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Thesis (MSc)--University of Stellenbosch, 2005. / ENGLISH ABSTRACT: Many territorial carnivores deposit faeces and other scent-marks at specific latrine sites, and their role in territorial defence is often assumed. However, recent empirical and theoretical work suggests that ultimate explanations of territoriality differ between the sexes. In this thesis, I investigate patterns of latrine-use in cooperatively breeding meerkats, Suricata suricatta. Meerkats exhibit high reproductive skew, and in such societies an individual’s optimal investment in territory defence and intruder deterrence will depend not only on its sex, but also its breeding status within the group. The spatial and temporal distribution of meerkat latrines reflects the diversity in intruder type. Shared latrine sites between neighbouring groups facilitate costeffective monitoring of predictable intruders and surrounding land tenure. In contrast, intruding transient groups and prospecting males are effectively intercepted by latrines concentrated in the core of the territories, close to refuges. This represents the optimal strategy, as meerkat territories are too large to allow effective scent-marking around their entire peripheries, and these intruders travel between refuges during intrusions. Temporal patterns of latrine-use suggest their importance in mate-defence. Latrine-use was correlated with encounters with prospecting males and oestrous periods of resident females, and reached a peak coinciding with the season of elevated dispersal and take-over events. Additionally, rather than cooperatively contributing to territorial defence, individuals participated selfishly at latrines. Males preferentially over-marked female scent-marks and scent-marked at significantly greater rates than females, which resulted in male-biased latrines that were unrepresentative of group composition. Although all individuals investigated female scent-marks for significantly longer than male scent-marks, females invested most, suggesting that intra-group monitoring is an important aspect of latrine visits for females. The deleterious effects of close inbreeding are well known, but regular dispersal in both sexes, and long dominance tenure, result in unfamiliar siblings having a high probability of encountering one another post-dispersal. As latrines are implicated in mate-defence, olfactory assessment of factors affecting mating decisions might be expected, but although individuals do recognise foreign faeces, discrimination does not appear to occur on the basis of kinship. Together, these findings have broad implications for our understanding of individual variation and sex differences in scent-marking behaviour and territoriality. / AFRIKAANSE OPSOMMING: Baie territoriale karnivore deponeer faeces en ander reukmerke by spesifieke latrines en die latrines se rol in gebiedsverdediging word dikwels aangeneem. Onlangse empiriese en teoretiese werk stel egter voor dat die uiteindelike verduidelikings van territorialiteit verskil tussen die geslagte. In hierdie tesis ondersoek ek patrone van latrine-gebruik in samewerkend-broeiende meerkaaie (Suricata suricatta). Meerkaaie toon ‘n hoë graad van voorkeuraanwas en in sulke gemeenskappe sal ‘n individu se optimale belegging in gebiedsverdediging en indringer-verjaging nie net van sy/haar geslag afhang nie, maar ook van sy/ haar teelstatus in die groep. Die ruimtelike en temporale verspreiding van meerkat latrines weerspieël die verskeidenheid van indringertipes. Gedeelde latrine areas tussen naburige groepe help die kosteeffektiewe bestekopname van voorspelbare indringers en omringende landsbesetting aan. In kontras hiermee word tydelike groepe en geleentheidsoekende mannetjies effektiewelik voorgekeer deur latrines wat gekonsentreer is in gebiedskerne, naby aan skuilplekke. Dit verteenwoordig die optimale strategie, aangesien meerkat territoriums te groot is om effektiewe reukmerking van die hele grens toe te laat, en synde hierdie indringers tussen skuilplekke reis tydens invalle. Tydspatrone van latrine-gebruik dui die belangrikheid hiervan in paarmaat-beskerming aan. Latrinegebruik korreleer met ontmoetings met geleentheidsoekende mannetjies en die oestrus tydperk van inwonende wyfies, en bereik ‘n toppunt tydens die seisoen van verhoogde verspreiding en oornames. Ook sal individue selfsugtig deelneem by latrines eerder as om samewerkend by te dra tot gebiedsverdediging. Mannetjies verkies om vroulike reukmerke oor te merk en reukmerk teen ‘n beduidend hoër koers as wyfies, wat lei tot mannetjie-geneigde latrines wat nie verteenwoordigend is van die groepsamestelling nie. Alhoewel alle individue vroulike reukmerke beduidend langer as manlike reukmerke ondersoek, belê wyfies die meeste, wat daarop dui dat intragroep monitering ‘n belangrike aspek van latrine-besoeke is vir wyfies. Die nadelige effekte van sterk inteling is goed bekend, maar gereelde verspreiding in beide geslagte en lang dominante posisiehouding lei daartoe dat daar ‘n groot kans is vir onbekende nabye familielede om mekaar te ontmoet na verspreiding. Aangesien latrines ‘n rol speel in paarmaat-verdediging kan dit verwag word dat daar olfaktoriese beoordeling sal wees van faktore wat paringsbesluite beïnvloed, maar hoewel individue wel vreemdelinge se faeces herken, toon hulle geen onderskeidingsvermoë gebaseer op verwantskap nie. Saamgevoeg, het hierdie bevindinge wye implikasies vir ons begrip van individuele variasie en geslagsverskille in reukmerk-gedrag en terriorialiteit.

Thesis (PhD)--Stellenbosch University, 2005. / ENGLISH ABSTRACT: Despite more than three decades of research, and the postulation of more than 30 hypotheses of function, the adaptive significance of play remains unknown. This study quantitatively evaluated a selection of hypotheses of function, using data collected from a wild population of small, social carnivore, the meerkat, Suricata suricatta. The study found that although play in meerkats carried an energetic cost, with individuals modulating their frequency of play in response to their energy intake, none of the hypotheses evaluated by the study could identify the adaptive benefits that meerkats derived from play. Play did not increase 'social harmony' by reducing aggression between playmates, nor did it strengthen an individual's bonds to its social group, such that it remained in the group for longer, or contributed more to the group's cooperative activities. There was no evidence that meerkats used play to strengthen alliances between individuals, and young meerkats played no more frequently with their future dispersal partners than with matched controls with which they did not disperse. Play fighting experience did not improve a meerkat's subsequent fighting skills, and individuals that ultimately won the dominant breeding position within a group (through serious fighting) played no more frequently, and no more successfully, as youngsters, than the littermates that they defeated in combat. Although play was inhibited by aggression, meerkats did not use play to contest, assert or establish dominance status, and there was little evidence to suggest that the preference young meerkats showed for play partners that were well matched in age, size and ability arose from their use of play for self-assessment. This study assessed only those hypotheses of function that predicted benefits that were of importance to the inclusive fitness of the study species. For example, the enhancement of social harmony and group cohesion should be invaluable to a species whose survival is dependent upon social cooperation; and the high reproductive skew exhibited by this species places huge value upon fighting skill and the ability to win social dominance. As a consequence, this study's negative findings suggest strongly that play is not capable of providing these benefits, and that play behaviour is unlikely to be used for these purposes in any mammal species. I conclude that the most likely function of play (based on play's ubiquitous characteristics, and the findings of neurological research on rats) is the promotion of growth of the cerebral cortex. / AFRIKAANSE OPSOMMING: Ten spyte van meer as drie dekades van navorsing en die voorstelling van meer as 30 hipoteses oor funksie, bly die aanpassingswaarde van spelonbekend. Hierdie studie is 'n kwantitatiewe evaluasie van verskeie hipoteses oor funksie, en gebruik data versamel vanuit 'n wilde bevolking van 'n klein sosiale karnivoor, die meerkat, Suricata suricatta. Die studie het bevind dat hoewel spel in meerkaaie 'n energetiese koste beloop, met individue wat hul spelfrekwensie aanpas by energie-inname, geen-een van die hipoteses onder beskouing die aanpassingswaarde van spel vir meerkaaie kon verduidelik nie. Spel het nie "sosiale harmonie" bevorder deur die afuame in aggressie tussen speelmaats nie, en het ook nie 'n individu se verbintenis tot sy sosiale groep versterk sodat hy langer in die groep sou bly of meer sou bydra tot samewerkingsaktiwiteite nie. Daar was geen bewyse vir die gebruik van spel in die versterking van bondgenootskappe tussen individue nie, en jong meerkaaie het nie meer gereeld met toekomstige verspreidings-venote gespeel as met gepaarde kontroles saam met wie hulle nie uiteengegaan het nie. Speelse gevegte het nie 'n meerkat se daaropvolgende gevegsvermoëns verbeter nie, en die individue wat uiteindelik die dominante voortplantingsposisie in 'n groep gewen het (deur ernstige stryd) het nie meer gereeld ofmeer suksesvol as jongelinge gespeel in vergelyking met die werpselmaats wat hulle in die stryd oorwin het nie. Hoewel spel deur aggressie onderdruk is, het meerkaaie spel nie gebruik om dominante range te beveg, bevestig of tot stand te bring nie. Daar was min bewyse ter ondersteuning van die voorstel dat jong meerkaaie se voorkeur vir speelmaats wat hul gelyke is in ouderdom, grootte en vermoë, onstaan het in die gebruik van spel vir selfondersoek. Hierdie studie het slegs die hipoteses van funksie beskou wat voorspellings gemaak het oor die voordele wat belangrik is in die inklusiewe fiksheid van die studie-species. Byvoorbeeld, die verbetering van sosiale harmonie en groepsamehang behoort van onskatbare waarde te wees vir 'n species wat afhanklik is van sosiale samewerking vir oorlewing; en die hoë graad van voorkeuraanwas duidelik in hierdie species plaas groot waarde op gevegsvaardighede en die vermoë om sosiale dominansie te wen. Gevolglik dui hierdie ondersoek se negatiewe bevindinge daarop dat spel nie hierdie voordele kan bied nie, en dat speelgedrag heel waarskynlik nie vir hierdie doeleindes in enige soogdier-species gebruik word nie. Ek kom tot die gevolgtrekking dat die heel waarskynlikste funksie van spel (gebaseer op spel se alomteenwoordige kenmerke en die bevindinge van neurologiese navorsing op rotte) die bevordering van groei in die serebrale korteks is.