崇明东滩堤内次生人工湿地冬季水鸟的夜间行为

2006年11月中旬至2007年2月中旬,以崇明东滩堤内次生人工湿地(鱼蟹塘)为主要研究区域,对8种水鸟越冬期夜间行为进行了连续观察。结果发现,斑嘴鸭(Anas poecilorhyncha)、绿头鸭(A.platyrhynchos)、银鸥(Larus argentatus)及白鹭(Egretta garzetta)等白天在塘内栖息和取食的水鸟,黄昏时飞离并栖息于堤外海滩或堤内农田和防护林,次日清晨飞回。夜间停留在鱼蟹塘的水鸟活动差异性显著。其中,夜鹭(Nycticorax nycticorax)白天栖息于堤内防护林,夜间17:00～17:30时后飞入鱼蟹塘,分散于塘内光滩及芦苇附近活动,在约23:30时后其行为以觅食为主,达70%以上。黑水鸡(Gallinula chloropus)和骨顶鸡(Fulica atra)活动频繁,主要分布于芦苇丛和周边水域,21:30～次日2:30时其觅食行为达到高峰,数量占60%～90%,2:30～3:30时后转为以休息为主。而白天活动频繁的小(Tachybaptus ruficollis)夜间停留在塘内,主要休息于水位较深区域。结果表明,越冬水鸟夜间行为具多样性,可能与昼间活动模式有关。

Waterfowl Nocturnal Behavior at the Artificial Wetlands behind the Chongming Dongtan Seawall in Winter

The nocturnal behavior of the 8 species waterfowls were observed from the middle of November 2006 to the middle of February 2007 at the artificial wetlands behind the seawall in Chongming Dongtan.The results showed that the waterfowls which forage or roost in the pond during the day,such as Spot-billed Duck(Anas poecilorhyncha),Mallard(A.platyrhynchos),Herring Gull(Larus argentatus) and Little Egret(Egretta garzetta),flied out of the pond during sunset and foraged or roosted in the farmland and forest area behind seawall and or intertidal mudflat at night,then flied in during sunrise.There was a strong significant difference between waterfowls which stayed in the fishing pond during the nocturnal period in their activities.Black-crowned Night-Heron(Nycticorax nycticorax)rested in the forest during the day and flied into the pond after 17:00-17:30,inhabiting bared mudflat and reed strip in the pond dispersedly,however foraging behavior actively observed after about 23:30 when the frequency of forage occurred over 70% of total nocturnal behavior.Moorhen(Gallinula chloropus) and Coot(Fulica atra) presented frequent activities at night on reed strip and water area around it.Their foraging behavior reached to the peak of 60%-90% during 21:30-2:30 and resting became the main behavior after 2:30-3:30.Little Grebe(Tachybaptus ruficollis)with frequently diurnal activities stayed in the pond at night and rested in the area with deep water.The results suggested that the nocturnal behavior of waterfowl was likely related with the mode of their diurnal activities.