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1020 Uppsatser om Prey selection - Sida 1 av 68

Födoval hos juvenil piggvar (Psetta Maxima) : effekter av bytesstorlek

The effects of prey size on prey choice in different cohorts of juvenile turbot (Psetta maxima)were studied in three nursery areas at Gotland. Prey length measurements showed that gobies(Gobiidae) increased in average length during the season, while mysids (Mysidae) did not.Experiments on predation capacity of different size classes of turbot on different size classesof prey showed that juvenile turbot easily can eat gobies that are up to two thirds of their ownbody length, while the body size of turbot does not have any effect on the predation capacityon mysids. Stomach content of 217 turbots, less or equal 35 mm, was analysed to see if therewas any change in diet during the season, but there was no significant change in diet. Theoverall conclusion was that early settlers most likely have an advantage due to greater accessof alternative prey..

Do prey-animals in zoos need predators?

Today is one of the goals with zoos to conserve endangered species and some animals may also become reintroduced. But behaviours can change in generations of captive animals because of environments that differ from the wild. Animals must then be prepared before being reintroduced and predator training enhances the animal?s chance to survive in the wild. When training animals to avoid predators it is often necessary to use frightening stimuli.

Predation som selektiv kraft bakom differentiering av populationer av sötvattensgråsugga, Asellus aquaticus

Predation is a strong dective force on invertebrate prey. Asellus aquaticus differs in pigmentation reed and submerged vegetation habitats in lakes. Light pigmented individuals al vegetation dominated by Chara sp. while dark pigmented individuals dominate in the reeds. These differences have been hypothesized to result from background matching.

Activity patterns of snow leopards (Panthera uncia) at their kill sites

The snow leopard (Panthera uncia) is an elusive felid, native to the mountains in central Asia. Basic knowledge about the snow leopards? ecology has long been lacking but is advancing with the help of the GPS-technology. GPS cluster analysis can provide insight in the diet and Prey selection of elusive predators, such as the snow leopard. Acceleration data from GPS collars can be used to study animal behavior but the two have never been combined to gain more detailed information of the feeding behavior of large carnivores.

Internetbaserad rekrytering: mål, möjligheter och praktiker : En fallstudie av urvalet vid rekryteringen av sommarvikarier i Luleå kommun

The purpose of this study is to examine web-based recruitment to short term summer jobs at the SocialServices Department in Luleå municipality in Sweden. Recruitment goals, selection options on therecruitment homepage Offentliga Jobb and recruitment practices were analysed in order to reach a deeperunderstanding of the interactions between these three levels in the selection process. Pre-selection throughOffentliga Jobb was a special concern of the study. Different consciousness levels in the selection process areemphasised according to Anthony Giddens' structuration theory. Ten recruiters from different parts of thedepartment were interviewed.

Klövspaltsinflammation : bakteriologi, terapival och möjliga anledningar till terapisvikt

Research concerning movement patterns of wild animals has been advancing since GPS technology arrived. But studying the snow leopard (Panthera uncia) is still difficult because of the harsh territory it inhabits in Central Asia. This study took place in south Gobi, Mongolia, and aimed to estimate the time spent at kills and the maximum distance away from kills between visits. Snow leopards were monitored with GPS collars that took a location every five or seven hours. Potential kill sites were established by identifying clusters of GPS-locations in ArcGIS and visited in the field for confirmation.

Comparison of two methods for evolving recurrent artificial neural networks for

n this dissertation a comparison of two evolutionary methods for evolving ANNs for robot control is made. The methods compared are SANE with enforced sub-population and delta-coding, and marker-based encoding. In an attempt to speed up evolution, marker-based encoding is extended with delta-coding. The task selected for comparison is the hunter-prey task. This task requires the robot controller to posess some form of memory as the prey can move out of sensor range.

Movement patterns of snow leopard (Panthera uncia) around kills based on GPS location clusters

Research concerning movement patterns of wild animals has been advancing since GPS technology arrived. But studying the snow leopard (Panthera uncia) is still difficult because of the harsh territory it inhabits in Central Asia. This study took place in south Gobi, Mongolia, and aimed to estimate the time spent at kills and the maximum distance away from kills between visits. Snow leopards were monitored with GPS collars that took a location every five or seven hours. Potential kill sites were established by identifying clusters of GPS-locations in ArcGIS and visited in the field for confirmation.

Genomisk selektion inom köttraser

Genomic selection (GS) is used for selection of breeding animals of dairy cattle. GS is though not as extensively used within the beef industry. One reason for that is the low accuracy (rTI) of the breeding value that is of great importance for the final genetic gain. Causes to the low accuracy are high effective population size, a small reference population and a genetically differentiated population. There is however a market for genomic selection with High Density (HD) tests for beef cattle.

E-böcker på högskole- och universitetsbibliotek ? En studie kring det digitala förvärvet

This study aims to find out how the selection and acquisitions of ebooks made by university libraries is affected by vendors terms of sale. The empirical data is based on interviews with libraries working with selection and acquisition of ebooks. The interviews points out, according to Evans? model of collection development, that the collection development doesn´t work the same way with printed and electronic books. The study also finds out that the complexity of the ebook marketplace implies the application of new method of ebook selection, by libraries..

Effektivisering av urvalsprocesser vid analysering av björnspillning : Ett förslag till den svenska förvaltningen av brunbjörn Ursus arctos

The aim with this report is to formulate a strategic method to optimize selection processes of DNA-samples from a faeces inventory to identify as many individuals in as few analyzes as possible, and by that keep down the costs of brown bear management. Brown bear management in Sweden founds today on results from faeces inventory and is substantially led by the county administration boards. Data from the years of 2004 and 2009´s inventories in Västerbotten was used to test and evaluate different methods in selection processes of which faeces that should be sampled. Comparison were made between making selection by chance, by spatial distribution and by calculating variations in logistic regressions coefficient b, in other words bear density and probability in finding same individual in several faeces. We can show making selection by chance is the most uncertain method.

Bilderboken i förskolan : Vad pedagoger tar hänsyn till när de väljer böcker

The aim of this study is to increase the knowledge regarding the selection process of picture books by pre-school educators. My intention is to find out which criteria educators use to select the books. I have restricted the study to pre-school educators, because I wish to find out how they work with the selection process and which criteria and considerations are included. I also want to know if the children have influence in the book selection and how the books get to the pre-school.The study is based on qualitative interviews with educators at a pre-schools in my area as well as relevant publications. The questions the educators were given were semi-structured.

Gymnasieungdomars kostvanor under skoldagen och deras uppfattningar om skolkafeteriornas utbud

The aim of this thesis was to investigate whether the selection of products in the school cafeterias in Uppsala county high schools' comply with NFA's (National Food Administration) recommendations. Furthermore, the intention was to examine pupils´ eating habits before and during the school day, and their views on the school cafeteria´s selection of products. To investigate this, an inventory of school cafeterias in six high schools in Uppsala County, and a survey among 60 pupils were carried out. The results showed that the NFA's recommendations not always were followed. The survey showed that there were healthy products in the cafeterias but unhealthy products nevertheless constituted a large part of the selection.

Effekter av "Billigaste väg" för Stora Enso Skogs transportverksamhet :

Transportation constitutes a large part of the forest industry's raw material costs. Transport also contributes a significant proportion of the carbon dioxide emissions. In order to reduce both the cost and environmental impact different types of decision support are required. These, in turn, require extensive information about the road network and correct information on road path selection and transport distances. In the development of national road data base for forestry (SNVDB) a road selection application has been included.

Pre-spawning habitat selection of subarctic brown trout (Salmo trutta L.) in the river Vindelälven, Sweden

Habitat selection of migratory brown trout at the upper reaches of River Vindelälven, wasstudied in September during the pre-spawning period. The fish migrate from down- orupriver lakes for spawning in the river and data was collected by habitat mapping andradio-telemetry. Habitat selection of fish was analysed with preference curves andstatistical modelling, using the physical variables; depth, stream velocity and streambedsubstrate. Preference curves were derived by comparing fish habitat use with their nearbyavailable environment while the statistical modelling aimed to answer three main questions.1) Do the trout have a specific preference of depth, water velocity and streambed substrate?2) Is there any difference in habitat selection between sexes? 3) Is there a shift in habitatselection over time? The preference curves indicated that trout favored water depths of 1-2m, velocity compositions characterized as glides (c.

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