The hummingbird community of a lowland Amazonian rainforest

Between October 1987 and September 1989, the British Ornithologists' Union Colombia Expedition recorded 16 species of hummingbird at Matamatá in the Amacayacu National Park, Amazonas, Colombia. Most of these species were resident breeders at the study site although two appeared to be local migrants. Six species of hermit hummingbirds (subfamily Phaethornithinae) occurred at Matamatá; although very similar in general morphology and behaviour, they showed different preferences for habitat, food plants and foraging technique. Hermits were predominant in the forest, but in areas of secondary vegetation and along riverine borders, "typical" hummingbirds (subfamily Trochilinae) were more common. The study site consisted of terra firme and várzea forest and an area of riverine secondary vegetation and contained around 60 species of flowering plants visited by hummingbirds. In contrast with most groups of organisms, hummingbirds and hummingbird-pollinated plants had similar species diversity in primary forest and secondary habitats. The overall abundance of hummingbirds and flowers was significantly higher in areas of riverine secondary growth. The hummingbird community at Matamatá is remarkably species rich when compared with study sites elsewhere in North and South America. However, random null model comparisons among Amazonian hummingbird communities reveal that they share many characteristics in their structure and show a high degree of species overlap.