Possibilities of testing the movement patterns of endangered orthopterans based on the study of Euchorthippus declivus (Orthoptera, Caelifera, Acrididae)

Abstract

In order to be able to organise the protection of the endangered Orthoptera populations, it is important to know the movement patterns of the species to be defended and the measurements of the territory used by them both under undisturbed conditions and in escape. We have tested the research possibilities of this question in a population in Bugac in a common Orthoptera species, in Euchorthippus declivus. We have used three methods during our research: (1) following the movement of the animals by mark-recapture in undisturbed grass, (2) following the change of the movement intensity by observing the daily activity of the population, (3) studying the distance covered by them after having been forced to escape. In our research we have processed data of 924 individuals, also revealing the differences between the two sexes. At various times after marking - with 14.4% recapture after six hours - we captured 78.6% of the animals at the marked territory. The difference of migration was perceptible between the sexes: males wandered in a greater territory than females and were more active as well. Their movement activity varied within one day: they did the greatest distance at 2 p.m., as far as 98 cm on average. When escaping, they proceeded with regular (28—48 cm long) jumps, taking 223 cm on average with 10 jumps. On the basis of all this the minimal area of the species in question can be determined more easily, and the consequences o f disturbance become more predictable, which are indispensable for the protection of the endangered species.