The "Coerebini": A Group of Marginal Areas, Habitats, and Habits

作者：M. Moynihan · 发表于：The American Naturalist · 年份：1968 · DOI：10.1086/282569 · 被引用次数：11 · 研究领域：Plant and animal studies、Lepidoptera: Biology and Taxonomy、Botany and Geology in Latin America and Caribbean

A small group of neotropical honeycreepers, which may be recognized as a tribe "Coerebini," includes the genera Coereba, Ateleodacnis, Conirostrum, and possibly Oreomanes. All the species of these genera are "marginal" in one way or another. They are most characteristic of islands and/or confined to distinctive habitats of comparatively restricted distribution (Mangrove, Cavanillesia forest, Polylepis woods) and/or commensals of man and his artifacts or of mixed flocks of other birds. These various types of "marginality" may all be expressions of the same basic general adaptation or preadaptation, a tendency to use indirect rather than direct clues to locate resources (food). All the Coerebini are partly nectarivorous, and nectarivorous species must necessarily use indirect clues more frequently than other species. Simply because indirect clues must be less reliable on the average than direct clues, it probably will be advantageous for the species which have to use them to use as many and as great a variety as possible. This must lead to increased opportunism. One would, therefore, expect species which use indirect clues to be more frequent and successful colonizers of new (previously unfamiliar) areas and habitats than otherwise similar species which rely upon direct clues. It also seems probable that the proportion of endemic species using indirect clues in any given area will be positively correlated with the degree of isolation and peculiarity of the area.