Jordbruksfåglarnas minskning i Stockholms län : En kvantitativ studie av fåglarna i jordbrukslandskapet

Sammanfattning: In the 1970s, a breeding bird survey was conducted to see how many birds are breeding in Sweden. This was done because the research at the time pointed out that there was a decrease in the number of bird species. This inventory became known as atlas inventory 1, and an additional inventory was done in the 2000s, which was called atlas inventory 2. The second inventory was carried out in order to see trends in bird population distribution and to be compared with atlas inventory 1. The purpose of this study was to examine if it is possible to compare the inventories with each other to see if there are any changes in the number of breeding birds in Sweden. The study was limited to the Stockholm report area, which includes all municipalities in Stockholm County except for Norrtälje. A limitation was also made to only examine agricultural birds, where six species were selected. The results show that the number of atlas squares with data for breeding birds within the Stockholm report area have decreased between atlas inventory 1 and atlas inventory 2. To obtain these results, information was retrieved from the website Artportalen, and was then compiled and processed in Excel and ArcMap. A comparison between the period 2013-2016 and atlas inventory 2 was also done, which showed a decrease in the number of atlas squares with available data, as well as a reduction in the number of observations of breeding birds.