The Marsh fritillary (Euphydryas aurinia) (Lepidoptera: Nymphalidae) has declined across Europe, including the Czech Republic. Current conservation strategies rely on prevention of habitat loss and degradation, and increase in habitat quality and connectivity via promoting traditional grassland management. The population structure and adult demography parameters of a single population was investigated for eight years (single system), and of all the known Czech populations (multiple populations) for a single year, using mark-recapture. There was substantial variation in the patterns of adult demography, both among years in the single system and among the multiple populations in a single year. In the single system, the date of the first flight of an adult varied by 18 days over the 8 years and total annual numbers varied with a coefficient of variation of 0.40 (females fluctuating more than males). The average density was ca 80 adults/ha. The population size displayed density-dependence, i.e. decreased following years with high adult numbers, with an equilibrium density of 90 individuals/ha. The average density of the multiple populations was ca 120 individuals/ha. The estimated total population for the Czech Republic was 25,000 individuals (17,000 males / 8,000 females) in 2007, which does not indicate an imminent threat of extinction. The regional persistence of E. aurinia is likely to depend on re-colonisation of temporarily vacant sites by dispersing individuals, facilitated by local shifts in adult flight phenology to that better adapted to local conditions. and Kamil Zimmermann, Pavla Blazkova, Oldrich Cizek, Zdenek Fric, Vladimir Hula, Pavel Kepka, David Novotny, Irena Slamova, Martin Konvicka.
S jedinou přežívající populací se hnědásek osikový (Euphydryas maturna) dlouho pohyboval na předních místech žebříčku našich nejohroženějších denních motýlů. Česká populace tohoto druhu chráněného domácí i evropskou legislativou je již 8 let bedlivě monitorována, aniž by se ovšem uskutečnily kroky k aktivní ochraně jejího stanoviště. Nejnovější zjištění z r. 2009 ukazují, kam pouhá zákonná ochrana bez aktivních opatření u kriticky ohrožených druhů vede. Hnědásek osikový s vazbou na dnes již zapomenuté typy lesního hospodaření se dostal na samou hranici vyhynutí. and Having had the only remaining population, the Scarce Fritillary (Euphydryas maturna) has long been ranked among the rarest butterfly species in the Czech Republic. The most recent information from 2009 shows that only formal legislative protection without appropriate management practices cannot improve the conservation status in critically endangered species. Because the Scarce Fritillary needs methods of forest management which have nowadays been forgotten, it has been pushed to the verge of extinction.