This dataset contains the results of the yearly summer camp of the Field Study Group (Dutch Mammal Society), organized from July 22th to August 2nd 2010 in Patvinsuo National Park, northern Karelia, Finland. The mammals of Patvinsuo and its surroundings were the main object of study, using various methods. Live traps were used to identify small mammals like shrews and mice. Data on bats was gathered with bat detectors and mistnets and a harp trap.Other mammal species were observed visually or by use of camera and video monitors. While recording mammals, attention was given to insects (butterflies, dragonflies and grasshoppers), amphibians, reptiles and birds as well. Locations were recorded with GPS.