Habitat associations and competition in Mastomys-Saccostomus-Aethomys assemblages on coastal dune forests

The northern coastal dune forests of KwaZulu-Natal, South Africa, are inhab ited by several rodent species. Three of these (Mastomys natalensis, Saccos tomus campestris and Aethomys chrysophilus) occur commonly. The hypothesis was investigated that habitat characteristics, and not species interactions , explain most of the variation in species-specific densities of these thre e species. Existing data were collated and the relationships between specie s-specific densities determined. In addition, a trapping programme was esta blished between July 1993 and February 1995, during which species-specific densities were estimated and 16 habitat variables measured. Multiple regres sion analyses were used to investigate the relationship (i.e. not causation ) between species-specific densities and a suite of habitat variables. No a dditional explanation of variation in species-specific densities by densiti es of other species were evident when habitat variables have been accounted for. It is concluded that most of the variation in species-specific densit ies of a Mastomys-Saccostomus-Aethomys assemblage can be explained by habit at variables rather than species interactions.