Population ecology of the endangered butterfliesMaculinea teleiusandM. nausithousand the implications for conservation

Abstract

AbstractButterflies of the genusMaculineaare highly endangered in Europe. The cuckoo speciesM. rebelihas been thoroughly investigated through both empirical and modelling studies, but less is known about the population ecology of predatoryMaculinea. We present the findings of a 2‐year research study on sympatric populations of two endangered butterflies:Maculinea teleiusandM. nausithousin the Kraków region, southern Poland. The study comprised mark–release–recapture sampling and laboratory rearing of butterflies from larvae collected in the field. For both species the sex ratio was slightly, but consistently, female‐biased and there was little year‐to‐year change in the seasonal population sizes. Daily numbers showed greater variation between the 2 years of the study due to the differences in daily survival rate. The average life span of laboratory‐raised butterflies kept in ideal conditions was more than 6 days, compared to only 2–3 days in the field. The recruitment of both males and females consistently followed a bimodal pattern. A small proportion of individuals (maximum 25%) changed sites, in spite of relatively short distances of ca. 100 m separating them. The results indicate that populations of both species are typically stable within their sites, possibly due to larval polymorphism, but there is little inter‐site mobility and thus landscape corridors seem necessary to enhance metapopulation viability. A further problem to be considered in the conservation ofMaculineabutterflies is the fact that their very short life span in relation to flight‐period length reduces the effective population size.