Density-dependent home-range size revealed by spatially explicit capture-recapture
Density-dependent home-range size revealed by spatially explicit capture-recapture
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DOI：
10.1111/ecog.01511
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发表时间：
2016-07-01
期刊：
影响因子：
5.9
通讯作者：
Qureshi, Q.
中科院分区：
文献类型：
--
作者：
Efford, M. G.;Dawson, D. K.;Qureshi, Q.
在同一物种的种群中，动物栖息地的大小通常与种群密度成反比。这一事实对使用空间明确的捕获-再捕获（SECR）模型进行种群监测具有启示意义，在该模型中，家园范围移动的尺度sigma和种群密度D通常作为参数出现，并且两者在种群中可能不同。对这些参数的特定于人口的值之间的结构关系建立模型往往是适当的，而不是假设它们是独立的。我们建议使用k(p) = sigma(p) D-p重新参数化SECR模型，其中k(p)与主范围之间的重叠程度有关，下标p用于区分种群。我们观察到，对于跨越一定密度范围的种群，k(p)通常几乎是恒定的。这证明拟合一个模型是合理的，其中单独的k(p)被单个参数k取代，sigma(p)是一个依赖于密度的衍生参数。利用探测器和动物位置之间的非欧几里得距离，也可以对西格玛的连续密度相关空间变化进行建模。我们用来自印度虎Panthera tigris的自动摄影数据来说明这些方法，其中变异是在种群之间的，来自美国马里兰州烤鸟Seiurus aurocapilla的雾网，其中变异是在单个种群内随时间的变化，以及来自新西兰刷尾负鼠Trichosurus vulpecula的活捕，模拟了一个种群内的空间变异。讨论了这些方法可能的应用和局限性。当密度变化时，k(p)不变的模型为SECR提供了一个简洁的零模型。零模型的参数k是主场距离大小和密度之间经验关系的简明总结，在比较研究中很有用。我们期望这个模型的偏差，特别是k(p)对协变量的依赖，在生物学上是有趣的。
The size of animal home ranges often varies inversely with population density among populations of a species. This fact has implications for population monitoring using spatially explicit capture-recapture (SECR) models, in which both the scale of home-range movements sigma and population density D usually appear as parameters, and both may vary among populations. It will often be appropriate to model a structural relationship between population-specific values of these parameters, rather than to assume independence. We suggest re-parameterizing the SECR model using k(p) = sigma(p) D-p, where k(p) relates to the degree of overlap between home ranges and the subscript p distinguishes populations. We observe that k(p) is often nearly constant for populations spanning a range of densities. This justifies fitting a model in which the separate k(p) are replaced by the single parameter k and sigma(p) is a density-dependent derived parameter. Continuous density-dependent spatial variation in sigma may also be modelled, using a scaled non-Euclidean distance between detectors and the locations of animals. We illustrate these methods with data from automatic photography of tigers Panthera tigris across India, in which the variation is among populations, from mist-netting of ovenbirds Seiurus aurocapilla in Maryland, USA, in which the variation is within a single population over time, and from live-trapping of brushtail possums Trichosurus vulpecula in New Zealand, modelling spatial variation within one population. Possible applications and limitations of the methods are discussed. A model in which k(p) is constant, while density varies, provides a parsimonious null model for SECR. The parameter k of the null model is a concise summary of the empirical relationship between home-range size and density that is useful in comparative studies. We expect deviations from this model, particularly the dependence of k(p) on covariates, to be biologically interesting.