There are local populations of African elephants (Loxodonta africana) which have increased to levels where they are implicated in altering vegetation types. The local reduction of elephant numbers for wildlife management objectives can involve contraception, killing excess animals, or translocation to alternative habitats. The effects these management decisions can have on the physiological stress response of free-ranging African savanna elephants are still not fully understood. We examined the effect of translocation on faecal glucocorticoid metabolite levels of an African elephant family group,which was translocated within the Kruger National Park, South Africa. We found that translocation resulted in a significant increase in faecal glucocorticoid metabolite levels (up to 646 ng/g wet weight) compared to (1) pre-translocation levels in this group, (2) post-translocation levels in this group, and (3) levels measured in undisturbed ‘control’ groups in the area. However, the faecal glucocorticoid metabolite levels had returned to <100 ng/g by the time the translocated animals had navigated their way back to their previous home range, covering 300 km in 23 days.

By 2001, elephants had been translocated (mainly from Kruger National Park) to 58 small, fenced reserves in South Africa. All but two introductions took place since 1989. We document important aspects of the population dynamics of elephants in these reserves using data collected in a survey conducted in 2001. The mean population size was 45 elephants, with an average density of 0.25 elephants/km2. Populations have a female bias with 0.79 males to females. Populations have 19% adult males, and 31% adult females. On average, almost 50% of the population comprises adult and subadult females, indicating an immanent potential for large population growth. Births were not significantly different froma 1:1 sex ratio. When two extreme populations were removed, mean mortality rate was 0.4% per annum.Population growth rates averaged 8.3%,but five reserves had growth rates above 13%, and the highest annual growth rate was 16.5% per annum. Twenty-seven populations already have densities above 0.2 elephants/km2, and eight reserves have densities above 0.4 elephants/km2. Assuming a 12% per annum growth (feasible given the data presented), over half the reserves will have densities above 0.33 elephants/km2 within five years. These results indicate that the translocation of elephants has been successful, with most populations reproducing at a rate far exceeding expectations. This has serious implications for owners and managers, as some form of population control (contraception, removals, culling etc.) needs to be urgently planned for implementation as soon as possible in most, and probably all small reserves.

It has been suggested that African savanna elephants Loxodonta africana produce 31 different call types (Langbauer 2000). Various researchers have described these calls by associating them with specific behavioural contexts. More recently Leong et al. (2003) have attempted to classify elephant call types based on their physical properties. They classified 8 acoustically distinct call types from a population of captive elephants. This study focuses on one of these call types, the rumble, in a wild population of elephants in Kruger National Park, South Africa. A single family group of elephants was followed to record group behaviours and vocalizations from January through August 2001. By measuring the physical properties of 663 rumbles and subjecting these to cluster analysis, we present evidence that shows that rumbles can be categorized by their physical properties and that the resulting rumble types are associated with specific group behaviours. We characterize three types of rumbles that differ significantly by ten acoustic parameters. Two rumble types were associated with the elephant group feeding and resting, while the third was associated with socializing and agitation.

No abstract available. / Dissertation (MSc)--University of Pretoria, 2008. / Zoology and Entomology / unrestricted

Thesis (Ph.D.), Faculty of Science, University of the Witwatersrand, 2004

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.

L’eau et le fourrage sont deux ressources non substituables pour les herbivores dans les écosystèmes arides et semi-arides. La distribution spatiale de l’eau de surface détermine la distribution et l’abondance des espèces dépendantes de l’eau. Cependant les processus impliqués à l’échelle individuelle demeurent méconnus. Treize groupes familiaux d’éléphants d’Afrique (Loxodonta africana) et dix mâles ont été équipé de colliers GPS dans le parc National de Hwange, au Zimbabwe, et à sa périphérie. Les éléphants fourragent autour de multiples points centraux : ils visitent un point d’eau périodiquement toutes les 5h, 24h, 48h ou 72h et s’éloignent plus de l’eau lorsque ils font des trajets de plus longue durée. Pendant la saison sèche, la température augmente et les ressources fourragères s’épuisent à proximité de l’eau. Les groupes familiaux d’éléphants visitent les points d’eau plus souvent en augmentant la fréquence des trajets courts et en abandonnant les trajets de 72h. Cependant, ils parviennent à se rendre plus loin de l’eau pendant les trajets de 24h en augmentant la vitesse de déplacement. Ainsi les patrons de déplacement révèlent que les capacités de locomotion et de navigation des éléphants sont au cœur de leur stratégie d’adaptation à la saison sèche. Malgré cela, ces capacités sont rarement incluses dans les modèles d’approvisionnement dans des environnements hétérogènes. Pendant ces trajets, les groupes familiaux sélectionnent les zones de faible densité de points d’eau à des échelles multiples. La force de la sélection pour ces zones de faible densité augmente avec la longueur du trajet et au cours de la saison. Malgré le fait que l’importance des échelles spatiales soit bien établie dans la littérature, les contraintes associées à l’utilisation de multiples points centraux distribués de manière hétérogène dans le paysage ont été négligé alors que cette distribution détermine le degré d’épuisement des ressources fourragères et les rétroactions sur la sélection de l’habitat. J’ai aussi montré que la faune sauvage évite fortement le bétail et les humains qui les conduisent en périphérie d’une zone protégée pendant la saison des pluies. Cependant cet évitement décline au cours de la saison sèche en raison de l’assèchement des points d’eau et de la raréfaction des ressources fourragères. Les éléphants sont de plus en plus contraints par la distribution de l’eau de surface en saison sèche en raison de l’augmentation de leur besoins en eau tandis qu’ils tentent de maintenir leur approvisionnement en fourrage. Cette étude donne une évaluation quantitative de la contrainte en eau à l’échelle individuelle ainsi que les effets de la distribution en eau dans le paysage sur un grand herbivore. Ces résultats peuvent guider les politiques de gestion de l’eau dans un contexte d’aridification dû au changement climatique. / Water and forage are key non-substitutable resources for herbivores in arid and semi-arid ecosystems. The distribution of surface water determines the distribution and abundance of water dependent animal species yet little is known about the processes involved at the individual level. Thirteen African savanna elephant family groups and ten bulls (Loxodonta Africana) were tracked with GPS collars within and on the outskirts of Hwange National Park, Zimbabwe. Elephants behave as multiple central place foragers: They visit waterholes periodically every 5h, 24h, 48h or 72h and travel further from water during longer trips. During the dry season, temperatures increase and forage becomes depleted closer to water. Elephant family groups visit waterholes more often by increasing the proportion of briefer trips and abandoning 72h trips. However, they forage further during 24h trips by increasing travelling speed. Elephant movement patterns revealed locomotional and navigational abilities are at the core of their coping strategies although they are seldom allowed to vary in most foraging models of animal's use of heterogeneously distributed resources. During these foraging trips, family herds select for areas with low waterhole density at multiple scales. Selection strength for low density areas increases with both distance to water and the advancement of the dry season. Although scaling effects are widely recognized, the effects of the spatial distribution of multiple central places constraining foraging have been ignored yet they determine depletion effects and their feedbacks on habitat selection. I also showed that wildlife strongly avoid livestock and people that herd them at the boundary of a protected area during the rainy season yet avoidance decreases during the dry season when foraging and drinking resources become scares. Elephants are increasingly constrained by surface water availability during the dry season as their drinking requirements increase while they strive to main their forage intake. This study provides quantitative assessment of individual water dependence and of landscape effects of surface water distribution on a large herbivore. These findings can inform surface water management in contexts of aridification resulting from climate change.

The aim of this study was to define the ovarian follicular reserve of wild African elephants in terms of its type of small follicles (SF), its establishment and distribution throughout the ovaries, and the change in numbers of SF in the embryo and fetus as well as throughout prepubertal and adult life. The large elephant population in Zimbabwe provided the opportunity to collect ovaries from elephants culled for management reasons and hunted professionally. In total, gross morphological and histological studies were done on the gonadal ridges from 5 embryos (76–96 days post conception) and ovaries from 11 fetuses (4.8–22.2 months), 29 prepubertal females (2 months–10 years), 24 adult females (11–55 years) and 7 aged females (56–70 years). Specimens were fixed in 4% buffered formalin before a series of 25 ìm thick sections were cut and examined using stereological protocols to count SF numbers in each section and thereby calculate the follicle reserve of the whole ovary. Prior to counting SF numbers, their distribution throughout the ovary was studied and the repeatability of counts was validated. Numbers of SF were highest in mid-term fetuses, lower in fetuses during the second half of gestation, even lower in calves younger than 4½ years, whereas the numbers in calves aged 4½–9 years were significantly higher than those in younger calves, and similar to what they were in late-term fetuses. The numbers of SF were substantially and highly significantly lower in elephant 10–15 years in age compared to calves aged 4½9 years, suggesting a reduction around puberty. Thereafter the ovarian reserve fell steadily until depletion around the age of 70 years. During adult life the ovarian reserve was composed of early-primary (EP) and true-primary (TP) follicles. By 45 years of age only TP follicles remained although these enabled oestrous cyclical activity for many more years; of 7 sets of ovaries recovered from females aged 57–70 years, 6 showed evidence of cyclical activity or pregnancy within the preceding 6 years. The study shows that EP and TP form the follicular reserve from before birth until 45 years, with TP forming the reserve thereafter, which depletes in some old elephants and persists to maximum life span in others. / Thesis (PhD)--University of Pretoria, 2012. / Production Animal Studies / unrestricted

The GnRH vaccine may offer an alternative to the current immunocontraceptive method in elephant cows which uses native porcine zona pellucida proteins derived from abattoir slaughtered pigs as the immunogen, greatly limiting its availability. The pZP vaccine is stored at -20 °C and must be mixed with an adjuvant before use. The GnRH vaccine Improvac® is commercially available, already contains the adjuvant and can be stored at 4 °C. The aim of this study was to evaluate the efficacy of the gonadotrophin releasing hormone (GnRH) vaccine Improvac® (Pfizer Animal Health, Sandton, South Africa) in the induction of anoestrus in elephant cows. The Improvac® was administered to eight adult, female, healthy, free-ranging elephants, located in Entabeni Private Game Reserve in the Limpopo Province, South Africa. Another four cows were left untreated and served as controls. The monitoring of the experimental population was conducted over a twelve-month observation period via non-invasive faecal steroid analysis. Progesterone metabolites in extracted samples were measured by Enzyme Immunoassay (EIA) to determine luteal activity and thus the effect of the GnRH vaccine on the endocrine correlates. This study started with a three-month control period prior to vaccination when faeces were collected from each study animal, as soon as possible after defecation to ensure positive identification of the individual with its sample. The three-month period was followed by the immunization protocol. The elephants all received a primary, followed by a booster vaccination dose five weeks later. Each dose of 3 ml contained 600 ìg of RnRF-protein conjugate; both treatments were applied via remote delivery. Monitoring continued until the end of the twelve-month observation period. Observations of oestrous behaviour during the twelve-month period were also recorded. The results showed no statistical difference between treated and control females. There was, however, marked individual variation in response to GnRH immunization. This was possibly influenced by physiological and environmental factors such as age, where the youngest cows showed a better response in terms of reduced progestagen secretion; as well as season, where progestagen levels increased 1.3 times during the rainy season compared to the dry season. There was no association between average progestagen concentration and social hierarchy ranking. A high percentage (86.48%) of behaviours that could be related to oestrus coincided with the onset of the luteal phase and a subsequent rise in progestagen concentrations. All the females (treated and control) showed some evidence of ovarian cyclicity during the study, although 75% of the cycles did not fall within the normal 13-17 week oestrous cycle range reported, suggesting that abnormal cycles are a common reproduction irregularity inherent to non-pregnant wild African elephants. Further research to determine the optimal vaccination protocol is indicated in order to obtain consistent responses to the vaccine that will provide an efficient and safe contraceptive for use in female African elephants. Copyright / Dissertation (MSc)--University of Pretoria, 2011. / Production Animal Studies / unrestricted

Objective To determine the cardiopulmonary and blood gas status of elephants during chemical capture (immobilisation) with a thiafentanil-azaperone drug combination kept in lateral recumbency. Study design Prospective descriptive study. Animal population Ten free-ranging adult African elephant bulls (estimated weight range 3000 to 6000 kg). Methods Elephants were immobilised using a thiafentanil (15-18 mg) and azaperone (75-90 mg) by darting from a helicopter. Once recumbent, the tidal volume, minute volume, end-tidal carbon dioxide, arterial blood pressure and pulse rate were recorded immediately after instrumentation and at five-minute intervals until T20. Arterial and venous blood gases were analysed at the time of initial instrumentation and at 20 minutes. On completion of the data collection, the thiafentanil was antagonised using naltrexone (10 mg mg-1 thiafentanil). A stopwatch was used to record time to recumbency (dart placement to recumbency) and time to recovery (administering antagonist to standing). Data was checked for normality and was found to be parametric. Data were compared using a one-way analysis of variance and reported as mean (± SD). Results All elephants were successfully immobilised and all physiological variables remained constant with minimal non-significant variation over time. Average time to recumbency was 12.5 minutes. The estimated expiratory tidal volume was 21 (± 6) L breath-1 or 4.8 ± 0.8 mL kg-1, and the measured minute volume was 103 (± 31) L minute-1. The heart and respiratory rates were 49 (±6) beats and 5 (± 1) breaths minute-1, respectively. The mean arterial blood pressure was 153 (± 31) mmHg. The elephants were acidaemic (pH 7.18 ±0.06; bicarbonate ion 20 ±4 mmol L-1; lactate 11 ± 4 mmol L-1), mildly hypoxemic (PaO2 68 ± 15 mmHg) and mildly hypercapnic (PaCO2 52 ± 7 mmHg). Average time to recovery was 2.2 minutes. Conclusion and clinical relevance African elephant bulls can be successfully immobilised using thiafentanil-azaperone. Recumbency was rapid, the cardiopulmonary variables were stable and within acceptable ranges, and recovery was rapid and complete. Mild hypoxaemia and hypercapnia were evident, but does not necessarily require oxygen supplementation. / Dissertation (MSc)--University of Pretoria, 2020. / Companion Animal Clinical Studies / MSc / Unrestricted