HABITAT SELECTION BY THE GERBILS GERBILLURUS-PAEBA AND GERBILLURUS-TYTONIS IN THE NAMIB DESERT DUNES

Habitat selection, in relation to plant species diversity, plant bioma ss, plant cover and substrate compaction was investigated in the pygmy hairy-footed gerbil Gerbillurus paeba and the dune hairy-footed gerbi l G. tytonis at three study areas situated across the Namib Desert dun efields. Plant species diversity and substrate compaction were the maj or habitat variables implicated in ecological segregation between the congeners. G. tytonis preferred habitats with high plant species diver sity, avoided compact soils and at the most easterly study site prefer red soft shifting sand. G. paeba avoided areas with high plant species diversity and preferred habitats with low plant species diversity. In the absence of G. paeba, G. tytonis selected habitats with a high pla nt species diversity suggesting that the presence of G. paeba did not influence the habitat selection of G. tytonis. There is no competitive release and G. tytonis does not invade habitats usually occupied by G . paeba.