The Experts below are selected from a list of 142437 Experts worldwide ranked by ideXlab platform
Hugh P. Possingham - One of the best experts on this subject based on the ideXlab platform.
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spatially explicit approach to estimation of total Population Abundance in field surveys
Journal of Theoretical Biology, 2018Co-Authors: Nao Takashina, Maria Beger, Buntarou Kusumoto, Suren I. Rathnayake, Hugh P. PossinghamAbstract:Population Abundance is fundamental in ecology and conservation biology, and provides essential information for predicting Population dynamics and implementing conservation actions. While a range of approaches have been proposed to estimate Population Abundance based on existing data, data deficiency is ubiquitous. When information is deficient, a Population estimation will rely on labor intensive field surveys. Typically, time is one of the critical constraints in conservation, and management decisions must often be made quickly under a data deficient situation. Hence, it is important to acquire a theoretical justification for survey methods to meet a required estimation precision. There is no such theory available in a spatially explicit context, while spatial considerations are critical to any field survey. Here, we develop a spatially explicit theory for Population estimation that allows us to examine the estimation precision under different survey designs and individual distribution patterns (e.g. random/clustered sampling and individual distribution). We demonstrate that clustered sampling decreases the estimation precision when individuals form clusters, while sampling designs do not affect the estimation accuracy when individuals are distributed randomly. Regardless of individual distribution, the estimation precision becomes higher with increasing total Population Abundance and the sampled fraction. These insights provide theoretical bases for efficient field survey designs in information deficiency situations.
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spatially explicit approach to Population Abundance estimation in field surveys
bioRxiv, 2017Co-Authors: Nao Takashina, Maria Beger, Buntarou Kusumoto, Suren I. Rathnayake, Hugh P. PossinghamAbstract:The Abundance of species is a fundamental consideration in ecology and conservation biology. Although broad models have been proposed to estimate the Population Abundance using existing data, available data is often limited. With no information available, a Population estimation will rely on time consuming field surveys. Typically, time is a critical constraint in conservation and often management decisions must be made quickly under the data limited situation. Depending on time and budgetary constraints, the required accuracy of field survey changes significantly. Hence, it is desirable to set up an effective survey design to minimize time and effort of sampling given required accuracy. We examine a spatially-explicit approach to Population estimation using spatial point processes, enabling us to explicitly and consistently discuss various sampling designs. We find that the accuracy of Abundance estimation varies with both ecological factors and survey design. Although the spatial scale of sampling does not affect estimation accuracy when the underlying individual distribution is random, it decreases with the sampled unit size if individuals tend to form clusters. These results are derived analytically and checked numerically. Obtained insights provide a benchmark to predict the quality of Population estimation, and improve survey designs for ecological studies and conservation.
Don O Hunter - One of the best experts on this subject based on the ideXlab platform.
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estimating snow leopard Population Abundance using photography and capture recapture techniques
Wildlife Society Bulletin, 2006Co-Authors: Rodney M Jackson, Jerry D Roe, Rinchen Wangchuk, Don O HunterAbstract:Abstract Conservation and management of snow leopards (Uncia uncia) has largely relied on anecdotal evidence and presence–absence data due to their cryptic nature and the difficult terrain they inhabit. These methods generally lack the scientific rigor necessary to accurately estimate Population size and monitor trends. We evaluated the use of photography in capture–mark–recapture (CMR) techniques for estimating snow leopard Population Abundance and density within Hemis National Park, Ladakh, India. We placed infrared camera traps along actively used travel paths, scent-sprayed rocks, and scrape sites within 16- to 30-km2 sampling grids in successive winters during January and March 2003–2004. We used head-on, oblique, and side-view camera configurations to obtain snow leopard photographs at varying body orientations. We calculated snow leopard Abundance estimates using the program CAPTURE. We obtained a total of 66 and 49 snow leopard captures resulting in 8.91 and 5.63 individuals per 100 trap-nights du...
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Estimating Snow Leopard Population Abundance Using Photography and Capture–Recapture Techniques
Wildlife Society Bulletin, 2006Co-Authors: Rodney M Jackson, Jerry D Roe, Rinchen Wangchuk, Don O HunterAbstract:Abstract Conservation and management of snow leopards (Uncia uncia) has largely relied on anecdotal evidence and presence–absence data due to their cryptic nature and the difficult terrain they inhabit. These methods generally lack the scientific rigor necessary to accurately estimate Population size and monitor trends. We evaluated the use of photography in capture–mark–recapture (CMR) techniques for estimating snow leopard Population Abundance and density within Hemis National Park, Ladakh, India. We placed infrared camera traps along actively used travel paths, scent-sprayed rocks, and scrape sites within 16- to 30-km2 sampling grids in successive winters during January and March 2003–2004. We used head-on, oblique, and side-view camera configurations to obtain snow leopard photographs at varying body orientations. We calculated snow leopard Abundance estimates using the program CAPTURE. We obtained a total of 66 and 49 snow leopard captures resulting in 8.91 and 5.63 individuals per 100 trap-nights du...
Nao Takashina - One of the best experts on this subject based on the ideXlab platform.
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spatially explicit approach to estimation of total Population Abundance in field surveys
Journal of Theoretical Biology, 2018Co-Authors: Nao Takashina, Maria Beger, Buntarou Kusumoto, Suren I. Rathnayake, Hugh P. PossinghamAbstract:Population Abundance is fundamental in ecology and conservation biology, and provides essential information for predicting Population dynamics and implementing conservation actions. While a range of approaches have been proposed to estimate Population Abundance based on existing data, data deficiency is ubiquitous. When information is deficient, a Population estimation will rely on labor intensive field surveys. Typically, time is one of the critical constraints in conservation, and management decisions must often be made quickly under a data deficient situation. Hence, it is important to acquire a theoretical justification for survey methods to meet a required estimation precision. There is no such theory available in a spatially explicit context, while spatial considerations are critical to any field survey. Here, we develop a spatially explicit theory for Population estimation that allows us to examine the estimation precision under different survey designs and individual distribution patterns (e.g. random/clustered sampling and individual distribution). We demonstrate that clustered sampling decreases the estimation precision when individuals form clusters, while sampling designs do not affect the estimation accuracy when individuals are distributed randomly. Regardless of individual distribution, the estimation precision becomes higher with increasing total Population Abundance and the sampled fraction. These insights provide theoretical bases for efficient field survey designs in information deficiency situations.
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spatially explicit approach to Population Abundance estimation in field surveys
bioRxiv, 2017Co-Authors: Nao Takashina, Maria Beger, Buntarou Kusumoto, Suren I. Rathnayake, Hugh P. PossinghamAbstract:The Abundance of species is a fundamental consideration in ecology and conservation biology. Although broad models have been proposed to estimate the Population Abundance using existing data, available data is often limited. With no information available, a Population estimation will rely on time consuming field surveys. Typically, time is a critical constraint in conservation and often management decisions must be made quickly under the data limited situation. Depending on time and budgetary constraints, the required accuracy of field survey changes significantly. Hence, it is desirable to set up an effective survey design to minimize time and effort of sampling given required accuracy. We examine a spatially-explicit approach to Population estimation using spatial point processes, enabling us to explicitly and consistently discuss various sampling designs. We find that the accuracy of Abundance estimation varies with both ecological factors and survey design. Although the spatial scale of sampling does not affect estimation accuracy when the underlying individual distribution is random, it decreases with the sampled unit size if individuals tend to form clusters. These results are derived analytically and checked numerically. Obtained insights provide a benchmark to predict the quality of Population estimation, and improve survey designs for ecological studies and conservation.
Rodney M Jackson - One of the best experts on this subject based on the ideXlab platform.
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estimating snow leopard Population Abundance using photography and capture recapture techniques
Wildlife Society Bulletin, 2006Co-Authors: Rodney M Jackson, Jerry D Roe, Rinchen Wangchuk, Don O HunterAbstract:Abstract Conservation and management of snow leopards (Uncia uncia) has largely relied on anecdotal evidence and presence–absence data due to their cryptic nature and the difficult terrain they inhabit. These methods generally lack the scientific rigor necessary to accurately estimate Population size and monitor trends. We evaluated the use of photography in capture–mark–recapture (CMR) techniques for estimating snow leopard Population Abundance and density within Hemis National Park, Ladakh, India. We placed infrared camera traps along actively used travel paths, scent-sprayed rocks, and scrape sites within 16- to 30-km2 sampling grids in successive winters during January and March 2003–2004. We used head-on, oblique, and side-view camera configurations to obtain snow leopard photographs at varying body orientations. We calculated snow leopard Abundance estimates using the program CAPTURE. We obtained a total of 66 and 49 snow leopard captures resulting in 8.91 and 5.63 individuals per 100 trap-nights du...
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Estimating Snow Leopard Population Abundance Using Photography and Capture–Recapture Techniques
Wildlife Society Bulletin, 2006Co-Authors: Rodney M Jackson, Jerry D Roe, Rinchen Wangchuk, Don O HunterAbstract:Abstract Conservation and management of snow leopards (Uncia uncia) has largely relied on anecdotal evidence and presence–absence data due to their cryptic nature and the difficult terrain they inhabit. These methods generally lack the scientific rigor necessary to accurately estimate Population size and monitor trends. We evaluated the use of photography in capture–mark–recapture (CMR) techniques for estimating snow leopard Population Abundance and density within Hemis National Park, Ladakh, India. We placed infrared camera traps along actively used travel paths, scent-sprayed rocks, and scrape sites within 16- to 30-km2 sampling grids in successive winters during January and March 2003–2004. We used head-on, oblique, and side-view camera configurations to obtain snow leopard photographs at varying body orientations. We calculated snow leopard Abundance estimates using the program CAPTURE. We obtained a total of 66 and 49 snow leopard captures resulting in 8.91 and 5.63 individuals per 100 trap-nights du...
Maria Beger - One of the best experts on this subject based on the ideXlab platform.
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spatially explicit approach to estimation of total Population Abundance in field surveys
Journal of Theoretical Biology, 2018Co-Authors: Nao Takashina, Maria Beger, Buntarou Kusumoto, Suren I. Rathnayake, Hugh P. PossinghamAbstract:Population Abundance is fundamental in ecology and conservation biology, and provides essential information for predicting Population dynamics and implementing conservation actions. While a range of approaches have been proposed to estimate Population Abundance based on existing data, data deficiency is ubiquitous. When information is deficient, a Population estimation will rely on labor intensive field surveys. Typically, time is one of the critical constraints in conservation, and management decisions must often be made quickly under a data deficient situation. Hence, it is important to acquire a theoretical justification for survey methods to meet a required estimation precision. There is no such theory available in a spatially explicit context, while spatial considerations are critical to any field survey. Here, we develop a spatially explicit theory for Population estimation that allows us to examine the estimation precision under different survey designs and individual distribution patterns (e.g. random/clustered sampling and individual distribution). We demonstrate that clustered sampling decreases the estimation precision when individuals form clusters, while sampling designs do not affect the estimation accuracy when individuals are distributed randomly. Regardless of individual distribution, the estimation precision becomes higher with increasing total Population Abundance and the sampled fraction. These insights provide theoretical bases for efficient field survey designs in information deficiency situations.
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spatially explicit approach to Population Abundance estimation in field surveys
bioRxiv, 2017Co-Authors: Nao Takashina, Maria Beger, Buntarou Kusumoto, Suren I. Rathnayake, Hugh P. PossinghamAbstract:The Abundance of species is a fundamental consideration in ecology and conservation biology. Although broad models have been proposed to estimate the Population Abundance using existing data, available data is often limited. With no information available, a Population estimation will rely on time consuming field surveys. Typically, time is a critical constraint in conservation and often management decisions must be made quickly under the data limited situation. Depending on time and budgetary constraints, the required accuracy of field survey changes significantly. Hence, it is desirable to set up an effective survey design to minimize time and effort of sampling given required accuracy. We examine a spatially-explicit approach to Population estimation using spatial point processes, enabling us to explicitly and consistently discuss various sampling designs. We find that the accuracy of Abundance estimation varies with both ecological factors and survey design. Although the spatial scale of sampling does not affect estimation accuracy when the underlying individual distribution is random, it decreases with the sampled unit size if individuals tend to form clusters. These results are derived analytically and checked numerically. Obtained insights provide a benchmark to predict the quality of Population estimation, and improve survey designs for ecological studies and conservation.