Biogeography and diversity of ants in Purnululu (Bungle Bungle) National Park and Conservation Reserve, Western Australia

We describe the diversity, composition, functional group organisation and biogeography of ants in Purnululu National Park (128°19 E, 17°19 S) in Western Australia's Kimberley region, located at a semi-arid/tropical zone boundary. Pitfall trapping collected a representative sample of ants from three main habitats within the park: spinifex, sandplain and gorges. In total, 154 species from 25 genera were collected. The richest genera were Melophorus, Iridomyrmex and Monomorium. Iridomyrmex was the most abundant genus, accounting for 80% of all individuals recorded in traps. Functional group composition was dominated by Dominant Dolichoderinae (41% of individuals collected) and Hot Climate Specialists (26%). Biogeographical composition was typical of semi-arid zone assemblages located on the overlap between Eyrean and Torresian zones: 50% of the species recorded represented Eyrean taxa, followed by 33% with Torresian affinities, and 10% Widespread. Differences in ant species richness, abundance and assemblage composition between the three habitat types were attributed to a combination of variation in vegetation structure and microhabitat composition. This paper provides baseline data on local ant communities in the semi-arid Kimberley, enabling a greater understanding of the conservation value of reserves within the Kimberley, one of Australia's least studied bioregions.