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Ronald J. Kendall - One of the best experts on this subject based on the ideXlab platform.
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Elevated parasite burdens as a potential mechanism affecting northern bobwhite (Colinus virginianus) population dynamics in the Rolling Plains of West Texas
Parasitology Research, 2018Co-Authors: Matthew Z. Brym, Cassandra Henry, Ronald J. KendallAbstract:Northern bobwhite quail ( Colinus virginianus ) are a highly sought-after Game Bird in the Rolling Plains of West Texas. Unfortunately, bobwhite populations in this area are subject to dramatic fluctuations and have been steadily decreasing over the past several decades. While many factors have been investigated as potential mechanisms of cyclic and declining bobwhite numbers, the effect of parasites on bobwhite populations has historically been undervalued. Between December 2017 and February 2018, we received 21 hunter-shot bobwhite from Garza and Mitchell counties in Texas and found peak caecal worm ( Aulonocephalus pennula ) and eyeworm ( Oxyspirura petrowi ) burdens averaging 599 and 44, respectively. These represent the highest average parasite loads we have documented in bobwhite from the Rolling Plains thus far and are coincident with widespread reports of declining bobwhite abundance. These elevated infections also followed a high point in bobwhite populations in the Rolling Plains, and our observations of infection dynamics during this time reflect other instances of potential parasite-induced host mortality. While the sample discussed in this communication is small, our findings highlight the need for additional research into how parasites may affect bobwhite population fluctuations in this region.
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An ecological risk assessment of lead shot exposure in non‐waterfowl avian species: Upland Game Birds and raptors
Environmental Toxicology and Chemistry, 1996Co-Authors: Ronald J. Kendall, C. Bunck, Thomas E. Lacker, Bernard Daniel, Crystal Driver, Christian E. Grue, Frederick A. Leighton, William Stansley, P.g. Watanabe, Molly WhitworthAbstract:There is increasing concern that Birds in terrestrial ecosystems may be exposed to spent lead shot. Evidence exists that upland Birds, particularly mourning doves (Zenaida macroura), ingest spent lead shot and that raptors ingest lead shot by consuming wounded Game. Mortality, neurological dysfunction, immune suppression, and reproductive impairment are documented effects of exposure to lead in Birds. An ecological risk assessment on the impact of lead shot exposure in upland Birds was conducted and is presented in the context of the new United States Environmental Protection Agency's Ecological Risk Assessment Paradigm. A considerable amount of spent lead shot is released into the environment each year from shooting and hunting. Doves collected from fields that are cultivated to attract mourning doves for hunting activities show evidence of ingestion of spent lead shot. Because lead can cause both acute and chronic toxicity if ingested by Birds, and because there is evidence of widespread deposition of lead shot in terrestrial ecosystems, concern for impacts on upland Game Birds and raptors seems warranted. Although this ecological risk assessment does not clearly define a significant risk of lead shot exposure to upland Game Birds, this issue merits continued scrutiny to protect our upland Game Bird and raptor resources.
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Annual Review AN ECOLOGICAL RISK ASSESSMENT OF LEAD SHOT EXPOSURE IN NON-WATERFOWL AVIAN SPECIES: UPLAND Game BirdS AND RAPTORS
1996Co-Authors: Ronald J. Kendall, T.e. Lacher, Bernard Daniel, Christian E. Grue, Frederick A. Leighton, William Stansley, P.g. Watanabe, Molly WhitworthAbstract:There is increasing concern that Birds in terrestrial ecosystems may be exposed to spent lead shot. Evidence exists that upland Birds, particularly mourning doves (Zenaida macroura), ingest spent lead shot and that raptors ingest lead shot by consuming wounded Game. Mortality, neurological dysfunction, immune suppression, and reproductive impairment are documented effects of exposure to lead in Birds. An ecological risk assessment on the impact of lead shot exposure in upland Birds was conducted and is presented in the context of the new United States Environmental Protection Agency's Ecological Risk Assessment Paradigm. A considerable amount of spent lead shot is released into the environment each year from shooting and hunting. Doves collected from fields that are cultivated to attract mourning doves for hunting activities show evidence of ingestion of spent lead shot. Because lead can cause both acute and chronic toxicity if ingested by Birds, and because there is evidence of widespread deposition of lead shot in terrestrial ecosystems, concern for impacts on upland Game Birds and raptors seems warranted. Although this ecological risk assessment does not clearly define a significant risk of lead shot exposure to upland Game Birds, this issue merits continued scrutiny to protect our upland Game Bird and raptor resources. Keywords—Environmental risk assessment Lead shot Wildlife Non-waterfowl Shooting sports
Lucy Gilbert - One of the best experts on this subject based on the ideXlab platform.
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a model to test how ticks and louping ill virus can be controlled by treating red grouse with acaricide
Medical and Veterinary Entomology, 2013Co-Authors: Rosalyn Porter, Rachel Norman, Lucy GilbertAbstract:Ticks are the most important vectors of disease-causing pathogens in Europe. In the U.K., Ixodes ricinus L. (Ixodida: Ixodidae) transmits louping ill virus (LIV; Flaviviridae), which kills livestock and red grouse, Lagopus lagopus scoticus Lath. (Galliformes: Phasianidae), a valuable Game Bird. Tick burdens on grouse have been increasing. One novel method to reduce ticks and LIV in grouse may be acaricide treatment. Here, we use a mathematical model parameterized with empirical data to investigate how the acaricide treatment of grouse might theoretically control ticks and LIV in grouse. Assuming a situation in which ticks and LIV impact on the grouse population, the model predicts that grouse density will depend on deer density because deer maintain the tick population. In low deer densities, no acaricide treatment is predicted to be necessary because abundances of grouse will be high. However, at higher deer densities, the model predicts that grouse densities will increase only if high numbers of grouse are treated, and the efficacy of acaricide is high and lasts 20 weeks. The qualitative model predictions may help to guide decisions on whether to treat grouse or cull deer depending on deer densities and how many grouse can be treated. The model is discussed in terms of practical management implications.
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Controlling tick-borne diseases through domestic animal management: a theoretical approach
Theoretical Ecology, 2011Co-Authors: Rosalyn Porter, Rachel Norman, Lucy GilbertAbstract:Vector-borne diseases are of global importance to human and animal health. Empirical trials of effective methods to control vectors and their pathogens can be difficult for practical, financial and ethical reasons. Here, therefore, we use a mathematical model to predict the effectiveness of a vector-borne disease control method. As a case study, we use the tick-louping ill virus system, where sheep are treated with acaricide in an attempt to control ticks and disease in red grouse , an economically important Game Bird. We ran the model under different scenarios of sheep flock sizes, alternative host (deer) densities, acaricide efficacies and tick burdens. The model predicted that, with very low deer densities, using sheep as tick mops can reduce the tick population and virus prevalence. However, treatment is ineffective above a certain threshold deer density, dependent on the comparative tick burden on sheep and deer. The model also predicted that high efficacy levels of acaricide must be maintained for effective tick control. This study suggests that benignly managing one host species to protect another host species from a vector and pathogen can be effective under certain conditions. It also highlights the importance of understanding the ecological complexity of a system, in order to target control methods only under certain circumstances for maximum effectiveness.
Simon R. Leather - One of the best experts on this subject based on the ideXlab platform.
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body condition is negatively associated with infection with syngamus trachea in the ring necked pheasant phasianus colchicus
Veterinary Parasitology, 2016Co-Authors: Owen J Gethings, R B Sage, Eric R Morgan, Simon R. LeatherAbstract:The role that parasites play in regulating animal populations is debated, however recent research hints at their pervasiveness among free-living animal populations. Parasites exert both direct and indirect effects on host populations, and can act to regulate populations. The Ring-necked pheasant is an important Game-Bird species in the UK, and large numbers of Birds are released annually. The impact of the ubiquitous tracheal nematode, Syngamus trachea on pheasant populations through effects on host condition was assessed on two pheasant estates in the south west of England. Pheasants infected with S. trachea demonstrated a significant reduction in host condition compared with uninfected controls, with as few as one pair of worms per Bird. Although there was no difference in worm burden between sexes, analysis of regression slopes revealed there was a significant difference between sexes in the magnitude of the effect of increasing worm burden on host condition, with detectable effects observed in hosts with one and three pairs of worms for males and females respectively. The observed reductions in host condition in Birds with even sub-clinical infections could be the cause of poor reproductive success and survival of pheasants post-release.
Rosalyn Porter - One of the best experts on this subject based on the ideXlab platform.
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a model to test how ticks and louping ill virus can be controlled by treating red grouse with acaricide
Medical and Veterinary Entomology, 2013Co-Authors: Rosalyn Porter, Rachel Norman, Lucy GilbertAbstract:Ticks are the most important vectors of disease-causing pathogens in Europe. In the U.K., Ixodes ricinus L. (Ixodida: Ixodidae) transmits louping ill virus (LIV; Flaviviridae), which kills livestock and red grouse, Lagopus lagopus scoticus Lath. (Galliformes: Phasianidae), a valuable Game Bird. Tick burdens on grouse have been increasing. One novel method to reduce ticks and LIV in grouse may be acaricide treatment. Here, we use a mathematical model parameterized with empirical data to investigate how the acaricide treatment of grouse might theoretically control ticks and LIV in grouse. Assuming a situation in which ticks and LIV impact on the grouse population, the model predicts that grouse density will depend on deer density because deer maintain the tick population. In low deer densities, no acaricide treatment is predicted to be necessary because abundances of grouse will be high. However, at higher deer densities, the model predicts that grouse densities will increase only if high numbers of grouse are treated, and the efficacy of acaricide is high and lasts 20 weeks. The qualitative model predictions may help to guide decisions on whether to treat grouse or cull deer depending on deer densities and how many grouse can be treated. The model is discussed in terms of practical management implications.
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Controlling tick-borne diseases through domestic animal management: a theoretical approach
Theoretical Ecology, 2011Co-Authors: Rosalyn Porter, Rachel Norman, Lucy GilbertAbstract:Vector-borne diseases are of global importance to human and animal health. Empirical trials of effective methods to control vectors and their pathogens can be difficult for practical, financial and ethical reasons. Here, therefore, we use a mathematical model to predict the effectiveness of a vector-borne disease control method. As a case study, we use the tick-louping ill virus system, where sheep are treated with acaricide in an attempt to control ticks and disease in red grouse , an economically important Game Bird. We ran the model under different scenarios of sheep flock sizes, alternative host (deer) densities, acaricide efficacies and tick burdens. The model predicted that, with very low deer densities, using sheep as tick mops can reduce the tick population and virus prevalence. However, treatment is ineffective above a certain threshold deer density, dependent on the comparative tick burden on sheep and deer. The model also predicted that high efficacy levels of acaricide must be maintained for effective tick control. This study suggests that benignly managing one host species to protect another host species from a vector and pathogen can be effective under certain conditions. It also highlights the importance of understanding the ecological complexity of a system, in order to target control methods only under certain circumstances for maximum effectiveness.
Carol J Cardona - One of the best experts on this subject based on the ideXlab platform.
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Analysis of geographic location and pathways for influenza A virus infection of commercial upland Game Bird and conventional poultry farms in the United States of America
BMC Veterinary Research, 2019Co-Authors: Amos Ssematimba, Kaitlyn M. St. Charles, Peter J. Bonney, Sasidhar Malladi, Marie Culhane, Timothy J. Goldsmith, David A Halvorson, Carol J CardonaAbstract:BackgroundAvian influenza (AI) is an infectious viral disease that affects several species and has zoonotic potential. Due to its associated health and economic repercussions, minimizing AI outbreaks is important. However, most control measures are generic and mostly target pathways important for the conventional poultry farms producing chickens, turkeys, and eggs and may not target other pathways that may be specific to the upland Game Bird sector. The goal of this study is to provide evidence to support the development of novel strategies for sector-specific AI control by comparing and contrasting practices and potential pathways for spread in upland Game Bird farms with those for conventional poultry farms in the United States. Farm practices and processes, seasonality of activities, geographic location and inter-farm distance were analyzed across the sectors. All the identified differences were framed and discussed in the context of their associated pathways for virus introduction into the farm and subsequent between-farm spread.ResultsDifferences stemming from production systems and seasonality, inter-farm distance and farm densities were evident and these could influence both fomite-mediated and local-area spread risks. Upland Game Bird farms operate under a single, independent owner rather than being contracted with or owned by a company with other farms as is the case with conventional poultry. The seasonal marketing of upland Game Birds, largely driven by hunting seasons, implies that movements are seasonal and customer-vendor dynamics vary between industry groups. Farm location analysis revealed that, on average, an upland Game Bird premises was 15.42 km away from the nearest neighboring premises with Birds compared to 3.74 km for turkey premises. Compared to turkey premises, the average poultry farm density in a radius of 10 km of an upland Game Bird premises was less than a half, and turkey premises were 3.8 times (43.5% compared with 11.5%) more likely to fall within a control area during the 2015 Minnesota outbreak.ConclusionsWe conclude that the existing differences in the seasonality of production, isolated geographic location and epidemiological seclusion of farms influence AI spread dynamics and therefore disease control measures should be informed by these and other factors to achieve success.
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Analysis of geographic location and pathways for influenza A virus infection of commercial upland Game Bird and conventional poultry farms in the United States of America
BMC Veterinary Research, 2019Co-Authors: Amos Ssematimba, Kaitlyn M. St. Charles, Peter J. Bonney, Sasidhar Malladi, Marie Culhane, Timothy J. Goldsmith, David A Halvorson, Carol J CardonaAbstract:Background Avian influenza (AI) is an infectious viral disease that affects several species and has zoonotic potential. Due to its associated health and economic repercussions, minimizing AI outbreaks is important. However, most control measures are generic and mostly target pathways important for the conventional poultry farms producing chickens, turkeys, and eggs and may not target other pathways that may be specific to the upland Game Bird sector. The goal of this study is to provide evidence to support the development of novel strategies for sector-specific AI control by comparing and contrasting practices and potential pathways for spread in upland Game Bird farms with those for conventional poultry farms in the United States. Farm practices and processes, seasonality of activities, geographic location and inter-farm distance were analyzed across the sectors. All the identified differences were framed and discussed in the context of their associated pathways for virus introduction into the farm and subsequent between-farm spread.
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Mortality-Based Triggers and Premovement Testing Protocols for Detection of Highly Pathogenic Avian Influenza Virus Infection in Commercial Upland Game Birds.
Avian Diseases, 2018Co-Authors: Amos Ssematimba, Kaitlyn M. St. Charles, Peter J. Bonney, Sasidhar Malladi, Marie Culhane, Timothy J. Goldsmith, David A Halvorson, Carol J CardonaAbstract:Outbreaks involving avian influenza viruses are often devastating to the poultry industry economically and otherwise. Disease surveillance is critically important because it facilitates timely detection and generates confidence that infected Birds are not moved during business continuity intended to mitigate associated economic losses. The possibility of using an abnormal increase in daily mortality to levels that exceed predetermined thresholds as a trigger to initiate further diagnostic investigations for highly pathogenic avian influenza (HPAI) virus infection in the flock is explored. The range of optimal mortality thresholds varies by Bird species, trigger type, and mortality thresholds, and these should be considered when assessing sector-specific triggers. The study uses purposefully collected data and data from the literature to determine optimal mortality triggers for HPAI detection in commercial upland Game Bird flocks. Three trigger types were assessed for the ability to detect rapidly both HPAI (on the basis of disease-induced and normal mortality data) and false alarm rate (on the basis of normal mortality data); namely, 1) exceeding a set absolute threshold on one day, 2) exceeding a set absolute threshold on two consecutive days, or 3) exceeding a multiple of a seven-day moving average. The likelihood of disease detection using some of these triggers together with premovement real-time reverse transcription PCR (rRT-PCR) testing was examined. Results indicate that the performance of the two consecutive days trigger had the best metrics (i.e., rapid detection with few false alarms) in the trade-off analysis. The collected normal mortality data was zero on 66% of all days recorded, with an overall mean of 0.6 dead Birds per day. In the surveillance scenario analyses, combining the default protocol that relied only on active surveillance (i.e., premovement testing of oropharyngeal swab samples from dead Birds by rRT-PCR) together with either of the mortality-based triggers improved detection rates on all days postexposure before scheduled movement. For exposures occurring within 8 days of movement, the protocol that combined the default with single-day triggers had slightly more detections than that with two consecutive days triggers. However, all assessed protocol combinations were able to detect all infections that occurred more than 10 days before scheduled movement. These findings can inform risk-based decisions pertaining to continuity of business in the commercial upland Game Bird industry.
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Avian Influenza in the U.S. Commercial Upland Game Bird Industry: An Analysis of Selected Practices as Potential Exposure Pathways and Surveillance System Data Reporting
Avian Diseases, 2018Co-Authors: Kaitlyn M. St. Charles, Amos Ssematimba, Peter J. Bonney, Sasidhar Malladi, Marie Culhane, Timothy J. Goldsmith, David A Halvorson, Eric Linskens, Carol J CardonaAbstract:SUMMARY Producing a smaller yield of higher-value Birds compared to conventional poultry production, the U.S. commercial upland Game Bird industry deals primarily in the sale of live Birds for recreational hunting. In this study, our aims were to gain insights into the occurrence of avian influenza (AI) in the U.S. commercial upland Game Bird industry in comparison to other poultry sectors, to identify the presence of the specific AI risk factors in the practices of raising ducks on site and having connections to live Bird markets (LBMs), and to assess how AI surveillance systems may have played a role in the reporting of the presence of exposure pathway–related information. We found that 23 AI epizootics involving upland Game Bird premises were reported, compared to 485 epizootics in the other poultry industries, and 86% of epizootics involving upland Game Birds were limited to only one premises. Regarding specific AI risk factors, 70% of upland Game Bird epizootics involved one of the two examined pract...
