛋岛和布哈河口,它们都是棕头鸥较好的取食地,鸬鹚岛和蛋岛由于有许多游客投喂食物;在繁殖中期,棕头鸥进入孵化阶段,活动区较繁殖前期明显缩小.由于湟鱼返回布哈河口一带产卵繁殖,棕头鸥经常聚集在此地取食;在繁殖后期,棕头鸥需要寻找大量的食物进行育雏,因此活动范围再度扩大;进入迁徙前期,幼鸟已经长大并学会飞翔,其活动区进一步扩大,与繁殖初期较为接近.

The studies on home range of breeding Brown-headed Gull (Larus brunnicephalus) in spring and autumn at Qinghai Lake, China

The home range and movements of Brown-headed Gulls (Larus brunnicephalus) were studied using radio telemetry from April to September 2006 at Qinghai Lake, China. Six Brown-headed Gulls were banded with radio transmitters. The results showed that the average Brown-headed Gull home range was larger in the early breeding period because of searching for food and mates. During this period, the gulls were often seen at Luci Island, Egg Island and Buhahekou, where food was abundant. The average home range size reduced dramatically in the mid breeding period due to egg laying and incubation. The birds frequently congregated at Buhahekou, where schools of fish gathered from the main lake and began to spawn in the spring. In the late breeding period, Brown-headed Gulls had to travel far from their nests, such as upstream of Buhahekou and Quanwan, to look for food to raise their fledglings. During this period, the home range sizes started to increase again. When the fledglings were able to fly in the early migration period, the home range size increased almost to the same size as the early breeding period. The home range size in the early breeding, mid breeding, late breeding, and early migration period were respectively (15.48 km2±4.54 km2), (1.61 km2±0.41 km2), (3.53 km2±2.63 km2), and (11.61 km2±9.36 km2).