摘要
安西自然保护区放归的普氏野马是一个孤立封闭的小种群,种群数量增长极其缓慢,同时,面临着严峻的捕食压力和近交衰退。因此,对这个种群制定长期的自然保护计划是当务之急。本研究通过对重引入普氏野马种群繁殖力和种群生存力进行分析,结果表明:(1)安西保护区野马种群数量增长缓慢是由低生育率(44.3%)和高幼驹死亡率(43.4%)造成,天敌捕食(35.3%)和疾病(26.5%)成为影响野马繁殖存活率的主要因素;普氏野马的繁殖具有明显的季节性特征,80.9%的幼驹出生在5月和6月;(2)种群生存力分析(PVA)预测本放归野马种群未来100年的灭绝概率是60%,野马种群数量达200匹以上才能保证100年后90%的存活率;(3)参数敏感度分析显示,外部因素——狼袭对保护区野马种群的灭绝和种群数量最具影响力,其次是决定生殖成功的内部因素——生育率、最大繁殖年龄;(4)保护区野马小种群效应明显,疾病和幼驹羸弱而死亡的比例高(分别为26.5%和8.8%),合理的补充新个体是降低种群灭绝风险长期的管理对策;同时,减小狼对野马的捕食压力,加强幼驹的保护,是目前改善本区内普氏野马小种群生存状态的有效手段。
The Przewalski' s horse (Equus przewalskii) population re-introduced in the Anxi Extra-arid Desert National Na- ture Reserve in northwest China, is a relatively isolated population with an extremely low growth rate. In addition, they are facing severe predation pressure as well as inbreeding recession. Hence, to develop a long-term protection strategy is of high urgency. In this study, the reproduction and population viability of reintroduced Przewalski' s horse have been ana- lyzed. The results showed that, ( 1 ) the low population growth of reintroduced Przewalski' s horse was caused by both low fertility rate (44. 3% ) and high foals mortality rate (43.4%). Low reproductive survival rate is mainly influenced by nat- ural enemies' predation and diseases. The Przewalski' s horses exhibited seasonal breeding, 80. 9% of foals were born in May and June; (2) We used the Population Viability Analysis model VORTEX in this case and predicted that the extinc- tion risk of this population is 60% after 100 years. A minimum population of 200 is required to guarantee a risk less than 10% ; (3) The sensitivity analysis showed that wolf attacks have the greatest influence on the extinction risk and final pop- ulation size, followed by intrinsic factors such as maximum breeding age and fecundity rate ; (4) This Przewalski' s horse population was trapped in a small population effect. The mortality caused by diseases and foal weakness was relatively high (26. 5% and 8. 82%, respectively). Hence, it is necessary to supplement the population with new individuals to prevent extinction. Some additional strategies, like mitigating wolves' predation pressure and strengthening foals' s security, can also effectively improve the Przewalski' s horse living condition.
作者
裴鹏祖
王亮
邵亚平
石存海
杨永伟
包新康
PEI Pengzu;WANG Liang;SHAO Yaping;SHI Cunhai;YANG Yongwei;BAO Xinkang(Administration of Gansu Anxi Extra-arid National Nature Reserve, Gaazhou, Gansu 736100, China;Forestry College of Gansu Agricultural University, Lanzhoa 730070, China;School of Life Sciences, Lanzhou University, Lanzhou 730000, China)
出处
《兽类学报》
CAS
CSCD
北大核心
2018年第2期128-138,共11页
Acta Theriologica Sinica
基金
环境保护部生物多样性保护专项"甘肃安西极旱荒漠国家级自然保护区生物多样性监测"项目
关键词
普氏野马
重引入
繁殖
种群生存力分析
Population viability analysis (PVA)
Przewalski' s horse
Reintroduction
Reproduction