Dispersal and colonisation history of Leucorrhinia caudalis in Switzerland - Leucorrhinia caudalis is considered a threatened dragonfly species in Central Europe. In Switzerland, the species was formerly widespread in the lowlands, but only a single known population was left in the 1980s. However, a spread has been observed in the 1990s, where close-by ponds at a distance of 0.5-7 km have been colonised. Additionally, two new populations at distances of 30 km and 50 km were discovered in the 2000s. In the present study, a combination of a mark-resight study with genetic methods was applied to investigate current migration and genetic footprints of colonisation history in Switzerland. Both the mark-resight and the genetic study showed that L. caudalis is a sedentary species that migrates only rarely, seldom exceeding distances of 5 km. The genetic results reflected the recent colonisation history in Switzerland. The oldest and largest population was genetically the most variable and acted as source for recent colonisations. The close-by but only recently founded populations also showed high genetic variability, implicating that close ponds are relatively easily colonised and establish well if functional connectivity is ensured.