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

Factors influencing human-elephant conflict intensity: an assessment in the Bia Conservation Area, Ghana

Lavelle, Jessica 28 March 2011 (has links)
Human-elephant conflict (HEC) occurs across Africa and is a major threat to the continued existence of the African elephant. To effectively implement mitigation measures, a thorough understanding of the spatial and temporal patterns of HEC is required. This study used a systematic, grid-based geographical information system (GIS) to analyse the spatial and temporal relations of HEC intensity in 2004 and 2008 with underlying environmental variables in a forest habitat, the Bia Conservation Area (BCA), Ghana. Relationships between crop-raiding incident data, Moderate Image Resolution Spectroradiometer (MODIS) Enhanced Vegetation Index (EVI) values and remotely sensed derived data were investigated at a 10 km2 scale using principal components analysis (PCA) and correlation analysis. Crop-raiding was found to be clustered into distinct areas. The onset of crop-raiding in 2004 and 2008 can be attributed to seasonal variation in vegetation biomass. Decreases in EVI values were matched with crop-raiding incidents. The high number of crop-raiding incidents in 2004 could be attributed to the large fluctuations in vegetation biomass in comparison to 2008. HEC intensity was not significantly related to the environmental variables analysed at the 10 km2 scale. These results suggest that HEC intensity may be influenced by vegetation quality, soil mineral content and/or human density. A grid-based GIS system with a 10 km2 resolution used in combination with remotely sensed data and statistical tools is useful for identifying spatial patterns of HEC, even with relatively small incident data sets. The methods used in this study could be applied to other forest habitats experiencing HEC for comparative analysis. The influence of vegetation quality, soil mineral content and human density on HEC intensity in forest habitats requires further analysis.
2

Konflikten bakom vildsvinsproblematiken ur ett "Crop-raiding"-perspektiv  : med fokus på svenska lantbrukare

Törnqvist Igelström, Cecilia January 2014 (has links)
Vildsvinstammen har ökat snabbt i södra och centrala Sverige sedan några individer rymde ifrån fångenskap på 1970-talet. Vildsvin har aptit för jordbruksgrödor vilket resulterar i en konkurrens om dessa grödor mellan arterna människan och vildsvin i en s.k. interspecifik konkurrens. Detta utgör i sin tur en konflikt mellan jordbrukare och vildsvin. Denna konflikt verkar även förvärras av jägares förvaltningsmetoder som, enligt lantbrukare, innefattar ett bristande jakttryck och utfodring i för stor skala. Mina resultat kunde visa en konflikt mellan jägare och lantbrukare som även verkar förvärras på organisationsnivå, d.v.s. Jägareförbundet respektive Lantbrukarnas riksförbund (LRF). Vildsvin anses som oönskade av flera respondenter och samtliga tycker att jakt är viktigt. Det finns olika sätt att öka lantbrukares toleransnivå för vildsvin i lantbruk vilket i sin tur kan minska konflikten mellan lantbrukare och vildsvin. Icke-dödliga förvaltningsmetoder bör vara anpassade för vildsvinens fysiska förutsättningar för att minska skador på lantbruk. Dödliga förvaltningsmetoder som jakt bör innefatta en snabb död för vildsvinet, vilket kräver god kommunikation mellan jägare samt tränade hundar i syfte att leta reda på det skjutna vildsvinet ifall det första skottet inte var dödligt. / Wild boar population has increased rapidly in the south and central parts of Sweden since some individuals escaped from captivity in the 1970s. Wild boars have an appetite for agricultural crops resulting in a competition for these crops between the species man and wild boar, in a so-called interspecific competition. This in turn represents a conflict between farmers and wild boar. Management practices by hunters seem to enlarge the conflict, according to farmers there is a lack of hunting pressure and too much feeding. My results could show a conflict between hunters and farmers, which seems to worsen at an organizational level, Association of Hunters and the Federation of Farmers. Wild boar is considered as undesirable by several respondents and all of them agree that hunting is important. There are various ways to increase farmers' tolerance for wild boar in agriculture, which in turn can reduce the conflict between farmers and wild boar. To have an effect, nonlethal control should be appropriate for the physical conditions of wild boar. Lethal control should include a quick death for the wild boar, which requires good communication between hunters and trained dogs in order to locate the shot wild boar in case the first shot was not fatal.
3

Pests and pest controlling organisms across tropical agroecological landscapes in relation to forest and tree-cover

Lemessa, Debissa January 2014 (has links)
A major challenge in agroecosystems is how to manage the systems so that it reduces crop pests and enhances natural pest control. This thesis investigates patterns of crop pests and top-down effects of birds and arthropod predators in relation to land-use composition across spatial scales. In paper (I) I examined the crop distribution and land-use types in relation to the crop raiding patterns in 15 transectsin sites close to and far from forests along with a questionnaire survey at household level. I found severe crop raiding close to forests, but it had no impact on crop composition growing between the two sites. In paper (II) I examined the effect of forest and tree cover, at local and landscape scales, on the abundance of arthropod predators by collecting specimens from 40 home gardens. My result showed higher abundance of arthropod predators when either the home garden or the surroundings had a high tree-cover, compared to when tree-cover at both scales was similarly either high or low. In paper (III) I investigated the effect of excluding birds and arthropod predators on leaf damage on rape seed in 26 home gardens. I found stronger top-down impacts from arthropod predators on crop pests in tree-poor gardens than in tree-rich gardens. There was no effect of birds. In paper (IV) I explored the effect of landscape complexity on bird and arthropod predation using plasticine caterpillars in 36 home gardens across landscapes. The rate of arthropod predation on caterpillars was higher in simple than in complex landscapes. The rate of bird predation did not vary between complex and simple landscapes. In simple landscapes, arthropod predation was higher than that of birds. The overall results suggest that simplified gardens/landscapes still have enough habitat heterogeneity to support arthropod predators for the significant top-down controlling effect on crop pests. However, I did not find clear effect of complexityon the top-down effect of birds. / <p>At the time of the doctoral defence the following papers were unpublished and had a status as follows: Paper 1: Manuscript; Paper 3: Manuscript; Paper 4: Manuscript</p>
4

Going to come : gorilla crop-raiding in Cross River National P(Ark)

Norberg, Patrik, J E January 2008 (has links)
Due to recent crop-raiding incidents an eight weeks field study to survey threats to endemic gorillas have been conducted in Okwangwo Division of Cross River National Park, Nigeria. The report ratifies that smaller mammals than gorillas are responsible for a majority of damage done to Okwangwo farm crops. Additionally the report identifies issues that need to be dealt with in order to secure regional gorilla protection; most acute is the necessity to relocate three villages that remains within the park, and inclusion of villages that are excluded from Support Zone status in the Bumaji area. Collected data expands previously established gorilla range; therefore valuations concerning gorilla habitat range with non-specific suggestions for restructure of park borders are submitted.
5

Going to come : gorilla crop-raiding in Cross River National P(Ark)

Norberg, Patrik, J E January 2008 (has links)
<p> </p><p>Due to recent crop-raiding incidents an eight weeks field study to survey threats to endemic gorillas have been conducted in Okwangwo Division of Cross River National Park, Nigeria. The report ratifies that smaller mammals than gorillas are responsible for a majority of damage done to Okwangwo farm crops. Additionally the report identifies issues that need to be dealt with in order to secure regional gorilla protection; most acute is the necessity to relocate three villages that remains within the park, and inclusion of villages that are excluded from Support Zone status in the Bumaji area. Collected data expands previously established gorilla range; therefore valuations concerning gorilla habitat range with non-specific suggestions for restructure of park borders are submitted.</p><p> </p>
6

Human-chimpanzee coexistence at Bossou, the Republic of Guinea : a chimpanzee perspective

Hockings, Kimberley January 2007 (has links)
The increasing rate of human population growth has expanded the human-primate interface, with more conversion of natural primate habitat to agricultural land. Elevated levels of crop-raiding by primates are a by-product of natural resources becoming less available, and the nutritional riches of agricultural production becoming increasingly known to the primates. It was the aim of this thesis to focus on the Bossou chimpanzees’ (Pan troglodytes verus) perspective of their habitat in the Republic of Guinea, West Africa, the risks and opportunities presented by a human-dominated landscape, and to detail their day-to-day coexistence with humans. I combined a variety of data collection techniques, from focal, scan and ad libitum behavioural sampling of the chimpanzees’ daily activities, to broad ecological and habitat surveys. The chimpanzees rely on cultivated foods, and thus are forced to respond to humans. However, significant variation in the importance of various cultivars in the chimpanzees’ diet exists; certain cultivars are mostly fallback foods, while others are preferred food items and taken according to their availability in orchards and fields. The usage patterns of wild and cultivated foods by the chimpanzees of Bossou are thus inextricably connected. Whilst engaged in crop-raiding the chimpanzees exhibit several behavioural adaptations, namely a decrease in vocalisation levels, and increases in the transportation of food and specific vigilance behaviour. Adult males and adult male-only parties crop-raid more than other age- and sex-classes/compositions, and are more likely to take risks by raiding in exposed environments with increased risk of human confrontation. The use of human cultivars also affects the socio-sexual behaviour of the chimpanzees: chimpanzees appear to share the fruits of their risky labours (crop-raiding) as a food-for-sex strategy, which allow adult males to advertise prowess and enhance affiliative relationships with reproductively valuable females (Hockings et al., in prep). In addition, behavioural adaptations to other anthropogenic high-risk situations such as road-crossing were found, with the chimpanzees exhibiting impressive levels of socio-spatial flexibility and cooperation (Hockings et al., 2006). The chimpanzees’ level of anxiety (as measured by rough self-directed scratching) increases when dealing with some of the challenges posed by their physical and social environment. The chimpanzees of Bossou have been forced to adapt ecologically and behaviourally to the various costs and benefits of living in a human-dominated environment.
7

Efficacy of an Electronic Scarecrow on 4 Mammalian Crop-Raiders in Limpopo Province, South Africa

Richardson, Merrie Renee 01 August 2014 (has links)
In South Africa, 2 primate species, Chacma baboons (Papio ursinus) and vervet monkeys (Chlorocebus pygerythrus), and 2 nocturnal mammals, Cape porcupine (Hystrix africaeaustralis) and bushbuck (Tragelaphus scriptus), are among many species of crop raiders. Currently, cost-effective, non-lethal solutions are lacking. From June through December 2012, I installed novel electronic scarecrows on two commercial citrus orchards and a private reserve and used video-recording remote cameras to assess cropraiders’ reactions to them in Limpopo Province, South Africa. I used focal animal sampling data from treatment and control group animals to examine differences in activity budgets and behaviors of interest between groups. Compared to animals at sites with an inactive or no scarecrow, I hypothesized that animals in the treatment group would have altered activity budgets and rates of behaviors; that they would forage or feed less, run more (as a result of being frightened), be more vigilant and thus scan their surroundings more often, and display a visible startle in response to stimuli from scarecrows. Bushbuck at treatment sites spent a larger proportion of their activity budget running, and were more often startled. However, foraging was never observed, and bushbuck in the control group scanned their surroundings more often. Porcupines at treatment sites spent a larger portion of their activity budget running, though foraging was only observed in 1 control group animal and looking was never observed. For primates, treatment (control, scarecrow) was meaningful in explaining differences in focal animal activity budgets of baboons (F = 5.49, P = 0.001) and vervet monkeys (F = 7.09, P = 0.001) as indicated by a permutational MANOVA in R. In baboons, treatment was positively correlated with running; ratios of baboons that ran to baboons that did not run differed between treatment groups (G = 15.78, P < 0.001). Treatment was negatively correlated with feeding; ratios of baboons that fed or foraged to baboons that did not feed or forage differed (G = 5.39, P = 0.02). Significant differences between groups of vervet monkeys were not found with G-tests for the same behaviors of interest. Electronic scarecrows are promising tools for human-wildlife conflict mitigation, particularly for nocturnal antelopes. For primates, further innovation in design of scarecrows to incorporate a visual stimulus is recommended.
8

Forest Edge Effects on the Behavioral Ecology of L'Hoest's Monkey (Cercopithecus lhoesti) in Bwindi Impenetrable National Park, Uganda

Ukizintambara, Tharcisse 26 February 2010 (has links)
No description available.

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