Microhabitat selection and digging activity in the terrestrial isopod Hemilepistus reaumurii as an adaptive response to life in arid environments

Habitat selection of surface dwelling invertebrates represents an adaptation to terrestrial life and may be influenced by biotic and abiotic factors. A field study was conducted monthly to investigate the variation of the biotope and the spatial distribution of Hemilepistus reaumurii burrows in the arid region of Bchachma (Tunisia). Results showed that H. reaumurii preferred to dig burrows mainly inside the south-eastern part of the small dunes (nebkas). The density of nebkas in this region was estimated to be 432 ± 51 nebkas /ha, month on average. The nebkas density showed a monthly fluctuation depending on environmental conditions (e.g. wind direction) and human actions (trampling, car driving, sheep presence). Human activity appeared also to influence the spatial distribution of H. reaumurii burrows.