Chemosensory discrimination of male age by female Psammodromus algirus lizards based on femoral secretions and feces

Chemical communication plays an essential role in several social and reproductive behaviors of many animals. In lizards, the main sources of semiochemicals are femoral or pre-anal gland secretions and feces. In male lizards Psammodromus algirus, there are age-related differences in the chemical composition of femoral gland secretions and in the reproductive strategies, with older males defending territories and females, while younger males adopting sneak-mating strategies. Females flee more often from mating advances of young males than from those of old males, which are more successful in obtaining matings. This suggests that age discrimination of males may be important for females. We tested here whether females showed differential chemosensory responses to chemical cues (femoral gland secretion and feces) of males of two age classes, and whether females use information from substrate scent marks of males of different ages to select where to stay. We found that females elicited more tongue-flicks to the secretion and feces of old males than to control or secretion and feces of young males. Also, the time spent by females on a scented paper depended on the treatment, suggesting that females tended to spend more time on scent marks made with femoral secretions of old males. Adult females seemed capable to discriminate between young and old males based on chemical cues alone and showed more interest in scents of old males. However, substrate scent marks did not seem to entirely determine site selection by females, suggesting that females might need additional cues to perform the choice. These results can be explained by the different age-dependent reproductive strategies of males, which can affect differentially to females.Financial support was provided by the Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP 2017/19640‐0) and by the Ministerio de Economía y Competitividad project MINECO CGL2014‐53523‐P