RELATIONSHIPS BETWEEN BODY SIZE, ABUNDANCE AND PHYLOGENY IN BIRD COMMUNITIES

1. Body size is not a good predictor of the abundances of the different species within bird communities, even though the correlation between the two variables sometimes achieves statistical significance. 2. The apparent weakness of the relationship for birds in comparison with other taxa does not seem to result from the three-dimensional nature of birds' environments. 3. When correlations with phylogeny are controlled for, no statistically significant covariation between body size and population abundance can be detected. This may be because birds tend to speciate into niches similar to those occupied by their ancestors.