ORGANIZATION OF A TROPICAL ISLAND COMMUNITY OF HUMMINGBIRDS AND FLOWERS
ORGANIZATION OF A TROPICAL ISLAND COMMUNITY OF HUMMINGBIRDS AND FLOWERS
复制标题
热带岛屿蜂鸟和花卉社区的组织
作者：
A. Kodric‐Brown;James H. Brown;Gregory S. Byers;D. Gori
本文研究了波多黎各西南部地区蜂鸟与蜂鸟传粉花之间的时空关系，以探讨竞争和互惠在该群落组织中的作用。我们记录了开花物候、花蜜产量、蜂鸟和盗蜜者访花和花粉负荷，并在两个6个月的时间内沿海拔样带对蜂鸟和花进行了形态学测量。这个群落由三种蜂鸟和至少13种专门为蜂鸟授粉的管状花植物组成。两种大型蜂鸟，炭疽胸鸟（Anthracothorax dominicus）和A. virdis，在很大程度上占据不重叠的觅食区域、栖息地和海拔，但在利用8种长管和分泌丰富花蜜的花方面是重叠的。另一种蜂鸟，绿stilbon maugaeus，要小得多，并且几乎完全以其他五种花为食，这些花有较短的管和不分泌的花蜜。因此，社区由两个很大程度上不重叠的亚单位组成。因为长管花限制了大型、长喙蜂鸟的合法觅食，而这些蜂鸟被其高水平的花蜜所吸引，而且因为短管花分泌的花蜜足以供小型蜂鸟（而不是大型蜂鸟）进行经济的觅食。竞争和互惠的相互作用在蜂鸟和花这两个离散亚群落的共同进化中似乎都很重要。
We studied the temporal and spatial relationships among hummingbirds and hummingbird—pollinated flowers on southwestern Puretor Rico in order to assess the roles of competition and mutualism in the organization of this community. We recorded flowering phenology, nectar production, hummingbird and nectar—robber visits to flowers, and pollen loads, and made morphological measurements of both hummingbirds and flowers along an elevational transect during two 6—mo periods. The community consists of three species of hummingbirds and at least 13 species of plants with tubular flowers specialized for hummingbird pollination. Two large hummingbirds, Anthracothorax dominicus and A. virdis, occupy largely nonoverlapping foraging areas, habitats, and elevations but overlap in their utilization of eight species of flowers that have long tubes and secrete copious nectar. The other hummingbird, Chlorostilbon maugaeus, is much smaller and forages legitimately almost exclusively on the other five species of flowers which have shorter tubes and secreteless nectar. Thus the community consists of two largely nonoverlapping subunits. Specificity is maintained because long—tubed flowers restrict legitimate foraging to large, long—billed hummingbirds, which are attracted to their high nectar levels, and because the short—tubed flowers secrete sufficient nectar for economical foraging by small, but not large hummingbirds. Both competitive and mutualistic interactions appear to have been important in the coevolution of these two discrete subcommunities of hummingbirds and flowers.