Assessing the population performance of the black rhinoceros in Kruger National Park
Assessing the population performance of the black rhinoceros in Kruger National Park
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DOI：
10.3957/056.041.0206
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发表时间：
2011-10-01
影响因子：
--
通讯作者：
Knight, Mike H.
中科院分区：
文献类型：
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作者：
Ferreira, Sam M.;Greaver, Cathy C.;Knight, Mike H.
种群规模小，保护管理人员寻求确保物种的持久性和说明保护的成功提供了几个挑战。黑犀牛Diceros bicornis minor就是这些挑战的缩影。在2008年10月，我们使用块调查，估计的可用性和观察员的偏见，以计算特定的黑犀牛丰度在南部地区的克鲁格国家公园，南非。我们分配年龄和性别的个人，提取的年龄分布，并估计生存和繁殖力的人口增长来自历史带状样带。区块计数，校正90.3%的可用性偏差，观察员遗漏3.8%，预测627（95% CI：588-666）黑犀牛居住在研究区域。种群以每年6.75%的速度增长，这是高存活率和估计的产犊间隔为2.45年的结果。年龄分布和人口增长预测，亚成年男性和女性有最低的年生存率，而依赖小牛和成年人有最高的年生存率。精确的估计，可以得到一个20%的研究面积覆盖使用块计数。这给出了方差系数，允许每两年从调查中检测5%的增长。检测2%的年下降率需要6年的半年调查。我们的研究结果表明，黑犀牛在克鲁格国家公园表现良好。
Small population sizes provide several challenges to conservation managers seeking to ensure species persistence and illustrating conservation success. Black rhinoceros, Diceros bicornis minor, epitomizes these challenges. During October 2008 we used block surveys, estimates of availability and observer bias to calculate landscape-specific black rhino abundances in the southern parts of Kruger National Park, South Africa. We assigned age and sex to individuals, extracted an age distribution, and estimated survival and fecundity given the population growth derived from historical strip transects. The block counts, corrected for 90.3% availability bias with observers missing 3.8% of those, predicted that 627 (95% CI: 588-666) black rhinos resided in the study area. The population increased at 6.75% per annum, the result of high survival and an estimated inter-calving interval of 2.45 years. Age distributions and population growth predicts that subadult males and females have the lowest annual survival, while dependent calves and adults have the highest annual survival. Precise estimates can be obtained with a 20% study area coverage using block counts. This gives coefficient of variances allowing detection of 5% growth from surveys every two years. Detecting 2% annual decline requires bi-annual surveys for 6 years. Our results illustrate that black rhinos are performing well in Kruger National Park.