• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 2
  • 1
  • 1
  • Tagged with
  • 8
  • 8
  • 2
  • 2
  • 2
  • 2
  • 2
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Elephant impact on marula trees, and African honeybees as a mitigation method

Cook, Robin Michael January 2017 (has links)
A dissertation submitted to the Faculty of Science, University of the Witwatersrand, in fulfilment of the requirements for the degree of Master of Science, Johannesburg, South Africa 2017 / Concerns exist over the continual decline of marula trees (Sclerocarya birrea subsp. caffra) as a result of African elephant (Loxodonta africana) impact and a lack of recruitment and regeneration. One strategy of protecting adult marula trees is the usage of elephant mitigation methods. This study took place in Jejane Private Nature Reserve (JPNR), a protected area which recently opened up to the Greater Kruger National Park and had not had elephants in over 100 years. The aim of the study was to investigate the changes to the marula population structure in JPNR three years after the migration of elephants to the area due to fence removal, and to test whether African honeybees (Apis mellifera subsp. scutellata) could be used as a mitigation method for elephant impact on marula trees. A previous size-class survey had been done on a sample of JPNR’s marula population in 2009, prior to the fence removal in 2013. A resurvey of these trees was used to assess the elephant-induced impact and mortality levels on the marula trees and to compare these levels to previously recorded impact and mortality levels on marula trees in the Kruger National Park (KNP). Marula seed predation levels and seedling recruitment were also assessed to address recruitment concerns. The resurveyed marula population had declined by 23.8% post-elephant migration, with the highest annual mortality rates (AMR) and impact scores recorded for trees in the 5 - 11 m height classes. Impact scores on marula trees in JPNR were higher than impact scores recorded on KNP marula trees. Only two marula seedlings were found across all transects, with evidence of high seed predation on marula endocarps. JPNR displayed an adult-dominated marula population with a lack of regeneration, possibly due to a lack of fire which has increased available shelter for seed predators such as small mammals. African honeybees were then used to investigate their effectiveness as an elephant mitigation method and to compare this method against wire-netting (a method experimentally used to prevent ring-barking by elephants). Fifty active beehives were hung from 50 marula trees, with another 50 dummy (inactive) beehives hung from branches on the opposite ends of each beehive tree’s main stem. Fifty additional marula trees were wire-netted and a further 50 were used as control trees. Elephant impact on all 150 trees was measured prior to the addition of treatments and post-treatment addition for nine months. 54% of the control trees received some form of elephant impact, in comparison to 28% of the wire-netted trees and only 2% of the beehive trees. Wire-netting protected marula trees against bark-stripping, but did not prevent elephants from breaking branches. Beehives proved highly efficient at mitigating all forms of elephant impact. The financial cost and maintenance required for the beehive mitigation method is greater than that of wire- netting, but the beehives can provide honey and pollination services as an additional benefit. The results of this study illustrate that African honeybees can be used as an effective non-lethal mitigation method for elephant impact on marula trees and are a viable strategy to reduce human-elephant conflict in South Africa’s protected areas. / MT 2017
2

Determinants of protected area boundary crossings by savannah elephants, Loxodonta africana

Lee, Tamara Ann 14 February 2013 (has links)
When elephants leave primary protected areas (PPAs), such as national parks and game reserves, they may come into conflict with people residing on the adjoining land. In this study, I attempted to determine why African savannah elephants leave the PPAs in which they were collared. To accomplish this, I used telemetry locations of collared elephants in PPAs throughout southern Africa and investigated whether a range of intrinsic and extrinsic variables could explain why elephants crossed the boundaries of the PPAs. Adjoining many of the PPAs were secondary protected areas (SPAs), which consisted of community conservancies, and collectively with the PPAs formed clusters of protected areas. Most (45 of 49) elephants roamed beyond the PPAs but they remained within the clusters of protected areas. The elephants utilised both the PPAs and the SPAs and appeared to not feel threatened when using the SPAs. The reasons for elephants leaving PPAs varied both seasonally and between the sexes. The females roamed beyond the PPAs more during the wet season than the dry season, whereas, for males there was no seasonal difference. During the wet season, female and male habitat selection was similar within and beyond the PPAs. During the dry season, more females and males beyond the PPAs selected for areas close to people, which could be indicative of water. The proportion of male and female home ranges beyond PPAs did not increase with increasing density of elephant populations within the PPAs, nor did the proportion of female home ranges beyond PPAs increase with increasing population growth rate of elephant populations within the PPAs. Therefore, high numbers of elephants within the PPAs did not drive elephants beyond the boundaries. Contrastingly, the proportion of male home ranges beyond the PPAs did increase with increasing population growth rate. However, the results were inconclusive due to small sample size. This study confirms that elephants are utilising the SPAs as well as the PPAs. Therefore, the importance of including the SPAs in conservation actions for elephants cannot be over-emphasized. / Dissertation (MSc)--University of Pretoria, 2013. / Zoology and Entomology / unrestricted
3

Elephant versus other browsers' long-term influences on savanna woodland dynamics : synergistic influences of elephant and other large mammalian herbivores on the structure and composition of woody plant communities in Hluhluwe-iMfolozi Park, South Africa

O'Kane, Christopher Anthony John January 2012 (has links)
A crucial question in the debate about reintroducing elephant culling is whether the long-term effects of elephants and mesobrowsers on woodlands are similar. Sufficiently high biomass-densities of mesobrowsers may, following reduction or removal of elephants, continue to heavily impact earlier life-history stages of a similar suite of woody plants that elephant impacted, preventing these species from maturing. Thus a similar end-point for woodland structure and composition is achieved. No study exists in the literature where woody plant and habitat utilisation of the savanna browser guild has been determined in the same locality over the same period. A review of 49 years of literature implied that the two groups impact the same core woody-species in the same habitats. Dietary and habitat utilisation of guild members was determined in Hluhluwe-iMfolozi Park, South Africa. A small suite (n = 8) of woody species formed the core diet of all guild members. Herbivores’ densities were determined using a novel GIS approach; all members of the guild showed extensive overlap in habitat use. GPS collars and a GIS were then used to detect zones of different density of impala in the landscape, thus defining, for the first time, a natural fine-grain browsing gradient. Densities of woody seedlings were significantly less (average 48% reduction) in areas of high versus low impala density. A simple browse-browser model, incorporating, in a novel approach, functional groups of plant species, was parameterised from these results and an extensive review of the literature. Outputs suggest that over the long-term (100 years), impala will have a similar impact on woodland structure as elephant. An apparently strong synergistic effect between impala and elephant impact, suggests that reduction or removal of either impala or elephant will radically reduce long-term destruction of woodlands. In smaller or medium sized reserves, where control of mesobrowser populations is practical, profitable and more acceptable than elephant culling, these findings imply a re-direction of management efforts. Management should consider the biomass-density of both groups, rather than just focus on the system’s perceived ‘keystone’ species. Such principles may also apply to temperate and other systems.
4

Effect of Lion Calls on African Elephants (<i>Loxodonta Africana</i>) in Addo Elephant National Park, South Africa

Hook, Margaret Rose 01 August 2012 (has links)
Perceived predation risk alters animals’ behavior. This shift in behavior often comes at the cost of attaining resources. Generally, African elephants (Loxodonta africana) experience little predation pressure; however, the risk of predation by lions (Panthera leo) increases other prey species are less abundant. In elephant herds, related females and their offspring travel together in family groups, led by the eldest female. Response to predation pressure was examined by playing lion calls to the population of 437 elephants at the Main Camp Section of Addo Elephant National Park (AENP) in South Africa. Unfamiliar lion calls from a single male and two males, static, and running water were played from a remote speaker to elephants at waterholes. These trials were recorded by video. Behaviors of elephants were then extracted from video into focal observations of thirty second segments before, during and after a sound was played. I analyzed these data using parametric t-tests and non-parametric randomization tests. When no sound was played, elephants did not alter their behavior. Water elicited low levels of distress behaviors. Elephants behaved in a threatened or annoyed manner toward static. Elephants changed their behavior more in response to lion calls than to the controls, namely by decreasing drinking and increasing walking and distress behaviors. I also examined how individuals differed in their responses to the lion calls based on a number of demographic factors. Adult and subadult females performed more social behaviors after lion calls when the matriarch was absent than when she was present. Furthermore, when group size was larger and more calves were present, females decreased drinking and increased time exhibiting distress behaviors. Based on this and other studies it can be concluded that elephants of different demographics perceived similar levels of elevated risk when hearing lion calls. Landscape of fear models are useful for assessing habitat use by prey species in response to real and perceived predation risk. The present study corroborates findings from a study in East Africa that elephants perceive threat from lions based on calls alone and appear to distinguish levels of threat by the number of lions calling.
5

Stress Physiology of Free-ranging Asian Elephants (Elephas maximus) : Influence of Ecological and Anthropogenic Stressors

POkharel, Sanjeeta Sharma January 2017 (has links) (PDF)
Various ecological and human-induced disturbances play an important role in defining the health of an animal. To cope up with such threats or challenges to its homeostasis, an animal responds by secreting stress hormones (glucocorticoids) to mobilize the energy. In general, glucocorticoids help animals to cope up with the ‘stressors’. Prolonged exposure to any ‘stressors’ may lead to an elevation in the levels of glucocorticoids, thereby leading to reproductive inhibition, immune system suppression, neuronal death and impaired cognitive function and hence, threatening the survival and fitness of an animal. However, the long-term effects of environmental or anthropogenic disturbances on the fitness and survival are difficult to analyze in a slow reproducing, long-lived species such as elephants. Spread over 3% of India’s geographical area, India shelters around 28,000 to 30,000 Asian elephants (Elephas maximus; Bist, 2002; Santiapillai and Sukumar, 2006). Protected areas in India are estimated to form 22% of elephant habitat; while the rest of the elephant habitats extend outside the protected areas (Lenin and Sukumar, 2011) making them vulnerable to human-induced threats. Consequently, there are increased incidences of human-elephant conflicts leading to crop and property depredation and human-elephant mortality. Most of the studies, in context of such conflicts, highlight the temporal, spatial scales of conflicts majorly focusing on mitigation measures. None of the studies so far have elucidated how escalating human-elephant conflicts would influence the physiological health of Asian elephants. This study, hence, focused on addressing the proximate causation of the stress-response in free-ranging Asian elephants of the Bandipur National Park, the Nagarahole National Park and Hassan district of Karnataka, using a non-invasive technique for measuring faecal glucocorticoid metabolites (fGCM). There are several factors which could act as possible stressors to the physiological state of an elephant, but depending upon the feasibility and time limitations of conducting the study, we selected those factors which we thought are essential to address the proximate causation of stress-response in Asian elephants. Being the first detailed study to explore the stress-response in free-ranging Asian elephants, this study attempted to understand the influence of some of the fundamental ecological (seasonality, group size, and body condition) and human-induced stressors. The main body of the dissertation is divided into six chapters. The first and the last chapters discuss the general introduction and conclusion while the rest four chapters highlight the main four objectives of the study. The main objectives of the thesis were: 1. The first objective of this thesis was to validate and standardize some of the crucial parts of protocols to avoid any technique-based bias while interpreting the levels of faecal glucocorticoid metabolites. Under the first objective, the influences of some of the fundamental intrinsic and extrinsic factors on the fGCM levels were also assessed. 2. The second objective was to assess the association between body condition, seasonality and stress response. 3. Having assessed the relationship between body condition and stress-status, the third objective focused on the influence of socio-ecological correlates such as group size, lactational status and the presence of adult females in a herd on the stress status of female adult elephants. 4. With above three objectives majorly highlighting the influence of ecological factors, the fourth objective was to assess the influence of anthropogenic factors on stress-response of free-ranging elephants under which we compared the stress-response between crop-raiding in human-dominated and nonraiding elephants in forested habitats. The study was conducted during dry season (February to May) and wet season (August to December) of 2013 and 2015. The dissertation is organized in the following way: Chapter 1: General Introduction The first chapter provides a general introduction about stress response and its physiological pathway. It also discusses the importance of non-invasive technique used in our study. It highlights the significance of this study based on the available literature on both African and Asian elephants. Chapter 2: General validation and standardization of field techniques and assays; influence of intrinsic and extrinsic factors on faecal glucocorticoid metabolites This chapter is divided into two parts. The first part deals with general validation and standardization of field techniques and the second part assesses the influence of fundamental intrinsic and extrinsic factors. Being the first study on stress-response of free-ranging Asian elephants, influence of various field-based techniques and variations were studied to facilitate the reliable interpretation of fGCM levels. We first conducted the experiments to standardize the field protocol and the laboratory protocol. Under the field protocol, we found that there was no within sample variation (as observed in many other species) in fGCM levels from thoroughly mixed faecal samples and samples from the center of the same dung bolus. The time of collection of samples had a significant influence, suggesting that the concentration of fGCM remains stable until 6-9 hours. Influence of storage of lyophilized samples suggested that the concentrations of fGCM levels decline if exposed to moisture. Under the laboratory protocol, A group specific 11-oxoetiocholanolone EIA, used for analyzing fGCM levels (μg/g), was modified to enhance the repeatability, accuracy and precision. EIA was analytically validated in every hormonal analysis by calculating the inter- and intra-assay coefficients of variation, specificity and parallelism. In the second part, we assessed the influence of age, sex and season on fGCM levels and found there was no age-wise variation and sex-wise variation. Season-wise variation was significant only in female elephants. We discuss the potential physiological reasons behind such variation. These findings suggest that aspects such as time of collection, proper storage of samples and the influence of extrinsic stresses (seasonality) should be considered for reliable and unbiased interpretation of fGCM levels. Chapter 3: Assessment of season-dependent body condition scores in relation to faecal glucocorticoid metabolites in free-ranging Asian elephants. (Published in Conservation Physiology; Pokharel et al., 2017; doi:10.1093/conphys/cox039) We studied seasonal and annual changes in visual body condition scores (BCS), and assessed how these scores were related to levels of fGCM levels in free-ranging Asian elephants in the seasonally dry tropical forests of the Mysore and Nilgiri Elephant Reserves in southern India. We assessed the animals’ BCS visually on a scale of 1 to 5; where 1 represents a very thin and 5 represents a very fat elephant. To understand the influence of seasonality on BCS, we sampled the population during dry and wet seasons of 2013 and 2015 while, for annual changes in BCS, we sampled nine free-ranging adult females from different family groups that had been repeatedly sighted over seven years. To evaluate the influence of body condition on fGCM, we measured the fGCM levels from fresh fecal samples collected from the body-condition scored animals. Effect of age and season on BCS in relation to fGCM was also studied. We found that the BCS was related with season, i.e. individuals with low BCS were more frequent during the dry season as compared to the wet season and fGCM levels were negatively associated with BCS. To be precise, concentrations of fGCM were highest in individuals with the lowest BCS (BCS-1) and then significantly declined till BCS-3. fGCM levels were almost comparable for BCS 3, 4 and 5. This pattern was more conspicuous in female than in male elephants. We discussed the possible reasons behind such relationship between fGCM and BCS. The findings from this chapter suggest that season-dependent BCS, hence, reflect the stress status as measured by fGCM, especially in female Asian elephants and could be used as an important non-invasive approach to monitor the physiological health of free-ranging elephant populations. This is the first study to compare the body condition scores and stress-response in free-ranging elephants. Chapter 4: Influence of ecological and physiological correlates on stress physiology of free-ranging female Asian elephants. We investigated the influence of herd size (HS), lactational status and number of adult females present in a herd on adrenocortical function in free-ranging adult female Asian elephants by measuring their fecal glucocorticoid metabolites (fGCM) levels. We found that there was a negative association between herd size and fGCM levels when only HS and fGCM were compared. Lactating females showed higher fGCM than that observed in non-lactating females, which might reflect the nutritional stress on mother and anti-predatory challenges against the calves. Herds with only one adult female had higher fGCM levels than herds with more than one adult female which could be because of social challenges. The poor association between herd size and fGCM when all predictor variables were combined elucidate that group size may not necessarily influence the adreno-cortical function. However, the numbers of adult females present in a herd and their lactational status has a significant role in defining the stress-response in free-ranging adult female Asian elephants. This study is the first study to document the influence of lactational status with the stress-response in free-ranging elephants. Chapter 5: How physiologically costlier it is to be a crop-raider in a human-dominated landscape? Diet quality as a possible ‘pacifier’ against stress. We studied the stress-response in crop-raiding elephants in a human-dominated landscape and non-raiding elephants in the protected forested areas. While raiding agricultural crops, elephants face various associated threats such as retaliation by humans, human-induced disturbances and stress of raiding which could enhance the energetic costs, ultimately elevating their stress levels. We hypothesized that crop-raiders (in human-dominated landscape; Hassan district of Karnataka, India) will exhibit higher faecal glucocorticoid metabolite (a proxy of stress-response; fGCM) levels as compared to the nonraiders (in forested areas; Bandipur and Nagarahole National Parks). Contrary to our hypothesis, fGCM levels were found to be higher in both nonraiding female and male elephants than female and male crop-raiders. To assess the influence of benefits obtained from crop-raiding as one of the possible factors for the lower fGCM in crop-raiders, the difference in vegetation between human-dominated landscape and forested areas were further analyzed by using a remotely sensed NDVI (Normalized Differential Vegetation Index) and was ground-truthed by measuring the quality of diet (C:N ratio through fecal samples). Interestingly, the NDVI values were higher at the human-dominated and the C:N ratio was lower (higher Nitrogen content) in faecal samples of crop-raiding elephants (both in females and in males) than the nonraiders in the forested areas. Positive correlation was observed between C:N ratio and fGCM levels. These findings suggest that crop-raiding comes with the benefits of easy access to good quality of diet which may help in reducing the stress-response in elephants while being in the human-dominated landscapes, provided there is a low intensity of human disturbance. This is the first study to document and compare the stress-status of crop-raiding Asian elephants with elephants in their natural habitats using NDVI and C:N ratio. Chapter 6: Conclusion In conclusion, the work presented in this dissertation provides an overview of how ecological and anthropogenic factors could influence the physiological health of free-ranging Asian elephants. This dissertation focused on providing detailed insights about the stress-response in free-ranging Asian elephants. The objectives have been achieved by assessing the relationship between ecological stressors such as seasonality, body condition, herd size, lactational status, a presence of individuals in a herd and anthropogenic stressors such as human-induced threats or crop-raiding using well-validated and standardized laboratory and field protocols. This study provides valuable insights into the physiological health or stress-response being synergistically influenced by various ecological, social and anthropogenic factors in free-ranging Asian elephants. Findings obtained from this study could help in addressing the issues related to the management of free-ranging elephant populations.
6

An examination of salivary cortisol concentrations and behavior in three captive african elephants (loxodonta africana) at zoo atlanta

Kelling, Angela Swilley 18 November 2008 (has links)
Salivary cortisol is becoming an effective method with which to quantify cortisol levels, including the ability to track diurnal patterns and acute stress fluctuations. The purpose of this study was to validate salivary cortisol for use in African elephants (Loxodonta Africana), establish baseline cortisol values in three African elephants at Zoo Atlanta and explore the relationship between cortisol and various behaviors and husbandry events. Elephant salivary cortisol was found to be a valid measure based on correlations with serum cortisol and serial dilution results. Salivary cortisol also decreased across the day, but no definitive patterns were revealed. Using baseline values, salivary cortisol was used to examine the effects of enrichment, maintenance and novel training, and a mild stressor. Maintenance training was found to lead to lower cortisol values than novel training. Salivary cortisol after enrichment did not differ from individual overall means. The mild stressor initiated a rise in salivary cortisol. The final focus of this study was to investigate the link between salivary cortisol and stereotypic behavior. Stereotypies are described as repetitive behaviors with little variance and no discernible function or goal. There is not a straightforward relationship between stereotypies and welfare. Analysis of salivary cortisol at various durations into swaying bouts established that swaying appears to decrease cortisol levels. Additionally, behavioral data were collected. Behavioral data confirmed anecdotal reports of circular dominance in these animals. Behavioral data also revealed that although these individuals spend the majority of their time consuming food, one individual in particular devotes a significant amount of her time to swaying, a percentage much higher than that found when Wilson, Bloomsmith, and Maple (2004) examined stereotypic swaying rates in these same animals. Results of this study have direct ramifications for the current management requirements for captive elephants around the world. It helps tap into aspects of psychological well being of captive elephants to elucidate factors influencing welfare and stereotypic behavior. Research of this nature is a critical endeavor if we are to appropriately manage these magnificent animals in captivity.
7

Poaching as a Sociological Phenomenon: Constructed Crossroads and Conflicts among the People and Pachyderms of Sub-Saharan Africa

Carlson, Shelby C. 12 June 2018 (has links)
No description available.
8

Desafios para conservação de elefantes na África / Challenges to the conservation of african elephants

Zacarias, Daniel Augusta 15 December 2017 (has links)
Submitted by Luciana Ferreira (lucgeral@gmail.com) on 2018-01-16T10:46:45Z No. of bitstreams: 2 Tese - Daniel Augusta Zacarias - 2017 (1).pdf: 10564997 bytes, checksum: 3beb8a6a9c5b45ffef1c47b91fb5ee3c (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Approved for entry into archive by Luciana Ferreira (lucgeral@gmail.com) on 2018-01-16T10:47:18Z (GMT) No. of bitstreams: 2 Tese - Daniel Augusta Zacarias - 2017 (1).pdf: 10564997 bytes, checksum: 3beb8a6a9c5b45ffef1c47b91fb5ee3c (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Made available in DSpace on 2018-01-16T10:47:18Z (GMT). No. of bitstreams: 2 Tese - Daniel Augusta Zacarias - 2017 (1).pdf: 10564997 bytes, checksum: 3beb8a6a9c5b45ffef1c47b91fb5ee3c (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2017-12-15 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / Biodiversity conservation is in crisis and urgent responses are needed to reverse the extinction of species, the proliferation of invasive species and the fragmentation of habitats. Among several approaches being implemented, the protection of species with great dispersal capacity and that play important ecological role has been advocated as a solution, since the protection of their habitat in parallel contributes to the protection of other species and habitats. The elephant, a megagardener of forests and savannahs, represents this type of species in the sense that it inhabits vast areas, has a high dispersal capacity and guarantees the dispersion and growth of plant species in extensive areas. Unfortunately, the current situation of the elephant is not positive and international efforts have been developed to reverse the current scenarios of reduction of its abundance and the protection of its habitat. This thesis focuses on African elephant species (Loxodonta africana and Loxodonta cyclotis) and aims to contribute to the knowledge of the main challenges that must be embraced for their protection, using an interdisciplinary approach involving scientometric analysis, climate niche modelling, multi-scale modelling of habitat connectivity, quasi-linear regression models and structural equations and knowledge syntheses. Chapter I presents a systematic review of conservation genetics studies of the African savannah elephant and discusses the main research areas, the elephant populations involved and the main lines of research addressed. Chapter 2 presents the modelling of the climatic niche response to multi-temporal climate change and determines the potential for connectivity between remaining elephant habitats and chapter 3 presents the interaction between environmental, socioeconomic and governance indicators to explain abundance of elephants in Africa, based on the most recent IUCN estimates. The fourth chapter discusses the main challenges associated with the introduction of African elephants as a strategy for the recovery of lost ecological functions with the extinction of megafauna in the Pleistocene, and the fifth chapter, which concludes, presents the synthesis of challenges and opportunities for the conservation of African elephants. / A conservação da biodiversade está em crise e são necessárias respostas urgentes para reverter a extinção de espécies, a proliferação de espécies invasoras e a fragmentação de habitats. Dentre as várias abordagens sendo implementadas, a proteção de espécies com grande capacidade de dispersão e que desempenham papel ecológico importante tem sido advogada como solução, na medida em que a proteção de seu habitat paralelamente contribui para a proteção de outras espécies e habitats. O elefante, megajardineiro das florestas e savanas, representa este tipo de espécies, no sentido em que habita vastas áreas, tem elevada capacidade de dispersão e garante a dispersão e crescimento de espécies vegetais por vastas áreas. Infelizmente a situação actual do elefante não é positiva e esforços internacionais têm sido desenvolvidos no sentido de reverter os atuais cenários de redução de sua abundancia e a proteção do seu habitat. Esta tese debruça-se sobre as espécies de elefante africano (Loxodonta africana e Loxodonta cyclotis) e procura contribuir para o conhecimento dos principais desafios que devem ser abraçados para a sua proteção, servindo-se de uma abordagem interdisciplinar envolvendo análise cienciométrica, modelagem de nicho climático, modelagem multi-escala de conectividade de habitats, modelos de regressão quasi-linear e de equações estruturais e sínteses de conhecimento. O capítulo 1 apresenta faz a revisão sistemática dos estudos de genética de conservação do elefante africano de savana e discute os principais eixos de pesquisa, as populações de elefantes envolvidas e as principais linhas de pesquisa abordadas. O capítulo 2 apresenta a modelagem da resposta do nicho climático em função de alterações climáticas multi-temporais e determina o potencial de conectividade entre os habitats remanescentes de elefantes e o capítulo 3 apresenta a interação entre indicadores ambientais, socioeconômicos e de governança para explicar a abundância de elefantes em África, tomando como base nas mais recentes estimativas da IUCN. O quarto capítulo discute os principais desafios associados à introdução de elefantes africanos como estratégia para a recuperação de funções ecológicas perdidas com a extinção da megafauna no Pleistoceno e o quinto capítulo, que faz de conclusão, apresenta a síntese dos desafios e oportunidades para a conservação dos elefantes africanos.

Page generated in 0.0471 seconds