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.

Thesis (MSc)--University of Stellenbosch, 2001. / ENGLISH ABSTRACT: Cordy/ us cataphractus and C macropholis naturally occur in groups on a year round basis. I examined whether limited shelter availability might be responsible for this phenomenon. Individuals were provided with an excess of shelter sites and the observed pattern of shelter occupation was contrasted to that obtained for the solitary living species C polyzonus. Cordy/us cataphractus consistently occupied fewer shelters than its two congeners. Results suggest that grouping behaviour in this species is not the result of a limitation in refuge sites. In contrast, the pattern of shelter occupation by C macropholis did not differ significantly from that of C polyzonus, thus the aggregative behaviour observed in the former species may partially be attributed to limited shelter availability in its natural habitat. Conspecific recognition by means of pheromonal detection has been reported in many lizard families, but only for one member of Cordylidae, namely Cordy/us cordy/us. Cordylus cataphractus individuals were exposed to ceramic tiles that had been labeled by conspecific male and female substrate deposits. Labeling was achieved by using ceramic tiles as the bottom half of a shelter in a lizard's home cage for ten consecutive days. Washed tiles were used as controls. Labeled tiles did not elicit significantly more tongue-flicks than control tiles from test specimens in a series of trials. The apparent lack of conspecific recognition via pheromonal detection might be attributable to the group-living nature of this species, which primarily use visual cues for identification purposes. Tongue-flicking is generally utilized in C cataphractus in the detection of novel stimuli. Spatial dynamics of the group-living cordylid, C cataphractus, were investigated by studying patterns of intergroup movement. To date, literature has assumed that C cataphractus groups represent family units, implying low or delayed dispersal rates and high group fidelity. A mark-recapture experiment on six groups included three recaptures outside of and three recaptures within the mating season. High percentages of male, female and juvenile lizards left their groups, but might be an artifact of microhabitat disturbance. High proportions of males, females and juveniles entering the groups, both outside of mld within the mating season, clearly implied a high rate of intergroup movement. Activity and foraging patterns were studied in group-living C. cataphractus lizards by conducting direct field observations between September 1998 and October 1999. The influence of general weather patterns as well as the effect of group size on these patterns were investigated by observing a small-sized, medium-sized and large group. Each group was observed for a minimum of three sunny days per season, with scans conducted every 30 minutes between the hours of 08:00 and 20:00. There was a high rate of activity during the mating season in spring (September). Activity declined sharply mld foraging ceased at the onset of warm, dry conditions (February). Virtually no activity occurred just prior to the first winter rains (July), after which the lizards emerged to forage and replenish energy stores before onset of the next mating season. Selective inactivity might be employed to reduce energy expenditure in this group-living lizard, where intraspecific competition is stringent. Groups of different sizes display different thresholds at which it becomes energetically viable for group members to emerge, as well as different patterns of spatial use around their respective home crevices. Members of larger groups perched further from their crevices, ran further to catch prey mld had less potential prey capture events per individual. Lizards in the larger groups also displayed sporadic lengthy foraging excursions. Such movements might explain the evolution of tail-biting behaviour and heavy armour, which are defensive strategies associated with open areas. / AFRIKAANSE OPSOMMING: Cordylus cataphractus en C. macropholis word dwarsdeur die jaar in groepe in hul natuurlike habitat aangetref. Daar is nagevors of 'n beperking in aantal beskikbare skuilplekke vir hierdie verskynsel verantwoordelik is. Individue is van 'n oormaat skuilings voorsien en die waargenome patroon van skuilplekbesetting is gekontrasteer met dié verkry vir '11 enkelwonende species, naamlik C. polyzonus. Cordylus cataphractus het voortdurend minder skuilplekke beset as sy kongeneriese species. Groepsgedrag in C. cataphractus is dus nie die resultaat van 'n tekort aan beskikbare skuilplekke nie. In teenstelling hiermee het die patroon van skuilplekbesetting vertoon deur C. macropholis nie noemenswaardig verskil van dié van C polyzonus nie. Dus mag die groepsgedrag wat gewoonlik in C. macropholis waargeneem word 'n uitvloeisel wees van 'n beperking op die beskikbaarheid van skuilplekke in sy natuurlike habitat. Herkenning van speciesgenote deur waarneming van ferornone is vir verskeie akkedisfamilies gerapporteer, maar slegs vir een lid van Cordylidae, naamlik C. cordylus. Cordylus cataphractus individue is blootgestel aan keramiekteëls wat gemerk is met substraat-neerleggings van manlike en vroulike speciesgenote. Sodanige merking is uitgevoer deur die keramiekteëls vir tien dae lank te gebruik as die onderste helfte van akkedisse se skuilplekke in hul tuishokke. Gewaste teëls is as kontroles gebruile Gemerkte teëls het nie statisties beduidend meer tongskiete van die akkedisse uitgelok as kontrole teëls in 'n reeks toetse nie. Die klaarblyklike afwesigheid van speciesgenootherkenning deur middel van feromoon waameming kan moontlik toegeskryf word aan die groeplewende gedrag van C. cataphractus, wat primêr visuele informasie vir identifikasie gebruik. Cordylus cataphractus gebruik tongskiete oor die algemeen vir die waarneming vannuwe omgewingsstimuli. Die ruimtelike dinamika van 'n groeplewende gordelakkedis, C. cataphractus, is ondersoek deur die patroon van intergroepbeweging na te vors en groepsgetrouheid te meet. Tot op datum is daar in die literatuur aanvaar dat C cataphractus groepe familie-eenhede verteenwoordig, wat lae of vertraagde verpreidingstempo' sasook' n hoë mate van groepsgetrouheid impliseer. 'n Merk-hervang eksperiment is op ses groepe uitgevoer, insluitend drie hervang episodes buite en drie binne die paarseisoen. 'n Hoë persentasie manlike, vroulike en onvolwasse akkedisse het hul groepe verlaat, maar dit mag bloot 'n uitvloeisel van versteuring van die mikrohabitat wees. 'n Hoë proporsie mannetjies, wyfies en onvolwassenes het egter by die groepe aangesluit, beide buite en binne die paarseisoen, wat onteenseglik op 'n hoë mate van intergroep beweging dui. Daar kom derhalwe veel vryer bewegingspatrone in hierdie species voor as voorheen vermoed en dit is hoogs onwaarskynlik dat groepe familie-eenhede verteenwoordig. Aktiwiteits- en voedingspatrone van die groeplewende akkedis, C cataphractus, is bestudeer in 'n reeks veldobservasies tussen September 1998 en Oktober 1999. Afgesien van die invloed van algemene weerspatrone. is die effek van groepgrootte op hierdie patrone ondersoek deur 'n klein, medium en groot groep te observeer. Elke groep is waargeneem oor . 'n minimum periode van drie dae per seisoen met opnames elke 30 minute, tussen 08:00 ten 20:00. 'n Hoë aktiwiteitsvlak is gedurende lente tydens die paarseisoen gehandhaaf (September). Met die aanvang van warm en droë kondisies (Februarie) het aktiwiteitsvlakke skerp begin daal en voedingsgedrag is gestaak. Feitlik geen aktiwiteit was waarneembaar kort voor die eerste winterreëns (Julie) nie, waamá akkedisse intensiefbegin voed het om energiestore op te bou voor die aanvang van paartyd. Selektiewe onaktiwiteit verminder moontlik energieverbruik in hierdie groeplewende akkedis, waar intraspesifieke kompetisie streng is. Verskillende groepgroottes beskik oor verskillende perke waar dit vir die individu energeties voordelig sou wees om uit die skeur te kom, asook 'n variasie in ruimtelike gebruik om die skeur. Individue van die twee groter groepe het nader aan hul rotsskeur gesit, het verder van die skeur af prooi vang en het beduidend minder potensiële voedingskanse gehad. Akkedisse in die groter groepe het voorts sporadiese lang voedingsekskursies getoon. Hierdie bewegings mag die evolusie van stertbytgedrag en 'n swaar pantser, verdedigingstrategieë wat met oop areas geassosieer word, verduidelik.

The animal kingdom contains a spectacular diversity in colour signals used to indicate quality. The challenge of understanding this diversity lies in identifying and interpreting constraints on signals that maintain signal honesty. I used an integrative approach to measure the effects of potential signal modulators on whole-animal performance, ornaments, condition and immunocompetence in the lizard P. i. wilhelmi. This approach attempts to remove some of the uncertainty surrounding the validity of existing handicap models. First, I investigated seasonal changes in testosterone, corticosterone and carotenoids and compared these to seasonal changes in endurance, immunocompetence and body condition male P. i. wilhelmi. I also determined which colour patches were predictors of male quality by relating them to morphology, endurance, body condition and immunocompetence. I found some support for the immunocompetence handicap hypothesis so I tested whether testosterone was modulating ornaments and constraining signals through its immunosuppressive properties. I tested the immunocompetencehandicap hypothesis in male P. i. wilhelmi while also conducting parallel studies with free-ranging and captive-housed lizards to assess whether there were differences between the groups that could indicate exogenous factors influencing signalling in their natural environment. While experimentally elevated testosterone did affect endurance and the properties of their colour patches, immunosuppression was only evident in free-ranging lizards. To measure the extent of organisational effects in males I also manipulated testosterone in females and found no evidence of immunosuppression although testosterone did affect some aspects of colouration and endurance. Next, I tested the stress-linked immunocompetence handicap hypothesis by experimentally elevating testosterone, corticosterone, or both at the same time. I found that corticosterone had an isolated effect on one colour patch, and testosterone and corticosterone had opposing effects on endurance that were negated when both were elevated. Different colour patches were affected by either testosterone or corticosterone with little overlap, and the combination of the two had a different action to either hormone elevated in isolation. Finally, I tested the oxidative stress hypothesis of carotenoids as a limiter of signal output due to their requirement in the oxidative stress response. I found that supplemented carotenoids vastly improved endurance, immune response and influenced different aspects of colouration to that of testosterone and corticosterone. My study examined four different hypotheses of constraints on signalling involving testosterone, corticosterone, interactions between testosterone and corticosterone and carotenoids in a consistent manner measuring multiple indices of quality as well as multiple colour signals. This study provides a unique integrative perspective on the roles played by each factor as well as prompting us to re-examine our approach to understanding constraints on signalling.

No description available.

Thermal ecology and movement of the Leopard Lizard, G. wistizeniwere studied at Frog Spring, adjacent to the Alvord Desert, and at various locations throughout the Alvord Basin. Seasonal activity is known to occur from early May to mid-October, but abundance. gradually decreases after late July. During favorable late spring, and summer weather lizards exhibit a bimodal pattern of diel activity with some activity occurring at all hours of the day between 0600 and 1800 H. At other times activity was unimodal. Emergence was apparently largely temperature dependent and did not occur until sand temperature approximated 21°C. Retreat appeared to be temperature independent, and was initiated by exogenous or endogenous stimuli at sand temperatures often above body temperatures acceptable for normal activity. For the period of study, juveniles exhibited diel activity patterns similar to adults, and were found during all hours in which adults were encountered. Body temperatures of field active lizards, largely affected by the immediate weather conditions, , ranged from 18.6° to 43.4°C. Because of a variety of thermoregulatory response (changes in location, posture, and orientation, color change, burrowing, shade-seeking, and panting), even during unfavorable weather conditions, most body temperatures fell within a narrower range. Nonetheless, the ability of field active lizards to precisely thermoregulate was limited, and the levels of body temperature maintained usually encompassed a broader range than those maintained in a thermal gradient. The mean body temperature of field active lizards during favorable weather conditions, and that of active lizards in a thermal gradient, did not differ significantly, and seemed to indicate a narrow range of body temperature preference. However, prevailing weather conditions were frequently unfavorable, thus limiting the extent of time during which selection of preferred body temperature could occur. Consequently, though activity depended on the attainment of certain temperature levels, G. wislizeni was forced to adapt to a broader range of body temperatures when performing most routine tasks. The necessity of precision thermoregulation is unclear, but apparently physiological efficiency was not greatly diminished over the broad range of body temperatures fiefd active lizards were often accepting. Relatively speaking, movement in G. wislizeni was extensive. Adult males occupied an average area more than twice the size of adult females and juveniles. Plotted polygons, constructed from sighting points, tended to be elongate. The extent to which lizards occupied a definite home range was uncertain. Adult males , continuously expanding the area occupied, probably lacked a home range. Adult females, demonstrating . little area expansion, perhaps maintained a home range. Territoriality by means of intraspecific display or aggression appeared negligible in G. wislizeni.Adult males did not demonstrate such behavior toward one another . Based on a limited extent of area overlap, adult females may have exhibited territoriality toward members of their sex. Movement per hour revealed results similar to area occupied, with adult males traveling an average distance of nearly three times as great as adult females and juveniles. Greatest distances frequently coincided with peak diel activity. Individual moves were frequent in adult males and juveniles, but infrequent in ~ adult females. Adult female long moves were similar in distance to adult males, but exogenous stimuli perhaps linked with home range maintenance restricted the frequency of such jaunts. Movement in G. wislizeni appeared independent of environmental thermal conditions when body temperature was within the range acceptable for normal activity. Diel movement appeared to be random in the species. Seasonal movement in juveniles, based on dispersion data, appeared directional.

Thesis (MSc)--University of Stellenbosch, 2004. / ENGLISH ABSTRACT: There is overwhelming evidence that the Armadillo Lizard, Cordylus cataphractus, forms permanent aggregations, and that termites are possibly the most important component of the diet of this species. In addition, the spinose morphology and defensive tail-biting behaviour displayed by this lizard species strongly imply that individuals move away from the crevice, where they are more vulnerable to predation. Therefore the aim of this part of the study was to investigate whether C. cataphractus harvest termites at the termite foraging ports and to discuss the likely ecological implications of termitophagy for this species. A quadrate at the Graafwater study site, including several crevices housing C. cataphractus groups, was measured out. All the foraging ports of the subterranean harvester termite (Microhodotermes viator) present in the quadrate, were located and their positions recorded in respect to the distance from the nearest crevice housing lizards. The presence of C. cataphractus tracks at the foraging ports was used to verify whether individuals visited specific termite foraging ports. Tracks were found at foraging ports located at an average distance of 6.1 m, but were also located at foraging ports up to 20 m from the nearest crevice. The results strongly support the hypothesis that C. cataphractus individuals move away from the crevice to feed on termites. Termitophagy and the heavy armature of C. cataphractus appear to be key factors in the group-living behaviour of this species. Termitophagy allows individuals to live in groups as competition for food at the home crevice will be limited. Theheavy armature of C. cataphractus renders it clumsy and slow-moving, compared to other cordylids. Group-living will, however, eliminate juvenile dispersal and mate-searching excursions, activities which, in the light of the heavy morphology of the species, may result in high predation impact. The global objective of the study was to investigate social structure and space-use in Cordylus cataphractus. For the correct interpretation of data on the latter, it was necessary to first establish an ethogram for the study animal. Members of a multi-male group located at the Graafwater site, including all age-sex classes, were observed in the field by telescope, for a total of 102 hours. All individuals were observed to predominantly display maintenance behavioural act systems, however, agonistic act systems were also observed. Aggression levels were determined for the respective agonistic behavioural acts observed. Males were highly aggressive and displayed the most aggression (67.42 %). Females and sub-adults displayed aggression for 34.97 % and 37.75 % of the total observation time, respectively. Juveniles did not display aggression at all. Mating behaviour was also observed and described. An ethogram was thus established for the first time for C. cataphractus, and was compared to the ethograms available for a few other cordylids. The spatial distribution of individuals within a population has an important impact on the social structure that ensues. Living in a group imposes several pressures on the individual and competition for mates is one. The main aim of the study was to determine the space-use of all theindividuals included in a multi-male Cordylus cataphractus group (n = 55), to elaborate on the mating system. Specific focus was on the adult males and females of the multi-male group, because, ultimately, the manner in which individuals, particularly the adult males and females, utilise space, determines the mating system. The mating system is an important aspect of social structure. A two-dimensional grid pattern was delineated at a free-living, multi-male group’s crevice, situated at the Graafwater study site, to be able to plot the position of each individual during observations. All marked individuals, that were visible, were scanned through a telescope and their respective positions were recorded at 30-minute intervals. Arcview 3.2 Geographical Information Software was used to create a computerised model replicate of the two-dimensional grid pattern at the crevice, and to graphically depict the recorded positions for each individual. The space-use of males overlapped greatly with the space-use of females (66.12 ± 31.81 %), but a 0 % overlap in space-use was observed among adult males. The space-use of sub-adults and juveniles overlapped highly among one another, as well as with the space-use of adult males and females. The results showed conclusively that adult male C. cataphractus are territorial, defending specific sites at the crevice. The territory of each male included in the multi-male group incorporated at least one female. The space-use of several females incorporated the space-use of two or more males. Males were observed to mate with one or more females, and one female was observed to mate with two different males on more than one occasion. Thus the evidence strongly suggests that C. cataphractus males display typical territorial polygyny whereas females may be promiscuous. / AFRIKAANSE OPSOMMING: Daar is oorweldigende bewyse dat die pantsergordelakkedis, Cordylus cataphractus, permanent in groepe bly en dat termiete waarskynlik die belangrikste komponent in die dieet van hierdie spesie is. Die stekelrige morfologie en die stert-byt beskermingsgedrag is verder sterk aanduidings dat hierdie akkedisse tyd weg van hul klipskeure spandeer waar hulle meer gevoelig vir predasie is. Die doelwit van die eerste deel van die studie was om te bepaal of C. cataphractus termiete by die voedingspoorte van die termietneste oes en verder ook om die moontlike ekologiese implikasies wat termitofagie vir die spesie inhou, te bespreek. ‘n Kwadraat was by die Graafwater studielokaliteit uitgemeet om verskeie akkedisgroepe in te sluit. Al die voedingspoorte van die suidelike grasdraer termiet (Microhodotermes viator) binne die kwadraat is gevind en die afstande na die naaste klipskeur wat akkedisse huisves, is vir elke voedingspoort bepaal. Die teenwoordigheid van C. cataphractus spore in die sand by die voedingspoorte was gebruik om besoeke aan spesifieke voedingspoorte te bevestig. Spore is by voedingspoorte gemiddeld 6.1 m vanaf die naaste akkedisgroep gevind, maar tot so ver as 20 m vanaf die naaste akkedisgroep. Die resultate verleen sterk ondersteuning vir die hipotese dat C. cataphractus individue op termiete weg van hul klipskeur af voed. Termitofagie en die swaar pantser van C. cataphractus is waarskynlik sleutelfaktore in die groeplewe-gedrag van die spesie. Termitofagie laat groeplewe toe omdat kompetisie vir voedsel by die klipskeur beperk sal wees. Die swaar pantser van C. cataphractus het tot gevolg dat die spesie lomp en stadig is in vergelyking met ander gordelakkedisse. Groeplewe sal egter natale spreiding en maatsoek-ekskursies, aktiwiteite wat in die lig van die lompheid van die spesie swaar predasie impak tot gevolg kan hê, uitskakel. Die oorhoofse doelwit van die studie was om die sosiale struktuur en spesifiek ruimtebenutting by C. cataphractus te ondersoek. Vir korrekte interpretasie van data oor lg. was dit egter eers nodig om ‘n etogram vir die studiedier saam te stel. Lede van ‘n multi-mannetjie groep, wat alle ouderdomsgrootte klasse ingesluit het, is by die Graafwater studielokaliteit m.b.v. ‘n teleskoop vir ‘n totaal van 102 uur dopgehou. Al die individue in die groep het oorwegend instandhoudingshandelingsisteme vertoon, alhoewel agonistiese handelingsisteme ook vertoon is. Aggressievlakke is vir die verskeie agonistiese gedragshandelings bepaal. Mannetjies was hoogs aggressief en het die meeste aggressie vertoon (67.42 %). Wyfies en subvolwassenes het aggressie vir 34.97 % en 37.75 % van die totale observasietyd respektiewelik getoon. Jong individue het geen aggressie getoon nie. Paringsgedrag was ook waargeneem en beskryf. ‘n Etogram is dus vir die eerste keer vir C. cataphractus opgestel en is ook vergelyk met etogramme van ander gordelakkedisse. Die ruimtelike verspreiding van individue binne ‘n populasie het ‘n belangrike invloed op die sosiale struktuur wat daaruit voortvloei. Om in ‘n groep te lewe, plaas verskeie drukke op die individue binne die groep en kompetisie vir maats is een hiervan. The hoofdoelwit van die studie was om die ruimtebenutting van al die individue binne ‘n multi-mannetjie groep van C. cataphractus (n = 55) te bepaal en om die paringsisteem in so ‘n groep te ondersoek. Die spesifieke fokus was op die volwasse mannetjies en wyfies, omdat die paringsisteem deur die wyse waarop volwasse individue ruimte benut, bepaal word. Die studie is by die Graafwater studielokaliteit gedoen. Die oppervlak buite ‘n klipskeur wat deur ‘n multi-mannetjie groep bewoon word is opgedeel in sektore om die kartering van die posisies van die individue tydens observasietye moontlik te maak. Al die individue is vooraf met verfkodes langs die kant van die kop gemerk en op gegewe observasiedae is individuele posisies elke 30 min aangeteken. Arcview 3.2 Geographical Information Software was gebruik om ‘n tweedimensionele, gerekenariseerde replikaat van die klipskeur en onmiddelike omgewing te skep en om die waargenome posisies van individue grafies voor te stel. Die ruimtebenutting van mannetjies het grootliks met dié van wyfies oorvleuel, terwyl zero oorvleueling tussen mannetjies waargeneem is. Ruimtebenutting van subvolwasse en jong individue het ook grootliks onderling oorvleuel en ook met dié van volwasse mannetjies en wyfies. Die resultate toon duidelik aan dat volwasse mannetjies territoriaal is en dat spesifieke standplase rondom die klipskeur verdedig word. Die territorium van elke volwasse mannetjie het of ‘n gedeelte of die hele ruimtebenutting van ten minste een volwasse wyfie ingesluit. Ruimbenutting van verskeie wyfies het met dié van twee of selfs meer mannetjies oorvleuel. Mannetjies is waargeneem om met meer as een wyfie te paar en ten minste een wyfie het met meer as een mannetjie gepaar. Die resultate dui dus sterk daarop dat C. cataphractus mannetjies tipies terrotoriale poligenie vertoon terwyl wyfies weer promisku is.

Thesis (PhD)--Stellenbosch University, 2003. / ENGLISH ABSTRACT: The sungazer, Cordylus giganteus, is an endangered lizard species belonging to the family Cordylidae. It has been speculated that the function of semiochemical communication is performed by two types of skin glands, the femoral glands and the generation glands, which are also found in this family of lizards. Other skin glands and also the cloacal glands are further possible sources of semiochemicals. The investigation of these potential sources of chemical messages in C. giganteus, served as a starting point towards a better understanding of the chemical communication of lizard species belonging to the family Cordylidae. In continuation of this study the femoral gland secretion of the Cape girdled lizard, C. cordylus, was also investigated. Gas chromatography, low resolution GC-MS, GC-HR-MS, MO-TMS derivatisation and retention time comparison were used as analytical techniques in the chemical characterization of the femoral and generation gland secretions of C. giganteus and the femoral gland secretion of C. cordylus. Some compounds were not identified because of their low concentration in the secretions and/or mass spectra could not be obtained for pure compounds because of co-elution with other compounds. Compounds identified in the femoral gland secretion include the following: Carboxylic acids - saturated and unsaturated Alcohols Ketones Aldehydes - saturated and unsaturated Esters - saturated and unsaturated Hydrocarbons - saturated and unsaturated Nitriles Amides - saturated and unsaturated y-Lactones Squalene u-Tocopherol Steroids Quantitative analysis of the femoral and generation gland secretions of a number of sungazers indicated distinct differences between the secretions of males and females (in the case of the femoral gland secretions), but no apparent trend could be found in the differences between the femoral and generation gland secretions of individual lizards of the same gender. Qualitative seasonal differences were however observed in the femoral gland secretions of all individuals of C giganteus. / AFRIKAANSE OPSOMMING: Die ouvolk, Cordylus giganteus, is 'n bedreigde akkedisspesie van die familie Cordilidae. Daar is gespekuleer dat twee soorte velkliere wat by hierdie familie akkedisse voorkom, naamlik die femorale- en generasiekliere, betrokke is by semiochemiese kommunikasie van hierdie diere. Ander velkliere, asook die kliere in die akkedisse se kloaka, is ook potensiele bronne van semiochemiese verbindings. Die bestudering van hierdie potensiele bronne van chemiese boodskappe by C. giganteus is as 'n beginpunt gebruik om die semiochemiese kommunikasie van die akkedisse van die familie Cordilidae beter te verstaan. Ter uitbreiding van hierdie studie is die femorale klierafskeiding van die Kaapse gordelakkedis, C. cordylus, ook ondersoek. Die femorale en generasieklierafskeidings van C. giganteus en die femorale klierafskeidings van C. cordylus is chemies gekarakteriseer deur van analitiese tegnieke, naamlik gaschromatografie, lae resolusie GC-MS, GC-HR-MS, MO- TMS derivatisering en retensietydvergelyking, gebruik te maak. Talle verbindings is nie geidentifiseer nie omdat hulle in 'n baie lae konsentrasie in die afskeidings voorkom, en/of saam met ander komponente elueer, wat veroorsaak dat daar nie massaspektra vir hierdie suiwer komponente verkry kon word nie. Verbindingstipes wat in die afskeidings voorkom, sluit die volgende in: Karboksielsure - versadig en onversadig Alkohole Ketone Aldehiede - versadig en onversadig Esters - versadig en onversadig Koolwaterstowwe - versadig en onversadig Nitriele Amiede - versadig en onversadig y-Laktone Skwaleen a-Tocopherol Steroiede Kwantitatiewe analises van die femorale en generasieklierafskeidings van verskeie ouvolk akkedisse het getoon dat daar duidelike kwantitatiewe verskille tussen die afskeidings van mannetjies en wyfies is (in die geval van die femorale klierafskeidings), maar dat daar geen duidelike patroon in die verskille tussen die femorale en generasieklierafskeidings van individuele akkedisse van dieselfde geslag is rue. Daar is kwalitatiewe seisoenale verskille tussen die femorale klierafskeidings van individue van C. giganteus gevind.