Relation of Park Size and Vegetation to Urban Bird Populations in Seattle, Washington

Abstract

A large forested park with a natural diversity of native vegetation was associated with a high diversity of native forest bird species, a diversity comparable to a forest tract outside the urban influence. While native diversity was preserved, there was no marked increase in number of species typical of the urban landscape. At the opposite extreme, the small or highly modified parks contained fewer species, a greater proportion of species typical of urban areas, few regularly occurring species, and most native forest species in reduced abundance or frequency. More precise measurement of vegetation structure, measurement of bird populations over longer periods of time and of breeding status are among several aspects to be considered for future research on the relationship of forest birds to urban habitats. However, this initial short-term study shows that a diverse avifauna characteristic of Pacific northwest [USA] lowland forests can be supported in urban areas as long as large park areas with native forest vegetation are maintained.