Restoring declining species through translocations: A test case using flightless grasshoppers in an urban setting

Abstract

O_LIPopulation translocations are used increasingly as a conservation strategy for vertebrates. However, relatively few attempts have been made to translocate invertebrates despite their potential benefits for food webs, and despite the practicality of undertaking such translocations in small areas including urban environments where space is limited. C_LIO_LIWe conducted 36 translocations of 1851 individuals of the generalist flightless grasshopper Vandiemenella viatica across urban Melbourne, where 93% of its original habitat has been lost. C_LIO_LIWe aimed to understand characteristics essential for grasshopper persistence and to investigate detection, occupancy, dispersal, and habitat suitability throughout its active period to improve insect translocation success in urban settings using revegetated sites and small remnant habitats. We also measured movement and detection probability after one week in short-term trials. C_LIO_LIThe one-week trial indicated that grasshopper sex and colour morph did not influence the probability of detection, and there was no evidence of directional movement by females and males. C_LIO_LIOne year after translocation, V. viatica were found in 28 out of 36 translocation sites. These surveys showed that detection probability changed across survey seasons and was influenced by soil temperature. Also, soil temperature positively affected detection in the winter surveys. Occupancy probability was influenced by graminoid cover, plant species richness and weed cover. We found no evidence of directional movement by females and males in the F1 generation. Abundance and presence/absence data were best explained by graminoid cover and plant species richness. C_LIO_LIOur findings suggest that wingless grasshopper translocations are feasible in small urban patches of suitable habitat, helping to restore invertebrate biodiversity and ecological services. C_LI