The exact ecological and economic role of lion Panthera leo populations on small enclosed reserves is poorly understood. The management and monitoring of such populations is important to ensure their long-term survival. The prey use, range use and habitat selection of an isolated lion population were investigated. The study was conducted on a small (> 1000km2), enclosed predator camp of Tswalu Kalahari Reserve, situated in the Northern Cape Province of the Republic of South Africa. The prey selection, prey preferences and prey biomass removal were determined by using indirect and direct observations. Kill sites, carcasses and scats were located by spoor tracking and opportunistic observations and collated into a prey selection list. The prey selection was used to determine any prey preferences and the prey biomass removal by the lion population. The scats data was corrected for relative prey biomass and compared to the kill data and uncorrected scat data. 19 prey types were used, with the gemsbok Oryx gazelle and blue wildebeest Connochaetes taurinus being utilized most. The lion population had clear preferences for specific small and large mammals which concurred with other studies done on Kalahari lion behaviour. The prey biomass removal (9.9kg/Lion feeding Unit/day) was higher than several other studies done on lion consumption rates. The range use and habitat selection were determined by using direct and indirect observations. The minimum convex polygon method and kernel density estimates were used to delineate the ranges of the lion population. The mean range size of the Tswalu lions (91 km2) was similar to those found for lions in more mesic environments. The lions also had clear habitat preferences which depended on the habitat preferences of the prey and the prey density. A population viability analysis, using VORTEX 9.72, was conducted. An Ecological capacity was determined and used to model various environmental scenarios. The population was found to be viable, but constant monitoring and updating are needed. Management recommendations for the conservation of lions and their prey are provided. / Dissertation (MSc)--University of Pretoria, 2010. / Animal and Wildlife Sciences / unrestricted

The movements of two vervet monkey troops were studied to determine whether they optimize their rate of food intake in relation to seasonal energy availability. The effect of variation in habitat structure on the troops’ foraging strategies while utilizing temporally and spatially distributed resources was determined. Troop home range boundaries were delineated, the various plant communities and species utilised by the troops identified and classified, and variations in home range and vegetation structure were reported. The diets of the troops were determined and compared. Effects of coexistence on competition were assessed. Vervet food trees were randomly selected, marked and seasonal phenological data collected. Samples of food items constituting the two troops diets were collected for energy analysis. Using geostatistical interpolation techniques, monthly energy values were extrapolated onto home range grids for the two vervet monkey troops. Grids were stored as database files that were interrogated through GIS simulation models. Using the stochastic processes inherent in Markov chain theory, a series of non-returning random walks were simulated for comparison to original routes taken by the two troops. Results from comparisons of home range energy, day range lengths and areas, shortest route energy to actual route energy, time spent in high energy areas, and energy utilisation from actual and randomly generated routes indicated that the two troops optimize resource energy available to them by adopting flexible foraging strategies. In environments where temporal and spatial variations in habitat structure affect the distribution of resources, it is essential that animals develop optimal foraging strategies to survive. For the two troops investigated, foraging strategies fluctuate between being time minimizers in more heterogeneous environments where resources are abundant, and energy maximisers in homogeneous environments where resources are constrained by low diversity and seasonality. / Environmental Sciences (Department) / D.Litt et Phil (Environmental Management)

A socioecologia investiga o efeito de fatores ecológicos sobre padrões de sistema social. Para muitos animais, o risco de predação tem sido apontado como a principal força seletiva favorecendo a sociabilidade. Entretanto, como determinante na variação dos sistemas sociais de primatas, esse fator tem sido considerado menos importante do que a competição por alimento. Os objetivos deste estudo foram (1) investigar a influência da disponibilidade de alimento e do risco de predação no uso do habitat pelo grupo estudado, para avaliarmos se o risco de predação é um fator relevante para essa população, (2) caracterizar o sistema social e (3) investigar se o risco de predação e/ou a oferta de alimento afetam o sistema social de Sapajus xanthosternos, espécie Criticamente ameaçada devido à caça e destruição do seu habitat, o que a torna relevante para o teste de hipóteses. Esta pesquisa foi realizada na Reserva Biológica de Una, cuja vegetação é classificada como floresta de tabuleiro e, na qual a população estudada ainda sofre pressão de caça. Um grupo foi acompanhado por 16 meses, num total de 2126 horas. O risco de predação foi avaliado em função do comportamento de vigilância, vocalizações de alarme, encontros com predadores e indícios de caça. Por meio do método focal árvore alimentação avaliamos o tamanho e qualidade das fontes agregadas. As interações agonísticas e afiliativas foram registradas pelo método de todas as ocorrências. A área de vida e os percursos diários foram calculados para avaliarmos a competição indireta intra e entre grupos. Os resultados foram comparados com os obtidos para uma população de S. nigritus e uma de S. libidinosus. O uso do habitat pelo grupo foi influenciado tanto pela distribuição e disponibilidade de recursos alimentares quanto pelo risco de predação. Os macacos-prego na Rebio Una formam grupos grandes e coesos, com filopatria de fêmeas e, a população é caracterizada por fissão de grupos grandes. O grande tamanho dos grupos favorece a hipótese de que o tamanho mínimo de grupo é determinado pelo risco de predação. O grupo apresentou um elevado número de machos (esperado devido ao número de fêmeas), o que também é considerado por alguns estudos como evidência de alto risco de predação. A estratégia reprodutiva das fêmeas foi relacionada à organização social e, consequentemente, ao risco de predação. S. xanthosternos consome tanto recursos agregados quanto dispersos e despendeu uma alta proporção de tempo forrageando por invertebrados. A hierarquia de dominância entre fêmeas foi parcial e as fêmeas de alto posto alimentaram-se conjuntamente com as fêmeas de baixo posto em fontes agregadas, enfatizando que fêmeas apresentaram relações tolerantes. A maioria das fontes agregadas utilizadas foi de tamanho intermediário em relação ao tamanho do grupo e produtiva e a competição direta por alimento envolvendo fêmeas intra-grupo não foi baixa. A competição indireta intra-grupo foi elevada, o que se constata pelas altas taxas de deslocamento e pelas grandes distâncias diárias percorridas. A competição direta entre grupos foi baixa e o risco de predação percebido foi alto em comparação com outros estudos. O padrão de sistema social, com grupo grande, elevado número de machos, e fêmeas com alto grau de afiliação e tolerância não está de acordo com o esperado por modelos que só consideram o efeito da competição por alimento, e sugere que o risco de predação afeta os componentes que caracterizam o sistema social deste grupo. Em conclusão, o sistema social de S. xanthosternos nesta população é uma resposta à pressão de predação e à oferta de alimento / Socioecology studies the effect ecological factors have on social system patterns. The predation risk has been said as the main selective force to favoring the sociability in many animals. However, as a determinant in variation of primates social systems, this fact has been considered less important than competition for food. The objectives of this study were (1) investigating how much the availability of food and the predation risk affect the habitat use by the group followed, in order to evaluate if the predation risk is a relevant issue in this population, (2) characterizing the social system and (3) investigating if the predation risk and/or availability of food affect the social system of Sapajus xanthosternos, a critically endangered species, owing to its hunting and habitat destruction, such fact makes it relevant for the hypothesis test. This study was made at the Una Biological Reserve, where the vegetation is classified as tabuleiro forest. The population in focus suffers from hunting stress. A group was followed during 16 months, a total of 2126 hours. The predation risk was evaluated concerning their vigilance behaviour, alarm vocalization, encounters with predators and hunting indication. We evaluated the size and the quality of the clumped food sources through the focal tree food method. Agonistic and affiliative interactions were recorded through all occurrences method. Home range and the daily traveling distances were calculated to evaluate if females experienced scramble competition within and between groups. The results were compared to the ones that had been obtained from a previous study with the population of the species S. nigritus and S. libidinosus. The use of habitat by the group was not only influenced by the distribution and availability food resources but also by the predation risk. The capuchin monkeys in Rebio Una live in large and cohesive groups, show female philopatry, and fission of very large groups. The large size of the groups favours the hypothesis that the minimum size of a group is determined by the predation risk. The group has shown a high number of males (expected due to the high number of females), a fact that is also considered by some studies as evidence of high predation risk. Female reproductive strategies were related to social organization and, therefore, to predation risk. S. xanthosternos consumes clumped and dispersed resources and spent more time foraging for invertebrates. There was a partial dominance hierarchy among females and the high-ranking females ate with the low-ranking females in clumped food sources. Such fact emphasizes that females hold tolerant relations. The majority of used clumped food sources had an intermediate size, concerning the size of the group, and was productive. The contest competition within group for food involving females was not low. Scramble competition within group was high, as shown by the high moving rates and the long daily travel distance. Contest competition between groups was low and the perceived predation risk was high in comparison to other studies. The social system pattern - large group size, high sex ratio, and females that show a high level of affiliation and tolerance - is not in accordance with the expected by models that only consider the result of competition for food. It suggests that the risk of predation affects the elements of social system in this group. As a conclusion, the social system of S. xanthosternos is affected by the risk of predation and food availability

A socioecologia investiga o efeito de fatores ecológicos sobre padrões de sistema social. Para muitos animais, o risco de predação tem sido apontado como a principal força seletiva favorecendo a sociabilidade. Entretanto, como determinante na variação dos sistemas sociais de primatas, esse fator tem sido considerado menos importante do que a competição por alimento. Os objetivos deste estudo foram (1) investigar a influência da disponibilidade de alimento e do risco de predação no uso do habitat pelo grupo estudado, para avaliarmos se o risco de predação é um fator relevante para essa população, (2) caracterizar o sistema social e (3) investigar se o risco de predação e/ou a oferta de alimento afetam o sistema social de Sapajus xanthosternos, espécie Criticamente ameaçada devido à caça e destruição do seu habitat, o que a torna relevante para o teste de hipóteses. Esta pesquisa foi realizada na Reserva Biológica de Una, cuja vegetação é classificada como floresta de tabuleiro e, na qual a população estudada ainda sofre pressão de caça. Um grupo foi acompanhado por 16 meses, num total de 2126 horas. O risco de predação foi avaliado em função do comportamento de vigilância, vocalizações de alarme, encontros com predadores e indícios de caça. Por meio do método focal árvore alimentação avaliamos o tamanho e qualidade das fontes agregadas. As interações agonísticas e afiliativas foram registradas pelo método de todas as ocorrências. A área de vida e os percursos diários foram calculados para avaliarmos a competição indireta intra e entre grupos. Os resultados foram comparados com os obtidos para uma população de S. nigritus e uma de S. libidinosus. O uso do habitat pelo grupo foi influenciado tanto pela distribuição e disponibilidade de recursos alimentares quanto pelo risco de predação. Os macacos-prego na Rebio Una formam grupos grandes e coesos, com filopatria de fêmeas e, a população é caracterizada por fissão de grupos grandes. O grande tamanho dos grupos favorece a hipótese de que o tamanho mínimo de grupo é determinado pelo risco de predação. O grupo apresentou um elevado número de machos (esperado devido ao número de fêmeas), o que também é considerado por alguns estudos como evidência de alto risco de predação. A estratégia reprodutiva das fêmeas foi relacionada à organização social e, consequentemente, ao risco de predação. S. xanthosternos consome tanto recursos agregados quanto dispersos e despendeu uma alta proporção de tempo forrageando por invertebrados. A hierarquia de dominância entre fêmeas foi parcial e as fêmeas de alto posto alimentaram-se conjuntamente com as fêmeas de baixo posto em fontes agregadas, enfatizando que fêmeas apresentaram relações tolerantes. A maioria das fontes agregadas utilizadas foi de tamanho intermediário em relação ao tamanho do grupo e produtiva e a competição direta por alimento envolvendo fêmeas intra-grupo não foi baixa. A competição indireta intra-grupo foi elevada, o que se constata pelas altas taxas de deslocamento e pelas grandes distâncias diárias percorridas. A competição direta entre grupos foi baixa e o risco de predação percebido foi alto em comparação com outros estudos. O padrão de sistema social, com grupo grande, elevado número de machos, e fêmeas com alto grau de afiliação e tolerância não está de acordo com o esperado por modelos que só consideram o efeito da competição por alimento, e sugere que o risco de predação afeta os componentes que caracterizam o sistema social deste grupo. Em conclusão, o sistema social de S. xanthosternos nesta população é uma resposta à pressão de predação e à oferta de alimento / Socioecology studies the effect ecological factors have on social system patterns. The predation risk has been said as the main selective force to favoring the sociability in many animals. However, as a determinant in variation of primates social systems, this fact has been considered less important than competition for food. The objectives of this study were (1) investigating how much the availability of food and the predation risk affect the habitat use by the group followed, in order to evaluate if the predation risk is a relevant issue in this population, (2) characterizing the social system and (3) investigating if the predation risk and/or availability of food affect the social system of Sapajus xanthosternos, a critically endangered species, owing to its hunting and habitat destruction, such fact makes it relevant for the hypothesis test. This study was made at the Una Biological Reserve, where the vegetation is classified as tabuleiro forest. The population in focus suffers from hunting stress. A group was followed during 16 months, a total of 2126 hours. The predation risk was evaluated concerning their vigilance behaviour, alarm vocalization, encounters with predators and hunting indication. We evaluated the size and the quality of the clumped food sources through the focal tree food method. Agonistic and affiliative interactions were recorded through all occurrences method. Home range and the daily traveling distances were calculated to evaluate if females experienced scramble competition within and between groups. The results were compared to the ones that had been obtained from a previous study with the population of the species S. nigritus and S. libidinosus. The use of habitat by the group was not only influenced by the distribution and availability food resources but also by the predation risk. The capuchin monkeys in Rebio Una live in large and cohesive groups, show female philopatry, and fission of very large groups. The large size of the groups favours the hypothesis that the minimum size of a group is determined by the predation risk. The group has shown a high number of males (expected due to the high number of females), a fact that is also considered by some studies as evidence of high predation risk. Female reproductive strategies were related to social organization and, therefore, to predation risk. S. xanthosternos consumes clumped and dispersed resources and spent more time foraging for invertebrates. There was a partial dominance hierarchy among females and the high-ranking females ate with the low-ranking females in clumped food sources. Such fact emphasizes that females hold tolerant relations. The majority of used clumped food sources had an intermediate size, concerning the size of the group, and was productive. The contest competition within group for food involving females was not low. Scramble competition within group was high, as shown by the high moving rates and the long daily travel distance. Contest competition between groups was low and the perceived predation risk was high in comparison to other studies. The social system pattern - large group size, high sex ratio, and females that show a high level of affiliation and tolerance - is not in accordance with the expected by models that only consider the result of competition for food. It suggests that the risk of predation affects the elements of social system in this group. As a conclusion, the social system of S. xanthosternos is affected by the risk of predation and food availability

The movements of two vervet monkey troops were studied to determine whether they optimize their rate of food intake in relation to seasonal energy availability. The effect of variation in habitat structure on the troops’ foraging strategies while utilizing temporally and spatially distributed resources was determined. Troop home range boundaries were delineated, the various plant communities and species utilised by the troops identified and classified, and variations in home range and vegetation structure were reported. The diets of the troops were determined and compared. Effects of coexistence on competition were assessed. Vervet food trees were randomly selected, marked and seasonal phenological data collected. Samples of food items constituting the two troops diets were collected for energy analysis. Using geostatistical interpolation techniques, monthly energy values were extrapolated onto home range grids for the two vervet monkey troops. Grids were stored as database files that were interrogated through GIS simulation models. Using the stochastic processes inherent in Markov chain theory, a series of non-returning random walks were simulated for comparison to original routes taken by the two troops. Results from comparisons of home range energy, day range lengths and areas, shortest route energy to actual route energy, time spent in high energy areas, and energy utilisation from actual and randomly generated routes indicated that the two troops optimize resource energy available to them by adopting flexible foraging strategies. In environments where temporal and spatial variations in habitat structure affect the distribution of resources, it is essential that animals develop optimal foraging strategies to survive. For the two troops investigated, foraging strategies fluctuate between being time minimizers in more heterogeneous environments where resources are abundant, and energy maximisers in homogeneous environments where resources are constrained by low diversity and seasonality. / Environmental Sciences (Department) / D.Litt et Phil (Environmental Management)