Dickman C R, Woodside D P
Department of Zoology, Australian National University, 2600, Canberra, ACT, Australia.
Oecologia. 1983 Oct;60(1):127-134. doi: 10.1007/BF00379332.
This study tests the hypothesis that competition occurs in a community of three species of small mammals (Antechinus stuartii and A. swainsonii, Marsupialia; Rattus fuscipes, Rodentia) in south-eastern Australia. The hypothesis was tested by using a simple model of competition that is based on two premises: I. competition results in a negative numerical or a negative spatial association between species, and II. competition is more intense where the densities of the competing species are relatively high. The model combines both premises and predicts that measures of association between competing species will be more negative where the species exist at high population densities than derived from the model and applied to data gathered in two study areas with contrasting mean animal densities. There was no evidence of numerical association among the species (three tests), but evidence of negative spatial association (three tests our of four). These latter findings were consistent with the predictions of the model. All species preferred the same broad kinds of habitat (macrohabitat), but they segregated into smaller, finer grained patches (microhabitat) when their numbers were relatively high. Such segregation was more evident between the two species of marsupials than between either species of marsupial and the eutherian rat. These findings suggested that competition occurs by interference, and reinforce the idea that an understanding of the behaviour of individuals is important to understanding competition between species.
在澳大利亚东南部的一个由三种小型哺乳动物（袋鼬属的斯氏袋鼬和史氏袋鼬，有袋目；帚尾大鼠，啮齿目）组成的群落中存在竞争。该假设通过使用一个基于两个前提的简单竞争模型进行检验：一、竞争导致物种之间出现负数量关联或负空间关联；二、在竞争物种密度相对较高的地方，竞争更为激烈。该模型结合了这两个前提，并预测在竞争物种以高种群密度存在的地方，竞争物种之间的关联度量将比从模型得出并应用于在两个平均动物密度不同的研究区域收集的数据时更为负面。没有证据表明物种之间存在数量关联（三项检验），但有证据表明存在负空间关联（四项检验中的三项）。后一项发现与模型的预测一致。所有物种都偏好相同的大致栖息地类型（宏观栖息地），但当它们的数量相对较高时，会分隔到更小、粒度更细的斑块（微观栖息地）中。这种分隔在两种有袋动物之间比在任何一种有袋动物与真兽类大鼠之间更为明显。这些发现表明竞争是通过干扰发生的，并强化了这样一种观点，即了解个体行为对于理解物种间竞争很重要。
