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Pellet group count of roe deer ( Capreolus capreolus ) at Herrevad Abbey : How has the hunting affected the population and how will it develop?Olsson, Cecilia January 2011 (has links)
The land around Herrevad Abbey consists mostly of pastures with a lot of old coarse oaks, a touch of broad-leaved decidous forest andmixed deciduous and coniferous forest. In the year 2010 the Swedish Environmental Protection Agency became owner of the area around Herrevad Abbey, previously owned by the Swedish National Fortification Administration. A high pressure from hunting occurred during the Swedish National Fortification Administration ownership. This resulted in a decrease of the roe deer (Capreolus capreolus L.) population. A pellet-group count is a reliable, indirect inventory method that is used with high frequence within wildlife management since the 1930s. Pellet-group count is used in Swedish Wildlife research since the 1977 at Grimsö Research Station and today an increasing interest for this method is seen both in nature management, among hunters and in the Swedish Association for Hunters. Through a pellet-group count of a roe deer population, an underestimated index of the total density is shown, which means that the investigated population can be larger than the survey shows. The pellet-group count in this study covered 3,20 km-2 with a total of 315 plots. The plot had a circular shape and covered 10m2, which is recommended for roe deer surveys. Each plot was investigated twice, one round clockwise and one round counter clock-wise to increase the precision of the survey. The calculation showed 10,76 roe deer per 1,00 km-2 in winter population during 2010; with a 10% set-off for winter mortality and 8,22 roe deer per 1,00 km-2 in winter population with a 30% set-off. The density with 10,76 roe deer /km-2 is low compared to experimental plots at Bogesund, Ekenäs, where the population is estimated to around 17-23 roe deer/ 1,00 km-2. A calculation for carrying capacity shows that the population will reach the density limit within four years at Herrevad Abbey.
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Comparison of plot survey and distance sampling as pellet group counts for deer in SwedenEckervall, Anneli January 2008 (has links)
Wildlife management deals with problems concerning sustainable harvest, conservation of threatened species and adjustment of wildlife populations to levels acceptable to for instance forestry, agriculture, traffic and conservation interests. A detailed knowledge of the population is then required. It is therefore important to develop reliable and cost-efficient survey methods. The purpose of this study was to test the distance sampling method where objects are observed while walking along a line, as a way of counting deer pellet groups and to compare the results with ordinary plot surveys. The inventory speed for distance sampling increases with increasing amount of droppings/km2. The amount of droppings seems to have little or no effect on the inventory speed of the plot survey method. Therefore the plot survey method could be a better alternative than the distance sampling method when the densities of droppings are high and vice versa. When comparing the two methods estimates of animal densities with data (orally) from game managers based on other surveys and flying observations and estimations in the different areas, both methods showed too low density for red deer in Valinge. This indicates that the supplementary feeding seem to have an effect on the results of red deer density for both methods.
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Comparison of plot survey and distance sampling as pellet group counts for deer in SwedenEckervall, Anneli January 2008 (has links)
<p>Wildlife management deals with problems concerning sustainable harvest, conservation of threatened species and adjustment of wildlife populations to levels acceptable to for instance forestry, agriculture, traffic and conservation interests. A detailed knowledge of the population is then required. It is therefore important to develop reliable and cost-efficient survey methods.</p><p>The purpose of this study was to test the distance sampling method where objects are observed while walking along a line, as a way of counting deer pellet groups and to compare the results with ordinary plot surveys.</p><p>The inventory speed for distance sampling increases with increasing amount of droppings/km2. The amount of droppings seems to have little or no effect on the inventory speed of the plot survey method. Therefore the plot survey method could be a better alternative than the distance sampling method when the densities of droppings are high and vice versa.</p><p>When comparing the two methods estimates of animal densities with data (orally) from game managers based on other surveys and flying observations and estimations in the different areas, both methods showed too low density for red deer in Valinge. This indicates that the supplementary feeding seem to have an effect on the results of red deer density for both methods.</p>
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Comparison of existing ZOI estimation methods with different model specifications and data.Mukhopadhyay, Shraddha January 2020 (has links)
With the increasing demand and interest in wind power worldwide, it is interesting to study the effects of running windfarms on the activity of reindeers and estimate the associated Zone of Influence (ZOI) relative to these disturbances. Through simulation, Hierarchical Likelihood (HL) and adaptive Lasso methods are used to estimate the ZOI of windfarms and catching the correct threshold at which the negative effect of the disturbances on the reindeer behaviour disappears. The results found some merit to the explanation that the negative effect may not disappear abruptly and more merit to the fact that a linear model was still a better choice than the smooth polynomial models used. A real-life data related to reindeer faecal pellet counts from an area in northern Sweden were windfarms were running were analyzed. The yearly time series data was divided into three periods : before construction, during construction and during operation of the windfarms. Logistic regression, segmented model, and HL methods were implemented for data analysis by using covariates as distance from wind turbine, vegetation type, the interaction between distance to wind turbine and time period. A significant breakpoint could be estimated using the segmented model at a distance of 2.8 km from running windfarm, after which the negative effects of the windfarm on the reindeer activity disappeared. However, further work is needed for estimation of ZOI using HL method and considering other possible factors causing disturbances to the reindeer habitat and behaviour.
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