scholarly journals Predicting Geographic Ranges of Marine Animal Populations Using Stable Isotopes: A Case Study of Great Hammerhead Sharks in Eastern Australia

2020 ◽  
Vol 7 ◽  
Author(s):  
Vincent Raoult ◽  
Clive N. Trueman ◽  
Kelsey M. Kingsbury ◽  
Bronwyn M. Gillanders ◽  
Matt K. Broadhurst ◽  
...  
Keyword(s):  
Marine Phytoplankton ◽  
Latitudinal Gradients ◽  
Marine Animal ◽  
Stable Carbon ◽  
Population Geography ◽  
Geographic Population ◽  
Geographic Ranges ◽  
The Core ◽  
Animal Populations ◽  
Eastern Australia

Determining the geographic range of widely dispersed or migratory marine organisms is notoriously difficult, often requiring considerable costs and typically extensive tagging or exploration programs. While these approaches are accurate and can reveal important information on the species, they are usually conducted on only a small number of individuals and can take years to produce relevant results, so alternative approaches may be preferable. The presence of latitudinal gradients in stable carbon isotope compositions of marine phytoplankton offers a means to quickly determine likely geographic population ranges of species that rely on productivity from these resources. Across sufficiently large spatial and temporal scales, the stable carbon isotopes of large coastal or pelagic marine species should reflect broad geographic patterns of resource use, and could be used to infer geographic ranges of marine populations. Using two methods, one based on a global mechanistic model and the other on targeted low-cost latitudinal sampling of fishes, we demonstrate and compare these stable isotope approaches to determine the core population geography of an apex predator, the great hammerhead (Sphyrna mokarran). Both methods indicated similar geographic ranges and suggested that S. mokarran recorded in south-eastern Australia are likely to be from more northern Australian waters. These approaches could be replicated in other areas where coastlines span predictable geographic gradients in isotope values and be used to determine the core population geography of highly mobile species to inform management decisions.

Growth of wedge-shaped plutons at the base of active half-grabens

2004 ◽  
Vol 95 (1-2) ◽  
pp. 309-317 ◽  
Author(s):  
S. W. Richards ◽  
W. J. Collins
Keyword(s):  
High Temperature ◽  
Structural Model ◽  
Tectonic Setting ◽  
Shear Bands ◽  
Shaped Body ◽  
The Core ◽  
Lachlan Orogen ◽  
Eastern Australia ◽  
Back Arc ◽  
East West

ABSTRACTCombined field and geophysical data show that plutons from the Bega Batholith are elongate, meridional, wedge-shaped bodies which intruded during a period of regional east–west extension in the Palaeozoic eastern Lachlan orogen, eastern Australia. Plutons within the core of the batholith have intruded coeval, syn-rift sediments and co-magmatic volcanics. The batholith is bound by high-temperature, dip-slip faults, and contains several major NE-trending transtensional faults which were active during batholith construction. In the central part of the batholith, the Kameruka pluton is an asymmetric, eastward-thickening, wedge-shaped body with the base exposed as the western contact, which is characterised by abundant, shallow-dipping schlieren migmatites which contain recumbent folds and extensional shear bands. A shallow (<30°), east-dipping, primary magmatic layering in the Kameruka pluton steepens progressively westward, where it becomes conformable to the east-dipping basal migmatites. The systematic steepening of the layering is comparable to sedimentary units formed during floor depression in syn-rift settings. The present authors suggest that the wedge-shaped plutons of the Bega Batholith are the deeper, plutonic expression of a hot, active rift. The batholith was fed and sustained by injection of magma through sub-vertical dykes. Displacement along syn-magmatic, NE-trending faults suggests up to 25 km of arc-perpendicular extension during batholith construction. The inferred tectonic setting for batholith emplacement is a continental back-arc, where modern half-extension rates of 20–40 mm yr−1 are not unusual, and are sufficient to emplace the entire batholith in ∼1 Ma. This structural model provides a mechanism for the emplacement of some wedge-shaped plutons and is one solution to the ‘room problem’ of batholith emplace

scholarly journals Abundance and genetic diversity responses of a lizard (Eulamprus heatwolei) to logging disturbance

2017 ◽  
Vol 65 (6) ◽  
pp. 362
Author(s):  
Francesca Lyndon-Gee ◽  
Joanna Sumner ◽  
Yang Hu ◽  
Claudio Ciofi ◽  
Tim S. Jessop
Keyword(s):  
Genetic Diversity ◽  
Forest Management ◽  
Management Practices ◽  
Forest Disturbance ◽  
Population Level ◽  
Landscape Scale ◽  
Population Abundance ◽  
Animal Populations ◽  
Eastern Australia ◽  
Logging Disturbance

Rotational logging practices are used with the goal of reducing forest disturbance impacts on biodiversity. However, it is poorly understood whether such forest management practices conserve the demographic and genetic composition of animal populations across logged landscapes. Here we investigated whether rotational logging practices alter patterns of landscape-scale population abundance and genetic diversity of a forest-dwelling lizard (Eulamprus heatwolei) in south-eastern Australia. We sampled lizards (n = 407) at up to 48 sites across a chronosequence of logging disturbance intervals (<10 to >60 years after logging) to assess site-specific population changes and genetic diversity parameters. Lizard abundances exhibited a significant curvilinear response to time since logging, with decreased numbers following logging (<10 years), increased abundance as the forest regenerated (10–20 years), before decreasing again in older regenerated forest sites (>30 years). Lizard genetic diversity parameters were not significantly influenced by logging disturbance. These results suggest that logging practices, whilst inducing short-term changes to population abundance, had no measurable effects on the landscape-scale genetic diversity of E. heatwolei. These results are important as they demonstrate the value of monitoring for evaluating forest management efficacy, and the use of different population-level markers to make stronger inference about the potential impacts of logging activities.

scholarly journals Monitoring the use of road-crossing structures by arboreal marsupials: insights gained from motion-triggered cameras and passive integrated transponder (PIT) tags

2015 ◽  
Vol 42 (3) ◽  
pp. 241 ◽  
Author(s):  
Kylie Soanes ◽  
Peter A. Vesk ◽  
Rodney van der Ree
Keyword(s):  
Individual Identification ◽  
Road Mortality ◽  
Pit Tag ◽  
Identification Methods ◽  
Passive Integrated Transponder ◽  
Crossing Structures ◽  
Animal Populations ◽  
Arboreal Marsupials ◽  
Eastern Australia ◽  
Wildlife Crossing Structures

Context Wildlife crossing structures are installed to mitigate the impacts of roads on animal populations, yet little is known about some aspects of their success. Many studies have monitored the use of structures by wildlife, but studies that also incorporate individual identification methods can offer additional insights into their effectiveness. Aims We monitored the use of wildlife crossing structures by arboreal marsupials along the Hume Freeway in south-eastern Australia to (1) determine the species using these structures and their frequency of crossing, (2) determine the number and demographic characteristics of individuals crossing, and (3) use the rate of crossing by individuals to infer the types of movement that occurred. Methods We used motion-triggered cameras to monitor five canopy bridges and 15 glider pole arrays installed at 13 sites along the Hume Freeway. The five canopy bridges were also monitored with passive integrated transponder (PIT)-tag readers to identify the rate of use by individuals. Key results Five species of arboreal marsupial were detected using canopy bridges and glider poles at 11 sites. Our analysis suggested that increasing the number and the distance between poles in a glider pole array reduced the rate of use by squirrel gliders. The PIT tag and camera footage revealed that the structures were used by adult males, adult females and juveniles, suggesting that all demographic groups are capable of using canopy bridges and glider poles. At two canopy bridges, multiple squirrel gliders and common brushtail possums crossed more than once per night. Conclusions Given that previous studies have shown that the freeway is a barrier to movement, and that many of the species detected crossing are subject to road mortality, we conclude that canopy bridges and glider poles benefit arboreal marsupials by providing safe access to resources that would otherwise be inaccessible. Implications Although the factors influencing crossing rate require further study, our analysis suggests that glider pole arrays with fewer poles placed closer together are likely to be more successful for squirrel gliders. The individual identification methods applied here offer insights that are not possible from measuring the rate of use alone and should be adopted in future monitoring studies.

The Litoria ewingi Complex (Anura:Hylidae) in South-Eastern Australia VIII.* Hybridization between L. ewingi and L. verreauxi alpina in the Mount Baw Baw Area, South Central Victoria

1985 ◽  
Vol 33 (2) ◽  
pp. 143 ◽  
Author(s):  
GF Watson ◽  
MJ Littlejohn ◽  
DF Gartside ◽  
JJ Loftus-Hills
Keyword(s):  
Northern Slope ◽  
Blood Proteins ◽  
Genetic Compatibility ◽  
Hybrid Swarm ◽  
Geographic Ranges ◽  
Central Victoria ◽  
South Central ◽  
Eastern Australia ◽  
High Level

Contacts between the geographic ranges of the widely distributed species, Litoria ewingi, and the montane-adapted taxon, L. verreauxi alpina, occur at about 1200 m on the Great Dividing Range in south central Victoria. Data for adult morphology, genetic compatibility, blood proteins (haemoglobins and transferrins), and structure of male advertisement calls, were obtained from seven populations at altitudes between 640 m and 1450 m in the region of the Mount Baw Baw Plateau. The results indicate that hybrids are present at intermediate altitudes (1140-1270 m), but that the nature of the interaction differs between overlap of parental taxa together with recombination products on the south-westem slope (the Baw Baw transect), and a hybrid swarm on the northern slope of the Mount Baw Baw plateau. Results of in vitro crosses (female L, ewingi by male L. v. alpina) indicate that there is a high level of genetic compatibility between the taxa. Estimates of the width of the hybrid zone on the Baw Baw transect vary from less than 4 km for morphology and calls, to between 10 and 24 km for blood proteins.

Theoretical aspects of transport cartography

2018 ◽  
Vol 932 (2) ◽  
pp. 48-58
Author(s):  
Ya.Yu. Chibryakov
Keyword(s):  
Economic Geography ◽  
Scientific Field ◽  
General Systems Theory ◽  
Population Geography ◽  
Technical Aspects ◽  
The Core ◽  
Transport Geography ◽  
General Systems ◽  
Special Scientific ◽  
History Of

The purpose of the article is to justify transport cartography as a special scientific field. The versatility of transport as an object of research leads to its socio-economic and technical aspects being studied by various sciences. The history of this field of knowledge is considered briefly in order to understand the place transport cartography occupies in the system of sciences, and its periodization has been carried out from the 1830s to today. When determining the position of transport cartography in the system of sciences, the core of this scientific direction is identified – it is the condominium of transport geography and the general theory of cartography, as well as its environment – a set of sciences attracted by transport cartography for studying reality. The disciplines allied to transport geography – such as population geography and general economic geography, as well as transport statistics, space researches, the ecology of transport, mathematics, general systems theory and the history of transport are taken as the environment. The boundaries of transport cartography as a scientific direction are delineated; its subject of study and eight major tasks are defined.

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