Records of the coastal wattled bat Chalinolobus orarius from northern Australia: an addition to the Australian bat fauna

A small, dark form of Chalinolobus gouldii (Gould’s wattled bat) has been recognised in the ‘Top End’ of the Northern Territory (i.e. north of ~18°S), Australia, for some time, but its taxonomic identity has remained uncertain. Re-examination of museum specimens showed several individuals differing from both C. gouldii and C. nigrogriseus (hoary wattled bat) in external morphology and dentition, notably by the combined presence of an enlarged pendent skin lobe at the base of the ear and an incipient secondary cusp on the upper first incisor, which are diagnostic traits of Chalinolobus orarius (coastal wattled bat), a species recently described from Papua New Guinea. Comparative analyses of cranial measurements and external features show close agreement between Northern Territory specimens and the type series of C. orarius, supporting their identification as C. orarius. All confirmed Northern Territory records occur within 5 km of the coast, below 100 m elevation, in mangrove and adjacent Eucalyptus open forest habitats. Current data suggest that the species is uncommon and possibly rare in northern Australia. The recognition of C. orarius in northern Australia represents an addition to the Australian bat fauna and highlights the need for targeted surveys across northern Australia to determine the species’ distribution, abundance, taxonomic status and conservation status. It also necessitates revised species identifications for all Chalinolobus specimens from northern Australia held in museum collections worldwide.