Som bytesdjur måste zebran ständigt vara på sin vakt för att undvika att falla offer för ett rovdjur. De tre zebraarter som finns i världen är bergzebra, stäppzebra och Grevyzebra. De olika arterna lever på olika platser och de har även olika sociala strukturer. Inom flocken använder zebrorna sig av olika strategier som gör att rovdjuren får svårare att anfalla dem. En del av dessa strategier är zebrornas vaktbeteende då de hjälps åt att vakta flocken mot rovdjur i olika situationer.

Horse owner?s knowledge about horse feeding and nutrition is directly linked to the horse?s health and welfare. According to several studies, both Swedish and foreign, horse owners generally have inadequate knowledge about horse feeding. The housing systems and feeding routines of today differs in many ways from what horses have adapted to through evolution. Wild horses live in harem herds and roam on large open fields, spending about 60 % of the day Grazing, mainly grass and herbs.

Outdoor housing of horses? best fulfils the horses? need for physical activity and it is an alternative to the more cost and energy demanding indoor housing in stables. Furthermore, if outdoor housed horses have access to shelter they can generally cope well with adverse weather conditions such as high or low ambient temperature, heavy rain or strong winds. In this study, the daytime shelter-seeking behaviour of three groups of horses housed outdoors was studied during the summer. The aim was to evaluate whether shelter use is related to weather variables (e.g., ambient temperature and wind speed) and insect harassment. The shelter-seeking behaviour was studied for three different groups of horses: Group 1) eight individually housed horses in paddocks that had access to three different shelter types (C: closed on three sides with roof, R: open on three sides with roof, W: closed on three sides without roof), Group 2) 25 group housed mares with foals on pasture with access to shelters C, and Group 3) ten mares without foals on pasture without access to shelter. Each group was studied for eight days.

The following thesis is a study of the forest history on the island of Ängsön-Marskär concentrating on the last three hundred years. The island is located in the administrative province of Stockholm, the local community of Haninge and it is situated approximately seven kilometres east of the island Ornö in the south of the Stockholm archipelago. The questions this thesis attempts to answer are: How where the natural resources on Ängsön-Marskär used through the centuries? How has the state of the forests developed since the 16th century? How will the nature develop onwards? The thesis is based on archival sources for Ängsön-Marskär and the surrounding areas. A field study was conducted where the entire island was investigated using an objective forest inventory method. The first map material existing over Ängsön-Marskär is from the year 1711.

Nature conservation has for a long time been founded on the assumption that high ecological values depend on low human impact. In Sweden this has led to forests with these characteristics being strictly protected from human influences. However, it is also known that historical land-use can enhance ecological values in forests. Mountainous forests in Sweden, which have not been affected by modern forestry, have for a long time been considered as untouched by people. However, forest history research has in recent years shown that even these areas have been used by people for a long period of time.

Biodiversity is under threat in Sweden and many species are on the brink of extinction. This is mainly due to the large-scale drainage projects during the 19th and 20th century and the increasingly intensive land use in agriculture and forestry. The intensive land use with sharply defined boundaries between the production units has in many cases led to either overGrazing or overgrowing. As a result many species have been pushed back to "leftover" habitats like shooting ranges, power line corridors, roadsides, dumps, embankments and other similar areas. Therefore the question has been raised, wether or not it is needed to re-introduce large herbivores into the wild in order to maintain the biodiversity that is related to the extensive land use.This study has been conducted as a literature review and will focus on the European bison?s (Bison bonasus) impact on other species and biodiversity; conditions for reintroducing large herbivores in Sweden are also discussed.Free roaming populations of large herbivores have a positive impact on plants, insects and many other groups of organisms.

SAMMANFATTNING När man i tidigare undersökningar studerat betesgång för mjölkkor har klimatet på betet inte beaktats. En höglakterande ko producerar mycket värme som hon måste avge till sin omgivning för att kunna bibehålla sin kroppstemperatur. De sätt som djuret kan avge värme på är begränsade och påverkas av flera klimatfaktorer samt djurets genetiska och biologiska förutsättningar. Antalet dagar som registreringar gjordes under denna studie blev av flera olika anledningar få, 18 dagar. Klimatet utomhus under studien registrerat som globtemperatur varierade från 22,4 till 34,7ºC. Då djurskyddslagen skall främja djurens hälsa och djurets naturliga beteende fick en grupp 126 höglakterande kor möjlighet att välja uppehållsplats under tiden 26 juli till 11 augusti. 2004. Korna fördes ut på betet vid niotiden på förmiddagen och var därefter fria att gå in och ur stallet efter egen vilja tills de togs in för kvällsmjölkning omkring klockan tre påeftermiddagen.

Detta arbete är en litteraturstudie som handlar om hur deltidsbete påverkar mjölkkors avkastning, foderintag och välfärd. I Sverige har vi beteskrav till skillnad från många andra länder i världen. Detta skapar problem då besättningstorlekarna ökar och det blir svårare att få marker i närheten av gården att räcka till alla kor. Det största problemet med mjölkkor på bete är dock att högavkastande kor inte producerar lika mycket på bete som inne på stall. Det är därför viktigt att finna ett sätt att lösa problemen som både gynnar kon och bonden.

During the summer of 2005 a number of steer producers in Skåne, Sweden, found that their animals graded less favourable according to the EUROP carcass grading system when slaughtered, than ordinary. The aim with this project was to determine factors that affects the production result in steer production and to find the reason to the lower classification. The project was initiated by Anita Persson, LRF, Skåne and was preformed with supervision from Ingemar Olsson, SLU, and Jens Fjelkner, Skånesemin. Ten producers of dairy steers located in Skåne was chosen for this study. The producers were interviewed to collect information about their steer production with respect to their planning and results.