从北美的研究看大熊猫的种群动态(英文)

Insights into population dynamics of giant pandas gained from studies in North America

尽管人们对大熊猫的种群动态了解很少 ,但是我们可以从对相似物种的研究和经历中了解一些基本原理。在不减少对后续的有关大熊猫种群特征、遗传学和行为研究的前提下 ,根据对北美食肉动物种群生物学的理解 ,我提出了下面一般性的结论。首先 ,弹性分析确认 ,大熊猫演变出了确保雌性个体高存活率的生活史。比较而言 ,繁殖率并不重要。成年雌性个体的存活率增加 ,比相应的繁殖输出要导致 5倍的保护效益。第二 ,在可能表现大熊猫种群特征的假设前提下 ,雄性 (甚至成年个体 )的存活率相对而言也是不重要的。第三 ,尽管都认为大熊猫繁殖很缓慢 ,但是从数学上来说 ,如果生境 (以及与其相关的存活率 )允许 ,大熊猫的种群能够比较快地增长。最后 ,北美西部对濒危物种再引入的经验提醒我们 ,保留大片尚未破碎化的生境非常重要。狼在 2 0世纪中叶就在美国西部灭绝了 ,但是目前由于有广阔的生存区域和丰富的食物 ,种群恢复很快。对比而言 ,最近从原野中消失的黑足鼬 ,在种群重建过程中遇到了很大的困难 ,尽管人们在科学上做出了巨大的努力。看来黑足鼬可能只是没有足够的野外栖息地 (猎物 )以维持生存。如果没有足够的栖息地 。

Although population dynamics of giant pandas Ailuropoda melanoleuca remain poorly known, basic principles can be safely transferred from studies of, and experience with, similar species. Without minimizing the importance of continued study of demographics, genetics, and behavior of pandas, I offer the following generalizations from our understanding of carnivore population biology in North America. First, elasticity analyses confirm that pandas have evolved life histories that prioritize high survival of adult females. In comparison, reproductive rates are unimportant. Increases in survival of adult females will yield approximately 5 times the conservation benefit of proportional increases in reproductive output. Second, under circumstances likely to characterize most panda populations, survival rates of males (even adults) are also relatively unimportant. Thirdly, notwithstanding its well deserved reputation as a slow breeder, giant panda populations are mathematically capable of growing surprisingly quickly, if habitats (and associated survival rates) allow. Finally, reintroductions of endangered species in western North America remind us of the critical role of maintaining large patches of unfragmented habitat. Wolves Canis lupus , extirpated from the western U S. before the mid 20 th century, have made a rapid and surprisingly painless recovery because wild areas and prey populations remained abundant. In contrast, black footed ferrets Mustela nigripes , lost from the wild more recently, have encountered great difficulty in becoming reestablished, despite tremendous scientific efforts. It appears that ferrets may simply no longer have sufficient wild habitat (i.e., prey) to persist. The best science will not be capable of saving pandas if sufficient habitat is not available .