The Experts below are selected from a list of 291 Experts worldwide ranked by ideXlab platform
Kim Murray Berger - One of the best experts on this subject based on the ideXlab platform.
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carnivore livestock conflicts effects of subsidized Predator Control and economic correlates on the sheep industry
Conservation Biology, 2006Co-Authors: Kim Murray BergerAbstract:Abstract: Despite the importance of carnivores in terrestrial ecosystems, many nations have implemented well-coordinated, state-funded initiatives to remove Predators, largely because of conflicts with humans over livestock. Although these Control efforts have been successful in terms of the number of carnivores removed, their effects on the viability of the industries they seek to protect are less understood. I assessed the efficacy of long-term efforts by the U.S. government to improve the viability of the sheep industry by reducing predation losses. I used regression analysis and hierarchical partitioning of a 60-year data set to explore associations among changes in sheep numbers and factors such as Predator Control effort, market prices, and production costs. In addition, I compared trends in the sheep industry in the western United States, where Predator Control is subsidized and coyotes (Canis latrans) are abundant, with trends in eastern states that lack federally subsidized Predator Control and that were (1) colonized by coyotes before 1950 or (2) colonized by coyotes between 1950 and 1990. Although Control efforts were positively correlated with fluctuations in sheep numbers, production costs and market prices explained most of the model variation, with a combined independent contribution of 77%. Trends in sheep numbers in eastern and western states were highly correlated (r ≥0.942) independent of the period during which they were colonized by coyotes, indicating either that Control has been ineffective at reducing predation losses or that factors other than predation account for the declines in both regions. These results suggest that government-subsidized Predator Control has failed to prevent the decline in the sheep industry and alternative support mechanisms need to be developed if the goal is to increase sheep production and not simply to kill carnivores.
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Carnivore‐Livestock Conflicts: Effects of Subsidized Predator Control and Economic Correlates on the Sheep Industry
Conservation Biology, 2006Co-Authors: Kim Murray BergerAbstract:Abstract: Despite the importance of carnivores in terrestrial ecosystems, many nations have implemented well-coordinated, state-funded initiatives to remove Predators, largely because of conflicts with humans over livestock. Although these Control efforts have been successful in terms of the number of carnivores removed, their effects on the viability of the industries they seek to protect are less understood. I assessed the efficacy of long-term efforts by the U.S. government to improve the viability of the sheep industry by reducing predation losses. I used regression analysis and hierarchical partitioning of a 60-year data set to explore associations among changes in sheep numbers and factors such as Predator Control effort, market prices, and production costs. In addition, I compared trends in the sheep industry in the western United States, where Predator Control is subsidized and coyotes (Canis latrans) are abundant, with trends in eastern states that lack federally subsidized Predator Control and that were (1) colonized by coyotes before 1950 or (2) colonized by coyotes between 1950 and 1990. Although Control efforts were positively correlated with fluctuations in sheep numbers, production costs and market prices explained most of the model variation, with a combined independent contribution of 77%. Trends in sheep numbers in eastern and western states were highly correlated (r ≥0.942) independent of the period during which they were colonized by coyotes, indicating either that Control has been ineffective at reducing predation losses or that factors other than predation account for the declines in both regions. These results suggest that government-subsidized Predator Control has failed to prevent the decline in the sheep industry and alternative support mechanisms need to be developed if the goal is to increase sheep production and not simply to kill carnivores.
Andrew N. Hoodless - One of the best experts on this subject based on the ideXlab platform.
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Predation of released pheasants Phasianus colchicus on lowland farmland in the UK and the effect of Predator Control
European Journal of Wildlife Research, 2018Co-Authors: Rufus B. Sage, Andrew N. Hoodless, Clare V. Turner, Maureen I. A. Woodburn, Roger A. H. Draycott, Nicolas W. SothertonAbstract:We present data accumulated over the last 25 years on predation of radio-tracked released pheasants. In studies of birds during the autumn/winter at six pheasant shoots with high-density releases managed by full-time gamekeepers, predation of released pheasants by foxes before the shooting season began (July–September) averaged 19.2 ± 4.0% per site, and during the shooting season (October 1st–February 1st), a further 15.9 ± 1.9% were predated. The range in 3-year average predation rates between sites before shooting began was 8.6 to 42.4%. At seven different sites during the spring and summer, between 20 and 71% of released or wild hens that survived the shooting season were predated, mainly by foxes, between mid-March and mid-July. Predation was significantly higher at sites with low-level Predator Control (59 ± 4.7%) compared to those with high-level Control (30 ± 5.3%). At three of the four sites with low Predator Control between 5 and 22% of nest failures were caused by incubating hens being predated by foxes. Our data quantify for the first time highly variable predation rates of released pheasants before and during the winter shooting season which we suggest was influenced by a range of site and management factors. During the spring and summer, our data provide evidence that predation of adult hen pheasants as well as nest predation can suppress breeding success and that Predator Control can reduce these losses.
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Impacts of Predator abundance on red grouse Lagopus lagopus scotica during a period of experimental Predator Control
Wildlife Biology, 2013Co-Authors: Kathy Fletcher, Andrew N. Hoodless, David BainesAbstract:During a nine-year study manipulating Predator abundances, post-breeding numbers of red grouse Lagopus lagopus scotica increased initially in response to experimentally reduced levels of key Predator species (i.e. red fox Vulpes vulpes, carrion crow Corvus corone, stoat Mustela erminea and least weasel M. nivalis), but subsequently declined whilst Predator Control continued. Raptors, which were not Controlled, were also present and may have influenced grouse demography. Our study examines the relative importance of Controlled Predators and raptors on grouse breeding success and survival. Raptor abundance did not differ between periods of Predator Control and periods of no Predator Control. However, during the breeding season, the survival of adult grouse was negatively correlated with the abundance of both raptors and Controlled Predators. Within the group of Controlled Predators, the strongest effects on red grouse adult survival were attributed to small mustelid abundance. Grouse breeding success was ne...
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changes in breeding success and abundance of ground nesting moorland birds in relation to the experimental deployment of legal Predator Control
Journal of Applied Ecology, 2010Co-Authors: Kathy Fletcher, David Baines, Nicholas J Aebischer, Robin Foster, Andrew N. HoodlessAbstract:Summary 1. An 8-year-field experiment on moorland in northern England manipulated the abundance of legally Controllable Predators whilst maintaining consistent habitat conditions. Subsequent changes in both the breeding success and abundance of five ground-nesting bird species were monitored: lapwing Vanellus vanellus, golden plover Pluvialis apricaria, curlew Numenius arquata, red grouse Lagopus lagopus scoticus and meadow pipit Anthus pratensis and the abundance only of snipe Gallinago gallinago and skylark Alauda arvensis. 2. Control of fox Vulpes vulpes, carrion crow Corvus corone, stoat Mustela ermina and weasel Mustela nivalis reduced the abundance of fox (−43%) and crow (−78%); no changes were detected in already low stoat or weasel abundances. 3. Reductions in foxes and crows led to an average threefold increase in breeding success of lapwing, golden plover, curlew, red grouse and meadow pipit. 4. Predator Control led to subsequent increases in breeding numbers (≥14% per annum) of lapwing, curlew, golden plover and red grouse, all of which declined in the absence of Predator Control (≥17% per annum). 5. Synthesis and applications. Controlling Predators is a potentially important management tool for conserving a range of threatened species. Considerable sums of public monies are currently spent on habitat improvement for conservation and some of these public funds should be used to underpin habitat works with Predator removal.
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Changes in breeding success and abundance of ground‐nesting moorland birds in relation to the experimental deployment of legal Predator Control
Journal of Applied Ecology, 2010Co-Authors: Kathy Fletcher, David Baines, Nicholas J Aebischer, Robin Foster, Andrew N. HoodlessAbstract:Summary 1. An 8-year-field experiment on moorland in northern England manipulated the abundance of legally Controllable Predators whilst maintaining consistent habitat conditions. Subsequent changes in both the breeding success and abundance of five ground-nesting bird species were monitored: lapwing Vanellus vanellus, golden plover Pluvialis apricaria, curlew Numenius arquata, red grouse Lagopus lagopus scoticus and meadow pipit Anthus pratensis and the abundance only of snipe Gallinago gallinago and skylark Alauda arvensis. 2. Control of fox Vulpes vulpes, carrion crow Corvus corone, stoat Mustela ermina and weasel Mustela nivalis reduced the abundance of fox (−43%) and crow (−78%); no changes were detected in already low stoat or weasel abundances. 3. Reductions in foxes and crows led to an average threefold increase in breeding success of lapwing, golden plover, curlew, red grouse and meadow pipit. 4. Predator Control led to subsequent increases in breeding numbers (≥14% per annum) of lapwing, curlew, golden plover and red grouse, all of which declined in the absence of Predator Control (≥17% per annum). 5. Synthesis and applications. Controlling Predators is a potentially important management tool for conserving a range of threatened species. Considerable sums of public monies are currently spent on habitat improvement for conservation and some of these public funds should be used to underpin habitat works with Predator removal.
Craig Packer - One of the best experts on this subject based on the ideXlab platform.
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PERSPECTIVES Keeping the herds healthy and alert: implications of Predator Control for infectious disease
2020Co-Authors: Craig Packer, Robert D Holt, Peter J Hudson, D Kevin, Andrew P DobsonAbstract:Predator Control programmes are generally implemented in an attempt to increase prey population sizes. However, Predator removal could prove harmful to prey populations that are regulated primarily by parasitic infections rather than by predation. We develop models for microparasitic and macroparasitic infection that specify the conditions where Predator removal will (a) increase the incidence of parasitic infection, (b) reduce the number of healthy individuals in the prey population and (c) decrease the overall size of the prey population. In general, Predator removal is more likely to be harmful when the parasite is highly virulent, macroparasites are highly aggregated in their prey, hosts are long-lived and the Predators select infected prey.
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sport hunting Predator Control and conservation of large carnivores
PLOS ONE, 2009Co-Authors: Craig Packer, Margaret Kosmala, Hilary S Cooley, Henry Brink, Lilian Pintea, David L Garshelis, Gianetta Purchase, Megan Strauss, Alexandra Swanson, Guy A BalmeAbstract:Sport hunting has provided important economic incentives for conserving large Predators since the early 1970's, but wildlife managers also face substantial pressure to reduce depredation. Sport hunting is an inherently risky strategy for Controlling Predators as carnivore populations are difficult to monitor and some species show a propensity for infanticide that is exacerbated by removing adult males. Simulation models predict population declines from even moderate levels of hunting in infanticidal species, and harvest data suggest that African countries and U.S. states with the highest intensity of sport hunting have shown the steepest population declines in African lions and cougars over the past 25 yrs. Similar effects in African leopards may have been masked by mesoPredator release owing to declines in sympatric lion populations, whereas there is no evidence of overhunting in non-infanticidal populations of American black bears. Effective conservation of these animals will require new harvest strategies and improved monitoring to counter demands for Predator Control by livestock producers and local communities.
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keeping the herds healthy and alert implications of Predator Control for infectious disease
Ecology Letters, 2003Co-Authors: Craig Packer, Robert D Holt, Peter J Hudson, Kevin D Lafferty, Andrew P DobsonAbstract:Predator Control programmes are generally implemented in an attempt to increase prey population sizes. However, Predator removal could prove harmful to prey populations that are regulated primarily by parasitic infections rather than by predation. We develop models for microparasitic and macroparasitic infection that specify the conditions where Predator removal will (a) increase the incidence of parasitic infection, (b) reduce the number of healthy individuals in the prey population and (c) decrease the overall size of the prey population. In general, Predator removal is more likely to be harmful when the parasite is highly virulent, macroparasites are highly aggregated in their prey, hosts are long-lived and the Predators select infected prey.
Jonathan K. Yoder - One of the best experts on this subject based on the ideXlab platform.
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Contracting over common property: cost-share contracts for Predator Control.
Journal of Agricultural and Resource Economics, 2000Co-Authors: Jonathan K. YoderAbstract:Predator Control cost-share contracts among livestock producers to Control coyote predation date back to 1630 in North America and are common today among sheep producers in western states. Typically, per unit assessments are imposed on a monitorable input, and revenues are used to purchase Predator Control for participants' land. This study presents a model which provides refutable implications for the structure and distribution of these contracts over time and space. Historical and contemporary state and county data on sheep producer assessments support a model that is applicable more generally to the problem of investment in common property inputs.
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CONTRACTING OVER COMMON PROPERTY: COST-SHARE CONTRACTS FOR Predator Control
1999Co-Authors: Jonathan K. YoderAbstract:Predator Control cost-share contracts among livestock producers in North America date back to 1630. A model is developed which provides refutable implications for the structure and distribution of these contracts over time and space. Historical and contemporary state and county level data on sheep producer coyote Control generally support the model.
Murray J Willans - One of the best experts on this subject based on the ideXlab platform.
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large scale Predator Control improves the productivity of a rare new zealand riverine duck
Biological Conservation, 2008Co-Authors: Amy L. Whitehead, Kerrianne Edge, Andrew F Smart, Gerard S Hill, Murray J WillansAbstract:Declines in avian populations are often attributed to the presence of introduced Predators but conservation managers frequently lack good information about the effectiveness of potential Predator Control regimes for protecting threatened species. Whio, Hymenolaimus malacorhynchos, are a threatened New Zealand waterfowl that has been declining in both distribution and abundance. We conducted a six-year study using a paired-catchment experiment in New Zealand Nothofagus forest as part of an adaptive management programme to assess whether whio populations responded positively to stoat (Mustela erminea) Control. Video monitoring identified stoats as the primary nest Predator. Year-round low-intensity stoat Control (10 traps per linear km) significantly reduced the stoat abundance index in trapped sites compared with untrapped sites. As a result, whio nesting success and productivity, the number of fledglings produced per pair, increased significantly in the trapped compared to the untrapped area. However, survival rates and the number of pairs did not change significantly between the treatments. These findings indicate stoats are the primary agent of decline for whio in this Nothofagus forest system, and show that low-intensity stoat Control is sufficient to improve the productivity of whio populations. Overall, the study demonstrates the value of an adaptive management approach whereby management techniques can be evaluated to ensure that the primary agent of decline is clearly identified and that Predator densities are kept sufficiently low.
