Camera trapping reveals trends in forest duiker populations in African National Parks
Camera trapping reveals trends in forest duiker populations in African National Parks
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DOI：
10.1002/rse2.132
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发表时间：
2019-11-11
影响因子：
5.5
通讯作者：
Strindberg, Samantha
中科院分区：
文献类型：
--
作者：
O'Brien, Timothy G.;Ahumada, Jorge;Strindberg, Samantha
丛林肉狩猎被广泛认为是整个非洲野生动物数量下降的原因。森林小羚羊（牛科，头羚亚科）是最受开发的物种之一。目前的收获率是否危及小羚羊是有争议的，因为准确评估人口趋势的困难。为了评估种群趋势，我们首先回顾了历史小羚羊种群估计的文献。其次，我们使用系统的相机陷阱监测，以评估人口的趋势，在中部和东部非洲的6个国家公园的9个小羚羊物种的15个种群。我们分析了年度监测数据使用罗伊-尼科尔斯异质性引起的占用模型，估计丰度/采样点，并获得占用估计。已发布的密度估计表明，1973年至2013年间，整个非洲的小羚羊数量大幅下降。根据物种的不同，密度有很大的差异（横隔上的x = 0.26-20.6 km（-1）），也取决于种群是被猎杀（横隔上的x =6.3 km（-1））还是未被猎杀（横隔上的x = 16.3 km（-1））。最近对相机陷阱监测的分析得出了不同的结果。随着时间的推移，四个种群的估计平均点丰度在0至0.99个个体/点之间，六个种群在1.0至1.99个个体/点之间，五个种群大于2.0。我们观察到五个种群的小羚羊点丰度呈负趋势，虽然只有一个趋势是显着的，点丰度估计三个种群在最后一年的调查超过2.0。6个种群的点丰度呈正趋势（3个显著），其余种群无趋势。除三个种群外，平均占有率很高（psi > 0.60）。虽然文献表明，历史人口下降发生，大多数小羚羊种群出现相对健康的监测公园。我们的研究结果表明，这些公园是有效的保护大多数小羚羊，尽管狩猎压力。我们建议，系统的，标准化的相机陷阱监测相结合的点丰度模型，以客观地评估森林有蹄类动物的人口趋势在其他非洲公园。
Bushmeat hunting is widely cited as cause for declines of wildlife populations throughout Africa. Forest duikers (Bovidae, Cephalophinae) are among the most exploited species. Whether current harvest rates imperil duikers is debated because of the difficulty of accurately assessing population trends. To assess population trends, we first reviewed literature for historical duiker population estimates. Second, we used systematic camera-trap monitoring to assess population trends for 15 populations of nine duiker species in six national parks in Central and East Africa. We analysed annual monitoring data using Royle-Nichols heterogeneity-induced occupancy models to estimate abundance/sample point and derive occupancy estimates. Published density estimates indicate that duiker populations declined significantly throughout Africa between 1973 and 2013. There was a wide range of densities depending on species (x over bar range: 0.26-20.6 km(-1)) and whether populations were hunted (X over bar =6.3 km(-1)) or unhunted (X over bar = 16.3 km(-1)). More recent analysis of camera-trap monitoring produced different results. Estimated mean point abundance over time was between 0 and 0.99 individuals/point for four populations, between 1.0 and 1.99 for six populations, and greater than 2.0 for five populations. We observed five populations of duikers with negative trends in point abundances, although only one trend was significant and point abundance estimates for three populations were above 2.0 in the final survey year. Six populations showed positive trends in point abundance (three significant), and the remaining populations displayed no trends. Average occupancy was high (psi > 0.60) except for three populations. While literature indicates that historical population declines have occurred, most duiker populations appear relatively healthy in monitored parks. Our results indicate that these parks are effective in protecting most duikers despite hunting pressure. We recommend that systematic, standardized camera-trap monitoring be initiated in other African parks in combination with point-abundance models to objectively assess forest ungulate population trends.