大庆龙凤湿地须浮鸥巢址选择研究

为了认知影响须浮鸥(Chlidonias hybridus)营巢的主要环境因素,于2011年6～7月,采用直接观察法和样方法在大庆龙凤湿地自然保护区内对须浮鸥的巢区进行了调查研究.在本次调查中共发现须浮鸥巢73个,逐巢进行了常规测量,并对须浮鸥巢址及附近无巢对照区域的生境进行了调查.主成分分析和独立样本t检验的结果表明,须浮鸥属于集群营巢,而影响须浮鸥巢址选择的主要因素依次为巢下水深、巢距植物距离、巢周明水面积、植物高度、植物密度和巢距干扰源距离.其中,前3个因素影响须浮鸥生境中食物的供给条件,后3个因素影响须浮鸥巢的隐蔽条件.须浮鸥选择巢址的条件是能提供丰富食物且具有较好隐蔽条件的生境.

Nest-site Selection of Whiskered Tern in Daqing Longfeng Wetlands

Nest-site selection of whiskered tern(Chlidonias hybridus)was surveyed in Daqing Longfeng Wetland Natural Reserve from June to July,2011.Both direct observation and sampling method were used to investigate the main environment factors which affect nest-site selection of whiskered tern.A total of 73 nests were found on the water and the characteristics of each nest were measured.Environmental factors of nest-sites and adjacent none-nest area as contrastive samples were investigated.There were 13 environmental factors had been measured,which included height and density of plants,underwater depth of nests,distance from the nest to plants,distance from the nest to interference source,open water area,distance from the nest to the same species ones,distance from the nest to the different species ones,the number of the nests in the same square.The results showed that the nests of whiskered tern were all located in open water;mean plant height around nests was 185.6 cm;the average density of plants surrounding the nests was 467 plant/m 2 ;the average depth underwater of nests was 87.3 cm;the average distance from the nests to plants was 7.9 m;the average distance from nests to the interference sources was 1.68 km;the water area around the nests was 728 m 2.The results of principal component analysis for environmental factors of the 73 nest-sites revealed that the variance contributions of the first four principal components had accumulated to 87.66%,containing 9 most informative factors.The 6 main factors which affected the nest-site selection were underwater depth of nests,distance from the nest to plants,water area,height and density of plants,distance from the nest to interference source.Results of t test of 73 nest-sites and 73 contrastive samples showed that there were significant differences between underwater depth of nests,distance from the nest to plants,water area,height of plants,and distance from the nest to interference source.Whiskered tern was tend to nesting together,it was found 54 nests of the same species in the same quadrat,and there were 30 nests of the other water fowls in the same quadrat,the other water fowls were white-winged tern(Chlidonias leucoptera),herring gull(Larus argentatus),common tern(Sterna hirundo),little grebe(Trachybaptus ruficollis),great crested grebe(Podiceps cristatus).It is a cluster of nest of whiskered tern,which is the result of its select group predation and collective defense.The acquisition of food is the first factor to nesting of whiskered tern,greater underwater depth of nests,distance from the nest to plants and water area meant the enough food was offered to whiskered tern,and the habitat,that has higher plants,greater distance to interference source,can provide the better cover conditions for nesting of whiskered tern,they were the second factors to nesting of whiskered tern.