Thesis (M.N.A.S.)--Missouri State University, 2008. / "May 2008." Includes bibliographical references (leaves 43-47). Also available online.

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

Thesis (M.S.)--Georgia Southern University, 2006. / "A dissertation submitted to the Graduate Faculty of Georgia Southern University in partial fulfillment of the requirements for the degree Master of Science" ETD. Includes bibliographical references (p. 74-79) and appendices.

Thesis (M.F.A.)--Georgia Southern University, 2006. / "A thesis submitted to the Graduate Faculty of Georgia Southern University in partial fulfillment of the requirements for the degree Master of Science" ETD. Includes bibliographical references (p. 54-58) and appendices.

Thesis (Ph.D.) (Zoology))-University of Pretoria, 2006. / Abstract in English. Includes bibliographical references. Available on the Internet via the World Wide Web.

Please read the abstract in the section 00front of this document / Dissertation (MSc (Zoology))--University of Pretoria, 2007. / Zoology and Entomology / MSc / unrestricted

The Asian elephant (Elephas maximus), a charismatic ‘flagship species’, is threatened by extinction in the wild, and the development of self-sustainable captive populations is a key conservation challenge. A third of the Asian elephant population is presently in captivity and information on the reproductive status, especially in females, is still lacking to a large extent. The onset of estrus in female Asian elephants is not associated with any visible physical signs, thus making the assessment of the reproductive status rather difficult. One approach to understanding reproductive cyclicity of animals is through generating profiles of reproductive hormones in blood (Wiseman et al. 1983; Brown et al. 1999, 2004). Profiles of reproductive hormones such as progesterone (P4), estrogen, luteinizing hormone and follicle stimulating hormone have already being demonstrated in Asian elephants (Brown et al. 1999, 2004; Brown 2000). In these studies, the reproductive status of females, maintained in zoos/captivity, was characterized based on circulating levels of hormones in blood samples. This is difficult to implement in the case of semi-captive or wild populations of elephants due to practical, legal and ethical considerations. In order to overcome this problem and to better understand the estrous status of female elephants, it is important to develop and validate non-invasive methods to monitor the reproductive status of female Asian elephants. An alternative approach to evaluating the reproductive status of females is to consider behavioral responses shown by males towards chemical signals produced by females to advertise their reproductive status. In order to understand the reproductive status of the individual belonging to the opposite sex, studies have shown that elephants rely on a variety of chemical signals produced in biological fluids such as urine, temporal gland secretion, inter-digital gland secretion, etc. (Krishnan 1972; Rasmussen & Schulte 1998). Chemical signaling is one of the prominent modes of communication in elephants, especially with respect to locating potential mates (Sukumar 2003). Thus, in most cases, elephants usually employ specific behavioral responses, for example sniff, check and place behaviors of trunk, for investigating the reproductive status of the conspecific individual, belonging either to the same or the opposite sex (Rasmussen et al. 1996; Schulte & Rasmussen 1999; Bagley et al. 2006). The objectives of the thesis are two-fold. First, to develop a non-invasive method of reproductive monitoring from fecal hormonal metabolites and also to understand the possible role of feces as an inter-sexual signal. The main body of thesis is divided into four chapters. 1) Development and validation of a non-invasive method to estimate progesterone metabolite in feces, to monitor the reproductive cyclicity of female elephants (Chapter 2). 2)Generation and characterization of progesterone and its metabolite, 5α-P-3-OH, profiles of semi-captive females using the developed non-invasive method to measure fecal metabolites (Chapter 3). 3) Validation of developed methodology and assay systems to a wild-population of female elephants (Chapter 4). 4) Feces as a potential source for inter-sexual chemical signaling in Asian elephants (Chapter 5). The above studies were carried out on semi-captive male and female elephants maintained in the forest camps of Mudumalai Wildlife Sanctuary (MWLS), Tamil Nadu and Bandipur National Park (BNP), Karnataka, India (Chapters 2, 3 and 5). For Chapter-4, free-ranging females of the MWLS were examined. 1. Development and validation of a non-invasive method to estimate progesterone metabolite in feces, to monitor the reproductive cyclicity of female elephants Niemuller et al. (1993) generated a profile of the progesterone metabolite, 5βpregnanetriol, to assess the estrous phase of Asian elephants based on non-invasive urine sampling. However, the collection of urine is difficult and to some extent impossible in the case of semi-captive and as well as that of wild elephants. Thus, the method of choice in this study was the development and validation of a non-invasive approach to measure fecal progesterone metabolites to assess reproductive status of females. Sampling was carried out at monthly intervals on three female elephants at the MWLS forest camp, while three other females maintained at the BNP forest camp were sampled fortnightly. An enzyme linked immuno-sorbent assay was developed to measure the concentration of the progesterone metabolite, 5α-P-3OH in the fecal samples of the semi-captive females. Using varying concentrations of the hapten (5α-P3OH), from low (0.1 mM) to high (1 mM), a standard curve was first generated, which had a linear range between 0.25 mM to 62.5 mM, with an EC50 of 1.37 mM. The linear range was then used to detect the concentrations of 5α-P-3OH in the fecal samples of females examined. The non-invasive method was further validated as there existed a positive correlation (p<0.1) between the levels of fecal 5α-P-3OH and that of concentration of circulating P4, measured in blood samples. This is the first valid documentation of a non-invasive method based on fecal progesterone metabolite pattern in order to assess the reproductive status of the female Asian elephants. 2. Generation and characterization of reproductive hormone profiles of semi-captive females using the developed non-invasive method to measure fecal metabolites With the establishment of a non-invasive method to understand occurrence of estrus in female elephants (described in Chapter 2), attempts were made to generate hormonal profiles over a longer time interval through more frequent sampling. Based on sampling at weekly intervals, the concentrations of both fecal 5α-P-3OH and that of native P4 hormone in the blood were determined, and the females were then identified as belonging to different reproductive states of hormonal cycling (follicular and luteal phases), non-cycling and pregnant categories. Of the 7 females sampled at both MWLS and BNP, three distinct categories of hormone-metabolite profiles emerged. The first category included four females that showed regular cyclicity throughout the sampling period, as monitored through the measurement of fecal 5α-P-3OH and serum P4 levels. The estrous cycle of all the four females was divided into two phases (follicular and luteal), based on the patterns of fecal 5α-P-3OH and serum P4 concentrations. The follicular phase of the estrous cycle was assigned when the values of both fecal 5α-P-3OH and serum P4 remained below 0.3 µg/gm and 0.3 ng/ml, respectively, for a considerable time period (viz. >2 wk). However, the luteal phase was characterized, when the levels of fecal 5α-P-3OH and serum P4 remained at or above 0.3 µg/gm and 0.3 ng/ml respectively, over a period of more than 2 - 3 wk. The second category had two females showing a ‘flat-lining pattern’ for the levels of fecal 5α-P-3OH and serum P4 concentrations, without any peak or dip in their concentrations. Since the reproductive pattern for both these females was flat-lined throughout their sampling period (51 wk), maintaining the levels of fecal 5α-P-3OH and serum P4 below 0.3 µg/gm and 0.3 ng/ml respectively, the females were considered to be non-cycling or anestrus. The third category had one female in which the levels of both fecal 5α-P-3OH and serum P4 measured were consistently high throughout the entire sampling period (26 wk). The levels of both fecal -P-3OH and serum P4 were above 0.3 µg/gm and 0.3 ng/ml, respectively. At the end of the sampling period, this female delivered a male calf; thus, the measured concentrations of fecal 5α-P-3OH and serum P4 signified the levels maintained during the gestational phase of this female. Sampling and hormonal analyses were also carried out for a male in the MWLS forest camps to investigate the baseline concentrations of fecal 5α-P-3OH and serum P4. The male showed consistently low concentrations of both fecal 5α-P-3OH and serum P4 throughout the sampling period (16 wk), below the margin of 0.3 µg/gm and 0.3 ng/ml, respectively. In this part of the study, it was confirmed that the reproductive status of a female elephant can be correctly assessed on the basis of measurements of fecal 5α-P-3OH alone, with repeated sampling of the female over a longer time scale. It was also shown that the strength of the positive correlation between the concentrations of the fecal 5α-P3OH and the serum P4 increased (p<0.01) for a larger sample size than that obtained for a comparatively smaller sample (described in Chapter 2). 3. Validation of developed methodology and assay systems to wild-population of female elephants So far, the non-invasive method to estimate fecal progesterone metabolite in order to predict occurrence of estrus of elephants was largely applied to semi-captive females (described in Chapters 2, 3). However, the necessity of such a method is being recognized for assessing the reproductive status of free-ranging females. Several findings have described differences in the rate and type of steroid metabolite excretion among individuals maintained under different diet regimes (Wasser et al. 1993; Smith et al. 2006). For instance, female elephants in the forest camps are provided with supplementary diet consisting of sugarcane, rice and millets. This diet is strikingly different from the feeding materials consumed by wild/free-ranging elephants (Sukumar 2003). Therefore, differences in dietary components can potentially influence the fecal steroid metabolites’ excretory patterns shown by semi-captive vis-a-vis wild females, which can affect the validity of measuring fecal 5α-P-3OH to predict females’ reproductive status. In order to examine this problem, the non-invasive method was applied to the population of wild elephants in the forests of MWLS, through random one time sampling of 30 individual female elephants. The steroid extraction efficiency (73 ± 11.0%, mean ± S.D., n =30) determined for the fecal samples collected from the wild females was not significantly different from the coefficient calculated in the case of the semi-captive females (80 ± 4.3%, mean ± S.D., n = 38). This indicated that dietary differences between wild and captive elephants did not influence levels of fecal hormonal metabolites in feces, unlike earlier observations on baboons (Wasser et al. 1993), old world primates (Wasser et al. 1988) and sheep (Smith et al. 2006). The values of the fecal allopregnanolone determined in the case of the wild females, ranged from as low as 0.06 µg/gm to as high as 23µg/gm of the sample, thus showing the heterogeneity of the samples, indicating that the females may be belonging to different reproductive phases. However, since sampling was carried out randomly, with an adult female being sampled just once, at this stage, it is not possible to identify or elaborate on the reproductive phase of the females. This is the first study reporting the values of the fecal progesterone metabolite in female Asian elephants in the wild. Further studies may be required to carry out long term monitoring of the wild females, through repeated collection of fecal samples over time from particular female. 4. Feces as a potential source for inter-sexual chemical signaling in Asian elephants In this Chapter-5, behavioral trials were conducted on male elephants to understand the role of fecal matter in conveying inter-sexual chemical signals. This was demonstrated by analyses of specific chemosensory behavioral responses shown by males towards the fecal samples of females that were strangers and belonging to different reproductive stages. Males showed four prominent behavioral responses namely ‘distant sniff’, ‘close sniff’, ‘check’ and ‘place’ towards the fecal samples of females. The sum of frequencies of these four responses (distant sniff, close sniff, check and place) was much higher for samples of the follicular (pre-ovulatory) phase females as compared to those of the luteal (post-ovulatory) phase females (p<0.005). Thus, for the first time, it was shown that male elephants are able to discriminate the different reproductive phases of females based on their specific behavioral response towards the fecal samples of the opposite sex. In conclusion, the thesis has focused on understanding and providing new insights regarding the reproductive biology of the female Asian elephants. This has been achieved through the development of the non-invasive method based on measuring the concentrations of the fecal progesterone metabolite and through the analyses of the chemosensory responses performed by the males towards the fecal samples of strange females. These methods can potentially be applied to the populations of both wild and captive/semi-captive female elephants in order to evaluate their reproductive status, through non-invasive measures. The information derived from the application of such methods will help in understanding the reproductive potential of the wild elephants under various environmental and ecological conditions. Further, the non-invasive measurement of reproductive hormones will help in monitoring the reproductive state of the individuals and thus aid in planning strategies for the welfare and management of the elephants maintained in captive or semi-captive conditions.

Thesis (MScConEcol)--Stellenbosch University, 2013. / ENGLISH ABSTRACT: The confinement of many elephant (Loxodonta africana) populations in southern Africa to fenced reserves has made the management of such reserves difficult as elephants are a keystone species. Elephants are also water-dependent; therefore the availability of water affects the location, extent and intensity of elephant impacts on vegetation. Majete Wildlife Reserve (Malawi) has undergone reform, during which it was fenced, artificial waterholes (AWPs) were created and wildlife reintroduced, including 220 elephants. Concerns have arisen as to the impact elephants may be having on the vegetation. In this thesis, two studies were conducted, along with a review of literature on elephant interactions with surface water. Woody vegetation changes in Majete were assessed by comparing woody vegetation cover datasets (based on remote-sensed vegetation classifications) of the reserve for 1985, 1990, 2000 and 2010. Woody cover loss was high between 2000 and 2010, therefore points of woody cover loss were further analysed in a spatial analysis. Using spatial and non-spatial environmental data, the effects of rainfall, fires, terrain (altitude, aspect, slope, hill and valley characteristics) and proximity to perennial water on woody vegetation cover were tested. Data analyses indicated that woody cover loss may have been caused by differing combinations of drought and herbivory or fire in different areas of the reserve. Where woody cover loss was attributed to herbivory, points of loss were not associated with proximity to perennial water. It was suggested that this is due to high perennial water availability in Majete, which would not limit herbivore foraging ranges in the dry season. Woody cover loss could not, however, be attributed to elephants in this study and further information on their use of and impacts around perennial water points was required. In a further study, the hypothesis tested was that different water point types (rivers, AWPs and springs) would be used at different intensities by elephants, and that perennial rivers would experience the most use. Elephant usage (including visits to water points, browsing levels and path use around water points) of selected perennial water points in Majete was monitored in the wet and dry season. The effects of season, water point characteristics (type, size and water quality) and habitat context (surrounding vegetation type, elevation and proximity to other water points) on elephant water point use were then tested. Elephant water point use was affected by season, as well as water point altitude and surrounding vegetation type. In areas of high perennial water availability, elephant browsing around water points did not decrease with increasing distance. It was suggested that this too could be because elephant browsing activity is not limited by water availability in Majete. Based on the findings of both studies, recommendations for water, elephant and fire management in Majete were proposed and discussed. / AFRIKAANSE OPSOMMING: Die beperking van baie olifantpopulasies tot omheinde reservate in Suider-Afrika bemoeilik die bestuur van hierdie parke omdat olifante (Loxodonta africana) as 'n hoeksteenspesie beskou word. Olifante is ook water-afhanklik en daarom word die plek, omvang en intensiteit van olifante se impak op plantegroei deur die beskikbaarheid van water beïnvloed. Die Majete Wildlife Reserve (Malawi) het hervorming ondergaan waartydens dit omhein is, kunsmatige waterpunte (AWP‟s) geskep is en wilde diere, insluitend 220 olifante, hervestig is. Kommer het ontstaan rondom die moontlike impak wat olifante op die plantegroei mag hê. In hierdie tesis word twee studies sowel as ʼn literatuurstudie aangaande olifantinteraksies met oppervlakwater uitgevoer. Houtagtige plantegroei veranderinge in Majete is geassesseer deur data van plantegroei-bedekking (op afstandswaarnemings van plantegroeiklassifikasies gebaseer) vanuit 1985, 1990, 2000 en 2010 met mekaar te vergelyk. Die verlies van houtagtige-bedekking tussen 2000 en 2010 was hoog en gevolglik is hierdie areas verder deur ʼn ruimtelike analise ontleed. Deur die gebruik van ruimtelike en nie-ruimtelike omgewingsdata, kon die effek van reënval, brande, terrein (hoogte, aspek, helling, heuwel- en vallei-eienskappe) en nabyheid aan standhoudende water op houtagtige plantegroei getoets word. Data-analise het aangedui dat verlies van houtagtige-bedekking deur verskillende kombinasies van droogte, herbivooraktiwiteit of brande in die verskillende dele van die reservaat veroorsaak word. Waar verlies van houtagtige-bedekking toegeskryf kon word aan herbivore, was die punte van verlies nie geassosieer met nabyheid aan standhoudende water nie. Daar is voorgestel dat hierdie waarneming verband hou met die hoë beskikbaarheid van water in Majete, wat gevolglik nie herbivoorbeweiding in die droë seisoen beperk nie. Hierdie studie kon dus nie die verlies van houtagtige-bedekking aan olifantteenwoordigheid toeskryf nie en verdere inligting rondom die verbruik en impak van olifante op standhoudende waterpunte word benodig. In 'n verdere studie is die hipotese dat verskillende tipes waterpunte (riviere, AWP‟s en fonteine) teen verskillende intensiteitsvlakke deur olifante benut word, en dat standhoudende riviere die meeste verbruik sou ervaar, getoets. Verbruik van geselekteerde standhoudende waterpunte deur olifante (insluitend besoeke aan waterpunte, beweiding en paadjiegebruik rondom waterpunte) in Majete is gedurende die nat- sowel as droë seisoene gemonitor. Die effek van seisoen, waterpunt-eienskappe (tipe, grootte en watergehalte) en habitatkonteks (omliggende plantegroei, hoogte bo seespieël en nabyheid aan ander waterpunte) is op die waterpuntverbruik van olifante getoets. Die waterpuntverbruik van olifante word deur seisoen, hoogte bo seespieël en omliggende plantegroei beïnvloed. In gebiede met hoë beskikbaarheid van standhoudende waterpunte, het olifantbeweiding rondom waterpunte nie met toenemende afstande afgeneem nie. Daar is voorgestel dat hierdie waarneming ook toegeskryf kan word aan die feit dat olifantbeweiding nie deur die beskikbaarheid van water in Majete beperk word nie. Gebaseer op die bevindinge van beide studies, word daar aanbevelings vir water-, olifant- en brandbestuur in Majete voorgestel en bespreek.

A thesis submitted to the Faculty of Science, University of the Witwatersrand, Johannesburg, in fulfilment of the requirements for the degree of Doctor of Philosophy. Johannesburg, 2015. / Decades of study devoted to solving the “elephant problem” have generally concurred that increasing elephant populations inevitably reduce biodiversity. However, recent evidence suggests that such reductions can be accompanied by increases in other components of biodiversity, and that ultimately elephant effects are scale-dependent. Although this new perspective now underpins elephant management strategies in savannas such as the Kruger National Park (KNP), South Africa, few empirical studies in support of this strategy have incorporated the contribution of spatial context, or allowed for the emergence of relevant scales, in their interpretations of heterogeneity. Moreover, use of traditional modes of scientific enquiry and statistical approaches for investigating heterogeneity in complex systems have been challenged. Recent advances in spatial statistics, together with an alternative mode of science that draws upon multiple lines of converging evidence rather than testing narrowlyfocused hypotheses, have the potential to address these challenges. However, their practical application for understanding elephants as agents of change remains lacking. Riparian zones along the ephemeral rivers in northern KNP provided an ideal landscape to explore the spatial and temporal parameters of elephant effects in response to surface water, as a critical resource, and hence to develop a framework for a heterogeneity approach for understanding and managing elephants as agents of change in savannas.

The wetlands of the semi-arid savanna ecosystem of Amboseli are the critical dry-season range for a diverse wildlife population, as well as for livestock and humans. Changes in the migratory patterns and increases in the population of the elephants in the ecosystem, as well as a shift in the lifestyle of the growing human population from predominantly nomadic pastoralist society to a sedentary agrarian community, has had far-reaching effects on the ecosystem and the wetlands. In this thesis, the current status of the wetlands and the changes in vegetation over the last four decades were examined using satellite imagery and long-term census data. Studies were also conducted to determine the impact of grazing by elephants and other large mammals on wetland vegetation, and the flooding patterns and extents of some of the wetlands were examined. <br /><br /> Long-term aerial count data indicated that the wetlands that are currently protected by the Amboseli National Park have been under increasing use year-round by elephants since 1975. These wetlands showed a rapid increase in extent between 1950 and 1976. This corresponds to the elephant-driven decline in <I>Acacia xanthophloea</I> woodlands, which may have changed the hydrology of the area. Since then, only one of the wetlands, Longinye, has shown dynamic changes in extent. This is either the effect of the blockage of water flow by vegetation or the creation of new channels by elephants and hippopotami. The wetlands had a diverse range of wetland habitat from areas of open water with scattered tall <I>Cyperus papyrus</I> communities in the centre of one wetland to large expanses of seasonally inundated <I>C. laevigatus</I> and <I>Cynodon dactylon</I> dominated habitats fringing the wetlands. Most of the wetland habitats were composed of short sedges and grasses, which was shown to be the direct result of elephant grazing. Elephants tended to keep the vegetation of a control wetland short and of low biomass during both wet and dry seasons, whereas the vegetation in a treatment wetland, where elephants were excluded, showed a rapid increase in biomass and height. Other herbivores were shown to maintain conditions of short vegetation of low biomass through grazing pressure in the dry season. The impact of natural and simulated grazing on growth of the vegetation was studied and only under simulated grazing pressure was growth increased in the seasonally inundated <I>C. dactylon</I> grasslands, as well as the floating mat communities dominated by <I>C. laevigatus</I> that occur in the shallow water wetlands. This indicates that natural grazing may be detrimental either to the plants or the soil. <br /><br /> The wetlands that are under human use had predominantly shallow water and seasonal wetland habitat. Deep water habitat with <I>C. papyrus</I> communities was only present in one of these wetlands, Kimana, which is also the only wetland outside the park that is used by livestock and wildlife, as well as to irrigate a large area of land around the wetland. Two other wetlands, Namelok and Lenkir that were predominantly used for irrigated agriculture, were largely composed of seasonally inundated wetland habitat. A fourth wetland, Esoitpus, has been almost completely drained and this has most likely resulted in the development of <I>A. xanthophloea</I> and <I>C. dactylon</I> dominated riverine and <I>C. laevigatus</I> / <I>C. dactylon</I> dominated seasonally inundated wetland communities. <br /><br /> Overall, the wetlands in the park provide a measure of habitat diversity that may be useful for various invertebrate and vertebrate communities. However, the present lack of tall sedges may negatively impact the bird community. This state can be reversed by the exclusion of elephants from some wetlands for short periods of time. On the other hand, the wetlands outside the park appear to be facing rapid draw-down. Hence, there is an urgent need for sound water management practices for these wetlands.