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50 Uppsatser om Carnivore predation - Sida 3 av 4

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Common species of freshwater mussels may, like the freshwater pearl mussel (Margaritifera margaritifera) have a drastic decline in number and there is several reasons, like sedimentation, a decline of host fishes, introduction of alien species, nutrition leakages from agriculture and pollutants of medic drugs and poison. Ann Gustavsson made in the year of 2007 a study over rejuventation of freshwater great mussels in nine watersystems and considered that the rejuventation within the populations were all along the line poor. This study orients from her work and points to determine if there is a connection between the poor juventation and pollution of nitrogen and phosphorous from industries and private sanitations. The study was performed with the software program ArcGIS9.2 to take out drainage areas for the concerned habitats and contact was made with the concerned authoritys. When it comes to supervision of private sanitations is it the countys and for industries is it the county administrative board.

Större och mindre växtätares samexistens : Möjlig interaktion och effekt på lokal biodiversitet

The purpose of this report was to investigate to which extent local presence of large herbivore mammals (Alces alces, Cervus elaphus, Capreolus capreolus, Dama dama and Sus scrofa) covaries with small rodents (Myodes glaerolus, Apodemus flavicollis and Apodemus sylvaticus? The hypothesis was that high abundance of wild ungulates would inhibit the density of small forest rodents. The data was collected during field work within FoMA (Environmental Monitoring Assessment)/SLU (Swedish University of Agricultural Science). The Ungulate dropping inventory and rodent trappings, which is the base in this report, where performed 2012 ? 2014 in Gnesta/Nyköping municipalities (G/N) with a relatively high density of wild ungulates and Vetlanda/Växjö municipalities (V/V) with relatively lower wild ungulate density.

Påverkar kallt och blött väder vid kläckning överlevnaden hos tjäderkycklingarna (Tetrao urogallus L.) i Sverige?

Tjäderpopulationen Tetrao urogallus L. har under det senaste årtiondet minskat i täthet i stora delar av sitt utbredningsområde. Det är därför viktigt att undersöka faktorerna som kan påverka tjäderns fortplantning och överlevnad. Det råder delade meningar kring den främsta orsaken till nedgången. De flesta är eniga om att klimatet har en påverkan, men samspel mellan olika faktorer och lokala förhållanden är oftast avgörande för hur stor denna påverkan blir.

Migration losses of Atlantic salmon (Salmo salar L.) smolts at a hydropower station area in River Åbyälven, Northern Sweden : passage fates at a reservoir, a power house and a bypass structure

A large number of rivers in northern Sweden have hydropower developments that cause negative effects on both up- and downstream migrations of anadromous species like Atlantic salmon. So far, most attention has focused on the hindrances of adult fish during their upstream spawning migration. However, since turbines in power stations cause losses on downstream passing fish, the focus on negative effects on smolts has increased. The aim of this study was to compare three different causes of losses of salmon smolts passing downstream through a power station area in the flow-controlled River Åbyälven in northern Sweden.A total of 61 wild salmon smolts were caught and radio-tagged in the River Åbyälven during their downstream migration in June 2009. The salmon smolts were released at three locations, 1.1 km upstream from the power station, in the turbine intake and in the upper part of a fishway, acting both for up- and downstream fish passage.

Finns det något samband mellan stormusslors (unionoida) föryngring och utsläpp i närheten av dess levnadsmiljö? : en jämförelse mellan vattendrag i Västra Götaland

Common species of freshwater mussels may, like the freshwater pearl mussel (Margaritifera margaritifera) have a drastic decline in number and there is several reasons, like sedimentation, a decline of host fishes, introduction of alien species, nutrition leakages from agriculture and pollutants of medic drugs and poison. Ann Gustavsson made in the year of 2007 a study over rejuventation of freshwater great mussels in nine watersystems and considered that the rejuventation within the populations were all along the line poor. This study orients from her work and points to determine if there is a connection between the poor juventation and pollution of nitrogen and phosphorous from industries and private sanitations. The study was performed with the software program ArcGIS9.2 to take out drainage areas for the concerned habitats and contact was made with the concerned authoritys. When it comes to supervision of private sanitations is it the countys and for industries is it the county administrative board.

Synchronizing migration with birth: an exploration of migratory tactics in female moose

Migration and giving birth are crucial decisions for animals during their life cycle, which may have lasting consequences on their population demography and fitness. Migration can entail a variety of possible effects for an individual, such as access to high quality food and reduced risk for predation. The moose (Alces alces) in northern Sweden is partially migratory and moose females are known to give birth to one or two calves. The synchrony between time of calving and timing of migration has not been compared before, especially in terms of energy maximizing and time minimizing perspectives, which may provide vital cues for fitness benefits of migration. I investigated effect of timing of birth and individual life history on distance, timing, stopovers and duration of 190 individually marked female moose that have been tracked for multiple years in ten different areas in northern Sweden.

Är den starkt växande vildsvinspopulationen ett hot mot tjäderns reden?

This case study is based on a previous documented method of manufacturing artificial nest containing pre-colored hen eggs. This method is going to be used to find, if the wild boar population, which is growing in number, is a threat to the capercaillie population.  In comparison to the wild boar population, the capercaillie population is diminishing in different parts of Sweden.  In order to find out if they are affect by each other, the case study was carried out during the months of April to May 2009. 100 artificial nests were placed out on various locations on the Södertuna estate just in the outskirts of Gnesta. The unique aspect of this study is that a fenced environment to keep out wild animals is used to conduct this study, which has been previously known to be free from wild boar, but the area outside has sittings of wild boar. So to fully understand how this affects the capercaillie population, 50 of the nests were placed outside the fence area, while the other 50 nests were placed inside the fenced area. The sites were visited on two separate occasions, and were noted of the changes inside and outside the fenced compounds.

Kan man genom kartstudier förutse häckningsframgång för ängshök (Circus pygargus) i Uppland? :

Montagu´s harrier (Circus pygargus) is a diurnal, Eurasian raptor, which migrates from its northern breeding grounds to winter in sub-Saharan Africa. In Sweden, its core breeding area is centred on the island of Öland, with a stable breeding population of approximately 40 pairs. The province of Uppland is on the northern end the distribution range, where 4-8 pairs have regularly bred since the 1980s. In Sweden, the Montagu?s harrier is classified as an endangered (EN) species. This classification is partly due to a lack of preferred nesting habitat, such as shrub-lands or dense wetlands with Claudium spp.

Herrelösa katter i Skåne : problem och hantering

The large number of surrendered and feral cats is a big animal welfare problem all over the world. Populations of feral cats arise through a large number of unwanted cats which can lead to surrender of these, through cats allowed to roam free outside which can lead to the owner losing these and through the reproduction that occurs amongst these surrendered or lost cats. One aim of this study is to give an account of this problem. It is however difficult to draw general conclusions about these populations of cats since studies all over the world has been carried out on different types of populations, during different conditions and different periods of time. The welfare of many of these cats is presumably low because they are exposed to risks as disease, starvation, climate, traffic, other animals and humans.

Den regionaliserade rovdjursförvaltningen: Om demokratisk legitimitet

Under det senaste decenniet har en förändring skett i formerna för samhällsstyrning, vilket ofta beskrivs som en övergång från government till governance (Hill, 2007: 18-20). De governancebetonade styrprocesserna vilar på andra demokratiideal än det traditionella representativa, nämligen det deliberativa ? vilket i praktiken innebär såväl begränsningar som möjligheter för demokratin. Ett brett deltagande, närhet till medborgarna och effektivitet tycks vara de nya ledorden för statlig styrning (Ostrom, 1994; Carlsson & Berkes, 2005; Píriz, 2005), samtidigt som forskare befarar att andra demokratiska kärnvärden såsom ansvarsutkrävande och politisk jämlikhet riskerar att hamna i skymundan (March & Olsen, 1989: kap 7). Hur övergången till nya styrformer påverkar demokratin, ur en legitimitetsaspekt, är en aktuell fråga i Sverige då governancepräglade styrprocesser såsom samförvaltning blivit ett vanligt inslag i den svenska förvaltningsmodellen.

Den smältande polarisens effekt på de endemiska valarna i Arktis

Klimatförändringarna har en stor påverkan på de arktiska valarna grönlandsval (Balaena mysticetus), vitval (Delphinapterus leucas) och narval (Monodon monoceros), mer än vad som tros vid en första tanke. I dagsläget får dessa valar utstå stora utmaningar som troligenkan komma att förvärras i framtiden om inte isens smältande kan bromsas. En del av utmaningarna innebär att valarna måste genomgå stora förändringar för att överleva, vilket innebär att deras förmåga att anpassa sig spelar en stor roll. Människans jakt på valen har alltid varit ett stort problem för de arktiska valarna, tack vare restriktioner om fångstkvoter och vem som får jaga val ser framtiden ljusare ut i alla fall för grönlandsvalen och vitvalen. För narvalen ser det dock inte lika ljust ut eftersom det är en art som är känsligare än många andra arktiska arter för effekterna som den globala uppvärmningen har på den arktiska miljön.I dagsläget har en del effekter på valarna blivit synliga såsom ändrade migrationsvanor och ökad predation.

Effekter av predationsrisk på sånglärkors (Alauda arvensis) habitatval på åkermark

Along with other European farmland birds, the skylark (Alauda arvensis) has declined rapidly since the 1970?s. Between 1975 and 2003, the Swedish population of skylarks declined with 64 %. In Britain, the decline is often explained by alterations in farming practices in general and the shift from spring-sown to winter-sown cereals in particular. The dense vegetation structure of winter cereals is limiting the number of breeding attempts possible, causing the entire population to decline.

Social and economic consequences of wolf (Canis lupus) establishments in Sweden

Wildlife contributes with many benefits to humans but also brings economic costs. From being eradicated in Scandinavia the grey wolf (Canis lupus) is returning to South-Western Sweden and people are not used to its presence. In Scandinavia carnivores have to co-occur with humans in a landscape used for many different interests. Consequences of wolf establishments are e.g. competition for moose, depredation on sheep and attacks on hunting dogs.

Isbjörnars (Ursus maritimus) interaktioner och hägnutnyttjande på Orsa björnpark

SAMMANFATTNINGIsbjörnen är mycket populär hos djurparksbesökare och en viktig symbol för klimathotet, trots detta finns fortfarande många frågetecken kring hur vi ger isbjörnar i djurparker hög välfärd. I litteraturen har vi länge talat om isbjörnar som solitära djur men trots detta låter vi dem ofta dela hägn med andra isbjörnar på djurparker. Det har observerats positiva effekter av grupphållning av isbjörnar, bland annat sänkt förekomst av stereotypa beteenden, men vi måste vidare utreda vilken påverkan det har på deras välfärd. Ytterligare problem för isbjörnar på djurparker är stereotypt vankande som har observerats hos flertalet karnivorer som i det vilda rör sig över stora områden eller hemytor. Syftet med denna studie var att titta på hur isbjörnarna på Orsa björnpark utnyttjar sitt hägn, vilka beteenden som kan observeras samt hur stor del av observationerna de spenderar tillsammans.

Varför är Grevyzebran men inte Grantzebran utrotningshotad?

Det finns tre arter zebror i världen ? stäppzebra, bergszebra och Grevyzebra. Bergszebran och stäppzebran har dessutom en del underarter. Grantzebran är en underart av stäppzebra som lever i östra Afrika, bl.a. i Kenya.

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