General research interests   At a first glance, my research topics are quite heterogeneous, but the projects are linked by two main questions: 1. How do genotypes and environments affect the behaviour of individuals? 2. How does the behaviour, in turn, affect individual fitness and the structure and dynamics of populations and communities? Within this principal conceptual framework, I am particularly interested in: • ecological stability and evolutionary perspectives for speciation of  an unusual sexual parasite-host system • ecology and evolution of mating systems, parental care, cooperative breeding and other forms of social behaviour • relationship between genetics, ecological conditions, fitness and proximate mechanisms, e.g. energy budgets, hormones and communication To embrace these topics, I use a multi-disciplinary approach that integrates comparative field studies, experiments, genetic and physiological analyses and mathematical modelling. Depending on the specific question, I study various suitable model species, mainly fishes, amphibians and birds. 1976, Lake Nakuru, Kenya 1991, Dischma Valley,           Switzerland 2004, University of Zurich, Switzerland