Wiens J A, Van Horne B, Rotenberry J T
Department of Biology, University of New Mexico, 87131, Albuquerque, NM, USA.
Department of Biological Sciences, Bowling Green State University, 43403, Bowling Green, OH, USA.
Oecologia. 1987 Aug;73(1):60-70. doi: 10.1007/BF00376978.
We documented patterns of activity and microhabitat use by breeding male Sage Sparrows (Amphispiza belli) and Brewer's Sparrows (Spizella breweri) in the semiarid shrubsteppe of northwestern U.S.A. to determine how their behavior varies in space and time and how these variations relate to environmental features. In analyses of several sites with multiple plots that were studied for 2-4 yr, the frequencies of activities and substrate use varied significantly with year, plot, and location. The major activities, foraging and singing, varied inversely with one another. Thus, although the general structure of the activity budgets of these species was stable (i.e. foraging and singing were always the most frequent activities), there was considerable variation in the quantitative details of their behavior in space and time. Using stepwise regression, we related these variations in behavior to variations in environmental features such as the densities of the same or other species, the number of species in the community, and coverages of the different substrate types. Few patterns emerged, and those that did were generally not in accord with our expectations. In particular, patterns of substrate use were not related to variations in coverages of those substrates. Sage Sparrows, for example, increased their use of sagebrush and grass with increasing grass coverage and with increasing densities of Sage Sparrows. Responses to both variables suggested nonlinear threshold patterns.We interpret the variations in behavior as indicating a loose coupling between behavior and proximate environmental conditions for these species. In such situations, the variability of behavior complicates attempts to test ecological hypotheses (e.g. behavioral niche partitioning) with data from a limited number of locations or years.
我们记录了美国西北部半干旱灌木草原地区繁殖期雄性鼠尾草雀（Amphispiza belli）和布鲁尔氏雀（Spizella breweri）的活动模式及微生境利用情况，以确定它们的行为在空间和时间上如何变化，以及这些变化与环境特征有何关联。在对多个样地进行了2至4年研究的几个地点的分析中，活动频率和底物利用情况随年份、样地和位置的不同而有显著差异。主要活动，即觅食和鸣叫，彼此呈负相关。因此，尽管这些物种活动预算的总体结构是稳定的（即觅食和鸣叫始终是最频繁的活动），但其行为在空间和时间上数量细节仍存在相当大的差异。我们使用逐步回归法，将这些行为变化与环境特征的变化联系起来，如同一物种或其他物种的密度、群落中的物种数量以及不同底物类型的覆盖率。几乎没有出现什么规律，即便有也通常与我们的预期不符。特别是，底物利用模式与这些底物覆盖率的变化并无关联。例如，随着草地覆盖率的增加以及鼠尾草雀密度的增加，鼠尾草雀对蒿属植物和草的利用也增加。对这两个变量的反应均呈现出非线性阈值模式。我们将行为变化解释为表明这些物种的行为与近缘环境条件之间存在松散的耦合关系。在这种情况下，行为的变异性使得利用来自有限数量地点或年份的数据来检验生态假说（如行为生态位划分）变得复杂。
