The Feeding Ecology of Five Sympatric Finch Species

Within habitats the overlap of food-size utilization of five sympatric finch species is almost 100% despite considerable differences in culmen lengths. It is suggested that the differences in bill size reflect differences in the proportion of large seeds in the set of habitats in which each species feeds and does not function to reduce competition within habitats. Although seed production was sufficient to maintain the finch populations through winter, the finches did eat at least 40% of the available seeds. Of the five finch species commonly present at least three seem to be limited by their winter food supply. The diversity of finches in the yield was not significantly correlated with either food abundance or food diversity.