Mainland versus island differences in behaviour of Podarcis lizards confronted with dangerous prey: the scorpion Buthus occitanus

Abstract

Rapid divergence in behaviour of populations invading novel habitats is often considered adaptive as it may allow a species to exploit novel resources. Here we explore the behavioural response of two closely related species of Podarcis lizards living in different habitats, the Spanish mainland and a dry volcanic island, towards a potentially dangerous prey. Our results show that whereas insular lizards attacked scorpions and consequently considered them to be potential prey, mainland lizards tended to flee or ignored them. Sexual differences in the response to scorpions were pronounced in the insular habitat. Males tended to attack scorpions while females tended to ignore them. Inter‐specific and inter‐sexual differences in the responses of lizards may be mediated by body size differences between populations and sexes. The rapid changes in behaviour allowing insular lizards to recognize scorpions as potential prey may have allowed these animals to capitalize on an abundant food resource in a depauperate environment.

Keywords:

• poison
• feeding
• Mediterranean
• Columbretes
• sexual differences
• evolution

Acknowledgements

We would like to thank the Generalitat Valenciana (GV) and the Secretaría General de Pesca Marítima (Ministerio de Agricultura, Pesca y Alimentación) for permission to work in the islands. We would also like to thank Marta Aguiló (GV), Guim Llacuna,Javier Pérez (Escuela de Capacitación Agraria de Solsona) and Enric Pastor, for their help during the field work. Also, many thanks to Jordi García‐Pausas and two referees for their constructive comments. Many thanks also to Pep Perolet and the boats CAT‐CAT and Clavel I for transportation. This work was conducted on a contract “Ramón and Cajal” from the Spanish National Science Foundation (CSIC, Ministerio de Educación y Ciencia) (to AMC), and the Project MEC CGL2005‐00391/BOS (J. Martín and P. López, MNCN‐CSIC).