The original non-volant land mammal fauna of Faure Island, Shark Bay, Western Australia

Abstract

Remains of four species of non-volant native mammals have been found on Faure Island: Perameles bougainvi1le (Western Barred Bandicoot), Bettongia penicillata (Woylie or Brush-tailed Bettong), Pseudomys fieldi (Shark Bay Mouse) and Rattus tunneyi (Pale Field-rat). Three of these species, Pe. bougainville, B. penicillata and Ps. fieldi, are abundant and their remains are recorded from several or most dune 'blowout' sites and all are recorded from a substantial cave deposit. These three were members of the original (i.e. immediately pre-European) fauna of Faure Island. Rattus tunneyi, in contrast, is known from a single specimen from a dune blowout, but is not recorded from the cave deposit. It appears unlikely to have been a member of the original fauna, but rather the specimen may be a relict from an earlier fauna, or may have been carried to the island from the mainland by a predator. Comparison with other islands in Shark Bay suggests that, at some 5800 ha in area, Faure Island should have carried more than three mammal species. There is no evidence that the island has been significantly smaller at any time since it was formed by rising sea level about 7000 years ago. A lack of habitat diversity or extremes of temperature or drought may have reduced the number of mammal species over the millenia, or it is just possible that the original fauna may have included other small species with restricted habitat requirements whose remains have not been detected. It is, however, very unlikely that any other medium-sized mammal originally occurred on the Island.