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. 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 2016‒2017 and 2017‒2018. 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/m2, 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. 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.

中文翻译：

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贵州草海湿地周边农区越冬黑颈鹤觅食的生境选择

了解越冬鸟类如何选择觅食生境对于保护管理非常重要。越冬的黑颈鹤（Grus nigricollis）以农田的农作物残渣为食。因此，对湿地周围的这种农田进行合理的保护管理对于黑颈鹤越冬种群至关重要；但是，尚不清楚黑颈鹤如何在农田中选择觅食地。在2016 ‒ 2017年和2017 ‒ 2018年冬季，对草海湿地周围农田的所有觅食地进行了彻底的野外定位调查，并通过黑颈鹤对栖息地选择进行了抽样分析。多种因素促成了农田觅食生境的选择，即食物因素（作物残留和耕作方法）> 人为干扰因素（到道路和居民点的距离）>地形因素（坡度），根据影响强度列出。此外，黑颈鹤倾向于选择没有耕作机耕地，农作物残渣大于500 g / m2，距住宅的距离为100至500 m，距道路的距离为50至100 m，斜坡表现出西方或东方方面。随着冬季的发展，可食用作物的数量仍在下降，其他主要因素的影响也发生了变化，即人为干扰因素（到道路和居民点的距离）变得不那么重要，而食物因素的影响（作物残留）得到加强。因此，道路附近的觅食场所变得更加重要。草海湿地周围的耕种面积对于越冬的黑颈鹤非常重要。食物因素和人为干扰因素是影响饲养场选择的主要因素。