长江中下游湿地大型水鸟种群动态和幼鸟比例研究

迁徙水鸟保护对生物多样性保护具有重要意义。开展水鸟种群数量和幼鸟比例监测，对科学评估其种群变化趋势、制定长期保护策略具有重要价值。长江中下游湿地是东亚-澳大利西亚迁徙路线上重要的水鸟越冬区之一。本研究采用野外同步调查等方法对该区域87个湿地的亟需保护和具有代表性的10种大型越冬水鸟，其中雁形目6种，分别是鸿雁Anser cygnoides、豆雁A.fabalis、灰雁A.grus、白额雁A.albifrons、小白额雁A.erythropus和小天鹅Cygnus columbianus;鹤形目4种，分别是白鹤Leucogeranus leucogeranus、白枕鹤Antigone vipio、灰鹤Grus grus和白头鹤G.monacha,进行了长期监测(2003—2019年冬季),并结合相关文献，评估其种群变化趋势、幼鸟比例和死亡率。研究结果如下：(1)2005—2019年3种水鸟(豆雁、灰雁和灰鹤)的种群数量呈上升趋势，7种水鸟(鸿雁、白额雁、小白额雁、小天鹅、白鹤、白枕鹤和白头鹤)种群数量呈下降趋势；(2)种群趋势下降组(N=7)和上升组(N=3)的幼鸟比例均值在2016—2...

Population dynamics and age ratio of large-bodied waterbird species in the wetlands of the Yangtze River floodplain

Migratory waterbirds protection is essential for biodiversity protection. It is particularly important to clarify the population dynamics based on the monitoring of population size and age ratio, so as to scientifically evaluate its population trend and formulate long-term protection strategies. Wetlands in the Yangtze River floodplain are one of important winterings for waterbird species on the East Asian-Australasian flyway. In this study, the overwintering waterbird species in 87 wetlands were monitored for a long time (in each winter from 2003 to 2019) by the field investigation and literature review, and the age ratio and the mortality of 10 large-bodied waterbirds (6 geese and swans species, Swan Goose Anser cygnoides, Bean Goose A. fabalis, Greylag Goose A. grus, Greater White-fronted Goose A. albifrons, Lesser White-fronted Goose A. erythropus, and Bewick''s Swan Cygnus columbianus; 4 cranes species, Siberian Crane Leucogeranus leucogeranus, White-naped Crane Antigone vipio, Common Crane Grus grus, and Hooded Crane G. monacha) were evaluated. The results are as follows:(1) the population size of 7 species of waterbirds (Swan Goose, Greater White-fronted Goose, Lesser White-fronted Goose, Bewick''s Swan, Siberian Crane, White-naped Crane, and Hooded Crane) decreased, 3 species of waterbirds (Bean Goose, Greylag Goose, and Common Crane) increased; (2) In 2016-2019, the average age ratio of the declining (N=7) and rising (N=3) groups were 0.168 and 0.173, with no significant difference between the two groups (P=0.601); (3) In 2016-2019, the average mortality of the declining and rising group were 0.245 and 0.125, with significant difference between the two groups (P=0.006). This study showed that the main factor leading to the decline of overwintering waterbird species population in the Yangtze River is high mortality, not low reproductive success rate. It is suggested to strengthen the protection of the 7 declined waterbirds in the future, collect the time, place and the cause of death, and further study the factors caused high mortality.