The migratory habits and migration schedules of waders can be understood better by analysing their measurements. Therefore, we need a clear characterization of breeding populations and the proper statistic tools. This book has a worldwide coverage of nearly all breeding populations and tries to fill the gap between descriptive and predictive statistics. It is of interest for all those people handling waders whether it be in the museum or in the field when trapping. It is also interesting for taxonomical researchers and workers dealing with breeding studies. Also people studying other species than waders can use this book, since they can construct their own data bases and produce their own predictions with the inserted POSCON programs on diskette.