Social structure of the lizard, Cordylus giganteus

[摘要] ENGLISH ABSTRACT:Cordylus giganteus is the largest lizard species of the family Cordylidae and is restricted indistribution to the highveld grasslands of the Free State, South Africa. Previous work on lifehistory and physiological ecology suggested the need for further investigation into the socialstructure of C. giganteus, with the aim of improving knowledge on South Africanherpetofauna and contributing towards better conservation plans. Observations, recaptures,behavioural experiments and chemical analyses were made to investigate chemicalcommunication, movements around and between burrows, spatial distribution and response tointruders. Sexual variation was found in both femoral gland proteins and lipids, whileseasonal variation was found in lipids. Femoral gland proteins do not vary intra-individually.These results suggest alternate roles in communication for femoral gland proteins and lipids.Female C. giganteus showed a possible discriminatory ability between their own femoralgland secretion and that of other individuals. Burrow movements were characterised by verylittle time spent between burrows, high burrow fidelity and limited dispersal during seasons,other than movements associated with mating activity. Lizards remained in very closeproximity to burrows. Male and female burrows were distributed in a clumped fashion, whilemale burrows were distributed randomly and female burrows were distributed randomly withrespect to one another. There was a high degree of spatial association of male and femaleburrows. Male and female resident lizards responded aggressively to experimentallyintroduced conspecifics of the same sex, but exhibited no differential response towardsneighbours or non-neighbours. Males and females exhibited similar levels of aggressiontowards intruders. The social system of C. giganteus can be defined as site defence, with verylow frequencies of agonistic interactions. The social system of C. giganteus seems to be wellsuited to other aspects of its life history.

[发布机构] Stellenbosch University