Large carnivores are experiencing range contraction and population declines globally. Prey depletion due to illegal offtake is considered a major contributor, but the effects of prey depletion on large carnivore demography are rarely tested. We measured African lion density and tested the factors that affect survival using mark–recapture models fit to six years of data from known individuals in Kafue National Park (KNP), Zambia. KNP is affected by prey depletion, particularly for large herbivores that were preferred prey for KNP lions a half-century ago. This provides a unique opportunity to test whether variables that explain local prey density also affect lion survival. Average lion density within our study area was 3.43 individuals/100 km² (95% CI, 2.79–4.23), which was much lower than lion density reported for another miombo ecosystem with similar vegetation structure and rainfall that was less affected by prey depletion. Despite this, comparison to other lion populations showed that age- and sex-specific survival rates for KNP lions were generally good, and factors known to correlate with local prey density had small effects on lion survival. In contrast, recruitment of cubs was poor and average pride size was small. In particular, the proportion of the population comprised of second-year cubs was low, indicating that few cubs are recruited into the subadult age class. Our findings suggest that low recruitment might be a better signal of low prey density than survival. Thus, describing a lion population’s age structure in addition to average pride size may be a simple and effective method of initially evaluating whether a lion population is affected by prey depletion. These dynamics should be evaluated for other lion populations and other large carnivore species. Increased resource protection and reducing the underlying drivers of prey depletion are urgent conservation needs for lions and other large carnivores as their conservation is increasingly threatened by range contraction and population declines.

中文翻译：

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狮子人口统计学和动力学对首选大型猎物丢失的反应

大型食肉动物在全球范围内正在经历范围缩小和人口下降。由于非法捕食造成的猎物消耗被认为是一个主要因素，但很少测试猎物消耗对大型食肉动物人口的影响。我们测量了非洲狮的密度，并使用符合赞比亚卡富埃国家公园 (KNP) 已知个体六年数据的标记-重捕模型测试了影响生存的因素。KNP 受到猎物枯竭的影响，特别是对于半个世纪前作为 KNP 狮子首选猎物的大型食草动物。这提供了一个独特的机会来测试解释当地猎物密度的变量是否也会影响狮子的生存。我们研究区域内的平均狮子密度为 3.43 只/100 公里²(95% CI, 2.79–4.23)，这远低于另一个具有相似植被结构和降雨量且受猎物消耗影响较小的 miombo 生态系统报告的狮子密度。尽管如此，与其他狮子种群的比较表明，KNP 狮子的年龄和性别特定的存活率总体良好，已知与当地猎物密度相关的因素对狮子的存活率影响很小。相比之下，幼崽的招募很差，平均狮群规模很小。尤其是二岁幼崽在种群中的比例很低，表明很少有幼崽被招募到亚成年阶段。我们的研究结果表明，与生存相比，低招募可能是低猎物密度的更好信号。因此，除了平均狮群大小外，描述狮子种群的年龄结构可能是初步评估狮子种群是否受到猎物消耗影响的一种简单而有效的方法。应对其他狮子种群和其他大型食肉动物物种评估这些动态。加强资源保护和减少猎物枯竭的潜在驱动因素是狮子和其他大型食肉动物的迫切保护需求，因为它们的保护越来越受到范围缩小和种群减少的威胁。