Thesis (MSc)--University of Stellenbosch, 2000. / ENGLISH ABSTRACT: Cordylus giganteus is the largest lizard species of the family Cordylidae and is restricted in
distribution to the highveld grasslands of the Free State, South Africa. Previous work on life
history and physiological ecology suggested the need for further investigation into the social
structure of C. giganteus, with the aim of improving knowledge on South African
herpetofauna and contributing towards better conservation plans. Observations, recaptures,
behavioural experiments and chemical analyses were made to investigate chemical
communication, movements around and between burrows, spatial distribution and response to
intruders. Sexual variation was found in both femoral gland proteins and lipids, while
seasonal 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 femoral
gland secretion and that of other individuals. Burrow movements were characterised by very
little time spent between burrows, high burrow fidelity and limited dispersal during seasons,
other than movements associated with mating activity. Lizards remained in very close
proximity to burrows. Male and female burrows were distributed in a clumped fashion, while
male burrows were distributed randomly and female burrows were distributed randomly with
respect to one another. There was a high degree of spatial association of male and female
burrows. Male and female resident lizards responded aggressively to experimentally
introduced conspecifics of the same sex, but exhibited no differential response towards
neighbours or non-neighbours. Males and females exhibited similar levels of aggression
towards intruders. The social system of C. giganteus can be defined as site defence, with very
low frequencies of agonistic interactions. The social system of C. giganteus seems to be well
suited to other aspects of its life history. / AFRIKAANSE OPSOMMING: Cordylus giganteus is die grootste akkedis spesie van die familie Cordylidae en is beperk in
verspreiding tot die hoeveld graslande van die Vrystaat, Suid Afrika. Vorige werk oor die
lewensgeskiedenis en fisiologiese ekologie het aangedui dat verdere inligting oor die sosiale
struktuur van C. giganteus nodig is, met die doelom kennis oor Suid-Afrikaanse herpetofauna
te verbeter, en om beter bewaringsstrategieë daar te stel. Observasies, hervangs,
gedragseksperimente en chemise analyses was uitgevoer om aspekte oor kommunikasie,
bewegings tussen en om gate, gat verspreiding en reaksie teenoor indringer akkedisse, te
bestudeer. Femorale klier afskeidings het seksuele variasie in beide die proteiene en die
lipiede getoon, terwyl net die lipide seisoenale variasie getoon het. Femoral klier proteiene
het nie seisoenale variasie binne individue getoon nie. Hierdie resultate dui op alternatiewe
funksies vir die femoral klier proteiene en lipiede. Wyfie C. giganteus het moontlik tussen
hule eie femoral klier sekreet en die van ander wyfies onderskei. Baie min tyd tussen gate,
hoë lojaliteit teenoor gate en beperkte bewegings weg van gate het gat bewegings
gekarakteriseer. Net gedurende die paarseisoen was daar meer bewegings tussen gate.
Andersins, het akkedisse baie naby hul eie gate gebly. Mannetjie en wyfie gate was naby
mekaar versprei, terwyl mannetjies ewekansig teenoor mekaar versprei was, en wyfies
ewekansig teenoor mekaar versprei was. Die verspreiding van mannetjies en wyfies het baie
van die verspreiding van die ander geslag afgehang, sodat daar 'n groot assosiasie tussen hulle
was. Akkedisse wat gate bewoon het, was baie aggressief teenoor indringer akkedisse, maar
het geen verskil in reaksie teenoor naburige akkedisse of nie-naburige akkedisse getoon nie.
Mannetjies en wyfies het dieselfde aggressiwiteit teenoor indringers getoon. Die sosiale
struktuur van C. giganteus kan geklassifiseer word as skuilings-beskerming, maar met baie
lae frekwensies van sosiale interaksies. Dit blyk dat die sosiale struktuur van C. giganteus
baie goed pas by ander aspekte van sy lewensstyl.
| Identifer | oai:union.ndltd.org:netd.ac.za/oai:union.ndltd.org:sun/oai:scholar.sun.ac.za:10019.1/51909 |
| Date | 12 1900 |
| Creators | Ruddock, Lanral |
| Contributors | Van Wyk, J. H., Whiting, M. J., Stellenbosch University. Faculty of Science. Dept. of Botany and Zoology. |
| Publisher | Stellenbosch : Stellenbosch University |
| Source Sets | South African National ETD Portal |
| Language | en_ZA |
| Detected Language | English |
| Type | Thesis |
| Format | 174 p. : ill. |
| Rights | Stellenbosch University |
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