Impact of grazing on individual male movement in Roesel's bush-cricket Metrioptera roeseli: One possible clue to species range expansion

One aid to understanding species distribution patterns is to gather detailed information on individual movement behavior. To gather information on dispersal capabilities in Roesel's bush-cricket Metrioptera roeseli an individual-based study was carried out. In four areas with two different cattle grazing regimes 35 individuals were released and their movements recorded for a mean of 80 h. Bush-crickets in grazed areas moved significantly further between the censuses and more individuals in grazed areas moved > 5 m from the release point. The further away an individual was from the release point, the more likely he was to continue moving away. There was also a positive correlation between distance from the release point and the step length of the individual. The movement pattern found may make it easier for the species to find and reach new favorable habitats and withstand the negative effects of fragmentation.