Eastern Queensland Research Articles

New insights into the hydrogeology and groundwater flow in the Great Barrier Reef catchment, Australia, revealed through 3D modelling

Study regionThe Great Barrier Reef catchment is located adjacent to the world's largest coral reef system, the Great Barrier Reef, in eastern Queensland, Australia. Study focusThis study characterized the geologic and hydrogeologic settings and evaluated the influence of regional faults on groundwater flow. 3D geological models of six regions within the catchment were constructed using drill-log data from >49,000 wells, digital elevation models and surface geological maps. The 3D models were then integrated with potentiometric surface maps and faults data to conceptualize the hydraulic relationships of aquifer units and estimate groundwater development potentials. Potentiometric surfaces and fault orientations were used to conceptualize groundwater flow directions. New hydrological insights for the regionThe 3D geological and hydrogeological characterizations revealed previously unknown faults and aquifer units in the study area. The study found that the central regions consisted of fractured and porous-unconfined aquifers, while confined aquifers, which extend to the coast and likely beyond, were also found in the northern and southern most regions. The orientations of the faults trended in NW-SE directions and could form conduits for south-easterly groundwater flow as opposed to the predominate easterly flow in the porous-unconfined and confined aquifers. The 3D models, aquifer connectivities and geometries provided crucial information to determine groundwater development potentials and offer a first step in developing local and regional groundwater flow and contaminant transport models.

Revision of Macroponema Mawson, 1978 (Nematoda: Strongylida) from macropodid marsupials with the description of two new species

BackgroundSpecies of Macroponema Mawson, 1978 are strongyloid nematodes which occur in the stomachs of macropodid marsupials in Australia. In this study, the genus Macroponema is revised, redescriptions of the two known species are provided, and two new species are added to the genus.MethodsA molecular characterisation of the internal transcribed spacers of the nuclear ribosomal DNA of representative specimens of Macroponema from all known host species was undertaken to confirm the status of M. cf. comani. This resulted in the identification of a further new species within the genus. Consequently, a review of all available material in museum collections was undertaken.ResultsThe two known species M. beveridgei Mawson, 1978 from Osphranter antilopinus (Gould) and O. robustus (Gould), and M. comani Mawson, 1978 from Macropus giganteus Shaw are re-described and their geographical distributions expanded. Two new species added to the genus are M. arundeli n. sp. from Ma. giganteus found in Queensland and the north east of New South Wales, and M. obendorfi n. sp. from O. antilopinus and O. robustus in the Northern Territory, the Kimberley Division of Western Australia and eastern Queensland. The latter species was formerly identified as M. cf. comani based on molecular studies. The specific identification of both of the new species is supported by ribosomal DNA sequence data.ConclusionsBased on the morphological and molecular characterisation of nematodes, this study has revealed the existence of four species within the genus Macroponema. The current phylogenetic data suggest that Macroponema spp. plausibly evolved by host switching; however, further studies are required to test this hypothesis.

Impacts of climate change on high priority fruit fly species in Australia

Tephritid fruit flies are among the most destructive horticultural pests posing risks to Australia’s multi-billion-dollar horticulture industry. Currently, there are 11 pest fruit fly species of economic concern in Australia. Of these, nine are native to this continent (Bactrocera aquilonis, B. bryoniae, B. halfordiae, B. jarvisi, B. kraussi, B. musae, B. neohumeralis, B. tryoni and Zeugodacus cucumis), while B. frauenfeldi and Ceratitis capitata are introduced. To varying degrees these species are costly to Australia’s horticulture through in-farm management, monitoring to demonstrate pest freedom, quarantine and trade restrictions, and crop losses. Here, we used a common species distribution model, Maxent, to assess climate suitability for these 11 species under baseline (1960–1990) and future climate scenarios for Australia. Projections indicate that the Wet Tropics is likely to be vulnerable to all 11 species until at least 2070, with the east coast of Australia also likely to remain vulnerable to multiple species. While the Cape York Peninsula and Northern Territory are projected to have suitable climate for numerous species, extrapolation to novel climates in these areas decreases confidence in model projections. The climate suitability of major horticulture areas currently in eastern Queensland, southern-central New South Wales and southern Victoria to these pests may increase as climate changes. By highlighting areas at risk of pest range expansion in the future our study may guide Australia’s horticulture industry in developing effective monitoring and management strategies.

New species of Eutarsopolipus (Trombidiformes: Podapolipidae) from the pterostichine genera Castelnaudia and Trichosternus (Coleoptera: Carabidae) in Australia.

Three new species of Eutarsopolipus Berlese are described from the flightless pterostichine carabid genera Castelnaudia Tschitscherine and Trichosternus Chaudoir found in rainforests in eastern Queensland: Eutarsopolipus piraticus sp. nov. from Trichosternus frater Darlington and T. mutatus Darlington in north-east Queensland; E. uncatus sp. nov. from C. obscuripennis (Macleay) in north-east Queensland; and E. verberatus sp. nov. from Castelnaudia eungella (Darlington) in middle-eastern Queensland and C. wilsoni (Castelnau) in south-east Queensland. These species are unique in Eutarsopolipus by having large hook-like unguinal setae on tarsi II-III. All species differ by only a few minor features, and the geographically isolated populations of E. verberatus could not be distinguished reliably. Surprisingly, the presence/absence of leg I claws and seta v″ on femur I, which have been used to create species groups, is intraspecifically variable. Species delimitation and the tarsal setation of Podapolipidae, particularly Eutarsopolipus, are also discussed.

Identifying climate refugia for 30 Australian rainforest plant species, from the last glacial maximum to 2070

Climate refugia—areas that remain suitable for species during periods of climate disruption—have played an important role in species persistence over time. Identifying and protecting these refugia is a key climate change adaptation approach for conservation planning. To identify climate refugia for Australian tropical/sub-tropical rainforest flora, from the Last Glacial Maximum to 2070. Habitat suitability models were calibrated for 30 species using Maxent, and projected onto climate data for: Last Glacial Maximum (LGM, ~ 22,000 ybp); mid-Holocene (MH, ~ 6000 ybp); current period; and 2070. The intersection of suitable habitat over consecutive periods was assessed, identifying: current refugia (LGM–MH–Current); future refugia (Current–Future); and High Value Refugia (HVR, suitable over all four periods). Refugial hotspots (regions suitable for at least 15 species) were also identified. Suitable habitat was generally projected to span the greatest area in the current period. Four current refugial hotspots were identified: Wet Tropics, Central Mackay Coast, South Eastern Queensland, and North Coast (New South Wales). While suitable habitat for most species may decline in the future, HVRs will likely be retained for all species to at least 2070, although restricted in size. Future refugia was also projected in areas beyond species’ dispersal ranges. HVRs are highly important for the conservation of these rainforest species, given their generation times, limited dispersal capabilities and additional anthropogenic barriers to movement. This study assists in understanding long-term spatial shifts in rainforest flora in response to climate change and in designing future conservation strategies.

Meta-analysis of Queensland’s coastal Indigenous fisheries: Examining the archaeological evidence for geographic and temporal patterning

Marine fisheries have been a critical part of Aboriginal and Torres Strait Islander people’s connection to land and sea country in Queensland, Australia for millennia. However, no archaeological studies have examined regional variability in the role of fish within subsistence regimes or the distribution of targeted fish species throughout the Holocene. We utilised a meta-analysis approach to conduct the first comprehensive assessment of Indigenous fisheries along the eastern Queensland coast. Data from 44 archaeological sites were grouped according to marine bioregion to facilitate broad comparison between sites across the study area. These sites were predominantly associated with mid-to-late Holocene occupation, and provided an assemblage of 45,052 recovered fish bones, of which 6606 were identified most commonly to family-level. Results indicate clear geographic patterning in the ubiquity of fish species captured, and for some marine bioregions an increase through time in the range of species targeted. Archaeological data indicate mixed species fisheries, with a complex range of habitats and diverse fish species harvested by people in relative proximity to the sites. These harvesting decisions were mediated by local ecological knowledge, awareness of fish behaviour, and cultural preference for certain species. These outcomes support existing models for the region, which document a shift in subsistence regimes during the mid-to-late Holocene, particularly an increased reliance on marine resources and expansion in diet breadth. Future research needs to address geographic gaps in data availability and implement globally recognised ichthyoarchaeological quantification and identification protocols to comprehensively examine geographic and temporal variability in Queensland’s Holocene Indigenous fisheries, and contribute to regional models of long-term subsistence change.

Description of three new velvet geckos (Diplodactylidae: Oedura) from inland eastern Australia, and redescription of Oedura monilis De Vis.

Inland eastern Australia has a complex array of habitats, driven by variation in topography, geology and moisture. This broad region is relatively poorly surveyed compared to coastal eastern Australia and likely contains significant numbers of undescribed reptiles. Oedura monilis is found through much of this region but has been shrouded in taxonomic uncertainty since its original description. Here I assess variation across the range of 'O. monilis' and show that it consists of two species: a widespread species in the northern half of the range and a widespread species in the southern half of the range. These two species are readily diagnosed by colour pattern and aspects of shape and scalation. I show that the name O. monilis applies to the northern species. I also show that the name O. attenboroughi Wells Wellington applies to the northern populations, making it a junior synonym of O. monilis. I describe the southern widespread species as Oedura elegans sp. nov.. I also describe two new, highly localised species from inland eastern Queensland that are allied to O. monilis: Oedura picta sp. nov. from a rocky range in the Moranbah-Dysart region, and Oedura lineata sp. nov. from brigalow forest remnants in the Arcadia Valley. These two species are distinct for colour pattern and aspects of size, shape and scalation. Oedura lineata sp. nov. has a very small and fragmented range, and is restricted to a highly threatened habitat type. It therefore warrants conservation attention. I also provide more detailed diagnoses for O. coggeri Bustard and O. tryoni De Vis, and demonstrate that the name O. ocellata Boulenger is a junior synonym of O. tryoni.

Caridina malanda, a new species of freshwater shrimp (Crustacea: Decapoda: Atyidae) from the Wet Tropics World Heritage area, north-eastern Queensland, Australia.

Integrated molecular and morphological studies of newly collected and curated specimens of the genus Caridina from the Atherton Tablelands, Wet Tropics World Heritage Area in north-eastern Queensland, Australia indicated the presence of an undescribed species belonging to the Caridina zebra Short 1993 complex. This species is somewhat intermediate, although distinct on the basis of molecular data and morphology, from two known sympatric species, Caridina zebra and C. confusa Choy Marshall 1997, and an allopatric species, C. spinula Choy Marshall 1997, from the Cape York Peninsula, about 500 km north. It is described here as a new species, C. malanda sp. nov., and compared with similar congeners. A key for the identification of the species, as well as notes on its distribution, ecology, and conservation, are provided.

Quantifying the interactions between koalas in a high-density population during the breeding period

A species’ social structure influences its patterns of gene flow and disease transmission. Knowledge of social structure therefore is critical for understanding conservation challenges and informing management strategies. We examined the social structure of 33 free-ranging koalas (Phascolarctos cinereus) in a high-density population (6.7 koalas per hectare) during the early and peak phase of the breeding period (August–December) at Cape Otway, Victoria. We used GPS and proximity loggers to quantify koala space use and interactions, and direct observations to determine behaviours associated with interactions. Our proximity loggers recorded 661 interactions (64% male–female, 28% male–male and 8% female–female). A peak in male–male interactions at the onset of the breeding period suggested that males may physically compete for mates at this time. Male–female interactions increased from the onset of the breeding period, and were mostly of short duration (median duration 5.5 min). From field observations of interactions, and the absence of pouch young in December, many of these interactions may have been unsuccessful copulation attempts. Space use and social network analyses revealed that most males had strong links (total interaction duration >30 min) with only one or two females, despite their spatial overlap and interactions with multiple females. Body mass did not influence a male’s mating success in terms of number of female mates. Our results contrast with those of a lower-density population in central eastern Queensland, suggesting that some aspects of koala social structure may be plastic relative to population density.

Short-tailed mice with a long fossil record: the genus Leggadina (Rodentia: Muridae) from the Quaternary of Queensland, Australia.

The genus Leggadina (colloquially known as ‘short-tailed mice’) is a common component of Quaternary faunas of northeastern Australia. They represent a member of the Australian old endemic murid radiation that arrived on the continent sometime during the late Cenozoic. Here we describe two new species of extinct Leggadina from Quaternary cave deposits as well as additional material of the extinct Leggadina macrodonta. Leggadina irvini sp. nov. recovered from Middle-Upper (late) Pleistocene cave deposits near Chillagoe, northeastern Queensland, is the biggest member of the genus, being substantially larger than any other species so far described. Leggadina webbi sp. nov. from Middle Pleistocene cave deposits at Mount Etna, central eastern Queensland, shares features with the oldest species of the genus, the Early Pleistocene L. gregoriensis. Based on the current palaeoecological interpretation of the type locality, L. webbi, represents the only member of the genus that inhabited rainforest. The succession of Leggadina species through the late Quaternary suggests an ecological replacement of the extinct large-bodied L. irvini with the extant, small-bodied L. lakedownesis at Chillagoe. At Mt. Etna, the extinct rainforest species L. webbi is replaced with the extant xeric-adapted L. forresti during the latest Middle Pleistocene. This replacement is associated with a mid-Pleistocene shift towards progressive intensifying seasonal and arid climates. Our study adds to the growing list of small-bodied faunal extinctions during the late Quaternary of northern Australia.

Detrital zircon U–Pb geochronology of Permian strata in the Galilee Basin, Queensland, Australia

ABSTRACTThe late Carboniferous to Triassic tectonic history of eastern Australia includes important periods of regional-scale crustal extension and contraction. Evidence for these periods of tectonism is recorded by the extensive Pennsylvanian (late Carboniferous) to Triassic basin system of eastern Australia. In this study, we investigate the use of U–Pb dating of detrital zircons in reconstructing the tectonic development of one of these basins, the eastern Galilee Basin of Queensland. U–Pb detrital zircon ages were obtained from samples of stratigraphically well-constrained Cisuralian and Lopingian (early and late Permian, respectively) sandstone in the Galilee Basin. Detrital zircons in these sandstones are dominated by a population with ages in the range of 300–250 Ma, and ages from the youngest detrital zircons closely approximate depositional ages. We attribute these two fundamental findings to (1) appreciable derivation of detrital zircons in the Galilee Basin from the New England Orogen of easternmost Australia and (2) syndepositional magmatism. Furthermore, Cisuralian sandstone of the Galilee Basin contains significantly more >300 Ma detrital zircons than Lopingian sandstone. The transition in detrital zircon population, which is bracketed between 296 and 252 Ma based on previous high-precision U–Pb zircon ages from Permian ash beds in the Galilee Basin, corresponds with the Hunter–Bowen Orogeny and reflects a change in the Galilee Basin from an earlier extensional setting to a later foreland basin environment. During the Lopingian foreland basin phase, the individual depocentres of the Galilee and Bowen basins were linked to form a single and enormous foreland basin that covered >300 000 km2 in central and eastern Queensland.

Style and intensity of late Cenozoic deformation in the Nagoorin Basin (eastern Queensland, Australia) and implications for the pattern of strain in an intraplate setting

AbstractEastern Australia was affected by late Cenozoic intraplate deformation in response to far-field stress transmitted from the plate boundaries, but little is known about the intensity and pattern of this deformation. We used recently surveyed two-dimensional seismic reflection lines and aeromagnetic data, and data from the recently released Australian Stress Map, to investigate the structure of the Nagoorin Basin in eastern Queensland. The western margin of the Nagoorin beds was displaced by the Boynedale Fault, which is a NNW-striking SW-dipping oblique strike-slip reverse fault with a vertical throw ofc.900 m andc.16 km sinistral displacement. A significant part of this large sinistral displacement is interpreted to have occurred prior to late Cenozoic time. Several low-angle (<30°) thin-skinned thrusts with a flat-ramp geometry also displaced the Nagoorin beds, which are interpreted to have developed along detachment surfaces in oil shales and claystone. The Boynedale Fault is a segment within longer NNW-striking faults that include the North Pine and West Ipswich fault systems in eastern Queensland. These NNW-striking faults are potentially active, and may accommodate neotectonic thrust movement in response to the present-day NE–SW orientation of SHmax. Results of this study, in conjunction with previous information on sedimentary basins in eastern Australia, indicate that Cenozoic contractional deformation is stronger at the continental margins, possibly due to the presence of pre-existing rift-related structures.

Rheumatic Heart Disease Prevalence is Under-Estimated in an Urban Adult Hospital Patient Population

Aim: To identify patients of the Princess Alexandra Hospital with rheumatic heart disease (RHD) as determined by cchocardiography findings. Current registry data suggests a low prevalence of RHD in metropolitan South Eastern Queensland.

Potential impacts of climate change on habitat suitability for the Queensland fruit fly

Anthropogenic climate change is a major factor driving shifts in the distributions of pests and invasive species. The Queensland fruit fly, Bactrocera tryoni (Froggatt) (Qfly), is the most economically damaging insect pest of Australia’s horticultural industry, and its management is a key priority for plant protection and biosecurity. Identifying the extent to which climate change may alter the distribution of suitable habitat for Qfly is important for the development and continuation of effective monitoring programs, phytosanitary measures, and management strategies. We used Maxent, a species distribution model, to map suitable habitat for Qfly under current climate, and six climate scenarios for 2030, 2050 and 2070. Our results highlight that south-western Australia, northern regions of the Northern Territory, eastern Queensland, and much of south-eastern Australia are currently suitable for Qfly. This includes southern Victoria and eastern Tasmania, which are currently free of breeding populations. There is substantial agreement across future climate scenarios that most areas currently suitable will remain so until at least 2070. Our projections provide an initial estimate of the potential exposure of Australia’s horticultural industry to Qfly as climate changes, highlighting the need for long-term vigilance across southern Australia to prevent further range expansion of this species.

Fluid flow characteristics of Bandanna Coal Formation: a case study from the Fairview Field, eastern Australia

ABSTRACTFluid flow characteristics of cleat systems in coalbed methane reservoirs are crucial in reservoir management and field development plans. This paper aims to evaluate the cleat system properties including cleat porosity, permeability, and aperture as well as the impact of permeability growth on production performance in the Bandanna Coal Formation of the Fairview Field, eastern Queensland. Owing to the presence of bad hole conditions and poor core recovery of the coal intervals, the petrophysical well logs and laboratory measurements cannot be used as a source of information for this purpose. Hence, a new approach is employed that utilises early water production data to measure water in place and absolute permeability of the coal. In addition, micro-computed tomography (CT) scan method is used to investigate the cleat system that is preserved in a core sample and results are compared with the ones obtained by analysis of production data. Cleat system evaluation by analysis of production data and micro-CT scan technique provides a comprehensive approach that brings confidence in measurements and helps to obtain cleat properties at the sufficient scale for reservoir engineering purposes. The necessary information including production data and core samples are collected from a dewatering well and the nearby observation well in the study area. Analysis of early water production data (single-phase flow) indicates that coal permeability is 189 mD and the average cleat porosity is approximately 5%. High cleat porosity describes the large volume of water produced over the life of the study well. The 3D model of the fossilised cleat system constructed by the micro-CT scan method reveals that coal is well-cleated and cleat spacing and mean cleat aperture are 4 and 0.136 mm, respectively. The average cleat porosity that is measured by the micro-CT scan method is 5.7%, which is fairly close to the cleat porosity measured by analysis of production data. Production data analysis indicates that effective permeability to gas starts to grow at the midlife of the well and it strongly controls the shape of the production profile. The results of this study help in future field development and infill drilling programs in the Fairview Field and provide important insights into cleat system of Bandanna Coal Formation.

The risk of pollen-mediated gene flow into a vulnerable eucalypt species

Hybridisation is recognized as a threat to the genetic integrity of rare, threatened and vulnerable species. Eucalypts are widely planted for plantation forestry and many species readily hybridise making “vulnerable”, locally-occurring species potentially at risk of genetic swamping. Eucalyptus argophloia (Queensland western gum or Chinchilla white gum) is a vulnerable species with limited distribution in South Eastern Queensland, Australia. The risks to this species from gene flow from surrounding forest or plantations are poorly understood. We investigated the breeding system and hybridisation potential of E. argophloia by controlled pollinations with selected sympatric and allopatric species. Treatments included self-pollination, outcross within species and hybridisation with E. crebra, E. microcarpa and E. moluccana (from within the same section, Adnataria) and E. pellita and E. resinifera (from a more distantly related section, Latoangulatae). The aim was to determine the degree of self-pollination and gene flow into E. argophloia from closely-related and more distantly-related sympatric and allopatric species.Eucalyptus argophloia is readily self-fertile. It also hybridises with a broad range of intra-sectional and inter-sectional eucalypt species. All crosses produced some pollen tubes, capsules and seed, and open pollination produced significantly more capsules and seeds than all controlled pollinations attempted. The number of seeds per capsule pollinated was not significantly different between pollen treatments. There is a potential risk of gene flow into E. argophloia populations from adjacent natural populations of the species tested as pollen parents, or from planted Eucalyptus species. This risk of foreign gene flow could be greater with open pollination than indicated by controlled pollination in this study because of the limiting effect of bud damage incurred during controlled pollinations. The ability to self-pollinate in the small population of E. argophloia raises the potential risk of genetic swamping from foreign pollen and elevated evolutionary pressure. These results will be useful for guiding management of this vulnerable species such as limiting plantings of cross-compatible species close to existing populations.

Oldest meiolaniid turtle remains from Australia: evidence from the Eocene Kerosene Creek Member of the Rundle Formation, Queensland

Poropat, S.F., Kool, L., Vickers-Rich, P. & Rich, T.H., September 2016. Oldest meiolaniid turtle remains from Australia: evidence from the Eocene Kerosene Creek Member of the Rundle Formation, Queensland. Alcheringa 41, XX–XX. ISSN 0311-5518.Fossil meiolaniid turtles are known only from South America and Australasia. The South American record is restricted to the Eocene, and comprises two genera: Niolamia and Gaffneylania. The Australasian meiolaniid record is more diverse, with three genera known (Ninjemys, Warkalania and Meiolania); however, the oldest known specimens from this continent are significantly younger than those from South America, deriving from upper Oligocene sediments in South Australia and Queensland. Herein, we describe the oldest meiolaniid remains found in Australasia to date. The specimens comprise a posterior peripheral, a caudal ring, and an osteoderm, all of which derive from the middle–upper Eocene Rundle Formation of The Narrows Graben, Gladstone, eastern Queensland. Despite their fragmentary nature, each of these specimens can be assigned to Meiolaniidae with a high level of confidence. This is particularly true of the partial caudal ring, which is strongly similar to those of Niolamia, Ninjemys and Meiolania. The extension of the Australasian meiolaniid record to the Eocene lends strong support to the hypothesis that these turtles arose before South America and Australia detached from Antarctica, and that they were consequently able to spread across all three continents.Stephen F. Poropat*† [stephenfporopat@gmail.com], Australian Age of Dinosaurs Natural History Museum, The Jump-Up, Winton, Queensland 4735, Australia; Lesley Kool*† [koollesley@gmail.com] and Thomas H. Rich [trich@museum.vic.gov.au], Melbourne Museum, 11 Nicholson St, Carlton, Victoria 3053, Australia; Patricia Vickers-Rich [pat.rich@monash.edu], Monash University, Wellington Rd, Clayton, Victoria 3800, Australia. *These authors contributed equally to this work. †Also affiliated with Monash University, Wellington Rd, Clayton, Victoria 3800, Australia.

Entangled Tropical Knowledges: Towards a Poetics of Knowledge and Place-Making in Nineteenth Century Voyaging Narratives

Footsteps mark the land as people walk through the north eastern Queensland tropics. Here, in the mid-1800s, botanical explorers from the survey ship HMS Rattlesnake scour their newly encountered environment for species that will be sent as specimens to the growing collections in London. Local Aboriginal people walk with them, perhaps as guides, possibly interpreters. The narratives for this voyage refer to some individual Aboriginal people who accompanied the Europeans as cotaiga, companion – a word from one of the Cape York Peninsula languages. Meetings and encounters between these voyagers and the local people take place around conversations and communications concerning local environmental knowledge. In this paper I look more closely at these ‘knowledge encounters’, to consider the complex poetics of entanglements between local Indigenous knowledges and Western modes of knowledge and representations of the local environment. Interrogating the voyaging narratives for their depictions of these encounters-in-place, my paper will meditate upon philosophies of movement, of walking and being in place, and of place making in the tropics. The paper will also ask questions about the role of historical representations of entangled tropical knowledge formations in present day concerns about climate and environmental change.

A new species of gecko from arid inland regions of eastern Australia(Diplodactylus; Diplodactylidae).

We describe a new species of small terrestrial gecko in the genus Diplodactylus from inland regions of western Queensland and New South Wales, Australia. Diplodactylus ameyi sp. nov. can be distinguished from its congeners in the Diplodactylus conspicillatus species-group by its relatively large size, bulbous tail which lacks an acute attenuated extension at tip, small first labial scale and comparatively robust head morphology (which includes a broadly rounded snout and no well-defined canthus rostralis). Related populations from eastern and central Queensland currently referred to D. platyurus include further deeply divergent lineages but additional material is required to resolve systematic boundaries in this region.

The Distribution and Density of Water Mice (Xeromys myoides) in the Maroochy River of Southeast Queensland, Australia.

The water mouse is a small and vulnerable rodent present in coastal areas of south-west Papua New Guinea, and eastern Queensland and the Northern Territory of Australia. Current knowledge regarding the distribution of the water mouse is incomplete and the loss of one local population has been documented in southeast Queensland, a region where pressures from urban and industrial development are increasing. Water mouse populations have not been studied intensively enough to enable the primary factors responsible for the local decline to be identified. We surveyed the distribution and density of the water mouse along the Maroochy River of southeast Queensland, near the southern extent of the species’ range, to gather baseline data that may prove valuable for detecting any future decline in this population’s size or health. All areas of suitable habitat were surveyed on foot or by kayak or boat over a three-year period. We found 180 water mouse nests, of which ~94% were active. Permanent camera monitoring of one nest and limited supplementary live trapping suggested that up to three individual mice occupied active nests. Water mouse density was estimated to be 0.44 per hectare of suitable habitat along the Maroochy River. Should future monitoring reveal an adverse change in the water mouse population on the Maroochy River, a concerted effort should be made to identify contributing factors and address proximate reasons for the decline.