Long distance movements and the use of fire mosaics by small mammals in the Simpson Desert, central Australia..

2001 ◽  
Vol 23 (2) ◽  
pp. 125 ◽  
Author(s):  
M Letnic
Keyword(s):  
Small Mammals ◽  
Arid Zone ◽  
Radio Telemetry ◽  
Movement Patterns ◽  
Long Distance ◽  
Habitat Mosaics ◽  
Central Australia ◽  
Single Night ◽  
Simpson Desert

Using recapture data and radio-telemetry, the movement patterns of small mammals occupying burned and unburned habitats in the Simpson Desert, western Queensland were investigated. Long-term, between trap sessions, recapture rates of small mammals ranged from 7.3 % for Sminthopsis youngsoni to less than 1 % for Pseudomys desertor. Seventeen individuals including Pseudomys hermannsburgensis, S. youngsoni and Notomys alexis were observed to make longdistance movements (> 500 m). The longest recorded movement in this study was 5.7 km by a male S. youngsoni. Telemetry and recapture data indicate that individual P. hermannsburgensis, S. youngsoni and N. alexis can move more than 700 m and up to 2 km in a single night. Radiotracked P. hermannsburgensis and N. alexis utilised a mosaic of burned and unburned habitats in a single night of foraging. Low rates of recapture for small mammals in the Australian arid zone suggest that the populations of many species consist largely of transient individuals. Some species of small mammals appear to have sufficient mobility to locate resource rich patches and utilise habitat mosaics along a continuum of scales. These range from long-distance and presumably unidirectional migrations of 10 km or more, through to nightly movements in the order of several hundred metres to 1 - 2 km.

Population dynamics of three species of dasyurid marsupials in arid central Australia: a 10-year study

2001 ◽  
Vol 28 (5) ◽  
pp. 493 ◽  
Author(s):  
Christopher R. Dickman ◽  
Adele S. Haythornthwaite ◽  
Gayle H. McNaught ◽  
Paul S. Mahon ◽  
Bobby Tamayo ◽  
...  
Keyword(s):  
Population Dynamics ◽  
Life Histories ◽  
Arid Zone ◽  
Early Spring ◽  
Early Summer ◽  
Late Winter ◽  
Sand Ridge ◽  
Red Foxes ◽  
Central Australia ◽  
Simpson Desert

This study investigated the population dynamics of three species of dasyurid marsupials in sand ridge habitat of the Simpson Desert, western Queensland, over a 10-year period between March 1990 and December 1999. The lesser hairy-footed dunnart (Sminthopsis youngsoni), was captured most consistently over the period of study, followed by the wongai ningaui (Ningaui ridei), and the mulgara (Dasycercus cristicauda). Rates of recapture were low (4.5–22.2%), probably because individuals of each species are very mobile. All species bred in late winter or early spring when animals were aged at least 8–10 months, and independent juveniles first appeared usually in summer. S. youngsoni reared a second litter in late spring or early summer in 3 of the 10 years studied, when the availability of food was likely to have been high; neither N. ridei nor D. cristicauda were known to attempt a second litter within a season. To explore factors that might influence population dynamics, we compared capture rates of each species with measures of rainfall, temperature, vegetation cover, abundance of predators [feral cats (Felis catus), red foxes (Vulpes vulpes), and goannas (Varanus spp.)], dragons, other dasyurids and indices of food abundance. The abundance of S. youngsoni appeared to depend primarily on the cover of spinifex 7–9 months earlier, that of D. cristicauda was related most strongly to rainfall 7–9 months earlier, while that of N. ridei was related to minimum temperature lagged by 1–3 months. While the dynamics of other arid-zone mammals are driven demonstrably by interactions between rainfall, resource availability and predation, our findings suggest that dasyurids have limited flexibility in their life histories and are influenced more subtly and by factors such as facilitation that are just beginning to become apparent.

P5 Clinical utility of stress echocardiography in remote indigenous and non-indigenous populations: a 10-year study in central Australia

2020 ◽  
Vol 41 (Supplement_1) ◽  
Author(s):  
S Ratwatte ◽  
B Costello ◽  
N Kangaharan ◽  
K Bolton ◽  
A Kaur ◽  
...  
Keyword(s):  
Stress Echocardiography ◽  
Multivariate Analyses ◽  
Dobutamine Stress ◽  
Long Distance ◽  
Normal Test ◽  
All Cause Mortality ◽  
Central Australia ◽  
Annual Mortality

Abstract Background Central Australia is a vast, geographical region spanning some 830,000 square kilometres. It is the most populous Indigenous region in Australia (44%) and a great distance from tertiary centres (1,500km). Non-invasive testing is important in this setting due to the high prevalence of cardiovascular disease and long-distance travel required for coronary angiography, the latter with significant logistical, financial, and cultural barriers. Although stress echocardiography has been extensively validated as a long-term prognostic tool in selected populations, we are not aware of prior studies in remote Indigenous and non-Indigenous individuals. Purpose To determine whether stress echocardiography can adequately risk stratify and quantify the long-term prognosis of Indigenous and non-Indigenous individuals in remote Central Australia. Methods Consecutive individuals undergoing stress echocardiography in Central Australia between 2007 and 2017 were included. Exercise or dobutamine stress echocardiography was performed and reported via standard protocols.  Individuals were followed up for the primary outcome of all-cause mortality. Results One thousand and eight patients (54% Indigenous, 63% dobutamine stress) were included. Indigenous patients were younger, more likely to be female, and had a greater prevalence of cardiometabolic comorbidities (p < 0.05 for all). Overall, 797 (79%) patients had no abnormality during rest or stress echocardiography, with no difference according to ethnicity (p > 0.05).  After a mean follow up of 3.5 ± 2.4 years, 54 (5%) of patients were deceased; 127 (14%) patients underwent revascularization and were censored from follow-up. In patients with a normal test, annual mortality averaged 1.3% over 5 years of follow up, with annual mortality being significantly higher in Indigenous compared to non-Indigenous individuals (2.0% vs 0.6% respectively). Individuals with either ischemia or scar had a significantly worse long-term outcome compared to those with a normal test (Figure). In multivariate analyses, increasing age (HR 1.04 [95% CI 1.01-1.08]), chronic kidney disease (HR 4.83 [1.79-13.02]), and lack of ACEI/ARB use (HR 0.19 [95% CI 0.09-0.42]) were associated with all-cause mortality. Although Indigenous ethnicity was a univariate predictor of mortality, this association was attenuated and non-significant in multivariate analyses. Conclusion Indigenous patients in remote Central Australia with a normal stress echocardiogram had a significantly higher annual rate of mortality compared to their non-Indigenous counterparts. However, this association may be in large part due to comorbid conditions. A normal test in Indigenous individuals was still able to adequately risk-stratify and identify a lower risk group of patients in whom ongoing local medical management and focusing on cardiometabolic risk factor reduction is likely to be appropriate. Abstract P5 Figure. Kaplan Meier survival curve

scholarly journals Advancement in long-distance bird migration through individual plasticity in departure

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Jesse R. Conklin ◽  
Simeon Lisovski ◽  
Phil F. Battley
Keyword(s):  
Bird Migration ◽  
Population Level ◽  
Breeding Site ◽  
Environmental Constraints ◽  
Adaptive Responses ◽  
Long Distance ◽  
Direct Observations ◽  
Breeding Resources ◽  
Plastic Responses

AbstractGlobally, bird migration is occurring earlier in the year, consistent with climate-related changes in breeding resources. Although often attributed to phenotypic plasticity, there is no clear demonstration of long-term population advancement in avian migration through individual plasticity. Using direct observations of bar-tailed godwits (Limosa lapponica) departing New Zealand on a 16,000-km journey to Alaska, we show that migration advanced by six days during 2008–2020, and that within-individual advancement was sufficient to explain this population-level change. However, in individuals tracked for the entire migration (50 total tracks of 36 individuals), earlier departure did not lead to earlier arrival or breeding in Alaska, due to prolonged stopovers in Asia. Moreover, changes in breeding-site phenology varied across Alaska, but were not reflected in within-population differences in advancement of migratory departure. We demonstrate that plastic responses can drive population-level changes in timing of long-distance migration, but also that behavioral and environmental constraints en route may yet limit adaptive responses to global change.

scholarly journals Non-Local and Multi-Scale Mechanisms for Image Inpainting

Sensors ◽  
2021 ◽  
Vol 21 (9) ◽  
pp. 3281
Author(s):  
Xu He ◽  
Yong Yin
Keyword(s):  
Markov Random Fields ◽  
Receptive Fields ◽  
Image Inpainting ◽  
Long Distance ◽  
Visual Appearance ◽  
Fine Grained ◽  
Multi Scale ◽  
Non Local ◽  
Relationship Of

Recently, deep learning-based techniques have shown great power in image inpainting especially dealing with squared holes. However, they fail to generate plausible results inside the missing regions for irregular and large holes as there is a lack of understanding between missing regions and existing counterparts. To overcome this limitation, we combine two non-local mechanisms including a contextual attention module (CAM) and an implicit diversified Markov random fields (ID-MRF) loss with a multi-scale architecture which uses several dense fusion blocks (DFB) based on the dense combination of dilated convolution to guide the generative network to restore discontinuous and continuous large masked areas. To prevent color discrepancies and grid-like artifacts, we apply the ID-MRF loss to improve the visual appearance by comparing similarities of long-distance feature patches. To further capture the long-term relationship of different regions in large missing regions, we introduce the CAM. Although CAM has the ability to create plausible results via reconstructing refined features, it depends on initial predicted results. Hence, we employ the DFB to obtain larger and more effective receptive fields, which benefits to predict more precise and fine-grained information for CAM. Extensive experiments on two widely-used datasets demonstrate that our proposed framework significantly outperforms the state-of-the-art approaches both in quantity and quality.

scholarly journals Geomagnetic imprinting predicts spatio-temporal variation in homing migration of pink and sockeye salmon

2014 ◽  
Vol 11 (99) ◽  
pp. 20140542 ◽  
Author(s):  
Nathan F. Putman ◽  
Erica S. Jenkins ◽  
Catherine G. J. Michielsens ◽  
David L. G. Noakes
Keyword(s):  
Magnetic Field ◽  
Temporal Variation ◽  
Ocean Circulation ◽  
Sockeye Salmon ◽  
Movement Patterns ◽  
Oncorhynchus Gorbuscha ◽  
Migration Routes ◽  
Long Distance ◽  
Spatio Temporal ◽  
Olfactory Imprinting

Animals navigate using a variety of sensory cues, but how each is weighted during different phases of movement (e.g. dispersal, foraging, homing) is controversial. Here, we examine the geomagnetic and olfactory imprinting hypotheses of natal homing with datasets that recorded variation in the migratory routes of sockeye ( Oncorhynchus nerka ) and pink ( Oncorhynchus gorbuscha ) salmon returning from the Pacific Ocean to the Fraser River, British Columbia. Drift of the magnetic field (i.e. geomagnetic imprinting) uniquely accounted for 23.2% and 44.0% of the variation in migration routes for sockeye and pink salmon, respectively. Ocean circulation (i.e. olfactory imprinting) predicted 6.1% and 0.1% of the variation in sockeye and pink migration routes, respectively. Sea surface temperature (a variable influencing salmon distribution but not navigation, directly) accounted for 13.0% of the variation in sockeye migration but was unrelated to pink migration. These findings suggest that geomagnetic navigation plays an important role in long-distance homing in salmon and that consideration of navigation mechanisms can aid in the management of migratory fishes by better predicting movement patterns. Finally, given the diversity of animals that use the Earth's magnetic field for navigation, geomagnetic drift may provide a unifying explanation for spatio-temporal variation in the movement patterns of many species.

scholarly journals Short- and long-term movement patterns of six temperate reef fishes (Families Labridae and Monacanthidae)

1995 ◽  
Vol 46 (5) ◽  
pp. 853 ◽  
Author(s):  
NS Barrett
Keyword(s):  
Natural Habitat ◽  
Movement Patterns ◽  
Reef Fishes ◽  
Long Term Results ◽  
Home Ranges ◽  
Temperate Reef ◽  
Effective Deterrent ◽  
Short And Long Term ◽  
Natural Boundaries

Movement patterns were studied on a 1-ha isolated reef surrounding Arch Rock in southern Tasmania. Short-term movements were identified from diver observations, and interpretation of long-term movements involved multiple recaptures of tagged individuals. Visual observations indicated that the sex-changing labrids Notolabrus tetricus, Pictilabrus laticlavius and Pseudolabrus psittaculus were all site-attached, with females having overlapping home ranges and males being territorial. In the non-sex-changing labrid Notolabrus fucicola and in the monacanthids Penicipelta vittiger and Meuschenia australis, there was no evidence of territorial behaviour and 1-h movements were in excess of the scale of the study. The long-term results indicated that all species were permanent reef residents, with most individuals of all species except M. australis always being recaptured within a home range of 100 m × 25 m or less. Only 15% of individuals of M. australis were always recaptured within this range category. The natural habitat boundary of open sand between the Arch Rock reef and adjacent reefs appeared to be an effective deterrent to emigration. The use of natural boundaries should be an important consideration in the design of marine reserves where the aim is to minimize the loss of protected species to adjacent fished areas.

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
Keyword(s):  
Habitat Use ◽  
Arid Environments ◽  
Desert Environment ◽  
Point Location ◽  
Dune System ◽  
Grazing Impacts ◽  
Water Point ◽  
Resource Poor ◽  
Central Australia ◽  
Simpson Desert

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.

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