Birds usually migrate by alternating flight bouts and stopovers for refueling. The decision when to leave a stopover place is of paramount importance for the success of migration. Despite its importance, little is known about which factors influence the departure decision. Using...

Decision making in informed animals is often described by optimality models. However, how information about an environment is acquired is rarely investigated. Cost/benefit considerations suggest that species differ in this respect according to their lifestyle. We tested the hypothesis that...

Only a few studies have focussed on the consistency of sexual selection patterns in space and time. One such case is the great reed warbler (Acrocephalus arundinaceus), for which studies in Germany in 1981--1982 and Sweden in 1987--1991 strongly suggested that the size of a male's song...