Wielgus Jeffrey, Gonzalez-Suarez Manuela, Aurioles-Gamboa David, Gerber Leah R
School of Life Sciences, Arizona State University, Tempe, Arizona 85287, USA.
Ecol Appl. 2008 Jul;18(5):1287-96. doi: 10.1890/07-0892.1.
A pressing need exists to develop new approaches for obtaining information on demographic rates without causing further threats to imperiled animal populations. In this paper, we illustrate and apply a data-fitting technique based on quadratic programming that uses stage-specific abundance data to estimate demographic rates and asymptotic population growth rates (lambda). We used data from seven breeding colonies of California sea lions (Zalophus californianus) in the Gulf of California, Mexico. Estimates of lambda were similar to those from previous studies relying on a diffusion approximation using trends in total abundance. On average, predicted abundances were within 24% of the observed value for the inverse estimation method and within 29% of the observed value for the diffusion approximation. Our results suggest that three of the seven populations are declining (lambda < 1), but as many as six may be at risk. Elasticity and sensitivity analyses suggest that population management in most sites should focus on the protection of adults, whose survival generally contributes the most to lambda. The quadratic programming approach is a promising noninvasive technique for estimating demographic rates and assessing the viability of populations of imperiled species.
迫切需要开发新方法来获取有关种群动态率的信息，同时又不会对濒危动物种群造成进一步威胁。在本文中，我们阐述并应用了一种基于二次规划的数据拟合技术，该技术使用特定阶段的丰度数据来估计种群动态率和渐近种群增长率（λ）。我们使用了来自墨西哥加利福尼亚湾七个加利福尼亚海狮（Zalophus californianus）繁殖群体的数据。λ的估计值与先前依赖于使用总丰度趋势的扩散近似法的研究结果相似。平均而言，对于逆估计方法，预测丰度在观测值的24%以内；对于扩散近似法，预测丰度在观测值的29%以内。我们的结果表明，七个种群中有三个正在减少（λ<1），但多达六个种群可能面临风险。弹性和敏感性分析表明，大多数地点的种群管理应侧重于保护成年个体，其生存通常对λ贡献最大。二次规划方法是一种很有前景的非侵入性技术，可用于估计种群动态率和评估濒危物种种群的生存力。
