Thesis (M.S.)--University of Pretoria, 2007. / Title from PDF title page (viewed on Nov. 12, 2008). Includes bibliographical references.

Thesis (MSc (Veterinary Science))--University of Pretoria, 2005. / Includes bibliographical references.

Thesis (M.S.)--Georgia Southern University, 2004. / "A thesis submitted to the Graduate Faculty of Georgia Southern University in partial fulfillment of the requirements for the degree Master of Science." Vita. Includes bibliographical references (p. 48).

A Research Report submitted to the Faculty of Science, University of the Witwatersrand, Johannesburg in partial fulfilment of the requirements for the degree of Master of Science. Johannesburg, February 2013. / The degree that different landscape features influence elephants use of space in the Kruger National Park and surrounding private game reserves (Balule, Timbavati, Klaserie and Umbabat) is not known. The aim of my study was to assess landscape features which influence elephant space use at two different spatial scales: at a large scale representing home range selection within the landscape and a small scale representing core area selection within the total home range. I investigated the space use of 15 male and 6 female adult elephants over a three year period (June2007-May 2010), using GPS data and satellite mapping analysis. The features selected for analysis as possible barriers to elephant space use were anthropogenic (fences, roads, railway lines and infrastructure) and natural features (rivers, geological features and vegetation). I also investigated the total and core home range size of elephants and whether elephant space use differed by sex and season. Males had larger total home ranges than females irrespective of season, but there were no size or seasonal differences of core home range size between the sexes. Elephants used features differently at the two spatial scales, differed in the use of features between seasons, and there was a difference between the sexes in the use of features. Fences, railways, rivers (in the wet season), geological features and vegetation types were the features that influenced elephant space use, and could be possible barriers at the large scale. Elephants occurred close to fences which possibly restricted their space use. Elephants also occurred close to railway lines but they might not have crossed the railway line. As expected elephants occurred less often at close distances to rivers in the wet season which could possibly be as a result of higher rainfall in this season, preventing elephants from crossing their usual riverbed corridors. Male and female elephants differed in the use of vegetation types found on particular geological features: males selected basalt and females selected granite areas for both the dry and wet seasons. Both male and female elephants were associated with a wider variety of vegetation types in the dry season, possibly because the limited food availability causes elephants to cover larger areas in search of food. Elephant space use was therefore governed by several features that may or may not restrict space use. My study, using satellite mapping analysis, can suggest what hinders movements of elephants and what is essential for assisting elephant space use, which could help conservation efforts for reserve design and corridor formation between reserves.

A thesis submitted in fulfillment of the requirements for the degree of Doctor of Philosophy / African elephants are one of the iconic mammalian species of the continent, and are the largest terrestrial mammals on the planet. While being a well-known species, with intensive behavioural studies having been undertaken, studies of the elephant brain are limited. Given that elephants do show a unique and interesting set of behaviours, including infrasonic communication, unique control of the trunk, and that they eat around 500 kg of low quality plant matter each day, the current study aimed to investigate the neural underpinnings of these and many other behaviours exhibited by elephants. While not all aspects of elephant neuroanatomy are covered in the current set of studies, the results have provided a great deal of data for regions of the brain that have not been examined for almost 50 years, and applied modern neuroanatomical methods to this task. This thesis outlines how to obtain elephant brains amenable to modern neuroanatomical study, demonstrates that the ventricles are of a size predictable for a mammal with a 5 kg brain, and that the cerebellum is relatively the largest mammalian cerebellum studied to date. A microscopic examination of the cerebellar cortex revealed that the elephants have a greater amount of a potentially more complexly organized cerebellar cortex. In addition, an architectonic study of the diencephalon and brainstem revealed that elephants, while having a mostly standard mammalian diencephalon and brainstem, do show unique features that correlate to control of specialized behaviours. In summary, the current study shows that the system for motor timing, infrasound production and reception, and the systems for satiety and wakefulness are specialized in the elephant, all of which correlate to the overt behaviours previously studied. In addition, the current studies indicate potential paths to follow for the study of behaviour in these species that will hopefully lead to a better understanding of these animals. There is still much to explore and learn about the elephant brain and it is hoped this thesis creates a platform that provides the impetus for many future studies

Prolactin (PRL) is a peptide hormone that is involved in a number of diverse physiologic roles, particularly with respect to reproduction, including: influencing sexual and parental behaviors, onset of puberty, regulation of seasonal reproduction, follicular maturation, ovulation, luteinization and corpus luteum (CL) function, steroidogenesis, mammary gland development and lactation, testicular and spermatozoal function, and immunomodulation of ovarian processes. Little is known about PRL's role in elephant reproduction. The present research was conducted to determine seasonal changes in PRL secretion in non-pregnant female African elephants. A corollary objective was to examine the potential functional interrelationships between secretions of PRL, cortisol and progesterone. Weekly blood samples for 18 months were taken from four female African elephants and the sera were analyzed by radioimmunoassay for progesterone, cortisol, and PRL concentrations. Estrous cycles averaged 14 weeks in length, and estrous cycle synchronicity was evident between pairs of elephants. The luteal phase was defined by serum concentrations of progesterone consistently above 200 pg/ml, and averaged 9 weeks in length (range: 5-12 weeks) with a mean (�� SE) concentration of 750.3 �� 171.9 pg/ml. The follicular phase was defined by serum concentrations of progesterone consistently below 200 pg/ml, and averaged 5 weeks in length (range: 4-8 weeks) with a mean concentration of 103.1 �� 17.5 pg/ml. Mean (�� SE) serum concentration of cortisol was 5.7 �� 1.3 ng/ml (range: 1.4-19.3 ng/ml), and concentrations of this adrenal steroid were negatively correlated with progesterone concentrations (r=-0.15; p<0.01). Serum concentrations of PRL averaged 3.91 �� 0.69 ng/ml (range: 0.84-15.8 ng/ml), were significantly lower during the luteal phase (p<0.0001; t-test), and were positively correlated with serum concentrations of cortisol (r=0.14; p<0.05). There was no significant effect of season on PRL concentrations. One of the elephants appeared to be hyperthyroid, but since removing her values from the data set did little to affect overall means, they were included in all of the calculations. These data suggest that stress may affect secretion of PRL in elephants, and cortisol and PRL may affect reproductive potential in elephants by altering luteal function. While this study did not demonstrate a seasonal effect on PRL secretion, it cannot be concluded that there is none because the reproductive effects of photoperiod are not always easy to detect. The higher serum concentrations of PRL detected during the follicular phase suggest that this hormone may play a role in modulating ovarian function in elephants during this stage of the estrous cycle. / Graduation date: 1998

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.

The elephant debate deals largely with population size, how elephant numbers change over time, how they may affect vegetation, and how their populations should be managed. Trends in elephant numbers frequently motivate management decisions, and past efforts to alleviate elephant impact aimed at controlling population size. However, methodological and statistical constraints may influence interpretation of trends and lead to incorrect management decisions. Furthermore, inferences about the response of elephant populations to specific management actions are seldom based on scientific evidence. In this thesis I assess the consequences of survey design and monitoring features on the interpretation and statistical reliability of population trends as well as the effect of population management on elephant densities and population growth rates. To do this, I collated information on elephant population estimates and past management actions across Africa. I used information from the northern Botswana elephant population to clarify temporal trends in elephant densities and numbers. Elephant numbers in northern Botswana increased from 1973 to 1993 while densities remained relatively stable. This difference in trends is due to an associated increase in survey area during the same time. In contrast, from 1996 to 2004 surveyed areas remained constant in size and neither elephant numbers, nor densities changed significantly during this time. This apparent stabilisation in numbers may have resulted from density-related elephant dispersal. This case study suggests that in open populations movements may complicate the interpretation of trends, and that differences in the rates of change in numbers and densities may have different management implications. The precision of population estimates, sample size, population size, and the magnitude of the annual rate of population change to be detected, affect power to identify trends. Two-thirds of the 156 time series that I assembled apparently were stable, and only 30 % of these had sufficient statistical power to detect population changes. These apparent stable trends without sufficient statistical power are inconclusive and should not be used to inform management decisions. Past elephant population management practices may have increased densities and growth rates in African elephant populations. Case studies of populations that were exposed to different management actions indicated that fencing of populations and water supplementation may have enhanced growth rates probably by influencing dispersal patterns. Thus, past management practices may have contributed to the ‘elephant problem’ by enhancing local elephant densities and population growth rates. In this thesis, I showed that trends based on elephant numbers may be misleading when the area over which elephants were counted, increased in size. Second, despite much effort and resources devoted to the monitoring of elephant populations for more than 50 years, population estimates and time series including such estimates had low quality, thereby reducing statistical power to detect trends in population change. Third, population growth rates were associated with management, where elephant population densities grew at faster rates when managed. Future conservation efforts should take into account the methodological and statistical constraints that may influence trend analyses of elephant populations and take cognizance of the fact that management decisions need to be evaluated against expected outcomes. Copyright / Dissertation (MSc)--University of Pretoria, 2009. / Zoology and Entomology / unrestricted

Enclosed game reserves are at risk of local vegetation over-utilization and homogenization by elephant. Understanding how the elephant spatial distribution is coupled to their seasonal resources use can aid future management given the threat of climate change. A comparison of home ranges and core area sizes across seasons and years was made between an elephant herd outside in an open system, compared to the elephant inside Limpopo Lipadi Game and Wilderness Reserve (LLGWR). Location data, obtained by GPS-GSM technology, was used to determine seasonal home ranges and core areas by local convex hull (LoCoH) methods and to generate seasonal General Estimating Equations (GEE). Remote sensing data was used to determine habitat variables. The home ranges of the elephant herd outside as expected, was twice as large during summers and a third larger during winters than the elephant herd inside the fenced reserve. The influence of seasonal rainfall on home range size was reflected at home range scale for the outside herd and for the core area scale for the herd inside the reserve. Increased rainfall overcomes the ‗magnet effect‘ of artificial waterholes on elephant distribution in the landscape only in the open system. Inside the reserve, contrary to expectation the winter home ranges were non-significantly larger than summer home ranges due to space limitation induced by fencing and permanent artificial waterhole density. Resource use was evaluated by using GEE models at a scale larger than established home ranges and therefore would reflect as home range determinants. The study confirms that elephant do not use resources randomly. A scale in resource selection of elephant cows exists, with distance to drainage lines at small scale preferred during winter, with aspect, slope, elevation, and NDVI at larger scales. Fencing furthermore, affects the scale at which selection occurs by limiting resource availability, especially during resource restrictive periods and limits range expansion during resource abundant periods. Elephant cows prefer gentle terrain, close to permanent water [<1.77km (SD inside the reserve, and <2.33km ( outside the reserve], moderately high NDVI, riparian vegetation during late winter and early summer if available. Generally, during lower rainfall periods lower elevations are preferred along the elevation gradient, and during higher rainfall periods, higher elevations. The elephant herd outside the reserve, furthermore prefer aspects in the landscape during hot summers that are cooling and cool winter aspects that are warming to facilitate energy saving and thermoregulation. Key words: Elephant home range, core areas, fencing, seasonal, artificial waterholes, open system, NDVI, elevation gradient, distance to water, seasonal GEE modelling.

Thesis (MSc(Zoology))--University of Pretoria, 2007. / Includes bibliographical references (leaves 85-95).