Fieldwork was conducted at the Carmabi foundation, Curaçao, and was funded by the Schure-Beijerinck-Popping fund of the Dutch Royal Academy of Science (KNAW). We wish to thank Martijn de Vries for his assistance in various experiments performed in Curaçao, Emiel van Loon and Ann Hagerman for useful discussions, and Michiel Kraak and anonymous reviewers for improving the manuscript.
Received: 9 January 2008
Accepted: 29 May 2008
Published online: 22 December 2008