人工生境已成为鄱阳湖越冬白鹤的重要觅食地

受自然生境退化和土地利用方式改变的影响,越来越多鸟类依赖于人工生境生存。白鹤为IUCN极危物种,全球种群数量约3 500～4 000只,其中约98%的个体在鄱阳湖越冬。白鹤曾被认为是专性栖息于浅水生境中的鸟类,在鄱阳湖主要在浅水区取食水生植物苦草的冬芽。然而,近几年大量的白鹤离开自然生境,前往稻田和藕田觅食。本研究基于2010/2011～2017/2018年越冬季五星垦殖场(目前发现白鹤数量最多的人工生境)的白鹤调查数据,首次报道了人工生境中白鹤数量的长期动态。结果表明白鹤数量呈现逐渐增长的趋势,2016/2017～2017/2018年越冬季增长至1 115只,约占全球总数量的30%。由此可见,人工生境已成为白鹤的重要觅食地。觅食地改变使白鹤面临高强度的人为干扰,对此,建议加强白鹤对人工生境的适应性研究,评估白鹤的生存现状,为保护政策的制度提供科学依据。白鹤等依赖于水生植被生存的鸟类的觅食生境变化表明鄱阳湖水生植被退化严重,生态环境质量不断恶化。

Man-Made Habitats Have Become Important Foraging Areas of Siberian Cranes

Due to natural habitat degradation and land-use change,birds increasingly rely on man-made habitats.Siberian cranes(Grus leucogeranus),listed as Critically Endangered in IUCN Red List of Endangered Species,number 3 500-4 000 individuals,with about 98%of its global population wintering at Poyang Lake,China.Siberian cranes typically use shallow water habitats,and feed on tubers of submerged plants,primarily Vallisneria spp.at Poyang Lake.However,in the last few years,numerous Siberian cranes were observed feeding at man-made habitats including rice paddies and lotus ponds.We investigated the abundance of Siberian cranes at Wuxing Farmland,where the largest numbers of cranes were found,during winter 2010/2011-2017/2018.To our knowledge,this is the first study to report long-term changes of Siberian crane at man-made habitats.Siberian crane numbers at Wuxing Farmland increased gradually to 1 115,about 30%of the global species population,during the winters of 2016/2017-2017/2018.Man-made habitats have become important foraging areas of Siberian cranes.Human disturbances at man-made habitats around Poyang Lake are intensive,thus,it is necessary to study the adaptation of Siberian cranes at such habitats,and to implement effective conservation measures.The changes in foraging habits of birds such as Siberian cranes that depend on aquatic vegetation indicate that the aquatic vegetation at Poyang Lake is seriously degraded and the quality of the ecological environment is deteriorating.