Community ecology is concerned with the patterns that characterize natural assemblages of species and understanding how these patterns came to be and how general they are in nature. The historical roots of community ecology lie in botanical studies of more than a century ago, but perspectives gained from investigations of birds have made major contributions to the development of the conceptual foundation that has guided and dominated activity in the discipline over the past quarter century. Avian studies have also contributed much of the evidence that supports community theory; in Schoener's (1974) review, for example, 34% of the 50 studies of resource partitioning in terrestrial animal communities cited were of birds. There is thus justification for considering the recent development, current problems, and future prospects of community ecology in the context of studies of bird communities.

In order to understand contemporary community ecology and its problems, it is necessary to consider its development over the past two or three decades. During the 1950s, two views of community structuring, each originally developed earlier in the century, were actively discussed, and each was expressed in studies of bird communities. On the one hand, ecologists following the view of Gleason (1917; see Mclntosh 1975) and Curtis (1959) suggested that the species within communities were arrayed along environmental gradients more or less independently of one another, each according to its own ecological requirements.