Abundance and distribution of five small mammals at a local scale.

2008 ◽  
Vol 30 (2) ◽  
pp. 65 ◽  
Author(s):  
G. G. Thompson, ◽  
S. A. Thompson
Keyword(s):  
Spatial Distribution ◽  
Population Density ◽  
Small Mammals ◽  
Western Australia ◽  
Current Practice ◽  
Local Scale ◽  
Vehicle Traffic ◽  
Abundance And Distribution ◽  
Survey Effort

In an area of approximately 210 ha 5 km west of South Hedland in Western Australia the population density of Dasycercus cristicauda (mulgara) was higher than 0.23 per ha, Dasykaluta rosamondae (little red kaluta) was higher than 1.88 per ha and Pseudomys hermannsburgensis (sandy inland mouse) was higher than 4.90 per ha. Densities for D. rosamondae and P. hermannsburgensis were appreciably higher than those reported elsewhere in the Pilbara. D. rosamondae and P. hermannsburgensis appear to be evenly distributed across the site, whereas D. cristicauda were concentrated in the centre and the western edge away from areas of higher vehicle traffic. The spatial distribution of Pseudomys desertor (desert mouse) was focussed on two areas. A trapping effort of 9,900 trap-nights appears to have captured most of the D. cristicauda but not all of the D. rosamondae, indicating that their density was higher than reported above. Approximately five D. cristicauda were caught per 1000 trap-nights, and given that this species was not evenly spread across the site, these data suggest that the survey effort necessary to detect the presence of D. cristicauda needs to be much higher than is the current practice of environmental consultants.

Small terrestrial mammals on Doongan Station, in the Northern Kimberley bioregion, Western Australia

2016 ◽  
Vol 38 (2) ◽  
pp. 164 ◽  
Author(s):  
Liberty G. M. Olds ◽  
Cecilia Myers ◽  
Jim Reside ◽  
George Madani ◽  
Alexander Dudley ◽  
...  
Keyword(s):  
National Parks ◽  
Small Mammals ◽  
Western Australia ◽  
Northern Australia ◽  
Terrestrial Mammals ◽  
Hydromys Chrysogaster ◽  
Petaurus Breviceps ◽  
Survey Effort ◽  
Broad Scale

There are significant gaps in knowledge of the small terrestrial mammals (<2 kg) in the Northern Kimberley bioregion (NOK). There have been no known extinctions of small mammals in the NOK, despite broad-scale declines being observed across much of northern Australia. The few studies in the NOK have focussed largely on three major national parks and NOK islands and thus may not be fully representative of the region. Mammal surveys were undertaken on Doongan Station, a pastoral property adjacent to these national parks to determine the presence/absence of small mammals. Five species were found to be common (Pseudomys nanus, P. delicatulus, Rattus tunneyi, Zyzomys argurus and Sminthopsis virginiae), two species were detected less frequently (Leggadina lakedownensis and Isoodon macrourus), and four species were scarcely detected (Melomys burtoni, Hydromys chrysogaster, Planigale maculata and Dasyurus hallucatus). Two species were detected only opportunistically outside of the survey effort (Petropseudes dahli and Petaurus breviceps). The trap success was consistently low, with levels in most years being below those regarded as critically low elsewhere in northern Australia.

Spatial Distribution of Dissolved Oxygen at Rapid Hydraulic Structures as an Indicator of Local-Scale Processes

2018 ◽  
pp. 377-387
Author(s):  
Agnieszka Rajwa-Kuligiewicz ◽  
Karol Plesiński ◽  
J. Russell Manson ◽  
Artur Radecki-Pawlik ◽  
Paweł M. Rowiński
Keyword(s):  
Spatial Distribution ◽  
Dissolved Oxygen ◽  
Local Scale ◽  
Hydraulic Structures

scholarly journals A Quantitative Evaluation of the Multiple Narratives of the Recent Sahelian Regreening*

2016 ◽  
Vol 8 (1) ◽  
pp. 67-83 ◽  
Author(s):  
Mimi Stith ◽  
Alessandra Giannini ◽  
John del Corral ◽  
Susana Adamo ◽  
Alex de Sherbinin
Keyword(s):  
Spatial Distribution ◽  
Population Density ◽  
Environmental Change ◽  
Burkina Faso ◽  
Social Dimensions ◽  
Adaptation To Climate Change ◽  
Southern Central ◽  
Second Category ◽  
The Impact

Abstract A spatial analysis is presented that aims to synthesize the evidence for climate and social dimensions of the “regreening” of the Sahel. Using an independently constructed archival database of donor-funded interventions in Burkina Faso, Mali, Niger, and Senegal in response to the persistence of drought in the 1970s and 1980s, the spatial distribution of these interventions is examined in relation to population density and to trends in precipitation and in greenness. Three categories of environmental change are classified: 1) regions at the northern grassland/shrubland edge of the Sahel where NDVI varies interannually with precipitation, 2) densely populated cropland regions of the Sahel where significant trends in precipitation and NDVI decouple at interannual time scales, and 3) regions at the southern savanna edge of the Sahel where NDVI variation is independent of precipitation. Examination of the spatial distribution of environmental change, number of development projects, and population density brings to the fore the second category, covering the cropland areas where population density and regreening are higher than average. While few, regions in this category coincide with emerging hotspots of regreening in northern Burkina Faso and southern central Niger known from case study literature. In examining the impact of efforts to rejuvenate the Sahelian environment and livelihoods in the aftermath of the droughts of the 1970s and 1980s against the backdrop of a varying and uncertain climate, the transition from desertification to regreening discourses is framed in the context of adaptation to climate change.

scholarly journals Geospatial characterizing of Under-Five Mortality in Alexandria, Egypt

2021 ◽  
Author(s):  
Mahmoud Adel Hassan ◽  
Ahmed Mohamed Ramadan ◽  
Mohamed Mostafa Tahoun ◽  
Abdelrahman Omran ◽  
Shimaa Gad El-karim Ali ◽  
...  
Keyword(s):  
Cardiac Arrest ◽  
Spatial Distribution ◽  
Cardiovascular Diseases ◽  
Population Density ◽  
Spatial Pattern ◽  
Under Five ◽  
Size Population ◽  
Access To Water ◽  
Alexandria City ◽  
Low Incidence

This study aimed to identify geo-spatial pattern of under-five mortality (U5M) in Alexandria and its key determinants. We analyzed the geospatial distribution of 3064 deaths registered at 24 health offices reported from January 2018 to June 2019. The localities of Alexandria city were clustered into high and low incidence areas. Neonates represented 58.7% of U5M, while post-neonates and children were 31.1%, 10.2% respectively. Male deaths were significantly higher (P=0.036). The main leading causes of U5M were prematurity (28.32%), pneumonia (11.01%), cardiac arrest (10.57%), congenital malformation (9.95%), and childhood cardiovascular diseases (9.20%). Spatial distribution of U5M (including the most common three causes) tend to be clustered in western parts of Alexandria (El Hawaria, Bahig, Hamlis and Ketaa Maryiut). Another 9 clusters are at risk of being hotspots. Illiteracy, divorce, and poor locality characteristics (household size, population density, and access to water supply and sanitation), were statistically significant predictors of U5M.

Remarks on the spatial distribution of a reproducing population

1977 ◽  
Vol 14 (03) ◽  
pp. 577-583 ◽  
Author(s):  
J. F. C. Kingman
Keyword(s):  
Spatial Distribution ◽  
Population Density ◽  
Poisson Process ◽  
Limiting Distribution ◽  
Statistical Equilibrium ◽  
Spatially Distributed ◽  
Simple Models

Several authors have noted that simple models for the evolution of a reproducing and spatially distributed population have no limiting distribution, although a Poisson process in statistical equilibrium has sometimes been implicitly assumed. It is shown that, even when a mechanism for restricting population density is postulated, a Poisson process is usually impossible to achieve, essentially because of an assumption of independent displacements. When this assumption is abandoned, a Poisson process is possible, at least for some highly idealised models.

scholarly journals Effects of climate and spawning stock structure on the spatial distribution of Northeast Arctic cod larvae

2020 ◽  
Author(s):  
Clarissa Akemi Kajiya Endo ◽  
Frode B Vikebø ◽  
Natalia A Yaragina ◽  
Solfrid Sætre Hjøllo ◽  
Leif Christian Stige
Keyword(s):  
Spatial Distribution ◽  
Environmental Variables ◽  
Barents Sea ◽  
Condition Index ◽  
Ocean Current ◽  
Larval Abundance ◽  
Near Surface ◽  
Spawning Stock ◽  
Long Time ◽  
Abundance And Distribution

Abstract The spatial distribution of fish early life stages can impact recruitment at later stages and affect population size and resilience. Northeast Arctic (NEA) cod spawning occurs along the Norwegian coast. Eggs, larvae, and pelagic juveniles drift near-surface towards the Barents Sea nursery area. In this study, a 35-year long time series of NEA cod larvae data was analysed in combination with factors that potentially may affect the distribution of eggs and larvae. These factors included biological aspects of the spawning stock, and environmental variables, such as water temperature, wind, ocean current, and prey abundance. Our aim was to shed light on how these factors influence larval abundance and distribution and how larval abundance and distribution influenced recruitment at age 3. We found that biomass and mean weight of the spawners were positively associated with larval abundance and that a high liver condition index of the spawners was associated with a north-easterly distribution of the larvae. The environmental variables showed generally weak or no correlations with abundance or distribution of larvae. Lastly, we found significant association between larval abundance and year-class abundance at age 3, while the spatial distribution metrics of the larvae, i.e. distribution extent, mean longitude, and mean latitude, showed no significant association with future year-class abundance.

scholarly journals Population Distribution in the Wake of a Sphere

Symmetry ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 1498 ◽  
Author(s):  
Taraprasad Bhowmick ◽  
Yong Wang ◽  
Michele Iovieno ◽  
Gholamhossein Bagheri ◽  
Eberhard Bodenschatz
Keyword(s):  
Reynolds Number ◽  
Spatial Distribution ◽  
Population Density ◽  
Density Distribution ◽  
Population Distribution ◽  
Fluid Velocity ◽  
Three Dimensional ◽  
Wake Flow ◽  
Sample Number ◽  
Scalar Fluxes

The physics of heat and mass transfer from an object in its wake has significant importance in natural phenomena as well as across many engineering applications. Here, we report numerical results on the population density of the spatial distribution of fluid velocity, pressure, scalar concentration, and scalar fluxes of a wake flow past a sphere in the steady wake regime (Reynolds number 25 to 285). Our findings show that the spatial population distributions of the fluid and the transported scalar quantities in the wake follow a Cauchy-Lorentz or Lorentzian trend, indicating a variation in its sample number density inversely proportional to the squared of its magnitude. We observe this universal form of population distribution both in the symmetric wake regime and in the more complex three dimensional wake structure of the steady oblique regime with Reynolds number larger than 225. The population density distribution identifies the increase in dimensionless kinetic energy and scalar fluxes with the increase in Reynolds number, whereas the dimensionless scalar population density shows negligible variation with the Reynolds number. Descriptive statistics in the form of population density distribution of the spatial distribution of the fluid velocity and the transported scalar quantities is important for understanding the transport and local reaction processes in specific regions of the wake, which can be used e.g., for understanding the microphysics of cloud droplets and aerosol interactions, or in the technical flows where droplets interact physically or chemically with the environment.

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