Identification of an eastern short-eared rock-wallaby (Petrogale wilkinsi) population in Queensland: a significant range extension

A new population of eastern short eared rock-wallaby (Petrogale wilkinsi) has been recorded in Queensland. The animals were photographed on a sandstone cliff face in Lawn Hill Gorge, Boodjamulla National Park, ~160km from the closest record on Wollogorang Station in the Northern Territory. The species was originally thought to occur north of the 600-mm rainfall isohyet, with most of the population found in the monsoonal tropics of the Top End. This record significantly extends the known range of this taxon to the south-east and places P. wilkinsi at the 450-mm rainfall isohyet. Sympatry in rock-wallabies is unusual but P. wilkinsi at Boodjamulla appears to be sympatric with the more common purple necked rock-wallaby (Petrogale purpureicollis). A recent taxonomic revision of the brachyotis group found that there was a significant mitochondrial DNA (mtDNA) divergence between the Wollogorang record and the rest of the P. wilkinsi group further north, but further genetic sampling across the southern Gulf of Carpentaria is required to determine whether these populations represent an additional distinct taxon.

Identification of a novel hybrid zone within the black-footed rock-wallaby (Petrogale lateralis) in Western Australia

It is increasingly recognised that intertaxon hybridisation is more common in vertebrates than previously thought. However, recent hybridisation has rarely been reported from wild marsupials, with only three instances of first generation (F1) hybrids reported, all in macropodids. In the 1990s a chromosomally anomalous population of black-footed rock-wallaby (Petrogale lateralis) was identified in the Townsend Ridges in central eastern Western Australia. Individuals from this population had chromosomes characteristic of two P. lateralis subspecies (P. l. centralis and P. l. kimberleyensis). This unusual mixture is suggestive of a novel hybrid zone between subspecies, but it could also represent a P. l. centralis population in which a 9–10 chromosome fusion has independently arisen. To test between these hypotheses, we compared mitochondrial DNA Control Region (CR) sequence data from Townsend Ridges individuals to published data for all P. lateralis subspecies. Two divergent lineages of CR haplotypes were identified at Townsend Ridges, suggesting that it represents a novel rock-wallaby hybrid zone, the third reported in the genus. While one CR haplotype clustered with those typical of P. l. centralis, the other Townsend Ridges haplotypes clustered with those from three different P. lateralis subspecies but not with P. l. kimberleyensis. Additional studies with multiple nuclear genes will be necessary to fully understand the nature of this novel hybrid zone.

Taxonomy of rock-wallabies, Petrogale (Marsupialia : Macropodidae). V. A description of two new subspecies of the black-footed rock-wallaby (Petrogale lateralis)

The black-footed rock-wallaby (Petrogale lateralis) is the most widespread member of the endemic Australian macropodid genus Petrogale. Considerable morphological and genetic diversity within this species has long been recognised and P. lateralis is currently divided into three described subspecies (P. lateralis lateralis, P. l. pearsoni, P. l. hacketti) and two undescribed forms (MacDonnell Ranges race, West Kimberley race). Chromosomal, morphological, genic and genomic studies have demonstrated that these five taxa are closely related but distinguishable. Here, we formally name the MacDonnell Ranges race and the West Kimberley race as subspecies of P. lateralis. Taxonomic registration: (LSID publication) http://zoobank.org/urn:lsid:zoobank.org:pub:71C3B7CE-CE3D-4A78-83A6-5EB50FBBA810