How Euphydryas maturna survived extinction in the Czech Republic : status of a relic population after intensive conservation management

In the Czech Republic, the scarce fritillary (Euphydryas maturna) had been considered extinct until the rediscovery of an extant population in Domanovicky les, Central Bohemia. Subsequent efforts to protect the locality were thwarted by disputes between landowners and researchers. In 2010, when the population size was reaching critically low levels, appropriate management was finally established at the locality. To evaluate the current status of the population, an intensive mark-release-recapture study was conducted in the area in 2016 and 2017, comprising several hundreds captured individuals. The total population size was estimated at 764 butterflies for 2016 and 518 butterflies for 2017. In comparison with the pilot study performed in 2002, the population size was slightly higher, but the dispersal rates were lower. These results indicate that Euphydryas maturna in the Czech Republic has managed to bounce back from a critical population size. On the other hand, the risk of extinction has not been averted due to continued habitat loss and stochastic environmental effects. Management efforts should aim to expand the habitats used by the breeding populations, at present predominantly confined to temporary forest clearings and to open canopy forest with low tree density. Moreover, assisted reintroductions of this only surviving population to the surrounding areas should be considered.