The African elephant (Loxodonta africana) is an iconic species that is globally threatened. Of the total continental population, 37% is found in Botswana, the highest number and density of elephants in Africa. Elephant management in this country remains challenging and complex as the population estimates and trends calculated by government and independent researchers (from aerial survey data) differ and continue to be highly debated, both locally and internationally. To add more clarity and potentially resolve this ongoing debate, this study evaluates aerial survey data collected by the Botswana government from 1990 to 2012 and compares it with population demographic field data collected in 2019-2020 to assess Botswana's elephant population trend in a multimodal fashion. I used two different methods to evaluate aerial survey count data, the log-linear regression model and the Exponential Growth Space State (EGSS) model. In addition, I used the population demographic field data to estimate the growth rate. From the results, the average annual growth rate from the linear regression and the EGSS were both 6.17%. The growth rate estimated from the population demographics field data was estimated to be 5.17%. The age structure was comprised of the six age classes with a general increase from one age structure to the next as expected with a non significant decline in age class 3 (5-10 years) likely associated with the difficulty in differentiating this age class from the bounding age classes. There were no significant differences in the sex ratio (0.49Males:0.51Females). The age structure remained the same from 2019 to 2020, suggesting no evidence that overharvesting impacted the elephant population age structure in northern Botswana. Range expansion has also been identified with the movement of the elephant population into the southern part of the country by 2012. Analysis of count and demographic data as well as the identification of range expansion suggest that the elephant population is growing at rate close to the maximum growth rate previously identified for this species. Data do not support assertions that the population is negatively impacted through illegal offtake. Independent studies that identify Botswana's elephant population as declining have relied on comparisons that are made between data sets obtained from divergent aerial survey methodology and survey area, elements that confound such conclusions. Estimating population trends and the growth rate of an open population is complex, never-the-less, with population growth potientially derived from both birth and/or external immigation. However, demographic data collected in during this study indicate that the fucundity rate is substantial and likely a dominating driver of the positive population growth trend. Multiple measures of population growth (aerial survey and demographic assessments) also provide the opportunity for cross-validation of derived population trends. Therefore, this study recommends that the Botswana government incorporate population demographic data (i.e., age classes) into their existing monitoring protocols. Longitudinal data collection provides a critical mechanism for understanding population trends over changing environmental dynamics and should be continued. Efforts to modify or change these approaches must employ mechanisms that will account for and standardize for differences in methodology. / Master of Science / Botswana, a semi-arid country with limited surface water sources, has the highest number of African elephants (Loxodonta africana) on the African continent. This iconic species is globally threatened, and its conservation status is highly debated, making its management complex for Botswana. The population trends for the Botswana population, from the aerial surveys, are highly debated locally and internationally. Therefore, this study re-evaluated the aerial survey data from the Botswana government (1990-2012) and estimated the population growth rate, then compared the growth rate from the aerial survey trends analysis to the growth rate from the elephant population demographics data (collected in 2019 and 2020). The results from the aerial survey data from 2012 estimated a total population of 207,545 (CI = 185,774 - 229,316) with an annual average population growth rate of 6.17%, similar to the growth rate 5% estimated from population demographic field data. Range expansion of the elephant population has also been detected since 2009, with elephants now found in previously unoccupied regions of the Central Kalahari Game Reserve and associated regions in Southern Botswana. These results suggest the elephant population in Botswana is growing at a rate close to the maximum growth rate identified for this species. There is no evidence for a declining or stable population trend or indicators suggesting harvesting pressures (poaching) are suppressing elephant numbers. The study shows the utility of incorporating various population sampling methodologies into species management in Botswana.

Translocation involves the movement of organisms, by human intervention, from one area to other suitable (receptor) habitats. In a conservation context, translocation can be employed to support species preservation, population restoration and/or for ecological research. Despite decades of internationally published research, translocation remains a controversial endeavour. However, due to continual degradation and fragmentation of natural habitats in the face of human development, translocation is becoming a vital component of conservation efforts. Prior to the development of an Exxaro coal mine in Mpumalanga, a population of an endangered Highveld succulent species, Frithia humilis Burgoyne (Aizoaceae/Mesembryanthemaceae), was saved from extirpation by means of translocation. Three receptor habitats were identified within the distribution range of the species. The largest part of the donor population was transplanted to sandstone outcrops of the Ecca Group (Karoo Supergroup), resulting in four subpopulations residing on geological substrates typical of the species’ habitat. The remaining portion of the donor population was experimentally translocated to two habitats containing non-native geologies, namely sedimentary outcrops of the Wilge River Formation (Waterberg Group) and (igneous) felsite oucrops of the Rooiberg Group (Transvaal Supergroup). A control population was identified, occupying Ecca and Dwyka Group (Karoo Supergroup) sediments, as a measure to compare the response of translocated populations. A monitoring programme, utilising a plant age classification system, was initiated in February of 2010 to elucidate demographic trends and to gauge the response of translocated populations to novel environments. Plant survival, plant growth, flowering, fruiting (representing reproductive response) and seedling emergence were chosen as indicators to measure translocation success over the short term. Furthermore, quantitative and qualitative entomological investigations into the identity of possible F. humilis pollinators, as well as the presence of pollinator species at receptor habitats, were made. A repeatable methodology for post-translocation monitoring and scientifically sound baseline data for future comparative purposes were successfully established. Initial results showed that F. humilis subpopulations replanted on Ecca standstones had positive responses to translocation: Subpopulations survived and all but one increased in size. Individual plant growth increased, higher reproductive output was evident and seedling emergence was pervasive. Positive responses indicated that F. humilis populations translocated onto typical geologies had the potential to establish and persist over three years. Knowledge of this early success is of immense value to the conservation of the species, as a limited number of known natural populations remain. Coal mining, targeting coal seams underlying typical F. humilis habitats, is also likely to remain a threat. The viability of translocating F. humilis populations to non-typical geological substrates has shown limited efficacy. Poor survival along with inferior reproductive response confirmed Wilge River Formation outcrops as poor receptor sites for translocated F. humilis populations. Rooiberg felsite outcrops also proved to be dubious receptor sites, primarily since there was a downward trend in seedling emergence over time, suggesting inferior germination conditions. Nevertheless, translocation to non-native geological substrates did not have disastrous short-term consequences for these populations, since flowering, fruit production and seedling emergence continued, albeit at reduced (or continually declining) rates. Potential pollinator species of F. humilis were not revealed through quantitative surveys of insect diversity. Qualitative surveys proved more efficient and accurate at pinpointing insect pollinator species. This study provided the first evidence of Apidae, Megachilidae (Hymenoptera) and Bombyliidae (Diptera) insect species pollinating F. humilis. The generalist nature of the plant-pollinator relationship, as well as the presence of generalist pollinator species at some receptor habitats, probably contributed to the initial positive response of F. humilis flowering and fruiting after translocation. Results from this study, however promising, should be viewed as initial indications of translocation success. The literature review revealed a plethora of literature recommending post-translocation monitoring programmes for five years to several decades. This study confirmed that successful establishment of F. humilis can be determined after three years, but that long-term monitoring is required to evaluate persistence. / MSc (Environmental Sciences), North-West University, Potchefstroom Campus, 2015

Translocation involves the movement of organisms, by human intervention, from one area to other suitable (receptor) habitats. In a conservation context, translocation can be employed to support species preservation, population restoration and/or for ecological research. Despite decades of internationally published research, translocation remains a controversial endeavour. However, due to continual degradation and fragmentation of natural habitats in the face of human development, translocation is becoming a vital component of conservation efforts. Prior to the development of an Exxaro coal mine in Mpumalanga, a population of an endangered Highveld succulent species, Frithia humilis Burgoyne (Aizoaceae/Mesembryanthemaceae), was saved from extirpation by means of translocation. Three receptor habitats were identified within the distribution range of the species. The largest part of the donor population was transplanted to sandstone outcrops of the Ecca Group (Karoo Supergroup), resulting in four subpopulations residing on geological substrates typical of the species’ habitat. The remaining portion of the donor population was experimentally translocated to two habitats containing non-native geologies, namely sedimentary outcrops of the Wilge River Formation (Waterberg Group) and (igneous) felsite oucrops of the Rooiberg Group (Transvaal Supergroup). A control population was identified, occupying Ecca and Dwyka Group (Karoo Supergroup) sediments, as a measure to compare the response of translocated populations. A monitoring programme, utilising a plant age classification system, was initiated in February of 2010 to elucidate demographic trends and to gauge the response of translocated populations to novel environments. Plant survival, plant growth, flowering, fruiting (representing reproductive response) and seedling emergence were chosen as indicators to measure translocation success over the short term. Furthermore, quantitative and qualitative entomological investigations into the identity of possible F. humilis pollinators, as well as the presence of pollinator species at receptor habitats, were made. A repeatable methodology for post-translocation monitoring and scientifically sound baseline data for future comparative purposes were successfully established. Initial results showed that F. humilis subpopulations replanted on Ecca standstones had positive responses to translocation: Subpopulations survived and all but one increased in size. Individual plant growth increased, higher reproductive output was evident and seedling emergence was pervasive. Positive responses indicated that F. humilis populations translocated onto typical geologies had the potential to establish and persist over three years. Knowledge of this early success is of immense value to the conservation of the species, as a limited number of known natural populations remain. Coal mining, targeting coal seams underlying typical F. humilis habitats, is also likely to remain a threat. The viability of translocating F. humilis populations to non-typical geological substrates has shown limited efficacy. Poor survival along with inferior reproductive response confirmed Wilge River Formation outcrops as poor receptor sites for translocated F. humilis populations. Rooiberg felsite outcrops also proved to be dubious receptor sites, primarily since there was a downward trend in seedling emergence over time, suggesting inferior germination conditions. Nevertheless, translocation to non-native geological substrates did not have disastrous short-term consequences for these populations, since flowering, fruit production and seedling emergence continued, albeit at reduced (or continually declining) rates. Potential pollinator species of F. humilis were not revealed through quantitative surveys of insect diversity. Qualitative surveys proved more efficient and accurate at pinpointing insect pollinator species. This study provided the first evidence of Apidae, Megachilidae (Hymenoptera) and Bombyliidae (Diptera) insect species pollinating F. humilis. The generalist nature of the plant-pollinator relationship, as well as the presence of generalist pollinator species at some receptor habitats, probably contributed to the initial positive response of F. humilis flowering and fruiting after translocation. Results from this study, however promising, should be viewed as initial indications of translocation success. The literature review revealed a plethora of literature recommending post-translocation monitoring programmes for five years to several decades. This study confirmed that successful establishment of F. humilis can be determined after three years, but that long-term monitoring is required to evaluate persistence. / MSc (Environmental Sciences), North-West University, Potchefstroom Campus, 2015

Amphibian decline is a major concern worldwide, and a lack of basic ecological and life history information for many species significantly limits our ability to evaluate the degree and possible causes of such declines, and to develop effective conservation strategies for threatened and endangered species. Not only is there a shortage of adequate long-term datasets necessary for robust analyses of population variability, but the elusive nature and obscure microhabitats of many species make it difficult to collect even the most basic natural history data. In a series of observational and experimental studies, I employed both traditional and novel ecological methodologies to examine environmental correlates of temporal population variability, foraging ecology and anti-predator behavior in endangered Barton Springs Salamander (Eurycea sosorum) from Austin (Travis County), Texas. Though headwater springs are typically thought of as habitats with relatively stable environmental conditions, I discovered that E. sosorum population abundance was strongly influenced by periodic extremes of rainfall that affect cycles in spring flow rates, water temperature, and other physico-chemical variables. I also found that population dynamics in E. sosorum are highly consistent with those expected for organisms with a storage effect life-history strategy, in which a few long-lived females capable of high fecundity and prolonged survival in subterranean habitat during adverse environmental conditions may be sufficient for population persistence. In addition, juveniles may use subterranean habitat as a thermal refuge. Using stable isotope analyses and macroinvertebrate prey censuses, I determined that at the population level, adult E. sosorum exhibits high electivity for planarian flatworms (Dugesia sp.). This would not have been detectable using traditional methods of dietary analysis such as stomach or fecal content analysis because Dugesia are soft-bodied animals. Additionally, stable isotope analyses revealed that adult E. sosorum exhibits inter-individual diet variation and is capable of diet switching. Finally, I discovered that anti-predator behavior in E. sosorum is influenced more strongly by visual and bioelectric cues from potential predators, but not olfactory cues. This is the first known demonstration of anti-predatory response mediated only by bioelectric stimuli in an amphibian, and one of very few to observe this phenomenon among aquatic vertebrates. / text

This study looked at the efficacy of using woodland caribou fecal pellets as a source of DNA to identify sampled animals and estimate population demographics. Fecal pellet samples were collected using systematic surveys of woodland caribou ranges in Jasper National Park, Alberta and the North Interlake region, Manitoba. Collection of pellet samples took place when snow was present to allow for tracking and location of caribou cratering areas and to obtain good quality DNA. DNA was amplified at ten polymorphic loci and one sex-specific primer. To estimate population size (N ̂) and population growth rate (λ), mark-recapture models were used. Model assumptions were evaluated and tested by stratifying available samples based on herd and gender information. In using the Mh (jackknife) model, the population sizes for south Jasper National Park were estimated at 125 animals in 2006-2007 (95% CI: 114, 143), 91 animals in 2007-2008 (95% CI: 83, 105) and 134 animals in 2008-2009 (95% CI: 123, 152); comparable to the mark-resight population estimates calculated over the same sampling periods. Genetic diversity indices for the different herds in Jasper National Park presented a lower genetic diversity for the smaller Maligne and Brazeau herds when compared to the larger Tonquin and A La Peche herds. Use of population assignment tests on samples collected in Jasper National Park indicated considerable admixture between the different herds despite earlier telemetry work demonstrating strong herd fidelity. The North Interlake population was estimated at 134 animals (95% CI: 122,151) in 2006-2007 and 106 animals (95% CI: 97, 121) in 2007-2008. Using data collected between 2005 and 2008, population growth rate for North Interlake was estimated at 0.83 (90% confidence interval: 0.65, 1.02). As a λ below 1 indicates a declining population, continue monitoring of the North Interlake herd is highly recommended. This studied clearly showed that the sampling of fecal DNA is a reliable and noninvasive alternative to monitoring woodland caribou population sizes and trends in the boreal and mountain regions.

This study looked at the efficacy of using woodland caribou fecal pellets as a source of DNA to identify sampled animals and estimate population demographics. Fecal pellet samples were collected using systematic surveys of woodland caribou ranges in Jasper National Park, Alberta and the North Interlake region, Manitoba. Collection of pellet samples took place when snow was present to allow for tracking and location of caribou cratering areas and to obtain good quality DNA. DNA was amplified at ten polymorphic loci and one sex-specific primer. To estimate population size (N ̂) and population growth rate (λ), mark-recapture models were used. Model assumptions were evaluated and tested by stratifying available samples based on herd and gender information. In using the Mh (jackknife) model, the population sizes for south Jasper National Park were estimated at 125 animals in 2006-2007 (95% CI: 114, 143), 91 animals in 2007-2008 (95% CI: 83, 105) and 134 animals in 2008-2009 (95% CI: 123, 152); comparable to the mark-resight population estimates calculated over the same sampling periods. Genetic diversity indices for the different herds in Jasper National Park presented a lower genetic diversity for the smaller Maligne and Brazeau herds when compared to the larger Tonquin and A La Peche herds. Use of population assignment tests on samples collected in Jasper National Park indicated considerable admixture between the different herds despite earlier telemetry work demonstrating strong herd fidelity. The North Interlake population was estimated at 134 animals (95% CI: 122,151) in 2006-2007 and 106 animals (95% CI: 97, 121) in 2007-2008. Using data collected between 2005 and 2008, population growth rate for North Interlake was estimated at 0.83 (90% confidence interval: 0.65, 1.02). As a λ below 1 indicates a declining population, continue monitoring of the North Interlake herd is highly recommended. This studied clearly showed that the sampling of fecal DNA is a reliable and noninvasive alternative to monitoring woodland caribou population sizes and trends in the boreal and mountain regions.

No description available.

No description available.