Background: Understanding how overwintering birds choose foraging habitats is very important for conservation management. The overwintering Black-necked Crane(Grus nigricollis) feeds on crop remains in farmlands;thus,...Background: Understanding how overwintering birds choose foraging habitats is very important for conservation management. The overwintering Black-necked Crane(Grus nigricollis) feeds on crop remains in farmlands;thus, reasonable conservation management of this type of farmland that surrounds wetlands is critical for the overwintering populations of the Black-necked Crane;however, it is not clear how the Black-necked Crane chooses the foraging land in the farmland.Methods: A thorough field positioning survey of all foraging sites in farmland areas around the Caohai Wetland and a-sampling analysis of habitat selection by the Black-necked Crane were conducted during the winters from 20162017 and 2017-2018.Results: Multiple factors contributed to the selection of foraging habitat in farmlands, i.e., food factors(crop remains and tillage methods) > human disturbance factors(distance to road and settlement) > topography factors(slope aspect), listed according to the strength of influence. Additionally, Black-necked Cranes tend to choose farmland sites where there was no machine tillage, the crop remains were > 500 g/m^2, the distance to residences ranged from 100 to 500 m, the distance to roads ranged from 50 to 100 m, and the slopes exhibited western or eastern aspects. As the winters progressed, the volume of the edible crop remains declined, and the influences of the other main factors also changed, i.e., the factors of human disturbance(distance to road and settlement) became less important, while the effect of the food factor(crop remains) was strengthened. Thus, the foraging sites near the road became more important.Conclusion: The farming area surrounding the Caohai Wetland is very important for the overwintering Black-necked Crane. Food factors and human disturbance factors are the main factors that influence the choice of feeding ground.展开更多
湿地生境可为水鸟提供保护场所、生存和繁殖所需要的能量以及种群延续的条件（Fretwell,1972;Heitmeyer,1980;Fredrickson,1981;Krapu,1981）.生境的可利用性、分布和质量会影响越冬期水鸟的集群、活动、能量分配和繁殖过程（Fredrickso...湿地生境可为水鸟提供保护场所、生存和繁殖所需要的能量以及种群延续的条件（Fretwell,1972;Heitmeyer,1980;Fredrickson,1981;Krapu,1981）.生境的可利用性、分布和质量会影响越冬期水鸟的集群、活动、能量分配和繁殖过程（Fredrickson et al.,1979;Paulus,1980）,同时会对水鸟的繁殖潜力造成影响（Miline,1976;Ankney,1977）.生境选择通常会使生物分布非随机化,这是自然选择的结果（Southwood,1977;Martin,1998;Clark et al.,1999）.这种非随机化分布方式的产生是由于生物体对环境因子具有选择性,即在相同生境中的随机区域选择位点进行测量,并将它们进行比较的结果（Wilson,1998）.展开更多
基金following projects:National Natural Science Foundation of China(NSFC)(31860610,31400353)Provincial Key Science and Technology Project of Guizhou([2016]3022-1)+3 种基金Provincial Science and Technology Plan of Guizhou([2014]7682[2019]1068)Science and Technology Plan of Education Administration of Guizhou Province([2018]102[2015]354).
文摘Background: Understanding how overwintering birds choose foraging habitats is very important for conservation management. The overwintering Black-necked Crane(Grus nigricollis) feeds on crop remains in farmlands;thus, reasonable conservation management of this type of farmland that surrounds wetlands is critical for the overwintering populations of the Black-necked Crane;however, it is not clear how the Black-necked Crane chooses the foraging land in the farmland.Methods: A thorough field positioning survey of all foraging sites in farmland areas around the Caohai Wetland and a-sampling analysis of habitat selection by the Black-necked Crane were conducted during the winters from 20162017 and 2017-2018.Results: Multiple factors contributed to the selection of foraging habitat in farmlands, i.e., food factors(crop remains and tillage methods) > human disturbance factors(distance to road and settlement) > topography factors(slope aspect), listed according to the strength of influence. Additionally, Black-necked Cranes tend to choose farmland sites where there was no machine tillage, the crop remains were > 500 g/m^2, the distance to residences ranged from 100 to 500 m, the distance to roads ranged from 50 to 100 m, and the slopes exhibited western or eastern aspects. As the winters progressed, the volume of the edible crop remains declined, and the influences of the other main factors also changed, i.e., the factors of human disturbance(distance to road and settlement) became less important, while the effect of the food factor(crop remains) was strengthened. Thus, the foraging sites near the road became more important.Conclusion: The farming area surrounding the Caohai Wetland is very important for the overwintering Black-necked Crane. Food factors and human disturbance factors are the main factors that influence the choice of feeding ground.
文摘湿地生境可为水鸟提供保护场所、生存和繁殖所需要的能量以及种群延续的条件（Fretwell,1972;Heitmeyer,1980;Fredrickson,1981;Krapu,1981）.生境的可利用性、分布和质量会影响越冬期水鸟的集群、活动、能量分配和繁殖过程（Fredrickson et al.,1979;Paulus,1980）,同时会对水鸟的繁殖潜力造成影响（Miline,1976;Ankney,1977）.生境选择通常会使生物分布非随机化,这是自然选择的结果（Southwood,1977;Martin,1998;Clark et al.,1999）.这种非随机化分布方式的产生是由于生物体对环境因子具有选择性,即在相同生境中的随机区域选择位点进行测量,并将它们进行比较的结果（Wilson,1998）.
