Marine prey in the diet of Podarcis atrata from the Columbretes Islands

Lizards of the genus Podarcis typically occupy terrestrial habitats and commonly feed on insects and occasionally on plant materials (Arnold & Ovenden, 2002). Despite many studies that have examined the diet of Podarcis species in insular ecosystems, marine prey are rare (Pérez-Mellado & Corti 1993; Díaz, 1995; see also references in Van Damme, 1997; Herrel et al., 2003). The only data on European lizards utilizing intertidial invertebrates (e.g., the isopod Ligia italica) are for Podarcis dugesii on Madeira Island, Atlanic, Portugal (Davenport & Dellinger, 1995) and P. wagleriana (Lo Cascio & Pasta, 2006). We also noted intertidial invertebrates (Amphipoda, Crustacea) as prey of an adult male P. muralis along the northern coast of the Basque Country (Guipúzcoa, Spain; pers. obs.). More recently (August 2007) Laura Gangoso (pers. comm.) observed in the Canary island of Alegranza (12 km_), one adult lizard Gallotia atlantica swimming a distance of 2 meters from the seashore to a rock without vegetation but with many snails and algae. Alfredo Valido (pers. comm.) has observed lizards (Gallotia sp.) in several occasions consuming crustacean copepods and other small invertebrates in the seashore.