Gilbert's Potoroo (Potorous gilbertii) recovery plan
July 2003-June 2008: Wildlife Management Program No. 32
Jackie Courtenay and Tony Friend for the Gilbert's Potoroo recovery team
Department of Conservation and Land Management
Western Australian Threatened Species and Communities Unit WA, 2004
About the plan
Gilbert's Potoroo, Potorous gilbertii (Gould, 1841), is a small macropodoid marsupial in the family Potoroidae. Adults range from 900 g to 1200 g and there is little sexual dimorphism. The body, but not the tapered tail, is densely furred.
John Gilbert collected the first specimens of Gilbert's Potoroo at "King George's Sound" in 1840 and alerted his employer John Gould that it was a distinct form. A small number of specimens were subsequently collected from the Albany region, the last in the 1870s. This was the last official record of the species and by 1909 it was believed to be extinct (Shortridge, 1910). Gilbert's Potoroo was rediscovered at Two Peoples Bay Nature Reserve, 35km east of Albany, in December 1994 by Elizabeth Sinclair (Sinclair, Danks & Wayne, 1996).
The species was described by Gould (1841) as Hypsiprymnus gilbertii. He noted that it "closely resembles Hypsiprymnus murinus" (= the Long-nosed Potoroo, P. tridactylus (Kerr, 1792)). Calaby (1971) treated it as a subspecies, P. t. gilbertii, of the Long-nosed Potoroo, as did Seebeck and Rose (1988) and Seebeck, Bennett and Scott (1989). Ride (1970) and Johnston (1995), however, considered it fully synonymous with P. t. tridactylus of south eastern mainland Australia.
The skull of P. gilbertii is smaller than that of P. tridactylus but is relatively broader, especially (as noted by Gould) in the maxillary region. The rostrum is very inflated both anterior to the incisors and above the molar row. The adult premolar is smaller in P. gilbertii and is flexed in appearance with a shelf-like extension on the anterior lingual side. All the molar teeth are relatively smaller in P. gilbertii but the palate is broader (Courtenay, unpublished).
Sinclair and Westerman (1997) used allozyme electrophoresis and sequence analysis of the cytochrome b gene to examine phylogenetic relationships of extant potoroos. Their two data sets are highly concordant. Gilbert's Potoroo differs from the two other partly sympatric taxa, P. longipes and P. tridactylus from south-eastern Australia by the same order of magnitude as they differ from each other. Sinclair and Westerman (1997) conclude that there are three potoroo lineages - P. gilbertii, P. longipes and a P. tridactylus group and that Gilbert's Potoroo should be referred to as Potorous gilbertii (Gould, 1841). On the basis of chromosome morphology, Sinclair et al. (2000) concluded that P. gilbertii may be more closely related to P. tridactylus than to P. longipes.