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Background Habitat quality is one main trigger for the persistence of butterflies. The effects of the influencing biotic and abiotic factors may be enhanced by the challenging conditions in high-alpine environments. To better our knowledge in this field, we performed a mark-release-recapture study with Boloria pales in the Southern Carpathians. Methods We analysed population structure, movement and foraging behaviour to investigate special adaptations to the alpine environment and to reveal differences between sexes. We compared these aspects in one sector with and one sector without grazing to address the effects of grazing intensity on habitat quality. Results We observed “soft” protandry, in which only a small number of males appeared before females, and an extended emergence of individuals over the observed flight period, dividing the population’s age structure into three phases; both observations are considered adaptations to high mountain environments. Although both sexes were mostly sedentary, movement differences between them were obvious. Males flew larger distances than females and were more flight-active. This might explain the dimorphism in foraging behaviour: males preferred nectar sources of Asteraceae, females Caprifoliaceae. Transition from the grazed to the ungrazed sector was only observed for males and not for females, but the population density was higher and the flight distances of the individuals were significantly longer on the grazed sector compared with the ungrazed one. Conclusion Soft protandry, an extended emergence of the individuals and an adapted behavioural dimorphism between sexes render to represent a good adaptation of B. pales to the harsh environmental conditions of high mountain ecosystems. However, land-use intensity apparently has severe influence on population densities and movement behaviour. To protect B. pales and other high-alpine species from the negative consequences of overgrazing, areas without or just light grazing are needed. Electronic supplementary material The online version of this article (10.1186/s12983-018-0298-1) contains supplementary material, which is available to authorized users.

Boloria pales 13 Nachweise: n = 18 Bartholom��berg, Itonskopf, 2050 m, 28.08.1984 (D); Silbertal, Kristberg, Falle, 1750 m, 18.08.1983 (D); Silbertal, Kristberg, Ganzaleita, 1600 m, 15.08.1980 (D); Silbertal, Kristberg, Im Ried, 1500 m, 20.08.1984 (D); Silbertal, Kristberg, Obere Wiese, 1850 m, 26.08.1981; Silbertal, Ob. Wasserstuben Alpe, 1730-1850 m, 16.07.2006; 1900-2100 m, 16.07.2006; Silbertal, Ob. Fresch Alpe, Langer See, 1950 m, 20.08.1998; Schruns, Sennigrat/Wormser H��tte, 2280-2300 m, 07.08.2003; Gaschurn, Valschavieltal, Gaschurner Winterj��chle, 2150-2300, 25.07.2006; Gaschurn, Valschavieltal, Mardusa, 2100 m, 25.07.2006; Gaschurn, Valschavieltal, Rossberg Alpe, 2050-2200 m, 12.08.1993; Gaschurn, Valschavieltal, Valschavieler Winterj��chle, 2300 m, 25.07.2006; Gaschurn-Partenen, Verbellatal, Br��llender See, 2300-2350 m, 27.07.2006; Gaschurn-Partenen, Verbellatal, Heilbronner H��tte, 2400 m, 27.07.2006; Gaschurn-Partenen, Zeinisjoch, Zeinissee, 1850-1970 m, 24.07.2007, Published as part of Aistleitner, E., 2014, Biodiversit��tsforschung in Vorarlberg, Austria occ. Zur Schmetterlingsfauna des Verwalls - 1. Teil Tagfalter, Spinner und Schw��rmer (Insecta, Lepidoptera, Diurna, Bombyces et Sphinges sensu, pp. 221-290 in Linzer biologische Beitr��ge 46 (1) on page 274, DOI: 10.5281/zenodo.4526236

Several thousand specimens of arctic butterflies were accumulated in the Canadian Northern Insect Survey. When the distributions of the various species were recorded and plotted on a map, some evidence appeared that these insects entered Canada in postglacial times from the northwest, and from the south. There is also some evidence that a few may have come from the north. The most common invasion was from the northwest, and it appears that some, such as Erebia youngi Holl., probably entered Canada rather recently, as it is only known to occur in the Yukon. Boloria pales D. & S. occurs from the Yukon to within about 150 miles west of Hudson's Bay. Colias boothii Curt. occurs as far east as Southampton Island, and Erebia rossii Curt. is distributed to Baffin Island. Others such as Boloria polaris Bdv. have spread to northern Quebec and Labrador. Thus it appears that there are successive stages of distributional spread from the northwest.