Introduction Knowledge on the mobility of threatened species is a clue to understanding population dynamics and is needed to develop appropriate conservation strategies. Here, we investigate movement patterns of the Bei-Bienko's Plump Bush-cricket (Isophya beybienkoi), an example of a flightless and critically endangered species endemic to the Slovak Karst (southern Slovakia, Central Europe). The capture-mark-recapture method was used to estimate the mobility of the species using fluorescent dye as a marking medium. We found that the mean (+/- SD) daily distance travelled by this species was only 3.2 +/- 2.6 m, with significant differences between males (4.1 +/- 3.0 m) and females (2.7 +/- 2.1 m). Our results indicate that I. beybienkoi is a short-distance disperser. Males disappeared faster than females from the study plots (at maximum, two females were recaptured even after 41 days). The observed movement patterns suggest that the most urgent conservation measure for this species is to improve the habitat quality of sites, which suffer from overgrowth, and to maintain the quality of other suitable sites that might increase the size of the existing subpopulations.Implications for insect conservation Our results show that I. beybienkoi is a short-distance disperser and wanders only within its optimal habitat. Hence, to incorporate movement behaviour into conservation, one of the measures that should mitigate this threat is to preserve or improve the quality of habitats that suffer from overgrowth, in order to increase the size of existing subpopulations. The observed movement patterns suggest that the species is probably incapable of responding to changes in the availability of suitable habitats by dispersing, indicating a limited exchange of individuals between isolated populations. Thus, to enhance structurally diverse mosaic of high-quality habitats, restoration of migration corridors former used as movement corridors for grazing animals may support the dispersal of the threatened bush-cricket.
