Climate change scenarios predict losses of cold-adapted species from insular locations, such as middle high mountains at temperate latitudes, where alpine habitats extend for a few hundred meters above the timberline. However, there are very few studies following the fates of such species in the currently warming climate. We compared transect monitoring data on an alpine butterfly, Erebia epiphron (Nymphalidae: Satyrinae) from summit elevations of two such alpine islands (above 1300 m) in the Jeseník Mts and Krkonoše Mts, Czech Republic. We asked if population density, relative total population abundance and phenology recorded in the late 1990s (past) differs that recorded early in 2010s (present) and if the patterns are consistent in the two areas, which are separated by 150 km. We found that butterfly numbers recorded per transect walk decreased between the past and the present, but relative population abundances remained unchanged. This contradictory observation is due to an extension in the adult flight period, which currently begins ca 10 days earlier and lasts for longer, resulting in the same total abundances with less prominent peaks in abundance. We interpret this development as desynchronization of annual cohort development, which might be caused by milder winters with less predictable snow cover and more variable timing of larval diapause termination. Although both the Jeseník and Krkonoše populations of E. epiphron are abundant enough to withstand such desynchronization, decreased synchronicity of annual cohort development may be detrimental for innumerable small populations of relic species in mountains across the globe., Martin Konvička, Jiří Beneš, Oldřich Čížek, Tomáš Kuras, Irena Klečková., and Obsahuje bibliografii
Dvouletý vývoj housenek je přizpůsobením horských motýlů na chladné klima a může se následně odrážet ve výkyvech početností dospělců. U okáče rudopásného (Erebia euryale) jsou výkyvy početností dospělců doloženy z Alp, nicméně z nižších horských masivů informace o tomto fenoménu chybí. Článek poprvé dokumentuje střídající se cykly početnosti dospělců okáče rudopásného v pohořích českého a moravského pohraničí - v Hrubém Jeseníku, Krkonoších a na Šumavě., Biennial development of mountain butterfly larvae involves adaptation to a cold climate, and subsequently could correspond with the biennial fluctuations of adult butterflies. The adult fluctuations of Large Ringlet (Erebia euryale) are known from the European Alps, but information is missing from lower mountain ranges. We present the first quantitative assessment of biennial fluctuations of E. euryale in Czech and Moravian border mountains - Hrubý Jeseník, Krkonoše (Giant Mts.) and Šumava (Bohemian Forest)., and Irena Klečková, Martin Konvička, Jiří Beneš, Jana Šlancarová.