Troyer Elizabeth M, Cameron Devitt Susan E, Sunquist Melvin E, Goswami Varun R, Oli Madan K
School of Natural Resources and Environment, University of Florida, Gainesville, Florida, United States of America; Department of Wildlife Ecology and Conservation, University of Florida, Gainesville, Florida, United States of America.
Department of Wildlife Ecology and Conservation, University of Florida, Gainesville, Florida, United States of America.
PLoS One. 2014 Jun 5;9(6):e98535. doi: 10.1371/journal.pone.0098535. eCollection 2014.
Populations of mesopredators (mid-sized mammalian carnivores) are expanding in size and range amid declining apex predator populations and ever-growing human presence, leading to significant ecological impacts. Despite their obvious importance, population dynamics have scarcely been studied for most mesopredator species. Information on basic population parameters and processes under a range of conditions is necessary for managing these species. Here we investigate survival, recruitment, and population growth rate of a widely distributed and abundant mesopredator, the northern raccoon (Procyon lotor), using Pradel's temporal symmetry models and >6 years of monthly capture-mark-recapture data collected in a protected area. Monthly apparent survival probability was higher for females (0.949, 95% CI = 0.936-0.960) than for males (0.908, 95% CI = 0.893-0.920), while monthly recruitment rate was higher for males (0.091, 95% CI = 0.078-0.106) than for females (0.054, 95% CI = 0.042-0.067). Finally, monthly realized population growth rate was 1.000 (95% CI = 0.996-1.004), indicating that our study population has reached a stable equilibrium in this relatively undisturbed habitat. There was little evidence for substantial temporal variation in population growth rate or its components. Our study is one of the first to quantify survival, recruitment, and realized population growth rate of raccoons using long-term data and rigorous statistical models.
在顶级食肉动物数量下降和人类活动不断增加的情况下,中型食肉动物(中等体型的食肉类哺乳动物)的种群数量和分布范围正在扩大,这导致了重大的生态影响。尽管它们显然很重要,但大多数中型食肉动物物种的种群动态几乎没有得到研究。了解一系列条件下的基本种群参数和过程对于管理这些物种是必要的。在这里,我们使用普拉德尔的时间对称模型和在一个保护区收集的超过6年的月度标记重捕数据,研究了一种分布广泛且数量丰富的中型食肉动物——北美浣熊(Procyon lotor)的存活率、补充率和种群增长率。雌性的月度表观存活概率(0.949,95%置信区间=0.936 - 0.960)高于雄性(0.908,95%置信区间=0.893 - 0.920),而雄性的月度补充率(0.091,95%置信区间=0.078 - 0.106)高于雌性(0.054,95%置信区间=0.042 - 0.067)。最后,月度实际种群增长率为1.000(95%置信区间=0.996 - 1.004),这表明我们的研究种群在这个相对未受干扰的栖息地已经达到了稳定的平衡。几乎没有证据表明种群增长率或其组成部分存在显著的时间变化。我们的研究是最早使用长期数据和严格统计模型来量化浣熊的存活率、补充率和实际种群增长率的研究之一。