野生朱鹮的种群数量和分布现状

2012年9-10月，我们对野生朱鹮（Nipponia nippon）的分布区和潜在分布区进行了调查，共发现其游荡期夜宿地23个，其中20个有朱鹮夜宿，分布在洋县（16个）、宁陕县（3个）和城固县（1个）。对这些夜宿地进行了的同步调查，共统计到野生朱鹮1 090只，其中97.2%分布在洋县境内。最大的夜宿集群数量为184只，集群数量超过40只的夜宿地共11个，累计停歇的朱鹮占总数的91.7%，表明野生朱鹮在游荡期有趋于集结较大群体夜宿的习性。朱鹮野生种群中当年出生的幼鸟占19.0%，据此估算，截至秋季朱鹮幼鸟的存活率约为67.2%。加强对保护区以外，尤其是野生朱鹮新扩散地区的的保护管理，将促进野生朱鹮种群的扩散，进一步增加这一濒危物种抵御风险的能力。

The Current Population and Distribution of Wild Crested Ibis Nipponia nippon

With the 30-years conservation efforts, the wild population of Crested Ibis Nipponia nippon has been increased and the distribution has been expanded to more than ten counties around Yang County of Shaanxi Province in China. However, it is difficult to investigate the exact population size and distribution status of the wild Crested Ibis, although these data were important and needed to conservation management. From September to October, 2012, an integrative survey on the population size and distribution of wild Crested Ibis was conducted. The roosting sites were surveyed in 11 distribution counties by field investigation, known sites visiting, community interview and information feedback. 23 currently-using roosting sites were confirmed and located. A three-day simultaneous survey was conducted at these 23 roosting sites from 17th to 19th October, 2012 by counting the roosting population of each site. 20 roosting sites were used during the simultaneous survey, with 16 in Yangxian County, three in Ningshan County, and one in Chenggu County. Totally 1 090 individuals were recorded with 97.2% of them distributed in Yangxian County. There were 11 roosting sites supporting more than 40 ibises, with the largest roosting population of 184, which accounted for 91.7% of the total wild population (Table 1, Fig. 1). 19.0% of the total population were fledglings, which indicated 67.2% of the fledglings could survive to the autumn. To improve the conservation of the new expanded areas could benefit to the dispersal of the wild population, so as to decrease the threats of this endangered species.