Changes in demographic features of the lion population in the south‐western Kgalagadi Transfrontier Park cause conservation concern. The ratio between adult males and females changed from 1♂:2♀ to 1♂:1♀ over a 32‐year period (1977–2010). This is atypical for undisturbed lion populations. We evaluated mechanisms that on their own or together could explain the trend by using both a discrete‐ and continuous‐time capture–recapture model to analyse 2 years of individual‐based observation data (May 2013–June 2015). Although most vital rates were within expected parameters, shifts in the sex structure remained similar to that reported for sub‐adults previously. The population comprised of 26.9% cubs and juveniles (<2 years), 14.2% sub‐adults (2–4 years) and 59% adults (>4 years). Litters had equal sex ratios at first detection. Birth rates were lower (0.44 cubs per female per year) than between 1998 and 2001 (0.69 cubs per female per year). The continuous model indicated a higher survival effect for female cubs, while both models showed higher survival rates/effects for sub‐adult and adult females relative to males. However, the sex ratio for sub‐adults was male‐biased. The shift in demographic signals may associate with changes in age‐related immigration rates of sub‐adult males.

中文翻译：

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西南加拉加迪边防公园的狮子（Panthera leo）人口统计

西南Kgalagadi边境公园的狮子种群的人口统计特征发生变化，引起了保护方面的关注。在32年间（1977-2010年），成年男女之间的比例从1 ::2♀变为1 ::1♀。这对于不受干扰的狮子种群而言是非典型的。我们通过使用离散和连续时间捕获-捕获模型来分析2年基于个人的观测数据（2013年5月至2015年6月），评估了可以单独或共同解释这种趋势的机制。尽管大多数生命率都在预期的参数范围内，但性别结构的变化仍与先前报道的亚成人相似。人口中有26.9％的幼崽和未成年人（<2岁），14.2％的亚成年人（2-4岁）和59％的成年人（> 4岁）。初次发现垃圾者的性别比例相同。出生率（1998年至2001年）低于1998年至2001年（女性每年0.69崽）。连续模型表明雌性幼崽具有更高的生存效果，而两个模型均显示出相对于雄性而言，亚成年雌性和成年雌性具有更高的生存率/效应。但是，次成年人的性别比例是男性偏见的。人口统计学信号的变化可能与亚成年男性与年龄有关的移民率变化有关。