Male traits and pairing success in the lizard Psammodromus algirus

Previous studies of lizard mating systems have provided morphological and e cological hypotheses that may explain variation in male reproductive succes s. We present the results of a field study of factors associated with pairi ng success in males and females of the lacertid lizard Psammodromus algirus . Operational sex ratio was male biased and varied during the mating season . Early ill the season. large females frequently paired sequentially with t wo males. However, late in the season, small females tended to pair with on ly one male. This suggests that male-male competition was stronger for larg er females at the beginning of the mating season or there were fewer fertil e females available. Pairs were observed together for 1-4 days, suggesting pre- or postcopulatory mate guarding behavior. Male pairing success was pri marily influenced by morphological traits; males with larger heads, larger snout-vent lengths, and more ornamentation paired with more females. Male h ome range size and number of females overlaped did not affect male pairing success. More active males, which may have selectively moved within home ra nges of paired females, had higher pairing success than less active males. The temporal distribution of receptive females seemed, to favor polygyny. H owever, only the largest males were successful in competition for females t hrough out the mating season.