This doctoral dissertation was conducted under the supervision of Prof. Dr. K. Brassel and Dr. sc. Techn. B. Allgöwer at the University of Zurich, Geographical Institute. I would like to thank my supervisors, Prof. Dr. B. Nievergelt and Prof. Dr. R. Weibel for their encouraging ideas and comments which added considerably to the quality of this thesis.
I would like to express my sincerest thanks to a number of researchers and organisations who offered their data for testing my methodological ideas. My warm thanks go to K. Hindenlang, A. Rainho, the Woodstork and CORA projects.
I would like to express my gratitude to R. Haller who contributed to this study not only by numerous discussions and critical remarks, but also supporting me through all stages of it.
My warm thanks go to Dr. O. Wigger, who generously supported me in diverse problems with computers. In this context I would like to thank all the members of the Spatial Data Handling Division and the Wildlife Research and Conservation Biology group at the University of Zurich for their support and helpful comments during this thesis.
Last but not least I want to thank my parents for making my studies possible in the first place and E. Ramseier for supporting me in many ways during most of the last three and a half years.