Abstract
One of the major concerns in rural areas these days is destruction of habitats of aquatic animal life and consequent loss of biodiversity, partly attributed to implementation of farmland consolidation projects. To cope with this problem, increasing efforts have been made to create animal sanctuaries in and around project areas. What we have yet to know, however, is how best to space these sanctuaries across the tracts of consolidated farmland. Obviously an index for their minimal spacing required is the dispersal distance of the aquatic life in question.
In this study, we targeted at the aquatic dragonflies of the Ischnura asiatica, supposedly low in flight ability, and investigated how far they flew away from their breeding ground and what environmental factors affected where they reappeared, using the mark-and-recapture method. We conducted the field survey in Utsunomiya City during the August-September period, 2000. The survey revealed that they moved no farther than 1.1-1.2km and submerged fallow paddies greatly affected where they reappeared.
