The use of canonical correlation analysis for ornithological evaluation of lakes in W Poland

The aim of the study was to evaluate the importance of lakes in the Wielkopolska region (western Poland) to migratory waterbirds on the basis of lake morphometry. Single bird surveys were conducted on 204 lakes in November between 1973–1975 and 1984–1986. The observed species distribution deviated from the model of random placement. The relationship between habitat variables and “avian indices” (number of species, abundance of single species and total abundance of birds) were analysed by canonical correlation. A high value of the canonical correlation coefficient between bird abundance and morphometric measures was recorded. We conclude that canonical correlation can be used to evaluate the attractiveness of lakes for birds. The advantages of this method are: (1) consideration of correlations between the data sets (morphometric measures and avian indices) and within these sets, (2) objectiveness and (3) possibility of evaluation of the lake in the case of lack of bird surveys. These data will facilitate the development of a regional monitoring programme, as well as provide baseline data for identifying the most valuable lakes.