Conservation possibilities of the rare grasshopper Stenobothrus eurasius Zubovski, 1898 are hampered by wild game in its fragmented western outposts

Abstract

The ecology of invertebrate steppe species requiring active conservation management has not been explored enough. Stenobothrus eurasius is a characteristic steppe species occurring very frequently in the Siberian and Central Asian grasslands, although on the western edge of its area it is present in small, isolated, endangered relict populations. We examined populations and habitats of St. eurasius in the Pannonian vegetation region to (1) seek predictor variables of its density and (2) explore potentially successful conservation management practices which could be used generally on declining steppe relict species. Our results showed that robust populations of St. eurasius are found in short, edaphic, relict steppe grasslands in which the proportion of coarse sand in the soil is high and which are free of significant disturbance by game (specifically by wild boar). According to our study, the most important approach for the enhancement of declining marginal populations of St. eurasius, existing as an umbrella species of steppe relicts, is to reduce individual numbers of game (mainly wild boar and mouflon) which have increased tenfold regionally in the last few decades (or at least to exclude them from the most vulnerable patches).