Movements and flight morphology in the endangered Large Blue butterflies

Movements and flight morphology of the endangered Large Blue butterflies Phengaris teleius and P. nausithous in southern Poland were studied with mark-release-recapture surveys and GIS analyses. Most individuals moved relatively small distances (<40 metres) within their habitat patches. Distances covered by both species were positively related to season progression and wing length, and negatively related to body mass. P. teleius movement distances slightly exceeded those of P. nausithous. In addition, females moved longer distances than males, although the difference was significant only in P. teleius. Morphological traits appeared to be good indicators of the inter-specific and inter-sexual differences in mobility. While P. teleius individuals were heavier than P. nausithous ones, they had considerably longer wings, which may explain longer movements in the former species. Similarly, females were heavier than males in both species, but they invested more in wing size, which is likely to compensate for the negative impact of body mass on movement distances. Our results indicate that combination of GIS analysis of movement distances recorded with mark-release-recapture methods and morphometric measurements taken in field during non-lethal handling of captured individuals proved useful for studying the mobility potential of the endangered insect species.