Nest-site characteristics of the avian community in the dune-ridge forest, Delta Marsh, Manitoba: a multivariate analysis

Abstract
Nest-site characteristics of nine bird species breeding in high densities in the dune-ridge forest at Delta Marsh, Manitoba, were analyzed using multivariate techniques. Varimax-rotated principal component analysis of the entire set of nest-site variables suggested partitioning of the data into nest-habitat and nest-tree subsets. Discriminant analysis of nest-habitat variables confirmed the ambiguous nature of species relationships in the factor analysis. Discriminant analysis of nest-tree variables identified three distinct groups of species, based primarily on vertical stratification. The existence of these groups and their memberships were supported by similar results derived from discriminant analysis of the entire nest-site data set. Within these groups, pairs of species showed sufficient similarity in nest sites to warrant detailed investigation.