Nest Site Settlement by the Pied Flycatcher: Does the Female Choose Her Mate for the Quality of His House or Himself?

Abstract

Here I report the results of nine field experiments with nestboxes made at Trondheim, Norway, during a three year period. By manipulating the positions of nestboxes (i.e. their attractiveness) after male settlement but before female arrival I demonstrated that female Pied Flycatchers Ficedula hypoleuca choose their mates primarily on the basis of nest site quality, not on male quality. Arriving males preferred upright nestboxes to tilted ones, but not to the extent expected from female preference. This was probably related to the fact that constraints of time and energy on the males prevented them from finding the best sites. The conclusion that male and female Pied Flycatchers do not make perfect choices of nest site is important to keep in mind when evaluating models of habitat settlement, such as the density limiting model, the density assessment model and the polygyny threshold model.