Abstract The distribution of mammals is determined by a suite of endogenous and exogenous factors. In territorial, polygynous species like tigers (Panthera tigris), males often center their space-use around female territories, repelling competitors from these areas. Competition among males for females leads to increased mortality of both sexes and infanticide of unrelated cubs, which can lead to population declines. We hypothesized that increased territorial overlap among adult male tigers and elevated levels of inter and intra-sex competition would be manifest in populations with male-biased adult sex ratios (ASR). We also assessed whether inter-sex variation in adult survival or degree of habitat connectivity resulted in skewed ASR. We evaluated these hypotheses using camera trap data from three tiger populations occupying habitat patches with varying levels of connectivity and ASRs. Data were analyzed using multi-state occupancy models, where states were defined as habitat use by one or more male tigers in sites with and without female use. As predicted, in populations with male-biased or even ASR we found evidence for increased spatial overlap between male tigers, particularly pronounced in areas adjacent to female territories. Given parity in adult survival, habitat fragmentation likely caused male-biased ASR. Our results suggest that the persistence of small tiger populations in habitat patches with male-biased ASR may be significantly compromised by behavior-mediated endogenous demographic processes that are often overlooked. In habitat fragments with pronounced male biased ASR, population recovery of territorial carnivores may require timely supplementation of individuals to compensate for population losses from intraspecific competition.

中文翻译：

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占据分散景观的领土食肉动物种内竞争的潜力增加

摘要 哺乳动物的分布是由一系列内源性和外源性因素决定的。在老虎（Panthera tigris）等领土上的一夫多妻物种中，雄性通常将其空间使用集中在雌性领土周围，从而击退来自这些地区的竞争者。雄性之间对雌性的竞争导致两性死亡率增加和无关幼崽的杀婴，这可能导致种群下降。我们假设成年雄性老虎之间领土重叠的增加以及性别间和性别内竞争水平的提高将在具有男性偏见的成年性别比例（ASR）的人群中体现出来。我们还评估了成虫存活率或栖息地连通性程度的性别差异是否导致 ASR 偏差。我们使用来自占据具有不同连通性和 ASR 水平的栖息地斑块的三个老虎种群的相机陷阱数据评估了这些假设。使用多状态占用模型分析数据，其中状态被定义为一只或多只雄性老虎在有和没有雌性使用的地点使用栖息地。正如预测的那样，在具有男性偏见甚至 ASR 的人群中，我们发现了雄性老虎之间空间重叠增加的证据，尤其是在与雌性领土相邻的地区。鉴于成虫存活率相等，栖息地破碎化可能导致男性偏向 ASR。我们的研究结果表明，在具有雄性倾向 ASR 的栖息地斑块中，小老虎种群的持续存在可能会受到经常被忽视的行为介导的内源性人口统计过程的显着影响。