Eremophila willsmithii Edginton (Scrophulariaceae), a new species from south-western Queensland, Australia

Diet and food availability of the greater bilby ( Macrotis lagotis ), was examined at two sites and over two summer and two winter seasons in Astrebla Downs National Park in south-western Queensland. The presence of both invertebrate and plant material in almost all faecal pellets (99.6% and 98.5%, respectively) indicated that bilbies in south-western Queensland are omnivorous. The plant component of the bilby diet consisted predominantly of Dactyloctenium radulans seeds (frequency of occurrence: 94.4%). The major invertebrate prey items were Isop-tera (termites, 73.1%) and Formicidae (ants, 77.6%). The frequency of occurrence of invertebrates in faecal pellets was higher during summer than winter, but the frequency of occurrence of plants was relatively constant regardless of season. Within the invertebrate categories, Isoptera and Acrididae (grasshoppers) displayed the greatest seasonal difference, with a significantly higher proportion of both categories in the diet during summer than winter at both study sites. The availability of invertebrate prey items also varied with season, and for most taxa, frequency of oc-currence was significantly higher in summer than winter. In contrast, the frequency of occurrence of seeds and bulbs ( Cyperus bulbosus ) varied only slightly with season. Seasonal changes in food availability were reflected by variation in dietary composition; however, relative proportions of some dietary items differed from their proportional availability. Therefore, bilbies were considered to be qualitatively opportunistic; selecting more invertebrates when their apparent availability increased, but continually exploiting the available seeds and bulbs. Additionally, although bilbies appeared to have some preferences for particular food items, several food items were selected almost randomly, and therefore bilbies were also considered to be dietary generalists. Such an opportunistic feeding strategy is advantageous to an arid-zone species as it permits the continuous exploitation of food resources that are unpredictable in their availability both spatially and temporally.

Thinning or complete clearing of dense mulga (Acacia aneura) woodlands in south western Queensland may lead to undesirable rangeland conditions unless sound property management is practised. Even ten years after thinning, ground storey vegetation in an ungrazed situation is still in a state of flux. Livestock management following clearing can markedly influence pasture composition and mulga regeneration. Poor rangeland management may lead to reductions in pasture basal area sufficient to reduce productivity and accelerate degeneration through soil and nutrient losses in run-off waters.

Interest in the petroleum potential of the central Eromanga basin area has been simulated by recent discoveries of oil and gas in the Eromanga and Cooper basin sequences in southwestern Queensland. The Bureau of Mineral Resources, in cooperation with the Geological Survey of Queensland, is assisting in petroleum exploration of this area by providing new regional information on the structural and depositional history of the Eromanga and underlying Cooper, Galilee, and Adavale basins. Several regional seismic reflection traverses up to 186 mi (300 km) long are being recorded over major structural features in the Eromanga basin, over the eastern margin of the Cooper basin, the southwestern Galilee basin, and the underlying Adavale basin. The seismic surveys are tied to existing seismic data to provide good quality structural and stratigraphic information. Seismic refraction, gravity, and magnetic, and magneto-telluric surveys are providing additional information on both sedimentary and basement structures; Landsat imagery studies are providing new perspectives on many regional features; and geochemical and source rock maturation studies are providing a basis on which a sound assessment of the petroleum prospectivity of the areas can be made. End_of_Article - Last_Page 977------------

Vertebrate remains in a collection of barn owl (Tyto alba) pellets from south-western Queensland were largely those of mammals, including Rattus villosissimus, Mus musculus, Leggadina forresti, Planigale tenuirostris, Sminthopsis macroura and S. crassicaudata. R. villosissimus was the most common prey item. P. tenuirostris had not been recorded previously from the area. Other vertebrate remains included those of birds, lizards and frogs. Some insects were also found in the pellets.

This study, combining geophysical and environmental approaches, was undertaken to investigate the causes of secondary salinity in the Goondoola Basin, in southwestern Queensland.A range of airborne and ground geophysical datasets were acquired, along with information on surface and subsurface materials and groundwater. Relationships established between various spatial and point datasets allowed us to generate predictive maps of surface materials, surficial salt stores and recharge potential. Investigation of groundwater and subsurface architecture identified subsurface salt stores and potential discharge areas.Salinisation in this area occurs as a result of local- and intermediate-scale processes, controlled strongly by regolith architecture. Management strategies can now be tailored specifically to prevent excess recharge and further salt mobilisation.

Feral goats were harvested in south-western Queensland at four sites under two regimes (opportunistic harvesting and sustained control). We assessed how this impacted on their contribution to total grazing pressure, on soil and pasture conditions and on the economics of goat management. The population impact was not consistent across sites with the same treatment, with 62% and 84% reductions in numbers in the two northern sites (one opportunistic harvesting site and one sustained control site) while numbers in the southern sites essentially remained the same. The contribution of goats to grazing pressure ranged from 3 to 30%; kangaroos contributed 16–36%; and livestock contributed 37–72%. Harvest rates of feral goats calculated for each of the sites ranged from 17 to 41%. There was no consistent relationship between population changes and the harvest rates. Seasonal conditions had greater influence on pasture and soil conditions than did changes in feral goat populations. The average cost of mustering goats (based on 34 operations) was $1.93 per head. Mustering costs increased markedly when goat density was lower than 10/km2. Average trapping costs (based on 7 trapping programs) were $2.08 per head. This compared with on-farm prices of $16–$25 per head in 1997. Personal circumstances and preferences of individual landholders were the key determinant of the level of control undertaken. Variability in price contributed to landholders being apprehensive about the viability of the goat industry. There are few simple tools available for landholders to estimate feral goat numbers and this makes effective management of total grazing pressure difficult.

The diet of the barn owl (Tyto alba) was determined by analysing pellets and bulk pellet debris found in the ruins of Baryulah Homestead, south-western Queensland. Nine species of mammal, at least eight bird, five reptile and three frog species were identified. The majority of prey consisted of small mammals and was dominated by Mus musculus, which accounted for almost 40 Prey Unit percent (PU%) of all prey. Rattus villosissimus was an important secondary prey species, which, due to its comparatively large mass, contributed 21.79 PU%. Other native mammals were present in low frequency only. Reptiles (primarily geckos) were more abundant than expected, collectively contributing >15 PU%, suggesting that they were an important component of the barn owl’s diet.

This article combines data from historical records, recently published maps and a field survey to document changes in the vegetation of a pastoral area in south-western Queensland. Examples are given where wildfire, ringbarking,clearing and grazing by both rabbits anddomestic stock have had major influences on the vegetation. The greatest change to the trees and inedible shrubs has been one of density. Evidence for changes in the herbaceous layer is less conclusive but it is likely that there has been a reduction in density of desirable perennial grasses and an increase in less palatable species.

The effects of cobalt (Co), selenium (Se), copper (Cu) and Co + Se + Cu plus manganese, iodine and zinc (All) supplements on the liveweight change, fleece weights, reproduction and survival of Merino ewes and their lambs were studied on 3 commercial properties (W, B and G) in south-western Queensland during 1978 and 1979. There was no significant effect of supplementation on ewe and lamb liveweights or ewe fleece weights in 1978 (723 mm rain). In 1979 (303 mm rain), ewes given Co and All supplements were significantly (P<0.05) heavier than all other ewes at weaning, but lamb weaning weights were not improved by any supplements. Zinc and manganese may have only been effective for a short period following dosing. Weaner lambs given supplements of Co, Se and Co+Se had significantly (P<0.05) higher greasy fleece weights (3.67 kg) than unsupplemented lambs (3.38 kg). In 1978, there was no significant effect of supplementation on reproductive rate. On property W, only 68% of maiden ewes successfully mated and this flock had a significantly (P<0.05) higher rate of reproductive wastage (27%) than did flocks on properties B (12.5%) and G (16.5%). The mean liveweights of maiden ewes for properties W, B and G in this year were 39.1, 35.1 and 37.1 kg, respectively. In 1979, ewes given the All supplement had significantly (P<0.05) lower overall rates of reproductive wastage (12.2%) than did ewes without supplement (30.2%). Supplementary treatments did not improve ewe or lamb survival. In 1978, ewe mortality between joining and weaning was significantly (P<0.05) higher on property W (24.2%) than on property G (7.0%). In 1979, there were no significant effects of either age or property on ewe mortality between joining and weaning. Neither trace element supplementation to ewes nor the sex of the lamb had a significant effect on lamb survival between marking and weaning.

ABSTRACTSouth-western Queensland supports a suite of threatened native species, including Night Parrots. We investigated why this species has persisted in the region and discovered low prevalence of the typical factors that are thought to explain fauna attrition elsewhere in central Australia. Foxes appear to be completely absent. Feral cats were recorded relatively infrequently and showed a significant preference for habitats less commonly used by Night Parrots, a partition that may be driven by the presence of dogs that were detected twice as frequently as cats. Our study area has had a long history of moderate grazing pressure, which is concentrated mostly in productive alluvial habitats. We detected very few herbivores, and dog scat analyses suggest that macropod populations are regulated by predation. Archival imagery shows that large fires are not a feature of this landscape, resulting in the long-term, stable availability of patchy Triodia habitats separated by natural no-fuel areas. Based on these empirical data, we postulate that low non-native predator pressure, long-term stable availability of Triodia cover and a productive landscape that has had only moderate grazing pressure are the interacting factors that may explain why Night Parrots have persisted in south-western Queensland. We present practical management actions that could enhance the suitability of this landscape for Night Parrots.

The birds of arid environments often exhibit nomadism, seasonal breeding and population fluctuations that respond to highly variable weather patterns. In this study we present data from a baseline bird survey in Bush Heritage Australia’s Pullen Pullen Reserve in south-western Queensland. We conducted seasonal surveys (October–November 2018, May 2019) in 40 sites representing Spinifex (Triodia spp.) grasslands, a complex of Mitchell Astrebla spp./chenopod grasslands and Georgina Gidgee Acacia georginae riparian woodlands, using a standardised 2-ha census. A total of 85 species was recorded in the standardised sites, as well as an additional 16 species recorded opportunistically. Twenty-six species (31%), many of which were nomadic, were recorded from only one of the surveys. Bird abundance and species richness were highest in the post-wet-season survey (May 2018), and there was strong variation in the composition of the bird species between the three habitats surveyed. These data provide a baseline to continue monitoring and to understand the resident and more peripatetic elements of this arid bird community, which should be surveyed regularly to investigate the role of changing management and the long-term influence of global environmental change.

Liveweight and carcass traits of 3-way Africander (A) x Simmental (S) x Hereford (H) crossbreds and purebred Herefords were monitored predominately on native pastures at Dirranbandi, Queensland, for 2 calf crops over 6 years. The relative breed compositions of the crossbreds were A4S2H2, A4S 1 H3 and A4H4. The mean liveweight of the A4S2H2 cattle ranked highest from about 250 days post-weaning to slaughter (520 days post-weaning) for steers, and at first joining for heifers (560 days post-weaning). Differences in liveweight were not significant at all times. The A4S2H2 and A4SlH3 steers had the highest (P<0.05) post-weaning average daily gains. Differences in weaning weight between crossbreds were carried through to slaughter for steers and to joining for heifers. The A4S2H2 steers had the highest (P<0.05) mean final liveweight (433 kg) and mean carcass weight (232 kg). There was no difference in carcass weight between the other crossbreds and Herefords. Fat depth at the P8 rump site of A4H4 crossbreds (8.5 mm) was higher (P<0.05) than that of Herefords (5.5 mm) and other crossbreds. Dressing percentages were similar for all breed types. The A4S2H2 maiden heifers had higher (P<0.05) liveweights at first joining (369 kg) than the A4S1H3 (353 kg) and A4H4 (337 kg) heifers. These data show that beef producers in southwestern Queensland can increase carcass weights with A4S2H2 crossbreds and produce carcasses that primarily meet the Korean-EC market and the requirements of domestic supermarket outlets.

The growth and development of eight perennial grasses, from sowing until flowering, was studied in the field on a sandy red earth near Charleville, south-western Queensland. They included four species native to this soil, Thyridolepis mitchelliuna, Aristida armata, Digitaria ammophila and Monachather paradoxa, and four exotic species Cenchrus ciliuris cv. Biloela, Anthephora pubescens, Eragrostis curvula and Schmidtia bulbosa. Cenchrus ciliaris, A. pubescens and S. bulbosa emerged much more promptly than the other species and much less viable seed was left in the soil after the fist germination event. The native species tillered and flowered earlier than the exotic grasses and survived better under adverse growing conditions. Average survival at the end of the first growing season, during which good seasonal conditions pre- vailed, was 30% of the emergent seedlings. Schmidtia bulbosa performed best within the exotic group and this was associated with early tillering and earlier flowering. The exotic species needed at least a four month growing season before they flowered under field conditions compared with two months or less for the native grasses. However this disadvantage was offset somewhat by their greater dry matter yield at this stage of development.

A recently abandoned artesian bore drain in south-western Queensland was sampled to investigate soil morphology and chemistry under, and adjacent to, the drain. Such drains are supplied with alkaline, sodium-rich artesian groundwater and they provide a long-term example of the impacts of these waters on soils. A Red Kandosol and a Grey Vertosol were sampled, in the drain and at 2, 4 and 25 m perpendicular to the drain. Morphological attributes indicative of long-term saturation, such as mottling, were evident around the drains, but were absent at the control sites (25 m away). At the Kandosol location, pH and exchangeable sodium were elevated within 4 m of the drain, and salinity data suggested a horizontally displaced wetting front at ~4 m from the drain. In the Grey Vertosol, which was naturally saline and sodic below 0.5 m, substantial leaching of salts had occurred around the drain, but a horizontal wetting front was also evident and exchangeable sodium was increased within 4 m of the drain. A thin, weak pan was detected in the subsoil of the Red Kandosol under the drain bank, but pans were otherwise absent under the drains. The results indicate that deep drainage is a feature not only of the Red Kandosol, but also the Grey Vertosol, despite it being sodic and despite the application of sodic, alkaline water. The findings reiterate the importance of investigating soil and water chemistry interactions when designing channels, storages and irrigation systems, in particular those using sodic–saline waters.

Seasonal changes in the quantitative floristics at a wide range of Astrebla grassland sites in south-western Queensland were monitored between 1972 and 1980 with a wheel point apparatus. Changes in the floristics were measured in terms of both relative abundance and basal cover. A large increase in the relative abundance of perennial grasses, particularly Aristida latifolia, Astrebla spp. and Dichanthium sericeum, occurred between 1972 and 1976. This increase was at the expense of annual grasses and forbs which declined in both relative abundance and number of genera present. The relative abundance of perennial grasses declined between 1978 and 1980 and this was associated with a large increase in the forbs such as Daucus glochidiatus and Plantago spp., particularly at southern sites. The contribution of annual grasses to botanical composition remained low throughout the period. Total basal cover differed between years although these differences were not significant. As perennial grass, particularly Astrebla spp., was the major vegetation component of total basal cover, changes in the latter were associated mainly with changes in the basal cover of Astrebla spp. Changes in the contribution of individual species to total basal cover were related to changes in the relative abundance of those species. Changes in botanical composition in Astrebla grassland may be influenced more by trends in seasonal rainfall than by grazing pressure.