Hernández-Camacho Claudia J, Bakker Victoria J, Aurioles-Gamboa David, Laake Jeff, Gerber Leah R
School of Life Sciences, Arizona State University, Tempe, Arizona, United States of America.
Department of Ecology, Montana State University, Bozeman, Montana, United States of America.
PLoS One. 2015 Sep 28;10(9):e0139158. doi: 10.1371/journal.pone.0139158. eCollection 2015.
Reliable data necessary to parameterize population models are seldom available for imperiled species. As an alternative, data from populations of the same species or from ecologically similar species have been used to construct models. In this study, we evaluated the use of demographic data collected at one California sea lion colony (Los Islotes) to predict the population dynamics of the same species from two other colonies (San Jorge and Granito) in the Gulf of California, Mexico, for which demographic data are lacking. To do so, we developed a stochastic demographic age-structured matrix model and conducted a population viability analysis for each colony. For the Los Islotes colony we used site-specific pup, juvenile, and adult survival probabilities, as well as birth rates for older females. For the other colonies, we used site-specific pup and juvenile survival probabilities, but used surrogate data from Los Islotes for adult survival probabilities and birth rates. We assessed these models by comparing simulated retrospective population trajectories to observed population trends based on count data. The projected population trajectories approximated the observed trends when surrogate data were used for one colony but failed to match for a second colony. Our results indicate that species-specific and even region-specific surrogate data may lead to erroneous conservation decisions. These results highlight the importance of using population-specific demographic data in assessing extinction risk. When vital rates are not available and immediate management actions must be taken, in particular for imperiled species, we recommend the use of surrogate data only when the populations appear to have similar population trends.
对于濒危物种而言，用于参数化种群模型的可靠数据很少能获取到。作为一种替代方法，来自同一物种或生态相似物种种群的数据已被用于构建模型。在本研究中，我们评估了利用在加利福尼亚海狮的一个繁殖地（洛斯伊斯洛特斯岛）收集的种群统计学数据，来预测墨西哥加利福尼亚湾另外两个繁殖地（圣豪尔赫岛和格拉尼托岛）同一物种的种群动态，而这两个繁殖地缺乏种群统计学数据。为此，我们开发了一个随机的种群统计学年龄结构矩阵模型，并对每个繁殖地进行了种群生存力分析。对于洛斯伊斯洛特斯岛繁殖地，我们使用了特定地点的幼崽、幼年和成年个体的存活概率，以及老年雌性的出生率。对于其他繁殖地，我们使用了特定地点的幼崽和幼年个体的存活概率，但成年个体的存活概率和出生率则使用来自洛斯伊斯洛特斯岛的替代数据。我们通过将模拟的回顾性种群轨迹与基于计数数据的观察到的种群趋势进行比较，来评估这些模型。当对一个繁殖地使用替代数据时，预测的种群轨迹接近观察到的趋势，但对另一个繁殖地则不匹配。我们的结果表明，物种特异性甚至区域特异性的替代数据可能会导致错误的保护决策。这些结果凸显了在评估灭绝风险时使用特定种群的种群统计学数据的重要性。当关键比率不可获取且必须立即采取管理行动时，特别是对于濒危物种，我们建议仅在种群似乎具有相似的种群趋势时才使用替代数据。
