Effects of Urbanization on Avian Community Organization

摘要: -The avian community of a mature residential area was studied and compared with an undisturbed climax beech-maple forest. Urbanization presumed to be responsible for decreasing species richness diversity, increasing biomass density, favoring dominance by few species. Foraging guilds shifted from forest insectivores that were canopy foliage gleaners or bark drillers urban ground gleaners. Analyses habitat structure showed although height diversity like the forest, contained only one-third total percent vegetative cover. As cover was: (1) significantly less in all but middle layer; (2) replaced man-made structures, ornamental vegetation low layers dominated high (3) highly discontinuous, existing as isolated strata. Differences organization between are discussed relation manipulation population-suppressing factors. Bird communities areas contain higher bird densities than outlying natural (Graber Graber 1963, Emlen 1974), edge supporting greater temperate zones. In addition factors controlling (Lancaster Rees 1979) birds is affected age neighborhood (Lucid 1974) type housing (Geis degree urbanization (Batten 1972). Few studies have avifauna cities measured both communities. The difficulties arise selecting comparable study quantifying synthetic parameters. this study, we determined how comparing ecological characteristics those regional climax,