Whats happening to the Scarce and Dusky large blue populations?
In July and August, the Centre for Cartography of Fauna and Flora (CKFF) carried out inventory of habitats of scarce (Phengaris teleius) and dusky (Phengaris nausithous) large blue butterflies. The main aim of the inventory was to identified important habitats as a basis for conservation agreements with land owners and as a basis for monitoring of the effectiveness of the conservation measures.
Scarce large blue (photo: G. Domanjko)
Scarce large blue is widespread in Slovenia, but rare, while the dusky large blue occurs only in NE Slovenia. Both butterflies are habitat specialist as they require not only the presence of the caterpillars food plant – the great burnet (Sanguisorba officinalis), but also the presence of the red ants as the butterflies spend the winter within the nests of the ants and feed on ant grubs. Goričko is one of the areas with the highest population density of this two species in Slovenia and together with Őrség National park in Hungary even maintain the largest continous distribution of this two butterflies in Central Europe. Both species occur in higher numbers in the eastern and central part of Goričko than in western part but unfortunatelly its habitats are decresing each year.
Selected 23 ha of meadows within Natura 2000 site Goričko were examined by CKFF, additional 300 ha of meadows were examined for the purpose of identifiying appropriate and the most important habitats for concluding conservation agreements.
Scarce large blue was present on 149 ha of meadows, while dusky large blue was found on 150 ha. In total 871 scarce large blue butterflies and 1119 dusky large blue butterflies were registered. More about the survey in report (in slovenian language).
