The study of the grey dune species' phenology patterns revealed interesting data on the occupation of this xerotherm habitat by several spider species groups. Apparently stenotopic erigonid species are totally absent during the summer months. A possible explanation for this phenomenon is the lack of suitable prey (Collembola). Larger species of the Gnaphosidae, Thomisidae, Salticidac, Lycosidae and Arancidae are present during the summer. Of these Haplodrassus dalmatensis characterised by clear seasonal migration from the litter border zone, where the juvenile development takes place, to the open grey dune as reproduction habitat. The smaller stenotopic erigonid species (Typhochrestus digitatus. Pelecopsis nemoralis) do not show a clear seasonal but instead a diurnal migration between these two habitats in their adult phase.