Tongue flick data

We compared the discriminatory abilities for self and conspecific chemical recognition of mainland and island Italian wall lizards (<i>Podarcis siculus</i>), a species much dependent on chemoreception. We sampled lizards from three locations on the Italian mainland and three Adriatic islands and assessed their tongue flick behaviour when confronted with water (control), their own odour, or that of conspecifics. We followed a habituation-dishabituation protocol during which each lizard was first presented with the same cotton swab permeated with the same stimuli for three consecutive trials followed by a fourth ‘dishabituation’ trial in which lizards were presented with a new cotton swab and a treatment stimulus. We exposed individuals to three different habituation-dishabituation treatments: self odour vs conspecific odour, a conspecific’s odour vs another conspecific’s odour, and blank control vs another blank control. Odours were extracted by rubbing cotton swabs damped with distilled water on the cloacal area and femoral pores of the donor lizards. For the blank control treatment, we used a clean cotton swab that was dipped in distilled water and did not contain any chemical cues. Each trial lasted 60 seconds during which we counted how many times lizards flicked their tongue towards the cotton swab.