Eastern range extension of Pseudomys hermannsburgensis in Queensland A.S. Kutt1, C. Eddie2 and R. Johnson2 1 School of Tropical Biology and Australian Centre for Tropical Freshwater Research, James Cook University, Townsville, QLD 4811. Current address: Queensland Parks and Wildlife Service (Environmental Protection Agency), PO Box 5391, Townsville, QLD 4810. Email: [email protected]. gov.au 2 Queensland Parks and Wildlife Service, PO Box 981, Roma, QLD 4455. Downloaded from http://meridian.allenpress.com/australian-zoologist/article-pdf/32/2/252/1475744/az_2003_007.pdf by guest on 27 September 2021 Introduction The Sandy Inland Mouse Pseudomys hermannsburgensis Despite earlier contentions of the exclusive distribution and the Delicate Mouse P. delicatulus are two closely allied patterns of these two species, evidence exists for sympatry members of the largest genus of Australian rodents (Watts between P. hermannsburgensis and P. delicatulus in Western and Aslin 1981). Currently 22 species are recognised in Australia (How et al. 1991) and the Northern Territory the genus Pseudomys (Cole and Woinarski in press), (J. Cole pers. comm. 2002, Northern Territory though the taxonomy of this large group has variably been Department of Infrastructure, Planning and considered “a repository for species hard to classify” Environment). In Western Australia, both were trapped (Watts and Aslin 1981). Taxonomic reassessment of the together in three sites at the Abydos-Woodstock Reserve, group is ongoing (Breed and Aplin 1995; Breed 1996; F. in very low open Eucalyptus and Acacia woodland, with Ford, pers. comm. 2002, James Cook University). Triodia spp. ground cover and sandy soils (How et al. Pseudomys hermannsburgensis and P. delicatulus occur widely 1991). In the Northern Territory distributions overlap in in Australia in sparsely grassed open woodlands, a band about 180 km wide. They are sympatric in the shrublands, Triodia grasslands and sand-plains, with P. Mitchell Grass Downs Bioregion (Astrebla pectinata hermannsburgensis more typical in treeless environments. grasslands), and within 5 km of each other in the Gulf Both are small to intermediate sized (6-18 g, 55-90 mm) Fall Uplands Bioregion (Eucalytus leucophloia low open burrowing rodents, P. hermannsburgensis being slightly woodland with Trioda sp.) and in the Tanami Bioregion larger (Cole and Woinarski in press). Pseudomys delicatulus (mixed Triodia/Plectrachne spp. grasslands) (J. Cole pers. is widely distributed in eastern Queensland, and though P. comm. 2002, Northern Territory Department of hermannsburgensis is widespread in central Australia, it has Infrastructure, Planning and Environment). This note only recently been confirmed as occurring in Queensland, reports on the opportunistic capture of P. hermannsburgensis despite long-held expectations of its presence (Covacevich in Queensland, identifying an eastern range extension and Easton 1974). Specimens collected in 1936 near and possible areas of overlap with P. delicatulus. Longreach and identified as P. minnie flavescens (P. australis) have been recently reassigned as P. hermannsburgensis (S. Van Dyck, pers. comm. 2001, Queensland Museum) and Study area and methods the species has been captured frequently in long-term studies in southwest Queensland (Murray et al. 1999; New localities for P. hermannsburgensis for Queensland Dickman et al. 1999). were obtained from three fauna surveys (Fig. 1). Firstly during a broad-scale vertebrate fauna survey undertaken The two species were considered to be mutually exclusive in the Desert Uplands bioregion in central-north in distribution, with P. delicatulus noted to have an almost Queensland between 1997 and 2000, two records of P. perfect Torresian occurrence (Braithwaite and Covacevich 1995), with P. hermannsburgensis Eyrean by default. They hermannsburgensis were collected via systematic cat gut are morphologically similar, and considered difficult to sampling (ASK unpubl. data) (Fig. 1). Both of the distinguish on external characteristics (Cooper 1993). localities are entirely encompassed by the distribution of Some workers have suggested distribution alone as an P. delicatulus and P. desertor, the two most common and appropriate surrogate for identification (Covacevich and widespread native species throughout the Desert Uplands Easton 1974; Watts and Aslin 1981). Both species derived and adjacent Northern Brigalow Belt (ASK unpubl. from a common ancestral Pseudomys form entering from data). This region has a typical dry tropical savanna New Guinea between 5-10 million years ago, with the climate, with rainfall between 500-750 mm. The Desert subsequent evolution of P. hermannsburgensis into an Uplands and Northern Brigalow Belt study areas, and inland species during a period of Pleistocene aridity and the quadrat and feral cat gut sampling techniques are divergence (Baverstock 1982). Pseudomys delicatulus, P. described in further detail in Kutt et al. (2002) and Kutt novaehollandiae and P. hermannsburgensis are all closely (2002a, b). related (Baverstock et al. 1981). 252 AustralianZoologist volume 32 (2) February 2003 Eastern range of P. hermannsburgensis Downloaded from http://meridian.allenpress.com/australian-zoologist/article-pdf/32/2/252/1475744/az_2003_007.pdf by guest on 27 September 2021 Figure 1. Distribution of P. delicatulus (l) and P. hermannsburgensis (s), using data from the Queensland Museum and the Desert Uplands survey (ASK unpubl. data). Location of new P. hermannsburgensis records in area of potential sympatry with P. delicatulus indicated by (H). CYP=Cape York Peninsula, GUP=Gulf Plains, WET=Wet Tropics, NWH=North-west Highlands, MGD=Mitchell Grass Downs, DEU=Desert Uplands, BRB=Brigalow Belt, CHC=Channel Country, MUL=Mulga Lands, CQC=Central Queensland Coast, SEQ=South-east Queensland The second location derives from results of long-term Cunnamulla in the semi-arid Mulga Lands. This survey terrestrial fauna monitoring using pitfall traps at Culgoa was conducted as part of a nature conservation extension Floodplain National Park, (CE unpubl. data) which lies project, and comprised of six sites (consisting of a single at the confluence of the Mulga Lands and Southern pitfall line of five buckets joined by 30 m of drift fence), Brigalow Belt/Darling Riverine Plains Bioregions, 170 sampled over four nights on two visits. The vegetation of km south-west of St. George. Predominant landforms at the property is predominantly mixed Eucalyptus and Culgoa are clay plains vegetated by mixed Eucalyptus Acacia woodland on alluvial plains interspersed with coolabah, E. largiflorens, Acacia harpophylla and A. Callitris glaucophylla and A. aneura on sandy dune ridges. cambagei woodlands, A. aneura communities on massive The climate here is also semi-arid. red earths, and low sand ridges dominated by Callitris The location of these P. hermannsburgensis records are glaucophylla. This survey aims to inventory the vertebrate firstly of note being substantially east of other known fauna and habitat relationships within the park, and was specimens found in the Channel Country and Mitchell commenced in 1996. Sampling sites consist of a pitfall Grass Downs Bioregions. Secondly, and in particular line of eight buckets joined by a linear drift fence 30-40 regards to the Desert Uplands records, they suggest a zone m in length. A total of 23 from 43 sites have been of potential overlap in the distribution of P. delicatulus and sampled to date. Three animals were collected at P. hermannsburgensis in Queensland. Though the Desert Culgoa, a typical semi-arid environment with rainfall Uplands records are definitive, their derivation from cat between 250-500 mm. gut samples means it is impossible to identify the exact Finally records of P. hermannsburgensis were obtained location and habitat where the P. hermannsburgensis prey during a fauna survey of Rosscoe Downs (RJ unpubl. items were taken. Conversely specific habitat data are data), a sheep-cattle property about 100km southeast of available for the live captured animals. February 2003 AustralianZoologist volume 32 (2) 253 Kutt et al. Locality descriptions Eragrostis setifolia, with occasional Astrebla lappacea and other grasses and forbs. The site is a seasonally flooded Summerdell Station, 23° 45.6’S 146° 3’E alluvial plain with deep grey cracking clay soils. A second A single animal was collected from the gut of a tabby adult male was caught and released at an adjacent pitfall adult male feral cat shot on 14 July 1998 (Queensland site (28º51’18”S, 146º49’00”E) on 18 December 1999. The Museum no. JM 13662). The vegetation at this site landform and vegetation is similar to that described above. consists predominantly of open-woodlands of Eucalyptus Rosscoe Downs Station 28034’30”S, populnea, E. melanophloia and E. similis with ground cover 0 of tussock and hummock grasses on a range of alluvial, 146 33’19”E sandy earths and texture contrast soils. Three individuals were caught between 28-30 March 1999, and one further individual between 6-8 July 1999, Hobartville Station, 23° 15’S, 146° 24.6’E all in pitfall traps. The sex of each was unrecorded though A Pseudomys hermannsburgensis hair sample, (B. Triggs, one individual lodged with the Queensland Museum as a Downloaded from http://meridian.allenpress.com/australian-zoologist/article-pdf/32/2/252/1475744/az_2003_007.pdf by guest on 27 September 2021 pers. comm. 2001, “Dead Finish”) and a P. delicatulus voucher (JM 13229). The vegetation at this site consisted (Queensland Museum