Pounce site characteristics of the Western Yellow Robin Eopsaltria griseogularis: the importance of assessing foraging microhabitat

2004 ◽  
Vol 10 (1) ◽  
pp. 21 ◽  
Author(s):  
Jarrad a. Cousin
Keyword(s):  
Leaf Litter ◽  
Substrate Composition ◽  
Habitat Features ◽  
Invertebrate Prey ◽  
Conservation Implications ◽  
Site Characteristics ◽  
Australian Birds ◽  
Close Proximity ◽  
Selection Of

The ground ecosystem represents an important foraging substrate for a large number of Australian birds, including the ground-pouncing Western Yellow Robin Eopsaltria griseogulari. The present study examined the foraging locations of E. griseogularis at the "extreme" microhabitat scale, by measuring ground substrate composition in a 300 mm by 300 mm area surrounding pounce sites, as well as habitat features surrounding pounce sites. Ground substrate composition of pounce sites remained relatively unchanged between seasons, and was characterized by a higher mean percentage of leaf litter and logs when compared to random points. The importance of logs was further emphasized by the closer proximity of logs to pounce sites than to random points. Selection of pounce sites in close proximity to logs and with abundant leaf litter reflects the higher abundance of invertebrate prey associated with these microhabitat attributes, although it may also represent a pounce in close proximity to a log utilized as a perch. During the warmer months of autumn, logs and their associated accumulations of leaf litter, provide sufficient moisture to maintain invertebrate prey, a resource diminished in the surrounding desiccated leaf litter. The conservation implications of these findings are discussed, as is the importance of examining foraging microhabitat in ground-foraging birds.

scholarly journals Caribou nursery site habitat characteristics in two northern Ontario parks

Rangifer ◽  
2007 ◽  
Vol 27 (4) ◽  
pp. 167 ◽  
Author(s):  
Natasha L. Carr ◽  
Arthur R. Rodgers ◽  
Shannon C. Walshe
Keyword(s):  
Rangifer Tarandus ◽  
Habitat Characteristics ◽  
Woodland Caribou ◽  
Mature Trees ◽  
Detection Distance ◽  
Northern Ontario ◽  
Habitat Features ◽  
Site Characteristics ◽  
Provincial Park ◽  
Selection Of

To prevent further range recession, habitat features essential to the life-history requisites of woodland caribou (Rangifer tarandus caribou) such as calving and nursery sites need to be protected for the persistence of the species. Woodland caribou may minimize predation risk during calving by either spacing out or spacing away from predators in the forest to calve on islands, wetlands, or shorelines. Our objective was to determine the characteristics of shoreline habitats used as calving and nursery sites by female woodland caribou in northern Ontario. Detailed vegetation and other site characteristics were measured at nursery sites used by cow-calf pairs in Wabakimi and Woodland Caribou Provincial Parks for comparison with shoreline sites that were not used by caribou within each park. Differences in habitat variables selected by female caribou in the two study areas reflect broad ecoregional differences in vegetation and topography. In Wabakimi Provincial Park, understorey tree density and ground detection distance played key roles in distinguishing nursery sites from sites that were not used. In Woodland Caribou Provincial Park, groundcover vegetation and shrub density were important in the selection of nursery sites by female caribou. Generally, female caribou in both parks selected nursery sites with greater slope, lower shrub density but thicker groundcover vegetation, including greater lichen abundance, and higher densities of mature trees than shoreline sites that were not used. The identification of these important features for caribou nursery sites provides a basis for improving their protection in future management policies and legislation.

scholarly journals Factors affecting nest-site selection of Sabine's Gulls in the eastern Canadian Arctic

2005 ◽  
Vol 83 (9) ◽  
pp. 1240-1245 ◽  
Author(s):  
Iain J Stenhouse ◽  
H Grant Gilchrist ◽  
William A Montevecchi
Keyword(s):  
Site Selection ◽  
Nest Site ◽  
Nest Site Selection ◽  
Breeding Habitat ◽  
Factors Affecting ◽  
Invertebrate Prey ◽  
Terrestrial Invertebrate ◽  
Individual Fitness ◽  
Sabine’S Gull ◽  
Selection Of

The selection of breeding habitat is of prime importance for individual fitness. Among birds, natural selection should favour the ability to recognize and select habitat suitable for nesting and rearing chicks. This study compares the characteristics of Sabine's Gull, Xema sabini (Sabine, 1819), nest sites with random points across a coastal tundra environment on Southampton Island, Nunavut, Canada. The availability of terrestrial invertebrate prey was also examined among habitats. Sabine's Gull nests were nonrandomly distributed in relation to vegetation, substrate, and proximity to water. Gulls nested within approximately 1 km of the coastline and selected sites with the greatest proportions of moss and standing water (i.e., they nested close to the edge of small freshwater ponds near shore). However, there were no detectable differences in characteristics between successful and unsuccessful nests within preferred habitat. The dynamics of terrestrial invertebrate prey communities varied between years, but the volume of invertebrates in Sabine's Gull nesting habitat was intermediate between the most productive habitats and the least productive habitats in both years. However, nest-site selection in Sabine's Gulls may also be influenced by the availability of aquatic invertebrates (not examined in this study) and their proximity to the marine coastline, where chicks are taken to be reared.

scholarly journals Habitat selection when killing primary versus alternative prey species supports prey specialization in an apex predator

2020 ◽  
Author(s):  
B Cristescu ◽  
S Bose ◽  
LM Elbroch ◽  
ML Allen ◽  
Heiko Wittmer
Keyword(s):  
Habitat Selection ◽  
Prey Species ◽  
Puma Concolor ◽  
Apparent Competition ◽  
Selection Function ◽  
Alternative Prey ◽  
Odocoileus Hemionus Columbianus ◽  
Ecological Processes ◽  
Habitat Features ◽  
Selection Of

© 2019 The Zoological Society of London Many predators specialize on one or several prey species that they select from the range of potential prey. Predator specialization on primary versus alternative prey is driven in part by encounter rates with prey and a predator’s habitat selection. Although habitat selection changes with behavioural state, this has not been well-recognized in the resource selection function (RSF) literature to date, often because auxiliary data on the predator’s behavioural states (e.g. hunting) are absent. We monitored habitat selection of pumas Puma concolor in a multi-prey system in northern California, where pumas specialized on black-tailed deer Odocoileus hemionus columbianus. We employed multiple RSF analyses on different datasets to test the following three hypotheses: (1) Pumas utilize habitats in proportion to their availability; (2) Pumas select specific habitat features when killing black-tailed deer, their primary prey; (3) Pumas do not select distinct habitats from those identified under hypothesis 1 when killing alternative prey. We found that pumas in our study selected for specific habitats and habitat features in general, but that their selection was more pronounced when killing black-tailed deer. In summer, kill sites of deer were associated with rugged terrain, but gentle slopes and northerly aspects. In winter, pumas killed deer at low elevations, on gentle slopes and on northerly and westerly aspects. Overall, evidence suggested that pumas tracked their primary prey across seasonal migrations, which were short in distance but resulted in pronounced changes in elevation. When killing alternative prey, pumas showed little evidence of habitat selection, suggesting they may kill alternative prey opportunistically. Our results hold implications for how data should be partitioned when modelling baseline habitat selection of predators, hunting habitat selection and predation risk for prey species, as well as for how we model ecological processes such as apparent competition.

scholarly journals Treating the Lips and Its Anatomical Correlate in Respect to Vascular Compromise

2019 ◽  
Vol 35 (02) ◽  
pp. 193-203 ◽  
Author(s):  
Sahar Ghannam ◽  
Sonja Sattler ◽  
Konstantin Frank ◽  
David Freytag ◽  
Katherine Webb ◽  
...  
Keyword(s):  
Ethnic Differences ◽  
Tissue Loss ◽  
Anatomic Study ◽  
Arterial Embolism ◽  
Close Proximity ◽  
Vascular Compromise ◽  
Diverse Society ◽  
Injection Techniques ◽  
Cadaveric Model ◽  
Selection Of

AbstractTreating the lips to increase facial attractiveness and youthfulness is challenging when trying to consider ethnic differences in an increasingly more diverse society. Multiple injection techniques are currently available for treating lip contour and volume, but a validation in the cadaveric model under the aspects of safety has not been performed yet. The injection techniques presented in this study are based on the experience and personal selection of the authors. The authors have assessed, treated, and evaluated for more than 20 years patients from the Middle East and Central Europe. Cadaveric verification was performed for each of the presented techniques to identify the positioning of the injected product inside the lips and its relation to the superior/inferior labial arteries. The results of the anatomic analyses revealed that in 58.3% of the performed injections, the product was placed close to the superior/inferior labial arteries. In 60.0% of the cases, applications using a needle placed the injected product in endangered locations, whereas 57.1% of the cases using cannulas placed the product in endangered locations (i.e., in the vicinity of the superior/inferior labial arteries). This anatomic study revealed that injected material into the lips is frequently placed in close proximity to labial arteries representing a high risk for intra-arterial applications, leading to tissue loss (necrosis) and potential end-arterial embolism (potential blindness). Nevertheless, treatment of the lips should be a multistep approach focusing first on the far (upper and middle face) and close (labiomandibular and labiomental) perioral regions.

Application of Taguchi Method to Optimization of Cutting Force and Temperature during Turning of Difficult to Cut Materials

2016 ◽  
Vol 686 ◽  
pp. 114-118 ◽  
Author(s):  
Grzegorz Struzikiewicz ◽  
Wojciech Zębala ◽  
Ksenia Rumian
Keyword(s):  
Taguchi Method ◽  
Cutting Force ◽  
Desirability Function ◽  
Optimal Solution ◽  
Regression Function ◽  
Function Optimization ◽  
Close Proximity ◽  
Optimal Setting ◽  
Steel Turning ◽  
Selection Of

The paper presents an analysis of the selection of the regression function in the optimization of steel turning using Taguchi method. The study attempts to investigate cutting force and temperature during turning of steel. Taguchi L16 (4) 2 orthogonal array has been applied for experimental design. S/N ratio and ANOVA analyses were performed to identify significant parameters influencing cutting force and temperature. Mathematical models for both response parameters i.e. cutting force and temperature roughness were obtained through regression analysis. The confirmation experiments carried out at optimal combination of parameters given by Taguchi’s analysis. The optimal solution provided by desirability function optimization was compared with the optimal setting of parameters given by Taguchi analysis. The optimization results provided by both techniques are in close proximity.

THE VALUE OF INTEGRATING BOREHOLE RESISTIVITY IMAGES WITH GEOLOGICAL DATA: RELEVANCE TO HYDROCARBON EXPLORATION

1997 ◽  
Vol 37 (1) ◽  
pp. 301 ◽  
Author(s):  
B. E. J. Messent ◽  
C.M. Yacopetti
Keyword(s):  
Poor Quality ◽  
Depositional Environments ◽  
Hydrocarbon Exploration ◽  
Qualitative Assessment ◽  
Low Permeability ◽  
Geological Data ◽  
Close Proximity ◽  
Potential Reservoir ◽  
Low Permeability Reservoirs ◽  
Selection Of

This paper outlines the contribution borehole resistivity images can make in a frontier exploration program when they are integrated with all available geological data. Specific examples are given from the Duntroon Basin.Dipmeter data and borehole resistivity images can be used to validate seismic structural interpretations. An example is given to show the comparison in interpretation of the different methods.Faults are identified on the borehole images and in addition, qualitative assessment of sealing potential can be made by determining the occurrence and extent of mineralisation. In Greenly-1 the hydrocarbon shows, which are interpreted as migrated hydrocarbons, are found In close proximity to faults identified on borehole images. It is postulated that the faults acted as a conduit for the migrating hydrocarbons. However, these fault planes are now mineralised and interpreted to be sealing. This interpretation is supported by the presence of isolated, over-pressured sandstones.Resistivity images readily identify the orientation of present day horizontal stresses with its implications for fault-trap integrity. However, this is not deemed to be an issue in the Duntroon Basin as there is evidence that at least some of the faults are sealing. Borehole images can also be used to assess caprock integrity by determining the presence or absence of fractures.Within potential reservoir units, borehole resistivity images assist in the interpretation of depositional environments, reservoir geometries and post-depositional changes which affect reservoir quality.Borehole resistivity images provide qualitative interpretations of permeability. It is therefore possible to use the images in the selection of pre-test seats and sampling points in poor quality boreholes or low permeability reservoirs.

Molecular diversity of small balsam populations in relation to site characteristics

2013 ◽  
Vol 8 (10) ◽  
pp. 1048-1061 ◽  
Author(s):  
Eugenija Kupcinskiene ◽  
Lina Zybartaite ◽  
Rasa Janulioniene ◽  
Judita Zukauskiene ◽  
Algimantas Paulauskas
Keyword(s):  
Molecular Diversity ◽  
Genetic Distances ◽  
Randomly Amplified Polymorphic Dna ◽  
Multiple Introductions ◽  
Habitat Features ◽  
Site Characteristics ◽  
Impatiens Parviflora ◽  
Geographical Distances ◽  
Favorable Conditions ◽  
Simple Sequence

AbstractClimatic shifts within recent decades created favorable conditions for invasive species flourishing in more Northern parts of Europe. Our study was aimed at evaluation of genetic variability and habitat features of Impatiens parviflora populations growing in Lithuania. Twenty one populations were selected and analysed using simple sequence repeat (SSR) and randomly amplified polymorphic DNA (RAPD) assays. Evaluated by SSRs, 315 individuals were all monomorphic and homozygous at 4 loci and heterozygous at 1 locus. RAPD analyses revealed that the percentage of polymorphic DNA loci (% P) per population ranged from 7 to 39% and genetic differentiation between populations was ΦPT=0.790 (P<0.01). Genetic distances among populations (0.135–0.426) correlated significantly with geographical distances (r=0.183; P<0.008). Populations in overmoistured soil contained higher % P (28.3) when compared to drier soil (18.7; P<0.05). All recorded populations were close to roads; their % P did not depend on proximity to buildings, light intensity or population size. Our RAPD analyses indicate multiple introductions of this species in Lithuania. Analyses of I. parviflora at SSR and RAPD loci show that the invasion process is reflected in genetic structure.

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