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1
Bigwood, Taryn. "Geomorphic impacts of Loxodonta Africana (African elephants) in Tembe Elephant Park". Diss., University of Pretoria, 2011. http://hdl.handle.net/2263/30370.
Testo completoAbstract (sommario):
Humans are modifying animal populations, indirectly accelerating or reducing the geomorphic alterations caused by animals. Species have been monitored and studied with focus on domesticated animals but little research has been undertaken on wild animals. This study analyses the geomorphic impact of elephants on Tembe Elephant Park, so that the changes they cause to the landscape may be quantified. To conduct this research four sites were chosen: an area where elephants had been excluded for twenty-five years, where excluded for five years, where elephants exist at present and where elephants mud wallow. Three of the four study sites were classed as sand forest (twenty-five-years exclusion, five-years exclusion and where elephants exist) and were analysed and compared to determine the similarities and differences in climate, microclimate, vegetation and the soil’s physical and chemical properties. The wallow site was not compared to any other study site, but was observed and mapped to quantify the geomorphic impact of elephants wallowing. When the sand forest sites were compared the climate, vegetation type and soil were found to be similar. Where elephants were present: the vegetation was inconsistent in basil cover, canopy height, structure and class. Soils were more compacted with a low infiltration rate, higher temperature, lower soil moisture, higher pH and a lower electric conductivity and air relative humidity was the highest. Where elephants have been excluded for twenty-five years, the opposite trends arose from the data analysis. The vegetation was consistent in basil cover, canopy height, structure and class, and the soils were less compacted with a high infiltration rate, low temperature, higher soil moisture, lower pH and a higher electric conductivity. The microclimate showed a trend where the air relative humidity was the lowest. At the elephant wallow site data showed that the wallows were in general circular in shape, 52.5m3 of soil was removed per month for the last nine months and the surface area of the wallows increased by 165.5m2 per month for nine months from April to December 2008. All the results from this study show that the elephant activity in Tembe Elephant Park has geomorphic consequences. From the results, it is possible to conclude that the geomorphic impacts of elephants on Tembe Elephant Park are contributing to a nutrient cycle shift in the sand forest biome, as they change aspects of the vegetation, microclimate, soil and landscape, which are the foundation of the cycle.Dissertation (MA)--University of Pretoria, 2011.
Geography, Geoinformatics and Meteorology
MA
Unrestricted
2
Jacobs, Zoe M. "African Elephant (Loxodonta Africana) Conservation in Tanzania". Scholarship @ Claremont, 2015. http://scholarship.claremont.edu/scripps_theses/568.
Testo completoAbstract (sommario):
Increasing human population and development in Africa restricts land and resources for African elephants (Loxodonta africana) and threatens the preservation of the species. Despite the importance of conservation for many governments in Africa, many local communities have negative views of elephants and exhibit anti-conservation behavior. By looking at the history of wildlife policy in Tanzania, this paper seeks to understand these opinions through a historical context. Three case studies of conservation initiatives were evaluated to determine what aspects of conservation initiatives promote long-term pro-conservation behavior on the part of the local community. Ultimately, conservation initiatives should establish a framework whereby local communities are empowered through conservation.
3
Hook, Margaret Rose. "Effect of Lion Calls on African Elephants (Loxodonta Africana) in Addo Elephant National Park, South Africa". TopSCHOLAR®, 2012. http://digitalcommons.wku.edu/theses/1196.
Testo completoAbstract (sommario):
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.
4
Gough, Katie F. "Relatedness, social behaviour, and population dynamics of the elephants (Loxodonta africana) of Addo Elephant National Park, South Africa". Thesis, Nelson Mandela Metropolitan University, 2015. http://hdl.handle.net/10948/3569.
Testo completoAbstract (sommario):
This study presents an investigation into the population dynamics and social structure of a small, closed elephant population. Specifically, it examined population growth rates for evidence of density-dependent regulation. It also quantified the association patterns of female elephants groups, and male elephants groups. Social structure was examined using Hamilton’s kinship theories of inclusive fitness, and age. Male-female patterns of association were also examined for inbreeding avoidance behaviours. The study population was located in Addo Elephant National Park, South Africa. Density-dependence was assessed using a long-term data set. Densities were considerably higher than estimated carrying capacities. Population growth rate was positively correlated with increasing density. No relationship between birth rate, the age of first calving or calf sex ratio and elephant density was detected but there was a positive relationship between birth rate and rainfall during conception year. Mortality rates, particularly for juveniles, were low, and mean inter-calf interval was 3.3 years. There is no evidence of density dependent regulation in this population. These findings indicate that density dependence should not be considered as an option in the control of elephant numbers in this Park, or where elephant resources are not seasonally limited. Examination of association patterns of the adult female component revealed that associations were not random at the population, family or individual scale. This is the second study on African elephants to confirm previous behavioural studies that predicted that preferred associates were close maternal relatives. This supports many studies showing that social species preferentially associate with their kin. The adult males in this population were found to have a well differentiated society with non-random associations. Generally, males were found to have weak associations with most other males and strong associations with only a few males. This association pattern was found to be persistent over the time frame of the study, as indicated by the time lag analysis. Males returned to their natal family, even when maternally related females were in oestrus. Oestrous females directed positive behaviours towards musth males. It appears that behavioural inbreeding avoidance mechanisms in this small, closed population are inhibited: musth status seems to override inbreeding avoidance. General principles from this case study were interpreted in terms of their applicability to other small, closed populations.
5
Wood, Jason Donald. "Communication and spatial cohesion of the African elephant, Loxodonta africana /". For electronic version search Digital dissertations database. Restricted to UC campuses. Access is free to UC campus dissertations, 2003. http://uclibs.org/PID/11984.
Testo completo
6
King, Lucy E. "The interaction between the African elephant (Loxodonta africana africana) and the African honey bee (Apis mellifera scutellata) and its potential application as an elephant deterrent". Thesis, University of Oxford, 2011. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.543016.
Testo completo
7
Nasseri, Nabil A. "The relationship of herpetofaunal community composition to an elephant (Loxodonta africana) modified savanna woodland of northern Tanzania, and bioassays with African elephants". Click here to access thesis, 2009. http://www.georgiasouthern.edu/etd/archive/spring2009/nabil_a_nasseri/Nasseri-Nabil-200901-ms.pdf.
Testo completoAbstract (sommario):
Thesis (M.S.)--Georgia Southern University, 2009."A thesis submitted to the Graduate Faculty of Georgia Southern University in partial fulfillment of the requirements for the degree Master of Science." Directed by Bruce A. Schulte. ETD. Includes bibliographical references (p. 25-45, 64-87) and appendices.
8
Wall, Jacob C. "Geospatial analysis of African elephant movement (Loxodonta africana and L. cyclotis)". Thesis, University of British Columbia, 2015. http://hdl.handle.net/2429/51929.
Testo completoAbstract (sommario):
African elephants (Loxodonta africana and L. cyclotis) are important species for geospatial study given their ecological role as megaherbivores, their large home ranges which pose challenges for conservation, and the ongoing ivory crisis. Using GPS tracking data, I address five research topics that contribute new information to the geospatial analysis of tracking data, to elephant movement ecology, and conservation :
1. What is an appropriate method to collect, store, disseminate, visualize and analyze elephant tracking data? I present a system (Loxobase) designed to provide an efficient and scientific basis for the treatment of wildlife tracking data. I demonstrate its utility by analyzing tracking datasets collected from 247 elephants (Chapter 2).
2. Can we leverage real-time tracking data for management and conservation? I present a monitoring system that implements continuous analysis of elephant GPS tracking data streams to identify positional and movement-based geospatial alert conditions. Four algorithms identify when wildlife slow or stop moving or cross into or near to spatial objects (Chapter 3).
3. Can we estimate wildlife space-use from tracking data? I develop the Elliptical Time-Density model to estimate an animal's utilization distribution from tracking data where parameters are directly linked to species biology. I demonstrate its performance in relation to other space-use estimators (Chapter 4).
4. What does tracking data tell us about the movement patterns of the Sahelian elephants in Mali? I use GPS tracking to study elephants in the Gourma, Mali to understand this unique and important population. The Gourma elephant's range was found to exceed those reported elsewhere in Africa and movements were correlated with patterns of rainfall and vegetation phenology. I also identified corridors and core areas of conservation priority (Chapter 5).
5. What does tracking data tell us about the factors influencing elephant range size across Africa? I present a comparative analysis of elephant range area measured in West, Central, East and Southern Africa. Using mixed effects models, I test hypotheses about elephant range size in relation to sex, species, region, vegetation phenology and quantity, protected areas, human footprint and terrain (Chapter 6).Arts, Faculty of
Geography, Department of
Graduate
9
Wood, JD, B. McCowan, R. Langbauer, J. Viljoen e L. Hart. "Classification of African elephant Loxodonta Africana rumbles using acoustic parameters and cluster analysis". Bioacoustics, The International Journal of Animal Sound and its Recording, 2005. http://encore.tut.ac.za/iii/cpro/DigitalItemViewPage.external?sp=1001005.
Testo completoAbstract (sommario):
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.
10
Rooney, Brigit. "Tourism and African Elephant (Loxodonta Africana) Behavior in Zambezi National Park, Zimbabwe". TopSCHOLAR®, 2019. https://digitalcommons.wku.edu/theses/3123.
Testo completoAbstract (sommario):
As charismatic megafauna and a flagship species, African elephants (Loxodonta africana) are vital to the African tourist economy. Conversely, high levels of wildlife tourism can induce behavioral shifts that push desired animals into less frequented areas and disrupt natural behaviors. In order to examine this trade-off, tourism levels and African elephant behaviors were studied in Zambezi National Park (ZNP) near Victoria Falls, Zimbabwe. Over the course of 14 weeks, in-person observations and camera traps in ZNP were used to collect geographic, demographic, and behavioral data from elephant sightings. As a proxy for human presence, geo-locational data were collected for each vehicle sighted in ZNP. These data of vehicles and elephants were mapped in ArcGIS to show a visual representation of their spatial relationship and identify high density and hotspot locations. Analyses from physical observations found that elephants were more frequently sighted in the park region with less vehicle traffic, as expected, but surprisingly also expressed more vigilance behaviors in that region. These results imply that elephants in high traffic regions become accustomed to vehicles but still avoid them when possible. Analyses from camera trap data revealed that only two of the six waterholes monitored had inversely related elephant and human presence, as predicted. There was no clear relationship between elephant and human presence. Future studies should account for habitat type differences in behavioral observations and compare elephant waterhole use in more heavily visited parks.
11
Mukeka, Joseph M. "ANALYZING THE DISTRIBUTION OF THE AFRICAN ELEPHANT (LOXODONTA AFRICANA) IN TSAVO, KENYA". Miami University / OhioLINK, 2010. http://rave.ohiolink.edu/etdc/view?acc_num=miami1278655589.
Testo completo
12
Lee, Tamara Ann. "Determinants of protected area boundary crossings by savannah elephants, Loxodonta africana". Diss., University of Pretoria, 2013. http://hdl.handle.net/2263/28764.
Testo completoAbstract (sommario):
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
13
Johnson, Mireille Bawe. "Genetic variation of the forest elephant Loxodonta africana cyclotis across Central Africa". Thesis, Cardiff University, 2008. http://orca.cf.ac.uk/54774/.
Testo completoAbstract (sommario):
The first comprehensive genetic study of central African forest elephants (CAEs) is presented here based on mitochondrial DNA (mtDNA) and nuclear microsatellite loci. MtDNA analysis revealed low genetic divergence between most groups. Haplotype distribution was not correlated with geographical localities, indicating high levels of gene flow. Two divergent haplogroups, illustrated by a bimodal distribution of pairwise differences in the control region, implies that secondary contact and ongoing introgression has occurred between populations expanding from at least two putative glacial refugia. Similarly, microsatellite analysis revealed low genetic differentiation among sites, suggesting high levels of gene flow as well as regional admixture with two genetically-based clusters inferred from Bayesian analyses. It is important to note through, that although both mtDNA and microsatellites identified two groups or genetic clusters, assignment of individuals to these clusters was not consistent across genomes possibly a result of differential admixture in nuclear and mitochondrial DNA. No correlation was found between genetic and geographical distances for both genomes. Previous phylogenetic analyses, using either on genetic or morphological characters, were based on a very limited number of forest elephant samples. A large-scale reassessment of mitochondrial DNA diversity in CAEs compared to published data on both forest and savannah forms revealed a complex phylogeographic history for African elephants, and an evolutionary trajectory more complex than prevailing two-taxon models have assumed. Mitochondrial control region and Cytochrome b sequences were analysed for CAEs and compared to other African elephant data. CAE populations fell into at least two lineages with West African elephants (both forest and savannah) sharing their mitochondrial history almost exclusively with Central African forest elephants. Extant African elephant populations therefore seem to have originated from multiple refugia lineages that have subsequently undergone introgression. Thus, the complex phylogeographic history of African elephants does not support a simple two-taxon model and management strategies incorporating the two-taxa model could be misinformed until further data give clarifies the origins of elephant populations throughout Africa.
14
Karimi, Rebekah R. Schulte Bruce A. "An assessment of perceived crop damage in a Tanzanian village impacted by human-elephant conflict and an investigation of deterrent properties of African elephant (Loxodonta africana) exudates using bioassays". Diss., Statesboro, Ga.: Georgia Southern University, 2009. http://www.georgiasouthern.edu/etd/archive/fall2009/lyndsay_a_itoh/Itoh_Lyndsay_A_200908_MS.pdf.
Testo completoAbstract (sommario):
"A thesis submitted to the Graduate Faculty of Georgia Southern University in partial fulfillment of the requirements for the degree Master of Science." Title from PDF of title page (Georgia Southern University, viewed on June 19, 2010). Bruce A. Schulte, major professor; Lissa M. Leege, J. Michelle Cawthorn, committee members. Electronic version approved: December 2009. Includes bibliographical references (p.76-78).
15
Chelopo, Ngwako David. "Physiological responses of African elephant (Loxodonta africana) immobilised with a thiafentanil-azaperone combination". Diss., University of Pretoria, 2020. http://hdl.handle.net/2263/77443.
Testo completoAbstract (sommario):
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
16
Goodyear, Sarah Elizabeth. "Habituation to Auditory Stimuli by Captive African Elephants (Loxodonta Africana)". TopSCHOLAR®, 2015. http://digitalcommons.wku.edu/theses/1481.
Testo completoAbstract (sommario):
Elephants are cognitive species that exhibit many types of learning. Associative, social, and insight learning have been investigated with elephants, but one of the simplest forms, habituation, has not. As an individual learns that a stimulus is neither harmful nor beneficial, it will decrease its response to the stimulus through the process of habituation. Elephants possess a well-developed sensory system and may habituate to stimuli that could be used for enrichment and/or management. The aim of this study was to examine the habituation process of elephants in response to repeated presentations of two auditory stimuli –buzzing by a disturbed beehive and the sound of banging on pots and pans, as these sounds invoke alert and avoidance behaviors in wild elephants as part of humanelephant conflict mitigation. I hypothesized that elephants would initially exhibit strong reactions to both sounds, but these responses would diminish over repeated trials. I also hypothesized that their responses to the bee sound would decrease more slowly than to the pot/pans sound because bee buzzing represents a biological cue that a threat is nearby. This study was conducted using four female African elephants (Loxodonta africana) at the Nashville Zoo. Elephants received each stimulus for a 10-day period. On the first sound presentation, the elephants reacted by exhibiting distress, avoidance, and vigilance behaviors. Over repeated presentations, the elephants stopped responding to the stimuli, suggesting habituation had occurred. They also seemed to generalize their habituation between the first and second sound, resulting in a faster habituation to the second sound. Although a preliminary study, the results suggest that elephants learn which stimuli are non-threatening and subsequently stop responding to them, most likely through habituation. Specifically, the elephants habituated to bee buzzing and banging pots and pans, two deterrents used to stop elephants from entering farmlands and eating crops. Habituation is a major concern for the development of effective human-wildlife conflict mitigation and zoo enrichment programs. The results from this study indicate that habituation is an important learning process that should be considered during the implementation of captive and wildlife management, even for highly intelligent species such as elephants.
17
Smet, Anna F. "A comparative cognition perspective on the production and use of visual signals by African savannah elephants (Loxodonta africana)". Thesis, University of St Andrews, 2015. http://hdl.handle.net/10023/11860.
Testo completoAbstract (sommario):
Elephants' complex societies, well-developed communication systems, evolutionary history and close working relationship with humans make them an important species for studies of cognition but research on elephant cognition is sparse. In this thesis I aim to illuminate the social cognition involved in the interpretation and production of visual signals by African elephants (Loxodonta africana). My results are intended to contribute to the cross-species literature on social cognition and help to elucidate wild elephant social behaviour. I studied captive elephants, housed at an elephant-back safari company in Victoria Falls, and wild elephants in Hwange National Park, both in Zimbabwe. Wild elephants display a vast array of postures, actions and signals. I found that elephants recognise visual attentiveness in others when they signal silently, producing more signals when their audience can see them, and using the body and face orientation of an audience to judge their attention. When responding to typically human visual signals, elephants immediately responded correctly to deictic gestures, including variants of pointing that they were unlikely to have already experienced. These results indicate elephants' astonishing sensitivity to even subtle social cues. I found no indication that elephants reason about mental states such as false beliefs, or rationality; however, limitations of the experimental design meant I was unlikely to find such an ability even if it is present in elephants. Furthermore, I discovered that elephants have a form of referential indication in their natural communication in the wild. Elephants match their direction of attention with a type of trunk action produced by a group member. Attending to human-like signals, and interpreting them as communicative is an advantage for any animal working with humans and that ability might explain the choice of species that are ancestors of today's domestic animals.
18
Holdgate, Matthew Robert. "Applying GPS and Accelerometers to the Study of African Savanna (Loxodonta africana) and Asian Elephant (Elephas maximus) Welfare in Zoos". PDXScholar, 2015. https://pdxscholar.library.pdx.edu/open_access_etds/2234.
Testo completoAbstract (sommario):
African savanna elephants (Loxodonta africana) and Asian elephants (Elephas maximus) are a focus of welfare research in zoos due to their high intelligence, complex social structure, and sheer size. Due to these challenges, some argue that zoos are inherently incapable of providing appropriate care for elephants, while others believe that zoos can fulfill the needs of these species with improved husbandry. There is a general consensus from both within and outside of zoos, however, that zoos must improve their elephant programs or cease exhibiting these animals altogether. Now more than ever, applied research on zoo elephant welfare is needed to provide context for this debate.
Researchers are interested in how far zoo elephants walk due to the potential health and welfare benefits of walking in these highly mobile species. Zoo researchers recently adopted GPS technology to study elephant walking, and preliminary evidence suggests that African elephants in large zoo exhibits walk distances that correspond with wild elephants under non-extreme conditions. However, data are limited from Asian elephants and from elephants in more typically-sized exhibits. In Chapter Two, I discuss important methodological considerations of utilizing GPS in a zoo environment, including an introduction to the technology, sources of error and mitigation, methods to improve GPS performance, and possible effects of GPS device attachment on animal behavior. This review shows GPS performance is adequate for tracking zoo elephant walking when proper methodological techniques are applied, and should serve as a useful reference for zoo researchers considering using GPS.
In Chapter Three, I used GPS anklets to measure outdoor daily walking distance in 56 adult female African (n = 33) and Asian (n = 23) elephants housed in 30 zoos. I collected 259 days of data and found that elephants walked an average of 5.34 km/day with no significant difference between species. Multivariate regression models predicted that elephants with more dynamic feeding regimens (more diverse feeding types and frequencies; unscheduled feeding times) will walk more. Distance walked was also predicted to be higher in elephants that spend time in a greater number of different social groups. Distance walked was predicted to decline with age. Finally, I found a significant negative correlation between distance walked and nighttime space experience. The results of the analysis suggest that zoos that want to increase walking in their elephants need not rely solely on larger exhibits, but can increase walking by adding quality and complexity to exhibits. However, my results failed to establish a definitive link between walking distance and other validated measures of elephant welfare. Thus, the direct health and welfare benefits of walking in zoo elephants remain unresolved.
Resting behaviors are an essential component of animal welfare, but have received little attention in zoological research. In Chapter Four, I used accelerometers in anklets to complete the first large-scale multi-species investigation of zoo elephant recumbence. I collected 344 days of data from 72 adult female African (n = 44) and Asian (n = 28) elephants at 40 zoos. I found that African elephants are recumbent an average of 2.14 hours/day, which is significantly less than Asian elephants at 3.22 hours/day. Multivariate regression models predicted that African elephant recumbence increases when they experience more space at night, and Asian elephant recumbence increases when they spend time housed alone. Both species showed a similar response to substrate, such that African elephants spending time on all-hard substrates are predicted to be recumbent less, while Asian elephants spending time on all-soft substrates are predicted to be recumbent more. The discovery that occasional non-recumbence is a common behavior in zoo elephants also introduces a new area of research that may have important animal welfare consequences. Finally, this study established that zoos should continue their efforts to replace hard substrate with soft substrate in order to provide zoo elephants with environments that facilitate recumbence.
Overall, this work assessed walking and recumbence in zoo elephants, which will allow zoos to gauge the prevalence of these behaviors in their elephants as compared to the sub-population studied here. A variety of factors that are associated with these behaviors were also identified. With this information, zoos can prioritize modifications to their facilities and animal management programs to create an environment that encourages zoo elephants to express walking and recumbence behavior, should they choose to do so.
This work is one component of the Elephant Welfare Project, the largest zoo animal welfare project ever undertaken, and is unprecedented in both scope and scale. The project was funded by the Institute of Museum and Library Services (IMLS), an independent, U.S., federal, grant-making agency that supports libraries, museums, and zoos. At the time of this writing, the first manuscripts from this project are being submitted to academic journals. These papers will describe the prevalence and distribution of a variety of elephant behaviors and welfare indicators, serve as a benchmark for future elephant welfare studies, and aid in decision making with regard to best practices in elephant management.
19
Derham, Kelly. "Wire Netting Reduces African Elephant (LOXODONTA AFRICANA) Impact to Selected Large Trees in South Africa". TopSCHOLAR®, 2014. http://digitalcommons.wku.edu/theses/1358.
Testo completoAbstract (sommario):
African elephants (Loxodonta africana) are ecosystem engineers in that they substantially alter the environment through their unique foraging and feeding habits. At high densities, elephants potentially have negative impacts on the environment, specifically to large trees. Because of this, recent increases of elephants in the Associated Private Nature Reserves (APNR) on the Western Boundary of Kruger National Park, South Africa have caused concern regarding the health of several species of tree. My objective was to assess the effectiveness of wrapping protective wire netting around the trunk of the tree in preventing and reducing bark stripping by elephants. 2,668 trees, 1352 marula (Sclerocarya birrea), 857 knobthorn (Acacia Nigrescens), and 459 false marula (Lannea schweinfurti), were assessed for elephant impact in the APNR, 1387 (52%) of which had previously been wrapped in protective wire netting (789, 548, and 50 respectively). For knobthorn and marula, wire netting significantly decreased the number of the trees that were bark stripped. For all trees, wire netting decreased the level of bark stripping especially for the highest impact levels. No trees wrapped with wire were ringbarked, compared to 23 unwired trees. In addition, wire netting had an effect on the distribution of damage for the highest impact class incurred regardless of type. A higher relative frequency of wired trees were found in lower impact categories compared to unwired trees. Wire netting is a low maintenance and ecologically valuable technique that alleviates bark stripping for some species. The judicial use of wire netting on trees could serve to maintain elephant and trees populations in areas of heavy confinement with locally high densities of elephants.
20
Ekobo, Atanga. "Conservation of the African forest elephant (Loxodonta africana) in the Lobeke, south-east Cameroon". Thesis, University of Kent, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.262645.
Testo completo
21
Bates, Melodie Joy. "Endocrine correlates of free-ranging African elephant (Loxodonta africana) treated with porcine zona pellucida vaccine". Diss., University of Pretoria, 2010. http://hdl.handle.net/2263/25181.
Testo completoAbstract (sommario):
Due to overpopulation of African elephants in South Africa and the consequent threat to biodiversity, the need for a method of population control has become evident. The potential use of the porcine zona pellucida (pZP) vaccine as a safe and effective means for population control is explored. While potential effects of pZP treatment on social behaviour of African elephants have been investigated, no examination of the influence of pZP vaccination on the endocrine correlates in treated females has been undertaken. The ovarian activity of freeranging, pZP-treated African elephant females was monitored non-invasively for one year duration by measuring faecal progestagen concentrations via enzyme immunoassay. Behavioural observations were recorded for comparison with progestagen concentrations and to determine any behavioural changes surrounding the pZP vaccine darting event. Each elephant under study showed progestagen concentrations rising above baseline at some period during the study indicating luteal functionality. Average progestagen concentrations were 1.61 ± 0.46 ìg/g. Within sampled females, 42.9% exhibited oestrous cycles within the range reported for African elephants, 14.3% had irregular cycles, and 42.9% did not appear to be cycling. Average oestrous cycle duration was 14.72 ± 0.85 weeks. Behavioural oestrous coincided with the onset of the luteal phase and a subsequent rise in progestagen concentrations. Focal sampling to determine activity budgets before and after the darting event revealed no significant change in behavioural activities. In the week following immunization, individual progestagen concentrations decreased significantly from overall average concentrations. Average progestagen concentrations positively correlated with rainfall and with herd dominance. No association between average individual progestagen concentrations or cyclicity status with age, lactation, or parity were detected. Earlier determination of efficacy was made indicating reproductive control was established 22 months post-treatment. Results indicate the presence of ovarian activity amongst pZP-treated female African elephants in two years following initial immunization. Further study should be aimed toward studying the long term effects of pZP vaccination on the reproductive function of female African elephants.Dissertation (MSc)--University of Pretoria, 2010.
Production Animal Studies
unrestricted
22
Benavides, Valades Gabriela. "Induction of anoestrus in free-ranging African elephant (Loxodonta africana) cows using a gonadotrophin-releasing hormone vaccine". Diss., University of Pretoria, 2012. http://hdl.handle.net/2263/24985.
Testo completoAbstract (sommario):
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. CopyrightDissertation (MSc)--University of Pretoria, 2011.
Production Animal Studies
unrestricted
23
Webber, Catherine Elizabeth. "A comparison of behavioural development of elephant calves in captivity and in the wild : implications for welfare". Thesis, University of Stirling, 2017. http://hdl.handle.net/1893/27503.
Testo completoAbstract (sommario):
Compromised welfare and wellbeing of elephants (Loxodonta africana and Elephas maximus) in captive facilities are significant and global problems. The period between birth and two years old is crucial for calf survival and social and environmental learning. Behaviour and developmental processes among captive elephant calves in these first years were compared with those seen in wild calves. Wild elephants calves develop within a complex, varied social context and provide one reference for normal patterns of development. Such comparisons enable insights into welfare at captive facilities. Eleven captive elephant calves born at three UK facilities were studied from birth to 18 months (AsianN=6; AfricanN=5). Older calves (AsianN=2; AfricanN=2) were also sampled up to 3.5 years; making a total of 15 calves studied from 2009 to 2014. Due to the small sample size, the 11 younger calves were also discussed as individual case studies. By 2017, only two of these case study calves were both alive and not orphaned. Three additional calves (AsianN=1; AfricanN=2) died on their day of birth and were not sampled. This small sample highlights the ongoing lack of self-sustaining populations of captive elephants. This thesis collated systematic behavioural observations on captive calves across 373 days (483.5hrs). Calf maintenance activities (feeding, resting, moving), associations with mother and others, interactions and calf play were compared with behavioural observations of wild AsianN=101 (74hrs, Uda Walawe, Sri Lanka) and wild AfricanN=130 (252hrs, Amboseli, Kenya) calves from ~birth to five yrs. Mothers’ (captive: AsianN=4; AfricanN=4; wild: AsianN=90; AfricanN=105) activities were also recorded to explore synchrony with calves. Captive calves raised by their mothers had similar activity budgets to those seen in the wild. Expected age-related declines in suckling were found in captivity. However, captive calves were more independent than wild calves for their age in distance from mother and spent significantly more time in play. A Decision Tree for whether to breed elephants in captivity was developed; benefits that a calf potentially brings to companions, e.g. multi-generational matrilineal groups, enabling social bonding and reducing abnormal behaviours, were considered against space required for families to grow and divide naturally over time, as well as ensuring that captive-bred males are socially sustained. It was recommended that facilities invest in future enclosure/housing designs which permit: free-access to other elephants; 24hr trickle feeding; juvenile males allowed to stay with their maternal group for longer, encouraging learning opportunities and further retaining age-structure/composition. Conversely, facilities unwilling to house a male or provide appropriate group size/composition are recommended to cease breeding.
24
Knott, Edward Joseph. "The effect of elephants (Loxodonta africana, Blumenbach, 1797) on Xeric Succulent Thicket". Thesis, Rhodes University, 2007. http://hdl.handle.net/10962/d1005359.
Testo completoAbstract (sommario):
This study looks at the impact of elephant feeding on the Xeric Succulent Thicket component of Eastern Cape Subtropical Thicket (ECST) in Addo Elephant National Park (AENP). Observations of elephant feeding were carried out and vegetation transects were surveyed for impact of elephant feeding. The results indicated that the Nyati elephants spent the majority of their time grazing (nearly 90%), particularly the cow-young herds, and especially when the herd gathered in larger numbers. Browsing events were concentrated on Acacia karroo (81%) and there was no significant difference between the sexes in their preference for this species. Despite being subjected to most of the browsing, the majority of A. karroo trees were undamaged and the effect of elephants was generally light. It appears unlikely that, three years after re-introduction to Nyati, the elephants have had an effect on community structure of the vegetation. Surveys were conducted on stands of the alien invasive weed prickly pear Opuntia ficus-indica, and it was recorded that elephants in Nyati have had a dramatic effect on prickly pear, utilising all adult plants assessed and destroying 70% of them. This level of destruction in such a short period of time suggests that prickly pear is a highly favoured species. The results from the present study suggest that elephants can play a role in the control of prickly pear. Results are discussed in terms of elephants as both megaherbivores and keystone species, and as agents of intermediate disturbance.
25
Ott, Theresia. "Landscape heterogeneity as a determinant of range utilization by African elephants (Loxodonta africana) in mesic savannas". Diss., Pretoria : [S.n.], 2007. http://upetd.up.ac.za/thesis/available/etd-0522208-131027/.
Testo completo
26
Evans, Kate Elizabeth. "The behavioural ecology and movements of adolescent male African elephant (Loxodonta africana) in the Okavango Delta, Botswana". Thesis, University of Bristol, 2006. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.431629.
Testo completo
27
Kelling, Angela Swilley. "An examination of salivary cortisol concentrations and behavior in three captive african elephants (loxodonta africana) at zoo atlanta". Diss., Georgia Institute of Technology, 2008. http://hdl.handle.net/1853/26586.
Testo completoAbstract (sommario):
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.
28
Codron, Jacqueline. "Annals of ivory : perspectives on African elephant Loxodonta africana (Blumenbach 1797) feeding ecology from a multi-decadal record". Doctoral thesis, University of Cape Town, 2008. http://hdl.handle.net/11427/4169.
Testo completoAbstract (sommario):
Includes abstract.Includes bibliographical references (leaves 202-256).
This thesis explores the dietary responses of African elephants (Loxodonta africana) to environmental change by testing the hypothesis that diet switching (from predominantly browse-based to more grass-rich diets) is driven by cyclical patterns of climate and habitat change in a southern African savanna. Elephants are thought to have substantial impacts on their environments, primarily because they consume large amounts of vegetation over sustained periods. However, the woody plant composition of their diet varies considerably across space and through time, so that in some instances they have been found to be almost pure grazers. Tracking these changes by traditional approaches (e.g. field observations) is difficult because of the geographical and temporal constraints inherent to these methods. Stable light isotope tracking of diet allows diet switching to be studied over multiple space/time scales. Here, I use stable isotope data from elephant faeces, tail hair, and ivory to record short- (monthly), medium- (seasonal to annual), and long-term (decadal) ecological variability, respectively, of elephant diets in the Kruger National Park, South Africa. Results from faeces collected at monthly resolution for one year confirm findings of a previous study (based on biannually-collected samples over two years) that elephants generally consume more grass in the more wooded habitats of the northern Kruger Park, but that there is a greater degree of seasonal diet switching in southern Kruger Park habitats. Moreover, diet changes also relate to changes in underlying bedrock across Kruger Park. Isotopic time-series produced by serial profiling of tail hairs confirm patterns observed in faeces. Long-term diet histories of individuals are derived from serial isotope sampling of ivory, yielding records that represent several decades of an animal’s life, at sub-annual (seasonal) resolution. Overlaying individual ivory series in time produces the first, to my knowledge, multidecadal record of African elephant diet, dating from 1903 to 1993. Contrary to expectations, stable carbon, nitrogen, and oxygen isotope records from ivory do not correlate well with cyclical climate trends for the study region. Rather, pronounced diet shifts are observed during extreme climatic events (floods and droughts), and the greatest levels of intra- and inter-annual variability coincide with significant changes in park management policy during the 20th century, i.e. the introduction of water provision programs after the mid 1930s, and the onset of elephant population control in 1967. It is proposed that such direct intervention has played the biggest role in disturbance of elephant-plant equilibria during the 20th century, and further studies to improve our understanding of this phenomenon will be instrumental to development of appropriate management strategies for the 21st century.
29
Mueller, Jenni Elizabeth. "Seasonal Changes in Behavior and Exhibit Use of Captive African Elephants (Loxodonta africana) and Black Rhinoceroses (Diceros bicornis)". Case Western Reserve University School of Graduate Studies / OhioLINK, 2008. http://rave.ohiolink.edu/etdc/view?acc_num=case1215524414.
Testo completo
30
Cooper, Alexandra Christine. "Change in Female Elephant Calf (Loxodonta africana) Distance to Different Family Members Over Time". Thesis, The University of Arizona, 2015. http://hdl.handle.net/10150/579148.
Testo completoAbstract (sommario):
At Reid Park Zoo, Tucson Arizona, spatial distances of the female African elephant calf (Loxodonta africana) were compared to the other five members of her herd for 14 weeks. Looking at average distances, maximum distances, and percent change it can be seen overall that the mother was the closest to the calf, then the 4-year old brother, 7-year old brother, father, and aunt. It was concluded that the calf spent most of her time with her mother and younger siblings compared to her father and aunt. Also, the mother and 7-year old brother were the only two members of the herd that had a statistically significant positive increase in distance away from the calf. Trends for the other members of the herd were not statistically significant. Results from this study were compared to P.C. Lee's study on wild elephants, which had similar conclusions in strong mother to calf bonds.
31
Du, Toit Jana. "Changes in diet resource use by elephants, Loxodonta Africana, due to changes in resource availability in the Addo National Park". Thesis, Nelson Mandela Metropolitan University, 2015.
Cerca il testo completoAbstract (sommario):
Animals are restricted in their diets by several factors, most notably the availability and quality of resources. Variation in resource availability causes herbivores to shift their diets seasonally and spatially. Elephants (Loxodonta africana), are known to have extensive impacts on plant communities, altering ecosystem functioning and causing a decline in biodiversity. In enclosed areas, these impacts are increased leading to a decline in resource availability and presumably resource quality. In the Addo Elephant National Park, the Main Camp section has a history of high elephant impacts and therefore reduced resource availability. Whereas, the recently added Colchester section has greater resource availability, due to the absence of elephants in this section since the fencing of the Park. This study investigated the changes in diet (diet breadth, preference and diet quality) of elephants due to an increase in resource availability. Three alternative hypotheses were contrasted: 1) elephants as generalist foragers, 2) elephants as optimal foragers, or 3) elephants learning foraging behaviour. Using microhistological analysis, the diets of elephants were described over five sampling periods (August 2010 – February 2014) in both sections. Forage availability was estimated using a modified line-intercept method, and was used to determine changes in preference by relating forage availability to use. In the Colchester section the diet breadth of elephants increased, and was coupled with a high initial variation between the diets of elephants, which decreased in subsequent sampling periods. This supported the elephants learning foraging behaviour hypothesis. However, there was no increase in diet preference by elephants in the Colchester section, which supported the elephants as generalist foragers hypothesis. There was also no difference in the diet quality of elephants in the Main Camp and Colchester sections, which did not support any of the three hypotheses. The elephants learning foraging behaviour hypothesis is proposed to be the link between the alternate two hypotheses, and given enough time, either of the two could be supported. The lack of difference in preference and diet quality between elephants in the Main Camp and Colchester sections is hypothesised to be due to the population level (not measured for individuals) at which these were measured. Microhistological analysis of faeces was used to describe the diet of elephants, which was compared to the diet described by DNA metabarcoding. Microhistological analysis is a traditional, favoured technique used in describing the diet of wild herbivores, whereas DNA metabarcoding is a relatively new and untested technique. These two techniques have not yet been compared in the diet of megaherbivores. Results indicated that microhistological analysis identified significantly more grass in the diet of elephants, than DNA metabarcoding did, which was expected as previous studies also found overestimation of grasses. Microhistological analysis identified more plant families in the diet of elephants, than DNA metabarcoding. Most of the differences between the two techniques can be attributed to the difference in taxonomic resolution, which was due to the lack of a complete reference collection for DNA metabarcoding. Although either of the two techniques can be used to describe the diet of elephants, the most reliable results would be obtained when using both techniques. The findings of this study suggest that due to the high initial variation between the diets of elephants, with an increase in resource availability, the impacts will also initially be highly varied. This suggests that identifying plant species to monitor elephants impacts initially will be difficult. However, important plant species, or those known to be vulnerable to elephants impacts should be carefully monitored initially and monitoring should not only occur annually, but also seasonally.
32
Valls, Fox Hugo. "To drink or not to drink? : the influence of resource availability on elephant foraging and habitat selection in a semi-arid savanna". Thesis, Montpellier, 2015. http://www.theses.fr/2015MONTS130/document.
Testo completoAbstract (sommario):
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 climatiqueWater 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
33
Von, Hagen Rebecca Lynn. "An Evaluation of Deterrent Methods Utilized to Prevent Crop Raiding by African Elephants (Loxodonta Africana) in the Kasigau Wildlife Corridor, Kenya". TopSCHOLAR®, 2018. https://digitalcommons.wku.edu/theses/3068.
Testo completoAbstract (sommario):
Escalating human elephant conflict (HEC) continues to be a contributing factor
towards elephant decline, and crop raiding is the most common form of negative
human-elephant interactions. For communities that cannot reverse or prevent crop
raiding, it is necessary to contain HEC events through deterrent measures. Few
deterrent measures exist that combine practicality and affordability while also
preventing habituation by elephants. This project focused on comparing the efficacy of
deterrent methods to assess which was the most successful at preventing elephants
from entering crops in the farming community of Sasenyi, Kenya. In this paired-control
study, four deterrent methods were evaluated: acacia fences, chili-pepper fences, a
new metal strip fence, and a combination of a chili and metal strip fence. Of the over
400 visits by elephants to individual fields containing crops recorded during two field
seasons, elephants entered farmer fields in the experimental area on 33 occasions
(<10%). Analysis of incidents when elephants approached at less than 50 m revealed
that the chili + metal fence and the metal fence were significantly more effective than
no deterrent. Following further verification of its effectiveness, this new deterrent
method could be a powerful new tool to alleviate elephant crop raiding and reduce HEC.
34
Codron, Jacqueline. "An isotope comparison of elephant (Loxodonta africana) diets in the Kruger National Park and Welgevonden Game Reserve". Master's thesis, University of Cape Town, 2004. http://hdl.handle.net/11427/10315.
Testo completoAbstract (sommario):
Bibliography: p. 116-128.The diet of African elephants (Loxodonta africana (Blumenbach, 1797)) living in savanna environments is unresolved. Elephants are known to include varying proportions of grass and browse into their diet, but there is uncertainty as to whether they are primarily grazers or browsers. This has implications for conservation in Africa, as elephants are considered a keystone species in wildlife areas, and are associated with a number of management issues. This dissertation focuses primarily on spatial and temporal variability in grass consumption by savanna elephants.
35
Fishlock, Victoria L. "Bai use in forest elephants (Loxodonta africana cyclotis) : ecology, sociality & risk". Thesis, University of Stirling, 2010. http://hdl.handle.net/1893/2758.
Testo completoAbstract (sommario):
Forest elephant (Loxodonta africana cyclotis) sociality is relatively little-studied due to the difficulties of making direct observations in rainforests. In Central Africa elephants aggregate at large natural forest clearings known as bais, which have been postulated to offer social benefits in addition to nutritional resources. This thesis explores the role of these clearings as social arenas by examining bai use within three main themes; ecology, sociality and risk factors. Seasonal changes in elephant use of the Maya Nord bai (Republic of Congo) are described, along with the demography of the visiting population. Elephant visit rate was highly variable; the number of elephants using Maya Nord in an observation day ranged from 0 to 117 animals. This variability was unrelated to local resource availability and productivity suggesting that bai use occurs year round. Elephants in Odzala-Kokoua do not show high fidelity to a single clearing; 454 elephants were individually identified and re-sighted an average of 1.76 times (range 1-10) during the twelve month study period. Previous bai studies have yet to quantify how elephants associate with one another within the bai area. This study examines socio-spatial organisation and associate choice using two measures of association within the 0.23 km2 bai area; aggregations (all elephants present in the clearing) and parties (elephants spatially co-ordinated in activity and movement) and distinguishes these from parties that range together (i.e. arrive and leave together). Social network analyses (SocProg) were used to describe inter- and intra-sexual multi-level organisation in the bai environment, and to illustrate the non-random nature of elephant aggregations and parties. Bais were shown to function as social arenas; female elephants showed active choice of certain associates and active avoidance of others when creating parties, whereas males were less discriminatory. Parties formed in the clearing (mean size= 3.93, SE= 0.186) were larger than ranging parties (mean size= 2.71, SE= 0.084) and elephants stayed for 50% longer in the clearing when they associated with individuals from outside their ranging party. Inter- and intra-sexual relationships were maintained within the clearing, and these are suggested to offer elephants essential opportunities for social learning. The patterning and nature of the relationships observed at the Maya Nord clearing indicates that forest elephants use a fission-fusion social structure similar to that of savannah elephants (Loxodonta africana africana); relationships are significantly structured by age- and sex- and underpinned by individual identity. Old experienced females hold key roles for forest elephants, and male relationships are superimposed on the network of female associations. Odzala-Kokoua elephants use bais to maintain their social relationships despite being highly sensitive to the anthropogenic risks involved in using these open areas. The results of this study suggest that forest and savannah elephants lie on the same social continuum, balancing social “pulls” to aggregate against the ecological “pushes” that force groups to fission. Previous models of savannah elephant sociality construct levels of association and social complexity upwards from the basic mother-calf unit (e.g. Wittemyer & Getz 2007). My results suggest that it may be more appropriate to consider elephant sociality and associations as in dynamic equilibrium between social and ecological influences acting at all levels of grouping, and to explicitly test how these underlie the opportunity costs that elephants are willing to pay in order to maintain social groupings.
36
De, Flamingh Alida. "Genetic structure of the savannah elephant population (Loxodonta africana (Blumenbach 1797)) in the Kavango-Zambezi Transfrontier Conservation Area". Diss., University of Pretoria, 2013. http://hdl.handle.net/2263/41004.
Testo completoAbstract (sommario):
Earlier studies investigated the genetic structure of fragmented or isolated elephant populations
by comparing the genetic characteristics of pre-defined populations. This study aimed to
determine if there was genetic evidence for spatial structuring in a continuous elephant
population in the Kavango-Zambezi Transfrontier Conservation Area (KAZA-TFCA).
I sequenced one mtDNA gene region for 88 individuals and genotyped 100 individuals for 10
nuclear microsatellite loci. Bayesian Clustering Algorithms incorporated in the program
Geneland were used to identify groups of genetically similar individuals. An Analysis of
Molecular Variance (AMOVA) determined if these groups (henceforth referred to as subpopulations)
were significantly differentiated. I used a Geographic Information System (GIS) landscape genetic toolbox to identify areas in the landscape with high genetic divergence
between individual samples to determine if there were identifiable genetic barriers in the
landscape.
There were three significantly differentiated mtDNA sub-populations (Fst = 0.787), and two
nDNA sub-populations that were not significantly differentiated (Fst = -0.02; Rst = -0.045),
implying obstructed mtDNA, but high nDNA gene flow across the study region. Also, gene flow
was apparent between Chobe and Kafue National Parks, where telemetry data has as of yet not
recorded inter-population movements between these parks.
The three mtDNA sub-populations were geographically differentiated and followed political
boundaries as apparent sub-populations in Botswana, Zambia and Zimbabwe. The differences
between mtDNA and nDNA genetic structuring may be explained by i) historical events that
shaped the current genetic structure (e.g. through founder-effects and persistent poaching
hotspots) and ii) intrinsic variables that influence genetic structure at a local scale (e.g. through
resource dependencies and social behaviour). The KAZA elephant population has a genetic
diversity (mtDNA diversity as the pairwise number of differences (π) = 2.59; nDNA diversity as
the mean alleles/locus and He = 7.5, 0.71) higher than other southern African populations, and
inter-population movements may be responsible for maintaining this genetic diversity.
I recommend continued support for conservation initiatives that aim at maintaining and restoring
connectivity between populations through landscape linkages, which in so doing may ensure
inter-population gene flow and uphold the current genetic state of the KAZA-TFCA elephant population.Dissertation (MSc)--University of Pretoria, 2013.
gm2014
Zoology and Entomology
unrestricted
37
Munishi, Linus Kasian. "The influence of genetic relatedness on sociality and demography of female African elephants". Thesis, Nelson Mandela Metropolitan University, 2011. http://hdl.handle.net/10948/d1011612.
Testo completoAbstract (sommario):
Many elephant populations across Africa were or are being devastated by poaching and habitat loss, making population and range size for the species important issues of conservation concern in elephant ranging areas, including Tarangire National Park (TNP). Poaching and/or overhunting are known to have direct effects on the demography of elephant populations. The current understanding of the indirect effects of poaching on the sociality and demography of elephant populations is relatively poor, both at the group and an individual level. In this thesis the importance of genetic relatedness (as influenced by poaching) on sociality and demography of the female elephants was studied, using a combination of genetic, observation of behaviour and two decades of demography data collected from the northern subpopulation of TNP. I investigated and characterized the relatedness categories within elephant groups. Using a conceptual model for group size analysis in aggregation economies, I hypothesized that elephant populations subject to social disruptions due to poaching would exhibit characteristics of the free entry model, whereas more stable, closed populations would better fit the group-controlled model. I present a rare quantitative analysis of genetic relatedness and group size patterns among groups of adult female elephants in two wild populations: one in Tarangire National Park (TNP), Tanzania, and another in Addo Elephant National Park (AENP), South Africa. I demonstrate that the group size in African elephant populations is governed by genetic relatedness, and that poaching/overhunting has a significant influence upon the apparent group formation and size in elephants. I then focused on the effect of relatedness on agonistic interactions between adult females. I hypothesized that individual-based aggressive interactions among adult female African elephants would vary according to degree of kinship, with closely related dyads showing less aggression towards each other in resource-limited environments, thereby leading to indirect fitness benefits for individuals. As predicted, females did not show agonistic interactions to their close kin most often, and the frequency and intensity of aggressive interactions was inversely related to the degree of relatedness of the interactants. The effect of group relatedness and structure on reproductive success of individual female African elephant in TNP was also investigated. Adult female reproductive success was significantly influenced by within- group relatedness and structure. Higher reproductive success (with higher frequency of calf production and survival and more female calves produced) were more evident in the closely related groups than groups with low relatedness, suggesting that females from genetically disrupted groups are less likely to be reproductive than those in closely related groups. The possibility of negative effects of poaching on the subsequent generation of poached adult females and the alternative of a positive demographic response through reduced density was assessed by analysing the demographic patterns of the first generation (F1) females of prime-aged adult female African elephants in TNP using within- group relatedness and size. I also compared vital rate (age of first birth and interbirth interval) responses of first generation (F1) cows from Tarangire (poached) elephants with other females from poached (Northern Luangwa National Park, Zambia) and unpoached (Amboseli National Park, Kenya and Addo Elephant National Park, South Africa) populations. Group relatedness had no significant effect on sex ratio of the F1 cows‟ calves. There was a significant difference between the mean age of first birth and interbirth interval of F1 cows from the two (poached, Tarangire and unpoached, Amboseli National Park) elephant populations, suggesting that elephant populations reduced by poaching to low levels show an increase vigour through release from density constraints. Based on these results, the broader implications of secondary effects of poaching on elephant populations are critically evaluated. Also the importance of understanding the consequences of these effects is highlighted in light of other elephant conservation and management approaches. This understanding is useful in making conservation and management decisions for elephants and other biodiversity.
38
Luther, Ilse. "Semen characteristics of free-ranging African elephants (Loxodonta africana) and Southern white rhinoceros (Ceratotherium simum simum) using Computer-aided sperm analysis, Electron microscopy and Genomics as diagnostic tools". University of the Western Cape, 2016. http://hdl.handle.net/11394/5443.
Testo completoAbstract (sommario):
Philosophiae Doctor - PhDThe survival of free-ranging (in situ) African elephant and Southern white rhinoceros populations are currently being challenged on a daily basis in Africa. Reproductive health is considered a vital component of species conservation. Conservation of the last mega land mammals may ultimately require intervention by breeding management or combined with assisted reproductive technologies (ART). There is a strong case for gathering baseline information, both physiological and biological, of any species, as opportunities arise. During this study a total number of 21 ejaculates collected over two seasons from 12 free-ranging African elephant bulls were characterised, as well as 10 ejaculates collected from 10 free-ranging Southern white rhinoceros bulls from two populations. Ejaculates were collected from adult bulls by means of electroejaculation under anaesthesia. Routine semen analysis was combined with Computer-aided sperm analysis (CASA), Computer-aided sperm morphology analysis (CASMA), Transmission electron microscopy (TEM) and Genomics as diagnostic tools. Additionally, sperm functionality within different media was investigated and sperm subpopulation classification according to the motion pattern displayed. The results presented is based on the evaluation and classification of ≈ 45 000 individual African elephant spermatozoa and ≈ 18 000 individual Southern white rhinoceros spermatozoa. The average elephant ejaculate contained a total number of 47 x 10⁹ spermatozoa (volume of 56 ± 38mL x concentration of 818 ± 750 x 10⁶/mL) that recorded a total motility of 81 ± 29% of which 62 ± 26% were progressively motile. CASA recorded velocities for curvilinear velocity (VCL 241 ± 58μm/s), straight-line velocity (VSL 173 ± 181μm/s) and average path velocity (VAP 201 ± 54μm/s), and kinematics at straightness of track (STR 86 ± 85%), linearity of track (LIN 67 ± 16%), amplitude of lateral head displacement (ALH 4 ± 0.75μm) and beat cross frequency (BCF 21 ± 3Hz). Structural analysis revealed 68 ± 11% of the spermatozoa were viable (intact plasma membrane) and 77 ± 11% maintained acrosome integrity. Ejaculates contained 55 ± 14% morphologically normal spermatozoa, CASMA measured sperm head lengths at 6.83 ± 0.26μm and width 3.32 ± 0.18μm (total head area of 20.17 ± 1.96μm²) of which 38.95 ± 0.92% is covered by an acrosomal cap. The average rhinoceros ejaculate contained a total number of 1.1 x 10⁹ spermatozoa (volume of 24 ± 24mL x concentration of 83 ± 96 x 10⁶/mL) that recorded a total motility at 82 ± 8% of which 28 ± 23% were progressively motile. CASA recorded velocities for VCL (85 ± 29μm/s), VSL (44 ± 25μm/s) and VAP (69 ± 30μm/s, and kinematics at STR (63 ± 14%), LIN (51 ± 16%), ALH (2 ± 0.16μm) and BCF (16 ± 6Hz). Structural analysis revealed 73 ± 10% of the spermatozoa were viable (intact plasma membrane) and 76 ± 4% maintained acrosome integrity. Ejaculates contained 62 ± 14% morphologically normal spermatozoa, CASMA measured sperm head lengths at 5.5 ± 0.17μm and width 2.9 ± 0.19μm (total head area of 14.8 ± 1.43μm²) of which 36.3 ± 0.59% is covered by an acrosomal cap. Based on a Boolean argument and CASA data exploration it was possible to derive elephant and rhinoceros CASA cut-off criteria to sort between activated and hyperactivated motile spermatozoa. For the genomic component of this study, the CatSper1 (Loxodonta africana) gene was identified,sequenced and verified in a free-ranging (natural) African elephant population. Multivariate analysis(MVA) was applied to examine the associations between the semen and sperm parameters and the traits they accounted for in this study. Our understanding of wildlife reproductive sciences can substantially progress as the analytical techniques applied and the combination thereof is expanded. This investigation presents a new set of comprehensive semen and sperm threshold values for future investigations.
39
Guldemond, Robert Abraham Rene. "The influence of savannah elephants on vegetation a case study in the Tembe Elephant Park, South Africa /". Pretoria : [s.n.], 2006. http://upetd.up.ac.za/thesis/available/etd-08242006-124305.
Testo completo
40
Stead, Sarah Kofie. "The assessment of stress in captive juvenile African elephants (Loxodonta Africana)". Pretoria : [s.n.], 2008. http://upetd.up.ac.za/thesis/available/etd-11092005-142633/.
Testo completo
41
De, Beer Yolandi-Mari. "Determinants and consequences of elephant spatial use in Southern Africa's arid savannas". Pretoria : [s.n.], 2008. http://upetd.up.ac.za/thesis/available/etd-08122008-141848.
Testo completo
42
Rasmussen, Henrik Barner. "Reproductive tactics of male African savannah elephants (Loxodonta africana)". Thesis, University of Oxford, 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.425895.
Testo completo
43
Landman, Marietjie. "Megaherbivores in succulent thicket: resource use and implications". Thesis, Nelson Mandela Metropolitan University, 2012. http://hdl.handle.net/10948/d1007956.
Testo completoAbstract (sommario):
This study aims to develop a predictive understanding of the resource use, impacts and interactions of elephant Loxodonta africana and black rhinoceros Diceros bicornis in the succulent thickets of the Eastern Cape, South Africa. While these megaherbivores typically dominate the biomass, elephant are more abundant, such that their impacts off-set that of all other herbivores. Consequently, this thesis has three main foci: first, developing a mechanistic understanding of the influences of elephant; second, developing predictive insights into elephant impacts on plant communities; finally, an understanding of the knockon-effects of the impacts for coexisting rhinoceros. Thus, by documenting the diet and dietary preferences of elephant, I firstly show that only about 18 percent of the species previously thought vulnerable to herbivory, occur in the diet. This refutes the generally held belief that elephant herbivory is the primary driver of decline among plants, and emphasizes the likely contribution of other mechanisms (e.g. trampling, knock-on-effects, etc.). Thus, the accurate prediction of the impacts caused by elephant requires an understanding of previously marginalized mechanisms. From here, I quantify >50 years of impacts on the thicket shrub community and test their spatial and temporal extent near water. I confirm the vulnerability of thicket to transformation (particularly near water) as the accumulated influences of elephant reduce community composition and structure, and predict that these impacts will eventually bring about landscape-level degradation and a significant loss of biodiversity. Importantly, results show an uneven distribution of effects between elements of this community: from community composition and structure, to the structure of individual canopy species and ecological functioning. While these findings confound our interpretation of the extent of the impacts, it demonstrates the importance of explicitly recognizing biodiversity and heterogeneity for the conservation management of elephant. Finally, I test the consequences of the impacts for coexisting rhinoceros. While I show that this causes rhinoceros to change their foraging strategies in the presence of elephant at high densities, I also show that elephant may facilitate access to food for rhinoceros at reduced densities. These findings indicate the importance of elephant in driving the structure and composition of the thicket shrub community and the consequences of this for coexisting large herbivores. Thus, developing a predictive understanding of the spatial and temporal variations of elephant impacts between elements of biodiversity and the mechanisms driving these changes are key to their management. This implies that the effective conservation management of elephant can only be achieved through the careful, scientific design of monitoring programmes.
44
Lessing, Joan Susanna. "Elephant feeding behaviour and forage offtake implications in the Addo Elephant National Park". Thesis, Nelson Mandela Metropolitan University, 2007. http://hdl.handle.net/10948/542.
Testo completoAbstract (sommario):
Elephants, as megaherbivores and keystone species have major impacts, both positive and negative, on ecosystems such as the Subtropical Thicket of the Eastern Cape. The feeding behaviour of elephants was quantified so as to firstly determine the preferred feeding heights of elephants, and secondly to determine if feeding behaviour and impact varies with size and sex. The preferred feeding height was determined with experimental feeding trials. Feeding height, pluck size, foraging rate and the proportion of plant material discarded were used to test for differences between elephants of different sizes and sexes in the Addo Elephant National Park. The influence of plant growth form on sex-specific feeding was also considered. Elephants preferred to feed at the lowest heights. The preferred feeding height was not related to body size. A wide range of feeding heights was recorded including and extending beyond, both the preferred and maximum feeding height of co-existing indigenous browsers. There was no difference in feeding height between the sizes and sexes. In free ranging conditions, all elephants fed at levels above the preferred foraging height when browsing. There was no difference in feeding behaviour between the different sized elephants, or between males and females. Adult elephants however exhibited larger ranges of feeding heights, pluck sizes, foraging rates and intake rates, including the maximum and minimum values. Growth form influenced the feeding of male and female elephants differently. Elephant feeding behaviour appears to limit opportunities for resource partitioning by way of feeding height segregation. Elephants are also capable of dominating the browse resources available to co-existing browsers by removing large amounts of forage at lower heights. The extent of elephant impact seems to be comparable between sizes and sexes, although adults and especially larger males are often able to use foraging opportunities that other elephants can not effectively utilize. Findings suggest that the feeding heights of elephants are determined by forage availability and reflect the diet in terms of browse or grass. The findings can be used, together with browse inventory methods, to determine browse resources available to elephants, and can also be used to develop monitoring tools to assess the impacts of elephants on plants.
45
Stead, Sarah Kofie. "The assessment of stress in captive juvenile African elephants (Loxodonta africana)". Diss., University of Pretoria, 2000. http://hdl.handle.net/2263/29337.
Testo completoAbstract (sommario):
In 1998, 30 juvenile elephants were captured in Botswana and transported to a holding facility in South Africa to be trained and sold to zoos and safari parks. The welfare of the 'Tuli Elephants' as they became known, became the source of acrimonious dispute between a number of conservation and animal groups. The case highlighted concerns over the welfare of elephants during capture, transport and confinement. Questions asked were: can an objective assessment of the effect on juvenile elephants on the removal from matriarchal group be made. This study was aimed to take an objective approach to assessing the welfare of captive juvenile elephants using behavioural and physiological methods of investigation. A behavioural study to identify indicators of stress was conducted in five groups of elephants subject to various husbandry systems. Thirteen behavioural indicators of stress were identified. A group of two elephants held in an enclosure 70 m2 that was devoid of mud and sand baths showed the highest number of behavioural indicators of stress. Elephants in larger enclosures with mud and sand baths showed fewer indicators of stress. The group able to range freely during the day showed the least number of stress¬related indicators. Conventionally the physiological assessment of adrenal responses to stress relies upon blood sample collection and the measurement of glucocorticoids but this is impossible without immobilisation or restraint that influences results. This study validated a recently established enzyme immunoassay (EtA) measuring faecal glucocorticoid metabolites in elephants. A preliminary investigation into the biological relevance of this non-invasive method was made for use in assessing welfare in elephants. Four juvenile elephants were injected i.m. with synthetic adrenocorticotrophic hormone (ACTH) (Synacthen, Novartis; 2.15 mg). Blood and faecal samples were collected over 4 hand 7 days respectively. Concentrations of serum cortisol and faecal cortisol metabolites were determined using immunoassay. Variability of basal and peak values in blood and faeces were observed among the elephants. After ACTH injection, serum cortisol concentrations increased by 400-700%. When compared to cortisol and corticosterone EIAs, 11-oxoaetiocholanolone EIA proved best suited to measure cortisol metabolites. Concentrations of faecal 11,17¬dioxoandrostanes increased by 570-1070% reaching peak levels after 20-25.5h. Samples left outside could be collected up to 8hrs after defecation without a significant effect on metabolite concentrations. A correlation between enclosure size, presence of stress-related behaviour and faecal 11,17 -DOAs was observed. Elephants kept in small enclosures exhibited more stress-related behaviour and had higher levels of glucocorticoid metabolites than those ranging in a larger area. The results of the study suggest that non-invasive faecal monitoring of glucocorticoid metabolites is useful in investigating adrenal activity in African elephants.Dissertation (MSc)--University of Pretoria, 2002.
Companion Animal Clinical Studies
MSc
Unrestricted
46
Napora, Erek Stephen. "Chemical signaling and resource use by African elephants (Loxodonta africana)". Click here to access thesis, 2007. http://www.georgiasouthern.edu/etd/archive/spring2007/erek_s_napora/Napora_Erek_S_200701_MS.pdf.
Testo completoAbstract (sommario):
Thesis (M.S.)--Georgia Southern University, 2007."A thesis submitted to the Graduate Faculty of Georgia Southern University in partial fulfillment of the requirements for the degree Master of Science." Under the direction of Bruce A. Schulte. ETD. Electronic version approved: May 2007. Includes bibliographical references (p. 33-37, 51-74) and appendices.
47
Selier, Sarah-Anne Jeanetta. "The social structure, distribution, and demographic status of the African elephant population in the central Limpopo River Valley of Botswana, Zimbabwe, and South Africa". Connect to this title online, 2007. http://upetd.up.ac.za/thesis/available/etd-06112008-154746/.
Testo completo
48
Meyer, Jordana Marie. "Sexual dimorphic social development and female intrasexual chemical signaling of African elephants (Loxodonta africana)". Click here to access thesis, 2006. http://www.georgiasouthern.edu/etd/archive/fall2006/jordana_m_meyer/Meyer_Jordana_M_200608_ms.pdf.
Testo completoAbstract (sommario):
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.
49
Olsson, Linnea. "Human-elephant conflicts : A qualitative case study of farmers’ attitudes toward elephants in Babati, Tanzania". Thesis, Södertörns högskola, Institutionen för naturvetenskap, miljö och teknik, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:sh:diva-24091.
Testo completoAbstract (sommario):
It is widely recognized that human-wildlife conflicts can reduce farmers’ support for long-term species conservation. The subject of human-elephant conflicts is highly relevant in villages around Babati District in North Central Tanzania because of the closeness to Tarangire National Park. The purpose of this study is therefore to examine local farmers’ attitudes toward elephants and the attitudes’ effects on conservation efforts. Primary data was collected through a qualitative approach of semi-structured interviews with twelve farmers in four villages around Babati, with Wildlife Officer Nashon Macokesha at Babati District Council and with Allan Carlson, Nature Conservation Expert at WWF. A thematic analysis was done to make comparisons between the answers from farmers, Macokesha and Carlson. The Theory of Planned Behavior and the Value-Belief-Norm theory were also used to analyze the underlying factors of the farmers’ attitudes. The results of this study show that around half of the farmers have positive attitudes toward elephants, while the other half think negatively of them. Elephants were identified as the most problematic species and crop-raiding as the most problematic type of human-elephant conflict. The problems that farmers experience do to crop-raiding and other types of human-elephant conflicts include the direct effects of lost livelihood and income and indirect effects like health impacts and security issues. The result also indicates that factors affecting farmers’ attitudes toward elephants include: 1) the proportion of available land affected by elephants, 2) the closeness of farmers’ fields to Tarangire National Park, 3) the lack of compensation, 4) the ability to affect the decision-making concerning the human-elephant conflicts and 5) the information about and knowledge of elephants and their importance. The underlying cause of the human-elephant conflicts is identified to be the spatial overlap of the two species. To prevent human-elephant encounters in the first place, thereby reducing the risk of human-elephants conflicts, better land use planning can be used to avoid settlement and cultivation close to protected areas. Buffer zones can be established around national parks and reserves to reduce the overlap between humans and wildlife. Mitigation through preventive and deterrent methods like lighting fires, making noises, using chili-dung or chili-grease to scare elephants off farmers’ fields can also be used. Another alternative is to switch from growing high-risk crops that elephants prefer to crops like chili or sesame which rarely gets eaten by elephants.Att konflikter mellan människor och djurliv kan minska bönders stöd för artbevarande åtgärder är välkänt bland forskare. Konflikter mellan människor och elefanter är vitt förekommande i byar i Babati-distriktet i norra Tanzania på grund av närheten till nationalparken Tarangire. Syftet med denna studie är därför att undersöka bönders attityder till elefanter och attitydernas effekter för bevarandeåtgärder. Primärdata samlades in genom ett kvalitativt upplägg med semistrukturerade intervjuer med tolv bönder i fyra byar i Babati, med Wildlife Officer Nashon Macokesha på Babati District Council samt med Allan Carlson, naturvårdsexpert på WWF. En tematisk analys utfördes för att jämföra svaren mellan bönderna, Macokesha och Carlson och the Theory of Planned Behavior samt the Value-Belief-Norm theory användes för att analysera de underliggande orsakerna bakom böndernas attityder. Resultatet från denna studie visar att ungefär hälften av bönderna har positiva attityder till elefanter, medan den andra hälften har negativa åsikter om dem. Elefanter identifierades som den mest problematiska arten för bönderna och förstörandet av grödor som den mest problematiska typen av konflikt mellan människor och elefanter. Problemen som bönderna upplever till följd av dessa konflikter inkluderar direkta effekter som förlorad inkomst och försämrade försörjningsmöjligheter, men också indirekta effekter som hälso- och säkerhetsproblem. Faktorer som enligt resultaten i denna studie kan påverka böndernas attityder till elefanter innefattar: 1) andelen tillgänglig mark som påverkas av elefanter, 2) närheten från böndernas mark till nationalparken Tarangire, 3) bristen på kompensation, 4) möjligheten att påverka beslutsprocessen gällande konflikten mellan människor och elefanter samt 5) information och kunskap om elefanter och deras betydelse. Den underliggande orsaken till konflikterna mellan människor och elefanter identifieras vara överlappet i användningsområden mellan de båda arterna. För att förhindra möten mellan människor och elefanter, och därmed minska risken för konflikter, behövs bättre markanvändningsplanering så att bosättning och jordbruk undviks i närheten av skyddade områden. Buffertzoner kan också anläggas runt nationalparker och reservat för att minska överlappet mellan människor och djur. Avskräckande åtgärder, som att tända eldar, göra oväsen, tända chilibriketter eller sätta upp chili-rep, för att hålla elefanter borta från böndernas åkrar kan också användas. Ett annat alternativ är att bönderna byter från att odla högriskgrödor som elefanter föredrar till att odla grödor som chili eller sesam, vilka sällan eller aldrig äts av elefanter.
50
Garai, Marion Elizabeth. "The development of social behaviour in translocated juvenile African elephants Loxodonta africana (Biumenbach)". Diss., University of Pretoria, 1997. http://hdl.handle.net/2263/61606.
Testo completoAbstract (sommario):
Groups of translocated orphaned juvenile African elephants were studied in holding pens and
following their release to assess how they re-organize and restructure socially by adopting roles,
and if they show behavioural signs of stress. An adult female adopted a young individual. In all
groups allomothering was observed to some degree. One 5 year old female prematurely
assumed the role of leader and this role appears to be learned. Most groups established a linear
dominance hierarchy.
Placing the trunk tip into a partner's mouth correlated with play-fighting and aggression. This
behaviour is suggested to be one of appeasement to reduce aggressive motivation and prevent
escalation thereof, and that the behaviour is ritualised. Four possible evolutionary steps are
presented.
Nearest Neighbour analyses illustrated the changing social positions of some juveniles relative to
other individuals. Tight grouping was assumed to indicate insecurity. There was a marked
difference in behaviour pattern during resting times. Groups without adults were within touching
distance of one another whilst resting. In a group containing an adult female some juveniles
dispersed more and some juveniles formed a subgroup. It appears that dominance hierarchies,
individual social relationships and caretaking of young were important factors which affected
group cohesion and could influence a more central position within a group.
Certain behaviour patterns were defined as being stress related and compared among the
groups. There was a significant decrease in arousal behaviour after the introduction of an adult
female. Aggressive behaviour was the most frequent behaviour in four groups whilst penned
and following their release. Play behaviour was absent in three penned groups, and tended to
gradually increase following the release. Temporal gland secretion occurred during excitement,
anticipation and nervousness. Secretion occurred in all age and sex classes. Females tend to
secrete more frequently than males and older individuals more than younger ones.
Frustrated or stressed animals vocalized more frequently than relaxed ones, as did calves below
2 years of age who tended to use louder calls, than older juveniles. Acoustical analyses of four
vocalizations are presented. Very young individuals appear to vocalize using marginally higher
frequencies.Dissertation (MSc)--University of Pretoria, 1997.
Zoology and Entomology
MSc
Unrestricted