Adult male aggression towards juvenile males in the large‐scaled girdled lizard, cordylus macropholis

Abstract

Agonistic behaviour and differences in adult male behaviour towards male and female juveniles were investigated in Cordylus macropholis during the mating season. Encounters (N = 7 in all cases) were staged between adult males, between adult males and juvenile males, and between adult males and juvenile females. Twelve behavioral acts were discerned, of which tail‐lashing, push‐ups, shuddering, face‐off circling and biting were identified as aggressive acts. Adult males showed aggression toward each other and toward juvenile males, but not toward juvenile females. Juvenile males also displayed aggression toward adult males, but were dominated by the adult males in all aggressive encounters. The results suggest that male aggression, territoriality, and shortage of plant shelters may be instrumental in the highly female‐biased sex ratio recorded for this species in the Lambert's Bay area along the west coast of South Africa.