Affiliation: | Reproductive Biology and Behaviour Group, Research Centre for Ornithology of the Max Planck Society, Postfach 1564, D-82305 Starnberg (Seewiesen), Germany;Reproductive Biology and Behaviour Group, Research Centre for Ornithology of the Max Planck Society, Postfach 1564, D-82305 Starnberg (Seewiesen), Germany E-mail: |