Non-random distribution across habitat types in sympatric, hardly catchable small mammals at a mountainous site in central Italy

A 17-year-long trapping study was carried out at a mountainous locality of central Italy (Majella National Park) in order to study the community structure of some infrequently caught small mammal species along the habitat niche axis. Null model analyses (with two competing randomization algorithms, RA2 and RA3) and Monte Carlo simulations were performed. The small mammal community was non-randomly structured according to RA2 with both Pianka and Czechanowski formulas, whereas it was random according to RA3 with both formulas. It is suggested that the observed pattern reflects mainly habitat checkerboards, with species being associated with different biotic and abiotic features of the sites which leads to less niche overlap than expected by chance.