In Scandinavia, Capercaillie are often associated with pine trees (Pinus sylvestris) in winter, with pine needles as the main diet. Few dietary studies have been conducted in Sweden and winter diet is subject to little debate. The interesting thing is that this "pine specialist? is also found in spruce (Picea abies) forest habitats where pine is scarce or unavailable. In many studies outside Sweden (primarily Central Europe) spruce is regularly observed in the winter diet, but I have found no reports on the selection of the diet in spruce forest areas in Sweden.

In the report parasites in the gastrointestinal tract and easily visible external symptoms of disease in Capercaillie, (Tetrao urogallus), was taken into account. The study was based on results from the examination of 62 fresh faecal samples, collected in spring 2003, and postmortem examination of 22 frozen birds that were collected between 1999 and 2003. All of the samples principally were from the north of Sweden. In total, 4 species of parasites, but no significant symptoms of disease were found. In the faeces low levels eggs of the roundworms Capillaria spp. (125 epg) and Ascaridia spp.

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.