Environmental Factors Affecting Bird Species Diversity

Abstract

Censuses of the breeding birds of areas large enough to support 25 pairs of all species combined were compared with measurements of the number of layers of vegetation. "Point censuses" of breeding birds whose territories include a given point were also calculated. Comparison of the whole census with the point census allows an estimate of horizontal (between point) diversity to be made. Finally, temporal diversity, measuring the amount of staggering of nesting seasons, was compared in England and Costa Rica, revealing very little difference between tropics and temperate.