The primary goal of the analyses demonstrated in this case study is to describe the variability of bird communities and to relate it to the differences in their habitat.

This data set originates from a field study by Mirek E. Šálek et al. (unpublished data) in the Velká Fatra Mts. (Slovak Republic) where bird assemblages were studied using a grid of equidistant points placed over a selected area of montane forest, representing a mix of spruce-dominated and beech-dominated stands. There was a varying cover of deforested area (primarily pastures) and individual quadrats differed in their altitude, slope, forest density, cover and nature of shrub layer, and other characteristics – see below for a description of recorded variables. The response data table contains the numbers of nesting pairs of individual bird species, estimated by listening to singing males at each point. Each value represents an average of four censuses (performed twice in each of two consecutive seasons).