The pine martens of Sweden
Words by Tim R. Hofmeester, Swedish University of Agricultural Sciences | Photograph credit to Tim R. Hofmeester, Swedish University of Agricultural Sciences
Within a large project looking into the timing of reproduction of seven medium-sized mammals, we are monitoring pine marten reproduction in three areas in Sweden (ranging from 57°N to 64°N). We are using a method developed by Vilmar Dijkstra in the Netherlands, using a wooden frame that we attach to a tree with a camera trap pointed towards the frame from a nearby tree. We bait the frames with peanut butter (which the pine martens love!). The frame is designed in such a way that the martens need to stand on their hind legs and reach for the peanut butter in a way so we can film their bib and belly (to identify individuals, sex, and hopefully lactation). Later in the season we also hope to monitor the family groups and whereabouts of kits if they stay in the area after the young of the year disperse. We started monitoring in summer 2024 giving the pine martens some time to find the bait stations. By now, most of the stations are visited by pine martens so we are thrilled to see what we will capture during the reproductive season of 2025.