For whom the bells toll: Demography of the last population of the butterfly Euphydryas maturna in the Czech Republic

Abstract

The last surviving population of the scarce fritillary Euphydryas maturna (L., 1758) (Lepidoptera, Nymphalidae) in the Czech Republic was studied using mark-recapture methods in 2002 in order to assess adult population structure and mobility, and by annual censuses of larval nests since 2001. The population is restricted to clearings within an isolated lowland deciduous forest situated in a densely populated landscape. Modelling demography using constrained linear models revealed that adult survival was constant in time and lower in males than in females; catchability was equal in sexes and varied in time, while recruitment was constant in sexes and time. Total population size was extremely small, numbering less then 200 individuals. Mobility was well described by a negative exponential function. Less than 5 per cent of individuals are predicted to cross distances of 500 metres, and long distance movements were highly unlikely. We conclude that the butterfly persists as a dynamic metapopulation that tracks early successional woodland clearings. Under recent high-forest management, its long-term survival is highly unlikely and the only chance for preserving it in the long term is the re- establishment of traditional coppicing with standards, which should provide a more continuous supply of the butterfly's biotope.