Feeding ecology of hummingbirds in the Serra do Mar, southeastern Brazil

The feeding behaviour of hummingbirds was studied in November and December 1983 at Boracéia, an area of very humid forest in the Serra do Mar, SE Brazil at 800-900 m. Six species of hummingbirds were present in the area, and were recorded taking nectar from 25 native plant species, of which 15 or 16 were considered to be hummingbird-adapted. Both the number of hummingbird specie~ and the number of individuals were small compared with the numbers occurring in humid forest e1~where in the neotropics. The rate of feeding ·visits to native plants was low, and the amount of insect-foraging was relatively high. It is argued that low hummingbird diversity and abundance were related to a sparse nectar supply. On the. basis of the limited data available, it seems that two plan~ families that are important for hummingbirds in the Andes and in other montane areas in the neotropics, the Rubiaceae and Ericaceae, provide little nectar for forest hummingbirds in the Sena do Mar, and that this may partly account for the lack of diversity in hummingbird bill lengths. The way in which the community of hummingbirds living in an area exploits the flowers of that area is of both ornithological and botanical interest. It is also of wider evolutionary interest, as it may throw light on the coevolution of hummingbirds and plants.