RIPARIAN-HABITAT USE BY BREEDING CAVITY-NESTING BIRDS IN SOUTHEASTERN WYOMING (FOREST BIRDS, WILDLIFE MANAGEMENT, ISLAND BIOGEOGRAPHY, COMMUNITY)

From 1982 through 1984, I studied habitat use by breeding cavity-nesting birds along the North Platte and Laramie Rivers in Platte and Goshen Counties, Wyoming. Structural, spatial, and floristic data were collected within and around a square, 0.09-ha plot that was centered on nest trees. At 30 random sites I measured all of the same variables, except those describing the nest cavity. I gathered spatial, areal, and structural habitat data for each of 34 habitat patches in 1983, and I recorded the number of individuals and species nesting in each patch in 1983 and 1984.;Linear and logistic regression models indicated habitat-patch features, such as size, shape, degree of isolation, and vegetative structure, significantly influenced the extent to which patches were used by breeding hole-nesting birds. These habitat variables were related to food and nesting resources required during the breeding season. Data describing habitat patches in which various species nested are included for use in planning activities and in efforts to minimize habitat-fragmentation effects on these birds.;Kruskal-Wallis tests, Dunn's pairwise comparisons, and G statistics indicated habitats surrounding species' nest trees and habitats at random sites were essentially indistinguishable, whereas species' nest cavities and nest trees differed substantially in their features. Nest trees also differed significantly from random trees. These differences were related to species' body sizes, their ability to excavate wood, and their innate behavior. Data from nest sites are included to describe the habitat conditions acceptable to the various species. These data can also be used to evaluate potential habitats for these species and to write habitat-management prescriptions.