2,534 research outputs found

    Peri-urban wild dogs : diet and movements in north-eastern Australia

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    Knowledge of peri-urban dingo or wild dog ecology can assist management agencies in developing management approaches that alleviate human-wildlife conflicts. Here we summarise (1) the food and dietary items identified in wild dog scats and (2) wild dog movement ecology in urban areas. Individual prey species commonly observed in scats included agile wallabies, northern brown bandicoots and swamp wallabies. Dietary overlap analyses indicated that wild dogs ate the same types or sizes of prey in different regions. In general, wild dogs occupied small fragments of bushland within an urban matrix, were active at all times of the day, and lived within a few hundred meters of houses and humans at all times. These data suggest that urban wild dog management strategies should focus on the mitigation of impacts at the individual or group level, and not population-level reductions in numbers

    Home ranges of rusa deer (Cervus timorensis) in a subtropical peri-urban environment in South East Queensland

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    Wild rusa deer (Cervus timorensis) are increasing in numbers and distribution in peri-urban eastern Australia. To effectively manage rusa deer, land managers need to know the extent of their movements to determine the appropriate scale of control through trapping and shooting. We found that in a subtropical peri-urban environment in South East Queensland, four rusa deer (three male, one female) with GPS collars annually ranged over areas of <400 ha with core areas of ~100 ha over a period of 10–17 months. Our limited data indicated their relatively small home ranges varied little in size and location from season-to-season, suggesting that these deer can be effectively managed at the local level

    Home ranges of rusa deer (Cervus timorensis) in a subtropical peri-urban environment in South East Queensland

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    Wild rusa deer (Cervus timorensis) are increasing in numbers and distribution in peri-urban eastern Australia. To effectively manage rusa deer, land managers need to know the extent of their movements to determine the appropriate scale of control through trapping and shooting. We found that in a subtropical peri-urban environment in South East Queensland, four rusa deer (three male, one female) with GPS collars annually ranged over areas of <400 ha with core areas of ~100 ha over a period of 10–17 months. Our limited data indicated their relatively small home ranges varied little in size and location from season-to-season, suggesting that these deer can be effectively managed at the local level

    Initiation of a Stable Convective Hydroclimatic Regime in Central America Circa 9000 Years BP

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    Many Holocene hydroclimate records show rainfall changes that vary with local orbital insolation. However, some tropical regions display rainfall evolution that differs from gradual precessional pacing, suggesting that direct rainfall forcing effects were predominantly driven by sea-surface temperature thresholds or inter-ocean temperature gradients. Here we present a 12,000 yr continuous U/Th-dated precipitation record from a Guatemalan speleothem showing that Central American rainfall increased within a 2000 yr period from a persistently dry state to an active convective regime at 9000 yr BP and has remained strong thereafter. Our data suggest that the Holocene evolution of Central American rainfall was driven by exceeding a temperature threshold in the nearby tropical oceans. The sensitivity of this region to slow changes in radiative forcing is thus strongly mediated by internal dynamics acting on much faster time scales

    The Relationship of Personality Style and Attention Deficit Hyperactivity Disorder in Children

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    Introduction. This study was to identify personality correlates ofchildren with a diagnosis of Attention Deficit Hyperactive Disorder(ADHD). The Jungian Personality Type dimensions primarilyconsidered were Sensing/Intuiting and Perceiving/Judging.A Sensing child is likely to be very present-centered. A Perceivingchild tends to be curious and resist order and structure. Methods. Children attending a general pediatric clinic with a diagnosisof ADHD were eligible to participate. Enrolled childrenwere administered the Murphy-Meisgeier Type Indicator forChildren. Binomial tests were performed comparing Perceivingand Sensing personality components to accepted population rates. Results. Participants (n = 117) were predominantly male(78%) with a median age of 10 years. The Sensing trait (72%)was more prevalent than expected, though prevalence for thePerceiving trait (44%) did not differ from population rates. Conclusions. Personality types occasioned with the diagnosisof ADHD could be useful in establishing/normalizingtreatment regimens and approaches to assist thesechildren and their families better. KS J Med 2017;10(2):26-29

    Estimating deer density and abundance using spatial mark–resight models with camera trap data

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    Globally, many wild deer populations are actively studied or managed for conservation, hunting, or damage mitigation purposes. These studies require reliable estimates of population state parameters, such as density or abundance, with a level of precision that is fit for purpose. Such estimates can be difficult to attain for many populations that occur in situations that are poorly suited to common survey methods. We evaluated the utility of combining camera trap survey data, in which a small proportion of the sample is individually recognizable using natural markings, with spatial mark–resight (SMR) models to estimate deer density in a variety of situations. We surveyed 13 deer populations comprising four deer species (Cervus unicolor, C. timorensis, C. elaphus, Dama dama) at nine widely separated sites, and used Bayesian SMR models to estimate population densities and abundances. Twelve surveys provided sufficient data for analysis and seven produced density estimates with coefficients of variation (CVs) ≤ 0.25. Estimated densities ranged from 0.3 to 24.6 deer km−2. Camera trap surveys and SMR models provided a powerful and flexible approach for estimating deer densities in populations in which many detections were not individually identifiable, and they should provide useful density estimates under a wide range of conditions that are not amenable to more widely used methods. In the absence of specific local information on deer detectability and movement patterns, we recommend that at least 30 cameras be spaced at 500–1,000 m and set for 90 days. This approach could also be applied to large mammals other than deer

    Estimating deer density and abundance using spatial mark–resight models with camera trap data

    Get PDF
    Globally, many wild deer populations are actively studied or managed for conservation, hunting, or damage mitigation purposes. These studies require reliable estimates of population state parameters, such as density or abundance, with a level of precision that is fit for purpose. Such estimates can be difficult to attain for many populations that occur in situations that are poorly suited to common survey methods. We evaluated the utility of combining camera trap survey data, in which a small proportion of the sample is individually recognizable using natural markings, with spatial mark–resight (SMR) models to estimate deer density in a variety of situations. We surveyed 13 deer populations comprising four deer species (Cervus unicolor, C. timorensis, C. elaphus, Dama dama) at nine widely separated sites, and used Bayesian SMR models to estimate population densities and abundances. Twelve surveys provided sufficient data for analysis and seven produced density estimates with coefficients of variation (CVs) ≤ 0.25. Estimated densities ranged from 0.3 to 24.6 deer km−2. Camera trap surveys and SMR models provided a powerful and flexible approach for estimating deer densities in populations in which many detections were not individually identifiable, and they should provide useful density estimates under a wide range of conditions that are not amenable to more widely used methods. In the absence of specific local information on deer detectability and movement patterns, we recommend that at least 30 cameras be spaced at 500–1,000 m and set for 90 days. This approach could also be applied to large mammals other than deer

    Effectiveness and costs of helicopter-based shooting of deer

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    Context: Helicopter-based shooting has been widely used to harvest deer or control overabundant populations in Australasia, but the effectiveness and cost of this method as a deer control tool has seldom been evaluated.Aims: We evaluated the effectiveness and costs of helicopter-based shooting of fallow deer (Dama dama) and chital deer (Axis axis) in eastern Australia by quantifying (1) reductions in density, (2) the relationship between numbers killed per hour and deer density (i.e. the functional response), (3) the costs of control and (4) the effort–outcome and cost–outcome relationships.Methods: We evaluated the costs and effectiveness of 12 aerial shooting operations aiming to reduce fallow deer (n = 8) or chital deer (n = 4) population densities at nine sites in eastern Australia. Sites were characterised by fragmented woodland, and all but one operation aimed to reduce grazing competition with livestock. We used pre-control population density estimates and operational monitoring data to estimate the costs and outcomes of each operation. We combined data from all operations to estimate the relationship between shooting effort and population reduction, as well as costs associated with different levels of effort.Key results: Population reductions for operations ranged from 5% to 75% for fallow deer, and from 48% to 88% for chital deer. The greatest population reductions occurred when effort per unit area was greatest, and the largest reductions in deer density occurred when shooting was conducted in consecutive years. The functional response of hourly kills to deer density was best described by a modified Ivlev model, with the asymptotic kill rate estimated to be 50 deer per hour. There was no support for the existence of a prey refuge, that is, a threshold population density below which no deer could be shot. Helicopter charter was the primary cost of helicopter-based shooting programs, followed by labour; firearm and ammunition costs were relatively minor.Conclusions: Helicopter-based shooting can rapidly reduce deer populations over large geographic areas, but the magnitude of the reduction depends on the effort (hours of shooting) per deer per km2.Implications: Aerial shooting operations should include a pre-control population survey so that (1) measurable objectives can be established, (2) the likely level of effort and cost required for objectives to be met can be estimated and planned for, and (3) the realised population reduction can be estimated

    Superconductivity in potassium-doped 2,2′'-bipyridine

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    Organic compounds are always promising candidates of superconductors with high transition temperatures. We examine this proposal by choosing 2,2′'-bipyridine solely composed by C, H, and N atoms. The presence of Meissner effect with a transition temperature of 7.2 K in this material upon potassium doping is demonstrated by the dcdc magnetic susceptibility measurements. The real part of the acac susceptibility exhibits the same transition temperature as that in dcdc magnetization, and a sharp peak appeared in the imaginary part indicates the formation of the weakly linked superconducting vortex current. The occurence of superconductivity is further supported by the resistance drop at the transition together with its suppression by the applied magnetic fields. The superconducting phase is identified to be K3_3-2,2′'-bipyridine from the analysis of Raman scattering spectra. This work not only opens an encouraging window for finding superconductivity after optoelectronics in 2,2′'-bipyridine-based materials but also offers an example to realize superconductivity from conducting polymers and their derivatives.Comment: 6 pages, 3 figure
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