滇西北鹤庆草海湿地紫水鸡生态适应的初步观察

中国南方紫水鸡(Porphyrio porphyrio)在快速扩散,探究其生态适应十分必要。2014年3月至2015年8月在云南鹤庆草海湿地的观察,得到以下结果。紫水鸡集中分布在以开阔水域为主并有足够植被覆盖的西草海,很少见于附近干扰频繁的其他湿地,其适宜的生境开阔水域约占49.6%、水生植被覆盖水面占39.3%、陆地占11.1%;紫水鸡早间(7:00~9:00时)频繁活动在开阔水域、高草丛、岸边草地,中午后逐渐远离岸边而藏掖草丛中;白天活动的紫水鸡集群大小在1~7只之间,1~2只的集群占62.0%,大的集群中常有司职警戒、领头的个体;紫水鸡用于觅食、休息、警戒的时间分别占47.8%、23.5%、15.1%,很少互动交流,但常驱赶靠近的其他鸟类以维护个体自身的"领域";紫水鸡应对干扰威胁的警戒、避让、惊飞平均距离分别是26.4 m、20.5 m和17.6 m。在鹤庆的紫水鸡集中分布于西草海湿地并避让人为干扰,说明其以避让和逃逸方式应对人为干扰和生境胁迫,应该考虑立法给予重点保护。

Preliminary Observations on the Ecological Adaptation of Purple Swamphen (Porphyrio porphyrio) in Heqing Caohai Wetlands of Yunnan Province

The Purple Swamphen (Porphyrio porphyrio) has dispersed rapidly in southern China,and been reported in northwestern Yunnan since 2000.During March 2014 to August 2015,we made field observations in the wetlands of Heqing Wetlands Yunnan Province to study the ecological adaptation of the Purple Swamphens.In our study area,the birds were mainly found in the West Caohai wetlands,and their habitats were mosaic of open water (accounted for 49.6％),water with dense vegetation coverage (39.3％) and shore land (11.1％).They appeared frequently in the habitat with open water,dense tall grasses,and lakeside grassland in the morning (7:00-9:00),went away from the lakeshore after noon and disappeared in the dense tall grasses in the evening (Fig.1).The flock size of the birds was between 1 to 7,with small sizes (1 or 2birds) accounted for 62.0％ of the total observations.When in larger flocks (6 or 7 birds),there was often one bird in charge of watching and guarding.The time they used for feed,rest and vigilance accounted for 47.8％,23.5％ and 23.5％,respectively (Fig.2).The Purple Swamphens often drove other water birds when the latter were close to them,implying the protection of their territory.Being approached by researchers,the average vigilance,avoidance and flush distances of the Purple Swamphens were 26.4 m,20.5 m and 17.6 m (n =20),respectively.The birds might adopt an ecological strategy of avoidance and escape to deal with the human disturbances and habitat stresses.Human disturbances,such as farming,grazing,weeding and wetland construction are very frequent in Heqing wetland areas,legislative protection for Purple Swamphen should be considered.