Habitat use and behaviour of cattle in a heterogeneous desert environment in central Australia

2012 ◽  
Vol 34 (3) ◽  
pp. 319 ◽  
Author(s):  
Anke S. K. Frank ◽  
Chris R. Dickman ◽  
Glenda M. Wardle

The activities of livestock in arid environments typically centre on watering points, with grazing impacts often predicted to decrease uniformly, as radial piospheres, with distance from water. In patchy desert environments, however, the spatial distribution of grazing impacts is more difficult to predict. In this study sightings and dung transects are used to identify preferred cattle habitats in the heterogeneous dune system of the Simpson Desert, central Australia. The importance of watering points as foci for cattle activity was confirmed and it was shown that patchily distributed gidgee woodland, which comprises only 16% of the desert environment, is the most heavily used habitat for cattle away from water and provides critical forage and shade resources. By contrast, dune swales and sides, which are dominated by shade- and forage-deficient spinifex grassland and comprise >70% of the available habitat, were less utilised. These results suggest that habitat use by cattle is influenced jointly by water point location and by the dispersion of woodland patches in a resource-poor matrix. The findings were used to build a modified conceptual model of cattle habitat use which was compared with an original piosphere model, and the consequences for wildlife in environments where the model applies are discussed.

2021 ◽  
Author(s):  
Shlomy Vainer ◽  
Yoav Ben Dor

<p>The extensivity of sand dunes in continental interiors makes the understating of their morphodynamical properties valuable for palaeoenvironmental reconstructions and the interpretation of landscape evolution. Nevertheless, the study of aeolian landscape development at the million-years timescale is hampered by the complex interaction of factors determining dune migration and the inherently self-destructive nature of their chronostratigraphy, thus limiting the applicability of traditional luminescence-based dating methods for configuring processes beyond ~300 Ka. In this study, we present a standalone program that simulates aeolian transport based on luminescence-derived chronologies coupled with numerical modelling of cosmogenic nuclides accumulation. This integrative approach reveals ancient phases of sand irruption and provides a data-based scheme facilitating the morphodynamical study of aeolian processes over multiple timescales. We present a case study of the program application by analyzing data from the Australian Simpson Desert, unfolding several phases of aeolian vitality since the late Pliocene. The synchronicity of the results with drastic changes in environmental settings exemplifies the applicability of process-based modelling in constructing a timeframe of key landscape evolution events in arid environments by studying aeolian landforms. Finally, the relationships between model parameters used to determine environmental settings on sand migration patterns make the program a powerful tool to further investigating triggers and mechanisms of aeolian processes.</p>


1981 ◽  
Vol 21 (1) ◽  
pp. 187
Author(s):  
M. Smyth ◽  
J. D. Saxby

Sediments from the Permian Pedirka Basin and the overlying Triassic Simpson Desert Basin have been studied to determine their potentials as source rocks for hydrocarbons. Principal techniques used are reflected light microscopy, including vitrinite reflectance, solvent extraction and kerogen isolation.Dispersed organic matter (DOM) occurs through the Permian and Triassic sequences, and is most abundant near the top of the Triassic, constituting up to 2 per cent of the sediments by volume. Of this DOM, 30 to 50 per cent is vitrinite plus exinite. The Permian and Triassic coals have vitrinite reflectivities of up to 0.9 per cent. The geothermal gradient in the vicinity of Poolowanna 1 is probably sufficient to cause the cutinite within the Triassic sediments to break down into petroleum hydrocarbons. In the case of the Poolowanna Jurassic oil show, migration up faults and accumulation in high-temperature reservoirs have been accompanied by the loss of volatile hydrocarbons.


2004 ◽  
Vol 26 (2) ◽  
pp. 205 ◽  
Author(s):  
AJ Williams ◽  
CR Dickman

Seven species of insectivorous bats were positively identified within a regional study area in the Simpson Desert in south-western Queensland. This paper describes habitat use by this bat assemblage and the degree to which presence of water, food availability and roosting potential impact on bat activity. Bats predominantly utilised water sources, rock outcrops, dune/swale areas near woodland, dry creek lines and coolibah woodland habitats. However, they rarely used open habitats (open plain and dune/swale), acacia scrub and gidgee woodland. The bats foraged most often over water and on calmer nights, when insects were more active. Although highly active over water in some areas, bats may survive in the Simpson Desert without access to permanent water. Food availability in terms of flying insect abundance and biomass did not appear to significantly determine the use of different habitats. However, activity over the entire study area was concentrated in areas with a higher roosting potential. Consequently both tree and cave roost sites may be a limiting resource, resulting in bat activity being restricted predominantly to oases in the Simpson Desert study area.


1998 ◽  
Vol 25 (1) ◽  
pp. 11 ◽  
Author(s):  
Paul S. Mahon ◽  
Peter B. Banks ◽  
Chris R. Dickman

Populations of feral cats, foxes and dingoes were assessed at four sites in the northern Simpson Desert from May 1995 to October 1996 using track counts. Counts were based on presence/absence of footprints on sandplots placed randomly throughout each of the four sites, with all habitats being sampled in accordance with their availability. Sandplots were repositioned between sampling periods so that data were temporally independent. This unbiased method was used to assess the reliability of more conventional indices of carnivore abundance based on spotlighting and counts of footprints on roads, which were run concurrently with the random sandplot counts. The sandplot data were also used to assess habitat use of the three study species. Counts on regularly spaced sampling plots along roads were correlated with random sandplot counts for foxes, but not for cats. Conversely, an index of activity based on counting individual tracks along roads was correlated for cats, but not for foxes. Spotlighting counts appeared to have little relationship with random sandplot counts for either species, with random sandplot counts and spotlight counts of foxes being correlated for only one of the four sites and no correlations being apparent for cats. The sandplot data showed that cats used dune crests preferentially over other habitats, while foxes preferred both dune crests and roads. Dune crests are probably used as natural runways by both species. Dingoes used roads preferentially over other habitats. It was concluded that differences in the use of roads and other runways by the carnivores can potentially lead to biases in indices collected along roadways. In relation to the random sandplot counts, foxes were overestimated by road counts and spotlighting relative to cats, the latter bias being related possibly to temporal differences in the activity patterns of the two species.


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