Expression of breeding coloration in European Green Lizards (Lacerta viridis): variation with morphology and tick infestation

According to the hypothesis of parasite-mediated sexual selection, for a communication system to work reliably, parasites should reduce the showiness of sexual signals of their host. In this study, we examined whether the expression of breeding coloration in free-ranging adult European Green Lizards ( Lacerta viridis (Laurenti, 1768)) is linked with infestation by their common ectoparasite Ixodes ricinus (L., 1758) (Acari: Ixodidae). We found that tick infestation was higher in males than in females. Males showing relatively heavier body for their tail length (predominantly males with regenerated tails) and relatively thinner tail base experienced higher infestation rates. In turn, relatively heavier females for their snout–vent length were less tick infested. Although some components of throat and chest coloration varied significantly with relative tail length, tail-base thickness, body mass, and head size, a measure of male throat and female chest color saturation seemed independent of lizard morphology. After correcting for the effects of morphology on skin coloration and tick load, the saturation of blue throat color in male lizards decreased with increasing level of tick infestation. In contrast, yellow chest color saturation increased with residual tick numbers in females. Considering presumably different signaling functions of male and female lizard coloration, our work suggests that tick infestation might represent a handicap for Green Lizards.

Food-deprivation affects tongue extrusions as well as attractivity and proceptivity components of sexual behavior in the lizard, Sceloporus jarrovii

Experiments were conducted to assess the effect of various levels of food deprivation (1, 2, 3, or 4-day periods) on tongue extrusions as well as attractivity and proceptivity components of sexual behavior in the sceloperine lizard Sceloporus jarrovii. Results showed sex differences with respect to effects of food deprivation on the attractiveness of male and female lizard odors toward conspecifics (attractivity). Males spent more time extruding their tongue to touch blocks containing odors of ad libitum-fed females as compared to odors from females deprived of food for 4 days, while spending a similar amount of time investigating blocks containing odors of ad libitum-fed females and females deprived of food for less than 4 days. In contrast, females spent similar amounts of time investigating odors associated with ad libitum-fed as well as food-deprived conspecifics. Results also showed that one day of food deprivation was sufficient to inhibit the desire to initiate or maintain contact with opposite-sex conspecifics (receptivity).