Scramble Competition: An Examination of Day Range Length Variation

灵长类动物行为研究的一个主要目标是了解雌性之间竞争关系的原因。从历史上看，解释竞争关系变化的尝试主要集中在所谓的“竞争竞争”上，这可能会导致支配地位的等级，这是描述女性关系的一个主要组织主题。然而，实地研究表明，女性关系中存在的差异比竞赛模型单独容纳或认识到的更大。此外，到目前为止，竞争模型对日范围大小的预测被证明是不充分的。本项目将关注竞赛竞争和争抢竞争的互补关系，这在过去还没有被如此广泛地研究过。人们普遍认为，随着群体规模的增加，群体内的竞争也会加剧。这种竞争加剧的一个结果是，在许多灵长类物种中，较大的群体每天比较小的群体走得更远。然而，并不是所有的物种都会通过每天更长的距离旅行来应对群体规模的增加。事实上，灵长类动物可以通过它们是否随着群体规模的增加而增加日间范围来明确区分。这种划分也明显地沿着组内统治等级的强弱(一种竞赛形式)来划分。伊斯贝尔认为，在那些随着群体规模的增加而增加白天活动范围的物种中，群体内雌性之间的优势等级关系很强，很容易被发现。相反，在那些没有随着种群规模的增加而增加日照范围长度的物种中，优势等级很弱或很难检测到。这项研究承诺澄清一些关于灵长类社会群体中竞争行为表达的基本问题。

A major goal of studies in primate behavior has been to understand the causes of competitive relationships among females. Historically, attempts to explain variation in competitive relationships have focused on what has been called "contest competition," which can lead to dominance hierarchies, a major organizing theme in describing female relationships. However, field studies have now shown that greater variation in female relationships exists than is accommodated or recognized by models of contest competition alone. Also, predictions of day range size from competition models have proved inadequate to date. This project will focus on the complementary relationship of contest competition and "scramble" competition, which has not been so widely examined in the past. It has been widely accepted that intragroup competition increases as group size increases. One result of this increased competition is that in many primate species larger groups travel farther per day than smaller groups. However, not all species respond to increases in group size by traveling longer daily distances. In fact, primates can be separated clearly by whether they do or do not increase their day ranges with increasing group size. This division also separates clearly along the strength of the dominance hierarchy within groups (a form of contest competition). Isbell argues that in those species that increase day range length with increasing group size, dominance hierarchies among females within groups are strong and easily detected. In contrast, in those species that do not increase day range length with increasing group size, dominance hierarchies are weak or difficult to detect. This study promises to clarify some fundamental issues regarding behavioral expressions of competition in social groups of primates.