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Artheriosclerosis in the African elephantMcCullagh, Keith Graham January 1970 (has links)
No description available.
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On the ecology and behaviour of the African elephantDouglas-Hamilton, Iain January 1972 (has links)
No description available.
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Genetic variation of the forest elephant Loxodonta africana cyclotis across Central AfricaJohnson, Mireille Bawe January 2008 (has links)
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.
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On the ecology of the Asian elephant Elephas maximum Linn. with particular reference to Malaya and Sri LankaOliver, Robert Charles Dacres January 1978 (has links)
No description available.
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A study on elephant and human interactions in Kodagu, South IndiaNarayana, Malavika Hosahally January 2014 (has links)
Increasing human populations have resulted in the extensive conversion of natural forests and range lands into agricultural lands, resulting in an expansion of the interface between people and elephants across the elephant range countries of Asia and Africa. This interface describes the nature of two-way interactions between people and elephants, which can be positive and reverential or hostile and negative. Elephant crop-raiding, one of the most negative interactions for people at the interface, is not only the result of decreased food resources and space, but has also been attributed to a preference for cultivated crops and to damage caused during elephant movements between habitats. The aim of this thesis was an attempt to understand the use of coffee agroforestry areas by elephant populations in a South Indian district, Kodagu, and to assess the risks to elephants and people of coffee plantations. Geographically, located at a significant position in the Western Ghats, Kodagu district is a part of one of the largest wild Asian elephant ranges harbouring India’s largest elephant population. Kodagu has a unique topography and coffee agroforestry system in considered as the boon for conservation. This thesis is the first long term (one year) study on the elephant populations using coffee estates in Kodagu. Crop-raiding events across Kodagu and their intensity of occurrence were determined from the Forest Department compensation records. Virjapet taluk was one of the three administrative units of Kodagu with frequent incidences of crop-raiding, including elephant mortality and human deaths. High rates of crop-damage in Virajpet included both coffee and paddy rice produce as the land is conducive for the cultivation of both. To understand the use of coffee estates by elephants, coffee estates in Virjapet were directly and indirectly monitored for the presence of elephants using dung sampling (N=202), camera trapping, video and photo documentation, as well as sightings (N=408) and reports by local workers, in order to identify the individuals or groups of elephants frequenting these coffee estates. Lone male and all male groups used coffee estates most frequently and family herds ranging in group size from 2 to 10 were present mainly during the peak season of coffee ripening (post monsoon). Presence of large numbers of elephants, especially with large female groups, was associated with crop-damage during the months of December-January. As seasonal movements of elephants in Kodagu districts are still not known, it is unclear why the number of elephants in coffee estates post-monsoon increases when food availability should also be higher in forests. These large coffee estates were used as refuge areas by elephants during the day by all individuals and groups, and feeding on estates occurred during the night to early morning hours. Dung analysis and observations suggested that coffee estates were attractive for elephants due to the constant availability of water (for irrigation), green fodder, and cultivated fruit trees, especially jackfruit. Coffee plants were damaged both due to consumption (47% of dung samples in this study) and accidental damage during elephant movements within the estates. Although the dung sampling could not confirm whether coffee had become a novel food resource, the presence of large number of elephants during the coffee ripening season suggested that the potential for coffee berries to be added regularly to the diet in the future, with potential consequences for coffee invasion of native forests through dung seed dispersal. People working on large coffee estates were accustomed to the presence of elephants and were generally knowledgeable of the areas that elephants frequented, thus avoiding fatal encounters. However, safety of farmers and other people working on the estates remains a major concern, especially for large coffee estates owners. The constant interaction between elephants and people also led to more negative perceptions of elephants, and reduced the tolerance of elephants in the area. The unique topography of Kodagu as a mosaic of forests and farms challenges the number of possible mitigation methods to prevent negative encounters between people and elephant. The elephants of Kodagu may have adapted behaviourally to the presence of people, but long-term monitoring of the elephant population is important to understand their ecological and social adaptations to the various costs and benefits of using this agroforestry landscape. Suggestions for management of the elephant-human interface and mitigation of negative attitudes and actions were made, through a model that incorporates a multiple stakeholder (including elephants) action plan.
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A comparative cognition perspective on the production and use of visual signals by African savannah elephants (Loxodonta africana)Smet, Anna F. January 2015 (has links)
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.
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