Status and conservation of the rodents of Victoria

Abstract

Nineteen species of rodents, in two families, have been recorded from Victoria in the modern era. Eighteen are of the family Muridae, represented by 15 native and 3 introduced species. The other species, now extinct in Victoria, was the introduced Sciurus carolinensis. Six of the native species are extinct, one is classified Critically Endangered, one Endangered and four Lower Risk – near threatened. Four of the extinct species were restricted to the semi-arid far north-west; these were Leporillus apicalis, L. conditor, Pseudomys bolami and P. desertor. The two other extinct species, Conilurus albipes and Pseudomys australis, inhabited open forest/woodland, and grassy ecosystems. Extant species include Rattus fuscipes and R. lutreolus, both in the sub-family Murinae; both are widespread and common, particularly in southern Victoria. The remaining seven species are in the sub-family Hydromyinae. Hydromys chrysogaster is widespread in waterbodies throughout the state. Notomys mitchellii and Pseudomys apodemoides occur in dry habitats in the north-west of Victoria; they are uncommon, but most of their habitat is reserved. Mastacomys fuscus, found in higher-rainfall areas of southern and eastern Victoria, from coastal dunes to alpine snowfields, is uncommon. The distribution of Pseudomys fumeus is disjunct, in four widely separated areas. It is classified as Endangered. P. shortridgei is restricted to the Grampians and south-western Victoria, where it may be locally common. The most geographically restricted rodent species in Victoria, Pseudomys novaehollandiae, is Critically Endangered and is the subject of special conservation measures. The most critical threats to rodent populations in Victoria are considered to be (1) the lack of active habitat management for those species that require early seral stages in vegetation, (2) predation by introduced carnivores, and (3) the fragmentation of species into small genetically isolated populations.