Ameca y Juárez Eric I, Ellis Edward A, Rodríguez-Luna Ernesto
Center for Tropical Research, University of Veracruz, Veracruz, México.
Am J Primatol. 2015 Jul;77(7):786-800. doi: 10.1002/ajp.22402. Epub 2015 Apr 2.
Long-term studies quantifying impacts of hurricane activity on growth and trajectory of primate populations are rare. Using a 14-year monitored population of Alouatta palliata mexicana as a study system, we developed a modeling framework to assess the relative contribution of hurricane disturbance and two types of human impacts, habitat loss, and hunting, on quasi-extinction risk. We found that the scenario with the highest level of disturbance generated a 21% increase in quasi-extinction risk by 40 years compared to scenarios of intermediate disturbance, and around 67% increase relative to that found in low disturbance scenarios. We also found that the probability of reaching quasi-extinction due to human disturbance alone was below 1% by 40 years, although such scenarios reduced population size by 70%, whereas the risk of quasi-extinction ranged between 3% and 65% for different scenarios of hurricane severity alone, in absence of human impacts. Our analysis moreover found that the quasi-extinction risk driven by hunting and hurricane disturbance was significantly lower than the quasi-extinction risk posed by human-driven habitat loss and hurricane disturbance. These models suggest that hurricane disturbance has the potential to exceed the risk posed by human impacts, and, in particular, to substantially increase the speed of the extinction vortex driven by habitat loss relative to that driven by hunting. Early mitigation of habitat loss constituted the best method for reducing quasi-extinction risk: the earlier habitat loss is halted, the less vulnerable the population becomes to hurricane disturbance. By using a well-studied population of A. p. mexicana, we help understand the demographic impacts that extreme environmental disturbance can trigger on isolated populations of taxa already endangered in other systems where long-term demographic data are not available. For those experiencing heavy anthropogenic pressure and lacking sufficiently evolved coping strategies against unpredictable environmental disturbance, the risk of population extinction can be exacerbated.
量化飓风活动对灵长类种群增长和发展轨迹影响的长期研究很少。我们以对墨西哥蛛猴进行了14年监测的种群作为研究系统，开发了一个建模框架，以评估飓风干扰以及栖息地丧失和捕猎这两种人类影响类型对近似灭绝风险的相对贡献。我们发现，与中等干扰情景相比，最高干扰水平情景下，到40年时近似灭绝风险增加了21%，相对于低干扰情景下的风险增加了约67%。我们还发现，仅由人类干扰导致达到近似灭绝的概率到40年时低于1%，尽管这种情景下种群数量减少了70%，而在没有人类影响的情况下，仅不同飓风严重程度情景下的近似灭绝风险在3%至65%之间。此外，我们的分析发现，捕猎和飓风干扰导致的近似灭绝风险显著低于人类导致的栖息地丧失和飓风干扰所带来的近似灭绝风险。这些模型表明，飓风干扰有可能超过人类影响带来的风险，特别是相对于捕猎导致的灭绝漩涡，它会大幅加快由栖息地丧失驱动的灭绝漩涡的速度。早期缓解栖息地丧失是降低近似灭绝风险的最佳方法：栖息地丧失停止得越早，种群对飓风干扰的脆弱性就越小。通过使用对墨西哥蛛猴进行了充分研究的种群，我们有助于理解极端环境干扰对其他系统中已濒危且缺乏长期人口统计数据的分类单元孤立种群可能引发的人口统计学影响。对于那些承受巨大人为压力且缺乏针对不可预测环境干扰充分进化的应对策略的种群来说，种群灭绝的风险可能会加剧。
