Spatial and temporal patterns of reptile roadkill in the north-west Australian tropics

2019 ◽  
Vol 25 (4) ◽  
pp. 370 ◽  
Author(s):  
Holly Hastings ◽  
James Barr ◽  
Philip W. Bateman
Keyword(s):  
Western Australia ◽  
High Rate ◽  
Survey Method ◽  
Road Mortality ◽  
Natural Ecosystems ◽  
Spatial And Temporal Patterns ◽  
Wet Season ◽  
North West ◽  
The North ◽  
Carcass Persistence

Roads present unavoidable challenges to wildlife, both in populated and in more remote regions. Both traffic infrastructure and road vehicles can have a detrimental impact on natural ecosystems and wildlife populations. This study aimed to gain a broad overview of the impacts of a stretch of road on native herpetofauna in north-western Australia. Reptile roadkill was surveyed along a 31-km stretch of the main road in Broome, Western Australia for eight months, during both the wet and dry seasons. There was a significantly higher rate of road mortality in the wet season despite a decrease in traffic intensity. Incidence of roadkill varied between reptile clades, with varanids being the mostly frequently recorded as roadkill. Carcass persistence experiments, however, highlighted a potential significant underestimation in roadkill due to an extremely high rate of carcass removal, emphasising the need to consider this variable when using roadkill as a survey method. We recommend that carcass persistence should be further investigated in order to accurately assess extent of reptile roadkill in the region, and how roads and traffic may impact at-risk species and populations.

scholarly journals Oceanographic influence on coastal zooplankton assemblages at three IMOS National Reference Stations in Western Australia

2020 ◽  
Vol 71 (12) ◽  
pp. 1672
Author(s):  
Erin McCosker ◽  
Claire H. Davies ◽  
Lynnath E. Beckley
Keyword(s):  
Western Australia ◽  
Detailed Comparison ◽  
Latitudinal Gradients ◽  
Zooplankton Abundance ◽  
Spatial And Temporal Patterns ◽  
North West ◽  
Leeuwin Current ◽  
National Reference ◽  
The North ◽  
E 32

Knowledge about the coastal zooplankton of the south-eastern Indian Ocean is limited, with few studies having compared assemblages across the latitudinal range of the western seaboard of Australia. The dominant oceanographic feature in this region is the Leeuwin Current, which transports warm, lower-salinity, tropical waters southward along the shelf-edge. This study examined data collected by Australia’s Integrated Marine Observing System at three coastal National Reference Stations located at 22°S 114°E, 32°S 115°E and 34°S 122°E. Spatial and temporal patterns in zooplankton abundance, composition and diversity were investigated, and differences in assemblage structure, particularly with respect to copepods, were related to oceanographic conditions. Clear dissimilarities among copepod assemblages were observed, becoming weaker in winter owing to enhanced connectivity of species driven by alongshore and cross-shelf transport in the Leeuwin Current. Both physical and biogeochemical factors were significant in structuring copepod assemblages, with seawater density, incorporating temperature and salinity, exerting the greatest influence. The results suggest that both broad-scale latitudinal gradients and mesoscale events contribute to variation in zooplankton assemblages in these waters. This study provides the first detailed comparison of zooplankton assemblages among the north-west, south-west and southern coastal waters of Western Australia, and enhances understanding of the processes influencing zooplankton distribution and structure.

Roof of the World: Tibet, Pamirs

2013 ◽  
Author(s):  
Mike Searle
Keyword(s):  
Tibetan Plateau ◽  
High Elevation ◽  
Tien Shan ◽  
Palm Tree ◽  
The Tibetan Plateau ◽  
Wet Season ◽  
North West ◽  
Mountain Ranges ◽  
The North ◽  
The World

The Tibetan Plateau is by far the largest region of high elevation, averaging just above 5,000 metres above sea level, and the thickest crust, between 70 and 90 kilometres thick, anywhere in the world. This huge plateau region is very flat—lying in the internally drained parts of the Chang Tang in north and central Tibet, but in parts of the externally drained eastern Tibet, three or four mountain ranges larger and higher than the Alps rise above the frozen plateau. Some of the world’s largest and longest mountain ranges border the plateau, the ‘flaming mountains’ of the Tien Shan along the north-west, the Kun Lun along the north, the Longmen Shan in the east, and of course the mighty Himalaya forming the southern border of the plateau. The great trans-Himalayan mountain ranges of the Pamir and Karakoram are geologically part of the Asian plate and western Tibet but, as we have noted before, unlike Tibet, these ranges have incredibly high relief with 7- and 8-kilometre-high mountains and deeply eroded rivers and glacial valleys. The western part of the Tibetan Plateau is the highest, driest, and wildest area of Tibet. Here there is almost no rainfall and rivers that carry run-off from the bordering mountain ranges simply evaporate into saltpans or disappear underground. Rivers draining the Kun Lun flow north into the Takla Makan Desert, forming seasonal marshlands in the wet season and a dusty desert when the rivers run dry. The discovery of fossil tropical leaves, palm tree trunks, and even bones from miniature Miocene horses suggest that the climate may have been wetter in the past, but this is also dependent on the rise of the plateau. Exactly when Tibet rose to its present elevation is a matter of great debate. Nowadays the Indian Ocean monsoon winds sweep moisture-laden air over the Indian sub-continent during the summer months (late June–September). All the moisture is dumped as the summer monsoon, the torrential rains that sweep across India from south-east to north-west.

Community Dynamics and Metabolic Potential of Petroleum-Degrading Microbes in the North West Shelf, Western Australia

2019 ◽  
Author(s):  
Darren Cheah ◽  
Kliti Grice ◽  
Cornelia Wuchter ◽  
Alan G. Scarlett ◽  
Marco J. L. Coolen
Keyword(s):  
Western Australia ◽  
Community Dynamics ◽  
Metabolic Potential ◽  
North West ◽  
The North

TWO AND THREE DIMENSIONAL ANALOGUE MODELLING OF EXTENSIONAL FAULT SYSTEMS WITH APPLICATION TO THE NORTH WEST SHELF, WESTERN AUSTRALIA.

1994 ◽  
Vol 34 (1) ◽  
pp. 555
Author(s):  
N. M. Lemon ◽  
T. Mahmood
Keyword(s):  
Western Australia ◽  
Three Dimensional ◽  
Sedimentary Sequence ◽  
Progressive Deformation ◽  
Plan View ◽  
North West ◽  
The North ◽  
Analogue Modelling ◽  
Extensional Structures ◽  
Geometry And Kinematics

The North West Shelf of Western Australia is an area of known extensional control with a number of inbuilt complexities related to variations in direction of extension and the existence of early fracture sets. Analogue modelling in a sandbox of modest construction and proportions can imitate the style of structures imaged by seismic on the North West Shelf. Models were constructed to simulate deformation in a sedimentary sequence above simple listric, ramp/flat and complex 3D detachment surfaces. A new 3D technique has been devised to simulate progressive deformation above complex detachment morphologies. Analysis of the structures produced has been achieved by marrying sequential plan view photographs of the model surface with serial vertical sections of the bulk of the model once the experiment has been completed and the sand stabilised. This technique also has the ability to simulate geometry and kinematics of extensional structures in a complex polyphase area. This 3D technique has proven particularly useful in the understanding of structures developed in regions where the sedimentary sequence has been subject to more than one period of extension, each with different orientations. The models provide the first understanding of the areal distribution of fault patterns and associated subsidiary troughs in areas of complex detachments. These models show the distribution of pre-rift and syn-rift sediments in extensional terranes and are valuable in the prediction of deformation in areas of poor seismic quality and for confirmation of seismic interpretation.

Extensional fault-related folding of the North West shelf, Western Australia

AAPG Bulletin ◽  
2020 ◽  
Vol 104 (4) ◽  
pp. 913-938
Author(s):  
Sam McHarg ◽  
Chris Elders ◽  
Jane Cunneen
Keyword(s):  
Western Australia ◽  
North West ◽  
The North

Community structure and zoogeographic affinities of the coastal fishes of the Dampier region of north-western Australia.

1985 ◽  
Vol 36 (2) ◽  
pp. 247 ◽  
Author(s):  
SJM Blaber ◽  
JW Young ◽  
MC Dunning
Keyword(s):  
Community Structure ◽  
Western Australia ◽  
High Tide ◽  
Organic Content ◽  
Tidal Range ◽  
Nursery Ground ◽  
North West ◽  
Physical Conditions ◽  
The North ◽  
North Western

The species composition and broad trophic structure of the mangrove creek and open shore fish communities of the Dampier region in tropical north-western Australia are described. The habitats are characterized by a lack of freshwater influence, low turbidity and a tidal range in excess of 4 m. Both mangroves and open shores have a diversity of species typical of Indo-west Pacific coastal waters but the physical conditions have modified the community structure both to exclude many families that prefer areas of higher turbidity and reduced salinity, and to include others that usually occur only in clear waters. The fish faunas of the mangroves (113 species) and open shores (106 species) are compared: 54 species were common to both. The deeper waters were dominated by piscivores, which penetrated throughout the mangroves at high tide. Iliophagous species were abundant, particularly in the mangroves where the organic content of the substratum (7.8-8.2%) was not reduced markedly compared with other areas of the Indo-Pacific, despite the lack of freshwater inflow. The clear and deep water in the mangroves at high tide favour predation on juveniles by piscivorous fishes and reduce the effectiveness of such areas as nurseries. There is virtually no overlap of the fauna with that of the deeper waters (>20 m) of the North West Shelf, and the inshore region is not a significant nursery ground for any of the commercially important deeper water species.

scholarly journals Conservation status and regional population estimates of the White-breasted MesiteMesitornis variegata, a rare Malagasy endemic

1994 ◽  
Vol 4 (4) ◽  
pp. 279-303 ◽  
Author(s):  
A. F. A. Hawkins
Keyword(s):  
Visual Detection ◽  
Deciduous Forest ◽  
Conservation Status ◽  
Survey Method ◽  
Suitable Habitat ◽  
North West ◽  
The North ◽  
Sand Forest ◽  
Regional Population ◽  
Logged Forest

SummaryThree different methods (visual detection on transects, call-playback and territory mapping) were used to estimate the densities of the White-breasted MesiteMesitornis variegatain western Malagasy deciduous forest. The species is threatened and belongs o t an endemic family of uncertain affinities. The population in the Menabe region, central-west Madagascar, surveyed using call-playback (the most efficient survey method), is estimated at 3,000-19,000 individuals; that of Ankarafantsika, north-west Madagascar, 6,000-26,000 individuals. Other western populations may be relicts. The White-breasted Mesite occurs at highest densities and with highest productivity in logged forest near rivers in the south of its range and in undisturbed sand-forest in the north, and is present at low density or absent from some areas of apparently suitable habitat, as well as forest that is secondary or has been severely damaged by burning. It is probably not immediately at risk from rats, dogs or selective exploitation, but hunting and forest burning through accidental bushfires or clearance for agriculture are locally important threats.Trois méthodes différentes (détection visuelle sur transect, réémission de chant, et délimitation du territoire) ont été utilisées pour faire des estimations de la densité de la Mésite VariéeMesitornis variegatadans la forêt sèche de l'ouest de Madagascar. L'espèce est considérée comme menacée et appartient à une famille endémique de relations obscures. La population dans la region du Menabe, centre-ouest Madagascar, estime avec la réémission de chant (la méthode la plus efficace) est entre 3,000-19,000; celle de l'Ankarafantsika, nord-ouest Madagascar, est entre 6,000-26,000. Les autres populations occidentales sont probablement des vestiges. L'habitat ou l'espece se trouve le plus commune est à côté des rivières dans la foret exploitée, dans la partie méridionale de son aire de distribution, et dans forêt intacte sur sable dans le partie septentrionale. L'espece parait etre absente dans d'autres régions, meme où l'habitat est similaire. Elle existe rarement ou pas du tout dans les forêts sécondaires ou brulees. Les rongeurs introduits et Sexploitation forestiere selective ne posent pas probablement un grand problème pour l'espece, mais la chasse et le defrîchement pour l'agriculture sont localement importante.

Pidgin Ngarluma

1998 ◽  
Vol 13 (1) ◽  
pp. 1-61 ◽  
Author(s):  
Alan Dench
Keyword(s):  
Western Australia ◽  
West Coast ◽  
Aboriginal People ◽  
North West ◽  
The North ◽  
Australian Languages

This paper discusses evidence of an early pidgin in use amongst Aboriginal people of the north west coast of Western Australia. The crucial evidence comes from an Italian manuscript describing the rescue, by local Aborigines, of two castaways wrecked on North West Cape in 1875. The data reveals that the local Aborigines attempted to communicate with the Italian-speaking survivors using what appears to be an Australian language spoken some 300 kilometers further along the coast, around the emerging center of the new Pilbara pearling industry. I present an analysis of the material, showing that it differs from Australian languages of the area in significant ways and can be considered a reduced variety. I conclude that this variety is an indigenous pidgin — the first to be described for Australia.

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