Habitat loss is affecting many species, including the southern mountain caribou (Rangifer tarandus caribou) population in western North America. Over the last half century, this threatened caribou population's range and abundance have dramatically contracted. An integrated population model was used to analyze 51 years (1973–2023) of demographic data from 40 southern mountain caribou subpopulations to assess the effectiveness of population‐based recovery actions at increasing population growth. Reducing potential limiting factors on threatened caribou populations offered a rare opportunity to identify the causes of decline and assess methods of recovery. Southern mountain caribou abundance declined by 51% between 1991 and 2023, and 37% of subpopulations were functionally extirpated. Wolf reduction was the only recovery action that consistently increased population growth when applied in isolation, and combinations of wolf reductions with maternal penning or supplemental feeding provided rapid growth but were applied to only four subpopulations. As of 2023, recovery actions have increased the abundance of southern mountain caribou by 52%, compared to a simulation with no interventions. When predation pressure was reduced, rapid population growth was observed, even under contemporary climate change and high levels of habitat loss. Unless predation is reduced, caribou subpopulations will continue to be extirpated well before habitat conservation and restoration can become effective.

中文翻译：

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针对受威胁的南部山区驯鹿的基于人口的恢复行动的有效性

栖息地丧失正在影响许多物种，包括南部山区驯鹿（驯鹿）北美西部的人口。在过去的半个世纪中，受到威胁的驯鹿种群的范围和数量急剧减少。使用综合人口模型分析了 40 个南部山区驯鹿亚群 51 年（1973 年至 2023 年）的人口数据，以评估基于人口的恢复行动对增加人口增长的有效性。减少对受威胁驯鹿种群的潜在限制因素为确定驯鹿数量减少的原因和评估恢复方法提供了难得的机会。 1991 年至 2023 年间，南部山区驯鹿数量下降了 51%，37% 的亚群被功能性灭绝。减少狼群是唯一在单独应用时能够持续增加种群增长的恢复行动，减少狼群与母亲圈养或补充喂养的结合可以提供快速的增长，但仅适用于四个亚种群。截至 2023 年，与没有干预的模拟相比，恢复行动已使南部山区驯鹿的数量增加了 52%。当捕食压力减少时，即使在当代气候变化和栖息地严重丧失的情况下，种群也会快速增长。除非减少捕食，否则在栖息地保护和恢复发挥作用之前，驯鹿亚群将继续被灭绝。