On three evenings of extremely hot days in July of 2018 and 2019 large groups of high-flying Spotted Darter (Sympetrum depressiusculum) were encountered in the Woldlakebos in the northwest of Overijssel. These swarms were not migrating but stationary. They were foraging on little insects that under these weather conditions were able to fly high.
The availability of opportunistic dragonfly data in the Netherlands spanning >100 years gave us the opportunity to quantitatively assess long term changes in range size. We estimated changes in the number of occupied 5 km × 5 km sites by applying a modified List Length method, which takes into account changes in observation effort. Trends […]