Biogeographic patterns of frogs of the Kimberley islands, Western Australia

WA Museum Records and Supplements | Updated 7 years ago

ABSTRACT – The islands off the Kimberley coastline of northern Western Australia are among Australia’s most isolated areas. To date, frogs of the Kimberley islands have been a particularly poorly surveyed group owing to the remoteness of the region and the need to conduct surveys during the summer wet season at night when frogs call and are most active. Here, we report on the results of a three-year survey of frogs on 22 Kimberley islands. We found several broad patterns such as the near-ubiquitous presence of three species on most islands (Limnodynastes lignarius, Litoria staccato and Uperoleia borealis), all of which breed in rocky creeks. In contrast, some species common on the mainland were largely absent from the islands (Litoria bicolor, ground hylids and medium to large burrowing species).

Insular assemblages of frogs along the Northern Kimberley coast are intrinsically interesting on account of their persistence on generally rocky islands, with a long dry season, and the retention of a range of ecologies present, including rocky creek associations and large climbing species. No new species were discovered, including any species found to be restricted to the islands. None of the recorded species are considered threatened, but the islands do harbour 10 endemic frogs of the Kimberley region. Potential threats to frogs on islands include the arrival of exotic species (e.g. Cane Toads), chytrid fungus and habitat destruction.