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.

The European Brown bear (Ursus arctos) has gone from basically being extinct in Sweden to, 2008 being estimated to a total of 3298 individuals. When looking at the new Swedish moose management system it is important to have an ecosystem-based approach and therefore include all the parts that moose impacts on and from in the management, especially the brown bear. Primarily in the spring and early summer the brown bear is a significant predator on moose calfs which must be taken into account in moose management. When the bear recolonize areas that it has previously been eradicated from, it will once again come in contact with people who are not accustomed to the bear's role in the ecosystem. We studied three groups of moose management areas with different Predation by bears.

Predation is one of many factors that form the structure of the macroinvertebrate community in lakes, wetlands and watercourses. Earlier studies lack an examination concerning how fish- and waterfowl Predation affect macroinvertebrates during shorter periods in the spring. I performed an exclosure study in the shallow eutrophic Lake Tåkern which is located in the western part of Östergötland County, Sweden. The experiment was performed during a three week period (1-21 April 2012) when the water temperature was low and the density of migrating diving ducks was high. The experimental cages used included three out of four different treatments; general Predation (open cages), bird exclusion (net with mesh size 90*45mm) and no Predation (net with mesh size 1*1mm).

Turbot (Psetta maxima) and flounder (Platichthys flesus) are two species of flatfish both having their nursery areas around the shores of Gotland in the Baltic Sea. The common brown shrimp (Crangon crangon) is a known predator on newly settled plaice (Pleuronectes platessa) in the North Sea area and is also found in the Baltic Sea. Experiments were carried out to see if the brown shrimp is predating on juvenile turbot and flounder, and if so on which sizes, and if the brown shrimp prefers any of the flatfish species, and also to see if there is a difference between day and night in density of the shrimp, i.e. when the fish might be subjected to Predation. The results showed that Predation decreased with size for both turbot and flounder.

Prey species make behavioral decisions to reduce the perceived risk of Predation and the time spent vulnerable to Predation. Behavioral responses to predators are for example selection of specific habitat types and the presence of predators influence individual vigilance. Furthermore, there is a variation in feeding niches with different herbivores focusing their foraging effort on different vegetation types which is also expected to affect the choice of habitat. Behavioral data on anti-Predation and foraging behavior at on waterhole is collected from Thomson?s and Grant?s gazelles at Ol Pejeta Conservancy (0°00?N, 36°56?E) located in semiarid bushed grassland in Laikipia district of central Kenya.

The level of neonate mortality in a free ranging fallow deer (Dama dama) population at the Koberg estate in south western Sweden was investigated using radio-tracking techniques. During this study a total of 36 fawns (17 ?, 19 ?) were captured and marked with vhf or gps radio collars; 12 fawns in 2008 and 24 fawns in 2009. The neonate mortality calculated by the Kaplan-Meier method was 23.6 % and the mortality caused by Predation was low, since only 1 of 8 non-surviving fawns died from Predation by red fox (Vulpes vulpes). The spatial behavior of the fallow deer neonates were examined at two different levels i.e.

Benthic invertebrates play important roles as feeding resources for many organisms in different food webs. Shifts in Predation of these organisms can generate cascading effects and potentially lead to the disappearance of one or more species from a site. Cascading effects can bring impacts to organisms who aren?t even directly involved, why studies in this field are important for understanding sudden changes in ecosystems. I examined the Predation from fish and waterfowl on benthic invertebrates in the shallow and eutrophic Lake Tåkern in the plains of Östergötland County, southern Sweden.

Most studies regarding wolf (Canis lupus) Predation on moose (Alces alces) have focused on the total annual consumption of moose within a wolf territory but few have tried to describe the spatial impact of wolf Predation on a local scale. In this study I have analyzed wolf movement data, wolf Predation, moose hunting statistics and moose hunter observations to investigate how wolf Predation affects the human harvest of moose in Scandinavia. Since wolves prey on mostly juvenile moose during summer, analysis of their summer movement patterns is crucial to understand its impact on the human harvest later during autumn. In this study both reproducing (n = 45) and non-reproducing wolves (n = 12) reduced their movement range during summer to 66% and 67% of their annual movement range, respectively. Reproducing wolves increased their movement range from early to late summer while non reproducing wolves did not.

Prevention of lion Predation towards African livestock is of great importance due to the economical losses farmers have because of this. Predation is also one of the main reasons for human-wildlife conflicts and lions often get killed because of it. Therefore, a pilot study using camera traps was conducted to monitor movements of lions and other wildlife through a wildlife corridor in Ol Pejeta Conservancy. The results were compared with a previous study that counted prints in the soil in front of the corridor. Due to theft risk the cameras had to be taken down and pictures were only collected from nine days.

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..

Detta är ett naturvetenskapligt arbete som omfattas både av en kvantitativ och en kvalitativ undersökning. Syftet med arbetet är att undersöka mellanskarvens födoval i sjön Sommen, samt att närmare studera huruvida det unika beståndet av röding och öring ingår i mellanskarvens födoval. Sommens Fiskevårdsområde har fått tillstånd till skyddsjakt på mellanskarv av Länsstyrelsen och det främsta skälet skulle vara att fågeln prederar röding och öring. Genom att analysera mellanskarvens spyboll och jämföra innehållet med referensfiskar fångade från samma sjö ska vi se om beslutet från Länsstyrelsen är befogat. Insamling av spybollar och referensfiskar utfördes i fält medan analys av spybollar utfördes på laboratorium.

Populationerna av både vildsvin (Sus scrofa) och varg (Canis lupus) ökar i Sverige. Då deras utbredningsområden först nyligen har börjat överlappa finns i det närmaste inga data på vargars Predation på vildsvin i Sverige. Då detta är av intresse för den framtida debatten kring hur populationerna bör skötas, är syftet i denna studie att undersöka vargars Predation och vildsvins beteende i Europa för att kunna dra paralleller till hur de två populationerna kan tänkas komma interagera i Sverige. Att göra en studie kring ett rovdjurs val av byte är problematiskt eftersom så många variabler kan tänkas påverka, i kombination med mätmetoder som ofta inte är de mest exakta eftersom det handlar om vilda djur. I jämförelser mellan olika studier måste man dessutom väga in skillnader i val av metod och analys, så att komma med definitiva slutsatser i frågan är inte rimligt. Särskilt eftersom älg, som nuvarande är svenska vargars huvudsakliga föda, inte är så vanligt förekommande i Europa och jämförelser istället får utgå ifrån hur vildsvin föredras i förhållande till hjort. Vargars diet skiljer sig vida mellan de studier från Europa som undersökts, även mellan relativt närbelägna områden.

I norra Europa började tjädern minska under mitten på 1900-talet när det moderna trakthyggesbruket tog fart. Man har länge ansett att minskningen av tjädern orsakats av storskaliga avverkningar i gammal skog och att gamla lekplatser dog ut. Idag har omfattande forskning visat att tjädern är flexibel och kan spela även i brukad skog och att den inte är beroende av gammal skog. Den svenska tjäderstammen ligger på en stabil nivå som sakta ökar och varierar i kortsiktiga cykler från år till år. Det avgörande för häckningsframgången är antalet hönor och kycklingar som överlever sommaren och dödligheten orsakas i huvudsak av Predation de första veckorna efter kläckning.

Benthic invertebrates play important roles as feeding resources for many organisms in different food webs. Shifts in Predation of these organisms can generate cascading effects and potentially lead to the disappearance of one or more species from a site. Cascading effects can bring impacts to organisms who aren?t even directly involved, why studies in this field are important for understanding sudden changes in ecosystems. I examined the Predation from fish and waterfowl on benthic invertebrates in the shallow and eutrophic Lake Tåkern in the plains of Östergötland County, southern Sweden.

Den svenska älgstammen har i stort sett levt i frånvaro av björn och varg under större delen av 1900-talet. Istället har stammen reglerats genom en intensiv älgjakt. Nu har både björn och varg återetablerats i våra skogar och expanderar i antal och utbredning. Syftet med denna studie är att ta reda på hur återkomsten av dessa stora rovdjur påverkar älgstammens antal, köns- och åldersstruktur och beteende, samt hur älgförvaltningen påverkas av närvaro av björn och varg. Rovdjursstammarna är ojämnt fördelade över landet och även älgtätheten varierar. Därför kommer en del områden att påverkas mycket och andra väldigt lite.