E. Lassiter, M. Asher, G. Christie, C. Gale, A. Massey, Cody Massery, C. Middaugh, J. T. Veon, B. DeGregorio
Northern bobwhite Colinus virginianus populations have been rapidly declining in the eastern, central, and southern United States for decades. Declines have been driven by land use change and an incompatibility between northern bobwhite resource needs and human land use practices. Here, we applied occupancy analyses on two spatial scales (state-level and ecoregion-level) to more than 5,000 northern bobwhite surveys conducted over six years across the entire state of Arkansas to explore patterns in occupancy and land use variables, and to identify priority areas for management and conservation. At the state level, northern bobwhite occupied 29% of sites and northern bobwhite were most likely to occur in areas with a high percentage of early successional habitat (grassland, pasture, and shrubland). The statewide model predicted that northern bobwhite were likely to occur (≥75% predicted occupancy) in <20% of the state. Arkansas is comprised of five distinct ecoregions, and analyses at the ecoregion spatial scale showed that habitat associations of northern bobwhite could vary between ecoregions. For example, northern bobwhite occupancy in both the Arkansas River Valley and Ozark Mountains ecoregions was best predicted by early successional habitat, but was further refined by other habitat associations such as the proportion of herbaceous habitat and hay-pasture habitat, respectively. Contrastingly, northern bobwhite occupancy in the Ouachita Mountains ecoregion was best predicted by richness of landcover classes alone. Ecoregion-level models were thus more discerning than the state level model and should be more helpful to managers in identifying priority conservation areas. However, in 2 of 5 ecoregions, northern bobwhite were too rarely encountered to accurately predict their occurrence. We found that likely occupied northern bobwhite habitat lay primarily on private properties (95%), but that numerous public entities own and manage land identified as suitable or likely occupied. We conclude that management of northern bobwhite in Arkansas could benefit from cooperation among state, federal, and military partners, as well as surrounding private landowners and that ecoregion-specific models may be more useful in identifying priority areas for management. Our approach incorporates multiple landscape scales when using remote sensing technology in conjunction with monitoring data and could have important application for the management of northern bobwhite and other grassland bird species.
{"title":"Northern Bobwhite Occupancy Patterns on Multiple Spatial Scales Across Arkansas","authors":"E. Lassiter, M. Asher, G. Christie, C. Gale, A. Massey, Cody Massery, C. Middaugh, J. T. Veon, B. DeGregorio","doi":"10.3996/jfwm-21-002","DOIUrl":"https://doi.org/10.3996/jfwm-21-002","url":null,"abstract":"Northern bobwhite Colinus virginianus populations have been rapidly declining in the eastern, central, and southern United States for decades. Declines have been driven by land use change and an incompatibility between northern bobwhite resource needs and human land use practices. Here, we applied occupancy analyses on two spatial scales (state-level and ecoregion-level) to more than 5,000 northern bobwhite surveys conducted over six years across the entire state of Arkansas to explore patterns in occupancy and land use variables, and to identify priority areas for management and conservation. At the state level, northern bobwhite occupied 29% of sites and northern bobwhite were most likely to occur in areas with a high percentage of early successional habitat (grassland, pasture, and shrubland). The statewide model predicted that northern bobwhite were likely to occur (≥75% predicted occupancy) in <20% of the state. Arkansas is comprised of five distinct ecoregions, and analyses at the ecoregion spatial scale showed that habitat associations of northern bobwhite could vary between ecoregions. For example, northern bobwhite occupancy in both the Arkansas River Valley and Ozark Mountains ecoregions was best predicted by early successional habitat, but was further refined by other habitat associations such as the proportion of herbaceous habitat and hay-pasture habitat, respectively. Contrastingly, northern bobwhite occupancy in the Ouachita Mountains ecoregion was best predicted by richness of landcover classes alone. Ecoregion-level models were thus more discerning than the state level model and should be more helpful to managers in identifying priority conservation areas. However, in 2 of 5 ecoregions, northern bobwhite were too rarely encountered to accurately predict their occurrence. We found that likely occupied northern bobwhite habitat lay primarily on private properties (95%), but that numerous public entities own and manage land identified as suitable or likely occupied. We conclude that management of northern bobwhite in Arkansas could benefit from cooperation among state, federal, and military partners, as well as surrounding private landowners and that ecoregion-specific models may be more useful in identifying priority areas for management. Our approach incorporates multiple landscape scales when using remote sensing technology in conjunction with monitoring data and could have important application for the management of northern bobwhite and other grassland bird species.","PeriodicalId":49036,"journal":{"name":"Journal of Fish and Wildlife Management","volume":" ","pages":""},"PeriodicalIF":0.7,"publicationDate":"2021-09-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45290779","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
L. E. Rucker, Donald J. Brown, C. D. Jacobsen, Kevin R. Messenger, E. Wild, T. Pauley
Documenting the sex of individuals encountered during wildlife research and monitoring activities is important for understanding and tracking changes in populations. However, sexing salamanders can be particularly difficult because secondary sex characters are often subtle or only visible during the breeding season, and guidance on species-specific sex determination is lacking from most field guides. The purpose of this guide is to provide a reference to assist biologists in the Central Appalachian region with identifying sex of live adult salamanders. In the main text we provide summary tables and figures to serve as concise references in the field. In Text S1 (Supplemental Material) we provide individual species accounts that contain concise yet comprehensive information for each species based on the published literature, as well as many images depicting sexually dimorphic characters. Our focal region encompasses partial or entire distributions for 56 species of salamanders in five families (Ambystomidae, Cryptobranchidae, Plethodontidae, Proteidae, and Salamandridae). We identified seven morphological characters that are strongly sexually dimorphic and useful for sexing live, non-anesthetized, adult salamanders in the field, with males of individual species exhibiting one to five of the characters. We identified >20 additional characters that are weakly sexually dimorphic, difficult to distinguish in the field, or species-specific. Our guide serves as a synthesis of sexually dimorphic characters available for salamanders in Central Appalachia, and we anticipate it will have broad value for researchers, monitoring programs, and salamander enthusiasts in eastern and central North America.
{"title":"A Guide to Sexing Salamanders of The Central Appalachians, USA","authors":"L. E. Rucker, Donald J. Brown, C. D. Jacobsen, Kevin R. Messenger, E. Wild, T. Pauley","doi":"10.3996/jfwm-20-042","DOIUrl":"https://doi.org/10.3996/jfwm-20-042","url":null,"abstract":"Documenting the sex of individuals encountered during wildlife research and monitoring activities is important for understanding and tracking changes in populations. However, sexing salamanders can be particularly difficult because secondary sex characters are often subtle or only visible during the breeding season, and guidance on species-specific sex determination is lacking from most field guides. The purpose of this guide is to provide a reference to assist biologists in the Central Appalachian region with identifying sex of live adult salamanders. In the main text we provide summary tables and figures to serve as concise references in the field. In Text S1 (Supplemental Material) we provide individual species accounts that contain concise yet comprehensive information for each species based on the published literature, as well as many images depicting sexually dimorphic characters. Our focal region encompasses partial or entire distributions for 56 species of salamanders in five families (Ambystomidae, Cryptobranchidae, Plethodontidae, Proteidae, and Salamandridae). We identified seven morphological characters that are strongly sexually dimorphic and useful for sexing live, non-anesthetized, adult salamanders in the field, with males of individual species exhibiting one to five of the characters. We identified >20 additional characters that are weakly sexually dimorphic, difficult to distinguish in the field, or species-specific. Our guide serves as a synthesis of sexually dimorphic characters available for salamanders in Central Appalachia, and we anticipate it will have broad value for researchers, monitoring programs, and salamander enthusiasts in eastern and central North America.","PeriodicalId":49036,"journal":{"name":"Journal of Fish and Wildlife Management","volume":" ","pages":""},"PeriodicalIF":0.7,"publicationDate":"2021-09-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47117805","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Stephanie Manzo, E. Nicholson, Zachary Devereux, R. Fisher, Christopher Brown, P. Scott, H. B. Shaffer
Accurate status assessments of long-lived, widely distributed taxa depend on the availability of long-term monitoring data from multiple populations. However, monitoring populations across large temporal and spatial scales is often beyond the scope of any one researcher or research group. Consequently, wildlife managers may be tasked with utilizing limited information from different sources to detect range-wide evidence of population declines and their causes. When assessments need to be made under such constraints, the research and management communities must determine how to extrapolate from variable population data to species-level inferences. Here, using three different approaches, we integrate and analyze data from the peer-reviewed literature and government agency reports to inform conservation for northwestern pond turtles (NPT) Actinemys marmorata and southwestern pond turtles (SPT) Actinemys pallida. Both NPT and SPT are long-lived freshwater turtles distributed along the west coast of the United States and Mexico. Conservation concerns exist for both species; however, SPT may face more severe threats and are thought to exist at lower densities throughout their range than NPT. For each species, we ranked the impacts of 13 potential threats, estimated population sizes, and modeled population viability with and without long-term droughts. Our results suggest that predation of hatchlings by invasive predators, such as American bullfrogs Lithobates catesbeianus and Largemouth Bass Micropterus salmoides, is a high-ranking threat for NPT and SPT. Southwestern pond turtles may also face more severe impacts associated with natural disasters (droughts, wildfires, and floods) than NPT. Population size estimates from trapping surveys indicate that SPT have smaller population sizes on average than NPT (p = 0.0003), suggesting they may be at greater risk of local extirpation. Population viability analysis models revealed that long-term droughts are a key environmental parameter; as the frequency of severe droughts increases with climate change, the likelihood of population recovery decreases, especially when census sizes are low. Given current population trends and vulnerability to natural disasters throughout their range, we suggest that conservation and recovery actions first focus on SPT to prevent further population declines.
{"title":"Conservation of Northwestern and Southwestern Pond Turtles: Threats, Population Size Estimates, and Population Viability Analysis","authors":"Stephanie Manzo, E. Nicholson, Zachary Devereux, R. Fisher, Christopher Brown, P. Scott, H. B. Shaffer","doi":"10.3996/jfwm-20-094","DOIUrl":"https://doi.org/10.3996/jfwm-20-094","url":null,"abstract":"Accurate status assessments of long-lived, widely distributed taxa depend on the availability of long-term monitoring data from multiple populations. However, monitoring populations across large temporal and spatial scales is often beyond the scope of any one researcher or research group. Consequently, wildlife managers may be tasked with utilizing limited information from different sources to detect range-wide evidence of population declines and their causes. When assessments need to be made under such constraints, the research and management communities must determine how to extrapolate from variable population data to species-level inferences. Here, using three different approaches, we integrate and analyze data from the peer-reviewed literature and government agency reports to inform conservation for northwestern pond turtles (NPT) Actinemys marmorata and southwestern pond turtles (SPT) Actinemys pallida. Both NPT and SPT are long-lived freshwater turtles distributed along the west coast of the United States and Mexico. Conservation concerns exist for both species; however, SPT may face more severe threats and are thought to exist at lower densities throughout their range than NPT. For each species, we ranked the impacts of 13 potential threats, estimated population sizes, and modeled population viability with and without long-term droughts. Our results suggest that predation of hatchlings by invasive predators, such as American bullfrogs Lithobates catesbeianus and Largemouth Bass Micropterus salmoides, is a high-ranking threat for NPT and SPT. Southwestern pond turtles may also face more severe impacts associated with natural disasters (droughts, wildfires, and floods) than NPT. Population size estimates from trapping surveys indicate that SPT have smaller population sizes on average than NPT (p = 0.0003), suggesting they may be at greater risk of local extirpation. Population viability analysis models revealed that long-term droughts are a key environmental parameter; as the frequency of severe droughts increases with climate change, the likelihood of population recovery decreases, especially when census sizes are low. Given current population trends and vulnerability to natural disasters throughout their range, we suggest that conservation and recovery actions first focus on SPT to prevent further population declines.","PeriodicalId":49036,"journal":{"name":"Journal of Fish and Wildlife Management","volume":" ","pages":""},"PeriodicalIF":0.7,"publicationDate":"2021-09-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47134519","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
M. Schnee, Niall G. Clancy, M. Boyer, S. L. Bourret
Nonnative fish eradication via the piscicide rotenone is an effective tool for fisheries management and conservation of native species. However, the long-term effects on non-target organisms, including benthic invertebrates and zooplankton in alpine lakes, are under-studied and are poorly understood. As part of a landscape-scale native fish conservation project, we assessed the effects of 50 ppb rotenone on the aquatic invertebrate community by comparing pre- and post-rotenone treatment density and diversity metrics of benthic invertebrates and zooplankton in 13 alpine lakes and their outlets in Montana, USA. Across study sites, decreases in density and diversity of some invertebrates, including Ephemeroptera, Plecoptera, and Trichoptera taxa, were observed the year following rotenone treatment, and within three years, densities and diversities were similar to and sometimes higher than pre-treatment values. These results demonstrate resilience of aquatic invertebrate communities following rotenone exposure in alpine lakes and streams and informs fisheries managers for planning rotenone projects and monitoring recovery of non-target organisms. Further studies will be useful to evaluate the mechanisms driving invertebrate recovery rates, including downstream drift from nontreated areas and terrestrial adult dispersal.
{"title":"Recovery of freshwater invertebrates in alpine lakes and streams following eradication of nonnative trout with rotenone","authors":"M. Schnee, Niall G. Clancy, M. Boyer, S. L. Bourret","doi":"10.3996/jfwm-20-040","DOIUrl":"https://doi.org/10.3996/jfwm-20-040","url":null,"abstract":"Nonnative fish eradication via the piscicide rotenone is an effective tool for fisheries management and conservation of native species. However, the long-term effects on non-target organisms, including benthic invertebrates and zooplankton in alpine lakes, are under-studied and are poorly understood. As part of a landscape-scale native fish conservation project, we assessed the effects of 50 ppb rotenone on the aquatic invertebrate community by comparing pre- and post-rotenone treatment density and diversity metrics of benthic invertebrates and zooplankton in 13 alpine lakes and their outlets in Montana, USA. Across study sites, decreases in density and diversity of some invertebrates, including Ephemeroptera, Plecoptera, and Trichoptera taxa, were observed the year following rotenone treatment, and within three years, densities and diversities were similar to and sometimes higher than pre-treatment values. These results demonstrate resilience of aquatic invertebrate communities following rotenone exposure in alpine lakes and streams and informs fisheries managers for planning rotenone projects and monitoring recovery of non-target organisms. Further studies will be useful to evaluate the mechanisms driving invertebrate recovery rates, including downstream drift from nontreated areas and terrestrial adult dispersal.","PeriodicalId":49036,"journal":{"name":"Journal of Fish and Wildlife Management","volume":"1 1","pages":""},"PeriodicalIF":0.7,"publicationDate":"2021-08-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70143866","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Cameron Goble, T. Zorn, N. Auer, J. Holtgren, D. Mays, Archie W. Martell
Arctic Grayling Thymallus arcticus were historically found throughout the northern half of Michigan’s Lower Peninsula but were extirpated from the state by 1936. By addressing issues from previous reintroduction efforts and employing instream rearing (Remote Site Incubator) approach to stocking, numerous partners are working to reintroduce Arctic Grayling to Michigan with hopes of reestablishing self-sustaining populations. With over 47,000 km of coldwater stream habitat in the state and limited numbers of eggs for reintroductions, a prioritization framework was needed to provide a standardized, fine-scale method for rating suitability of streams for reintroductions. Through facilitated discussions with stakeholders and experts, we developed an overall prioritization framework for rating Michigan streams with components evaluating a reach’s thermal, instream habitat, biological, and connectivity characteristics. Within the context of this broader framework, we developed the habitat rating component for assessing suitability of instream conditions for egg, fry, juvenile, and adult life stages of Arctic Grayling. Life-stage specific habitat metrics and scoring criteria from this effort were used to rate habitat conditions for 45 reaches in tributaries of Michigan’s Manistee River, enabling identification of reaches likely having instream habitat most suitable for Arctic Grayling. Numbers of reaches meeting or exceeding 60%, 70%, and 80% of the maximum score for overall habitat suitability were 31, 8, and 1. Upon completion of the fish assemblage and connectivity components, the prioritization framework and habitat rating process described here will be used for comparing suitability among streams throughout the historic range of Arctic Grayling in Michigan and guiding reintroduction efforts. Though it will take considerable time before instream habitat suitability criteria can be evaluated for all life stages of Arctic Grayling in Michigan, the collaborative stream prioritization framework developed for Arctic Grayling reintroduction can be readily adapted to reintroduction efforts for other species elsewhere.
{"title":"Rating the potential suitability of habitat in Michigan stream reaches for Arctic grayling","authors":"Cameron Goble, T. Zorn, N. Auer, J. Holtgren, D. Mays, Archie W. Martell","doi":"10.3996/jfwm-20-050","DOIUrl":"https://doi.org/10.3996/jfwm-20-050","url":null,"abstract":"Arctic Grayling Thymallus arcticus were historically found throughout the northern half of Michigan’s Lower Peninsula but were extirpated from the state by 1936. By addressing issues from previous reintroduction efforts and employing instream rearing (Remote Site Incubator) approach to stocking, numerous partners are working to reintroduce Arctic Grayling to Michigan with hopes of reestablishing self-sustaining populations. With over 47,000 km of coldwater stream habitat in the state and limited numbers of eggs for reintroductions, a prioritization framework was needed to provide a standardized, fine-scale method for rating suitability of streams for reintroductions. Through facilitated discussions with stakeholders and experts, we developed an overall prioritization framework for rating Michigan streams with components evaluating a reach’s thermal, instream habitat, biological, and connectivity characteristics. Within the context of this broader framework, we developed the habitat rating component for assessing suitability of instream conditions for egg, fry, juvenile, and adult life stages of Arctic Grayling. Life-stage specific habitat metrics and scoring criteria from this effort were used to rate habitat conditions for 45 reaches in tributaries of Michigan’s Manistee River, enabling identification of reaches likely having instream habitat most suitable for Arctic Grayling. Numbers of reaches meeting or exceeding 60%, 70%, and 80% of the maximum score for overall habitat suitability were 31, 8, and 1. Upon completion of the fish assemblage and connectivity components, the prioritization framework and habitat rating process described here will be used for comparing suitability among streams throughout the historic range of Arctic Grayling in Michigan and guiding reintroduction efforts. Though it will take considerable time before instream habitat suitability criteria can be evaluated for all life stages of Arctic Grayling in Michigan, the collaborative stream prioritization framework developed for Arctic Grayling reintroduction can be readily adapted to reintroduction efforts for other species elsewhere.","PeriodicalId":49036,"journal":{"name":"Journal of Fish and Wildlife Management","volume":" ","pages":""},"PeriodicalIF":0.7,"publicationDate":"2021-08-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46628893","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
M. Valente, Catherine E. Benson, Matthew S. Chmiel, Matthew Lewis, E. Peatman, H. Eaton
We report genetic and morphological evidence for the presence of Redeye Bass Micropterus coosae, in the Verde River of Arizona, previously thought to be Smallmouth Bass Micropterus dolomieu. We performed meristic measurements on 15 individuals sampled from the Upper Verde River Wildlife Area, Yavapai County, Arizona. Meristic data for lateral line scales, scales above lateral line, and scales below lateral line were all consistent with Redeye Bass and not Smallmouth Bass. We analyzed mitochondrial and nuclear genetic data to determine if one of the black bass (Genus Micropterus) species historically introduced to the Verde River was Redeye Bass and that they persist in the system. We extracted DNA from fin clips of five individuals for phylogenetic analysis of the NADH dehydrogenase subunit 2 (ND2) mitochondrial gene and for analysis of nuclear DNA using a diagnostic Single Nucleotide Polymorphism (SNP) panel. Results of the ND2 genetic sequencing and phylogenetic analysis indicated that these fish likely originated from native Redeye Bass stock from the Coosa River system of Alabama, Georgia, and Tennessee. Similarly, nuclear SNP data from the five individuals collected from the Verde River aligned with Redeye Bass reference genotypes based on STRUCTURE analysis. These results support the hypothesis that at least one of the introductions of black bass in Arizona’s Verde River founded a previously unrecognized population of Redeye Bass. Further work is needed to determine the extent of the Redeye Bass presence in Arizona, whether Smallmouth Bass are also present in the Verde River system, and if hybridization of Redeye Bass and other black basses is occurring.
{"title":"A case of mistaken identity: Genetic and morphological evidence for the presence of Redeye Bass in the Verde River, Arizona","authors":"M. Valente, Catherine E. Benson, Matthew S. Chmiel, Matthew Lewis, E. Peatman, H. Eaton","doi":"10.3996/jfwm-21-013","DOIUrl":"https://doi.org/10.3996/jfwm-21-013","url":null,"abstract":"We report genetic and morphological evidence for the presence of Redeye Bass Micropterus coosae, in the Verde River of Arizona, previously thought to be Smallmouth Bass Micropterus dolomieu. We performed meristic measurements on 15 individuals sampled from the Upper Verde River Wildlife Area, Yavapai County, Arizona. Meristic data for lateral line scales, scales above lateral line, and scales below lateral line were all consistent with Redeye Bass and not Smallmouth Bass. We analyzed mitochondrial and nuclear genetic data to determine if one of the black bass (Genus Micropterus) species historically introduced to the Verde River was Redeye Bass and that they persist in the system. We extracted DNA from fin clips of five individuals for phylogenetic analysis of the NADH dehydrogenase subunit 2 (ND2) mitochondrial gene and for analysis of nuclear DNA using a diagnostic Single Nucleotide Polymorphism (SNP) panel. Results of the ND2 genetic sequencing and phylogenetic analysis indicated that these fish likely originated from native Redeye Bass stock from the Coosa River system of Alabama, Georgia, and Tennessee. Similarly, nuclear SNP data from the five individuals collected from the Verde River aligned with Redeye Bass reference genotypes based on STRUCTURE analysis. These results support the hypothesis that at least one of the introductions of black bass in Arizona’s Verde River founded a previously unrecognized population of Redeye Bass. Further work is needed to determine the extent of the Redeye Bass presence in Arizona, whether Smallmouth Bass are also present in the Verde River system, and if hybridization of Redeye Bass and other black basses is occurring.","PeriodicalId":49036,"journal":{"name":"Journal of Fish and Wildlife Management","volume":" ","pages":""},"PeriodicalIF":0.7,"publicationDate":"2021-08-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49664520","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Many applications in wildlife management require knowledge of the sex of individual animals. The Yuma Ridgway’s Rail Rallus obsoletus yumanensis is an endangered marsh bird with monomorphic plumage and secretive behaviors, thereby complicating sex determination in field studies. We collected morphometric measurements from 270 adult Yuma Ridgway’s Rails and quantified the plumage and mandible color of 91 of those individuals throughout their geographic range to evaluate inter-sexual differences in morphology and coloration. We genetically sexed a subset of adult Yuma Ridgway’s Rails ( N =101) and used these individuals to determine the optimal combination of measurements (based on discriminant function analyses) to distinguish between sexes. Males averaged significantly larger than females in all measurements and the optimal discriminant function contained whole-leg, culmen, and tail measurements and classified correctly 97.8% (95% CI: 92.5-100.0%) of genetically sexed individuals. We used two additional functions that correctly classified ≥95.5% of genetically sexed Yuma Ridgway’s Rails to assign sex to individuals with missing measurements. These simple models provide managers and researchers with a practical tool to determine the sex of Yuma Ridgway’s Rails based on morphometric measurements. Although color measurements were not in the most accurate discriminant functions, we quantified subtle inter-sexual differences in the color of mandibles and greater coverts of Yuma Ridgway’s Rails. These results document sex-specific patterns in coloration that allow future researchers to test hypotheses to determine the mechanisms underlying sex-based differences in plumage coloration.
{"title":"Sexual dimorphism in morphology and plumage of endangered Yuma Ridgway’s Rails: a model for documenting sex","authors":"Eamon J. Harrity, L. Michael, C. Conway","doi":"10.3996/jfwm-20-095","DOIUrl":"https://doi.org/10.3996/jfwm-20-095","url":null,"abstract":"Many applications in wildlife management require knowledge of the sex of individual animals. The Yuma Ridgway’s Rail Rallus obsoletus yumanensis is an endangered marsh bird with monomorphic plumage and secretive behaviors, thereby complicating sex determination in field studies. We collected morphometric measurements from 270 adult Yuma Ridgway’s Rails and quantified the plumage and mandible color of 91 of those individuals throughout their geographic range to evaluate inter-sexual differences in morphology and coloration. We genetically sexed a subset of adult Yuma Ridgway’s Rails ( N =101) and used these individuals to determine the optimal combination of measurements (based on discriminant function analyses) to distinguish between sexes. Males averaged significantly larger than females in all measurements and the optimal discriminant function contained whole-leg, culmen, and tail measurements and classified correctly 97.8% (95% CI: 92.5-100.0%) of genetically sexed individuals. We used two additional functions that correctly classified ≥95.5% of genetically sexed Yuma Ridgway’s Rails to assign sex to individuals with missing measurements. These simple models provide managers and researchers with a practical tool to determine the sex of Yuma Ridgway’s Rails based on morphometric measurements. Although color measurements were not in the most accurate discriminant functions, we quantified subtle inter-sexual differences in the color of mandibles and greater coverts of Yuma Ridgway’s Rails. These results document sex-specific patterns in coloration that allow future researchers to test hypotheses to determine the mechanisms underlying sex-based differences in plumage coloration.","PeriodicalId":49036,"journal":{"name":"Journal of Fish and Wildlife Management","volume":" ","pages":""},"PeriodicalIF":0.7,"publicationDate":"2021-08-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48371886","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
E. Paulukonis, B. Crawford, J. Maerz, S. Wenger, N. Nibbelink
Effective management of wildlife populations benefits from an understanding of the long-term vulnerability of species to anthropogenic stressors. Exposure to potential habitat change is one measure of vulnerability that wildlife managers often use to assess and prioritize individual species or groups of species for resource allocation or direct management actions. We used species distribution models for 15 species occurring in the coastal plain ecoregion of Georgia to estimate the current amount and distribution of potential habitat and then predict exposure to changes in habitat due to inundation from sea level rise (using the Sea Level Affecting Marshes model) and urban growth (using the Slope Land-use Excluded Urban Topology Hillshade Growth model) for four future time points. Our results predict that all focal species were likely to experience some exposure to habitat change from either sea level rise or urbanization, but few species will experience high exposure to change from both stressors. Species that use salt marsh or beach habitats had the highest predicted exposure from sea level rise (25–69%), while species that use more inland habitats had the highest predicted exposure to urban growth (10–20%). Our models are a resource for managers considering tradeoffs between prioritization schemes under two future stressors. Results suggest that managers may need to prioritize species (or their habitats) based on the predicted magnitude of habitat loss, while also contextualizing prioritization with respect to the current amount of available protected habitat and species global vulnerability.
{"title":"Prioritization of Vulnerable Species Under Scenarios of Anthropogenic-Driven Change in Georgia's Coastal Plain","authors":"E. Paulukonis, B. Crawford, J. Maerz, S. Wenger, N. Nibbelink","doi":"10.3996/JFWM-20-089","DOIUrl":"https://doi.org/10.3996/JFWM-20-089","url":null,"abstract":"Effective management of wildlife populations benefits from an understanding of the long-term vulnerability of species to anthropogenic stressors. Exposure to potential habitat change is one measure of vulnerability that wildlife managers often use to assess and prioritize individual species or groups of species for resource allocation or direct management actions. We used species distribution models for 15 species occurring in the coastal plain ecoregion of Georgia to estimate the current amount and distribution of potential habitat and then predict exposure to changes in habitat due to inundation from sea level rise (using the Sea Level Affecting Marshes model) and urban growth (using the Slope Land-use Excluded Urban Topology Hillshade Growth model) for four future time points. Our results predict that all focal species were likely to experience some exposure to habitat change from either sea level rise or urbanization, but few species will experience high exposure to change from both stressors. Species that use salt marsh or beach habitats had the highest predicted exposure from sea level rise (25–69%), while species that use more inland habitats had the highest predicted exposure to urban growth (10–20%). Our models are a resource for managers considering tradeoffs between prioritization schemes under two future stressors. Results suggest that managers may need to prioritize species (or their habitats) based on the predicted magnitude of habitat loss, while also contextualizing prioritization with respect to the current amount of available protected habitat and species global vulnerability.","PeriodicalId":49036,"journal":{"name":"Journal of Fish and Wildlife Management","volume":"1 1","pages":""},"PeriodicalIF":0.7,"publicationDate":"2021-08-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70143510","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Consumer-grade side-scan sonar has become a versatile fisheries management tool. First applied to assess habitat, its use has expanded to surveying fishes in recent years. However, an important consideration is the skill and experience of users, which can impact both the accuracy and comparability of surveys. To this end, we characterized the ability of a small sample of novice users (N = 8) to identify alligator gar Atractosteus spatula in imagery, as well as the effect of a two-hour training exercise on user performance. Prior to training, mean accuracy (expressed as the difference between observed and expected counts) among participants ranged from -2.6 to 1.3 fish and precision ranged from ± 1.2 to 2.4 fish, with the majority of participants underestimating the number of alligator gar present in the imagery. False positives (i.e., identifying alligator gar in imagery when none were present) were common among participants. Post-training mean accuracy ranged from -3.1 to 0 among participants and precision ranged from ± 1.6 to 3.2 fish. The frequency of false positives was significantly reduced following training, and participants reported significant increases in confidence associated with image interpretation. The relatively high accuracy and precision we observed prior to training indicated that side-scan sonar can be easily incorporated into large-scale fishery monitoring efforts for alligator gar. However, our results also suggested that a rather minimal investment in training can further improve consistency and reduce uncertainty among novice users.
{"title":"Effects of Training on Side-Scan Sonar Use as a Fish Survey Tool: a Case Study in Alligator Gar","authors":"D. Daugherty, B. Fleming","doi":"10.3996/jfwm-21-026","DOIUrl":"https://doi.org/10.3996/jfwm-21-026","url":null,"abstract":"Consumer-grade side-scan sonar has become a versatile fisheries management tool. First applied to assess habitat, its use has expanded to surveying fishes in recent years. However, an important consideration is the skill and experience of users, which can impact both the accuracy and comparability of surveys. To this end, we characterized the ability of a small sample of novice users (N = 8) to identify alligator gar Atractosteus spatula in imagery, as well as the effect of a two-hour training exercise on user performance. Prior to training, mean accuracy (expressed as the difference between observed and expected counts) among participants ranged from -2.6 to 1.3 fish and precision ranged from ± 1.2 to 2.4 fish, with the majority of participants underestimating the number of alligator gar present in the imagery. False positives (i.e., identifying alligator gar in imagery when none were present) were common among participants. Post-training mean accuracy ranged from -3.1 to 0 among participants and precision ranged from ± 1.6 to 3.2 fish. The frequency of false positives was significantly reduced following training, and participants reported significant increases in confidence associated with image interpretation. The relatively high accuracy and precision we observed prior to training indicated that side-scan sonar can be easily incorporated into large-scale fishery monitoring efforts for alligator gar. However, our results also suggested that a rather minimal investment in training can further improve consistency and reduce uncertainty among novice users.","PeriodicalId":49036,"journal":{"name":"Journal of Fish and Wildlife Management","volume":" ","pages":""},"PeriodicalIF":0.7,"publicationDate":"2021-08-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43142920","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Matthew Kutugata, Jeremy A. Baumgardt, J. Goolsby, A. Racelis
Camera traps provide a low-cost approach to collect data and monitor wildlife across large scales but hand-labeling images at a rate that outpaces accumulation is difficult. Deep learning, a subdiscipline of machine learning and computer science, can address the issue of automatically classifying camera-trap images with a high degree of accuracy. This technique, however, may be less accessible to ecologists or small-scale conservation projects, and has serious limitations. In this study, we trained a simple deep learning model using a dataset of 120,000 images to identify the presence of nilgai Boselaphus tragocamelus, a regionally specific nonnative game animal, in camera-trap images with an overall accuracy of 97%. We trained a second model to identify 20 groups of animals and one group of images without any animals present, labeled as “none,” with an accuracy of 89%. Lastly, we tested the multigroup model on images collected of similar species, but in the southwestern United States, resulting in significantly lower precision and recall for each group. This study highlights the potential of deep learning for automating camera-trap image processing workflows, provides a brief overview of image-based deep learning, and discusses the often-understated limitations and methodological considerations in the context of wildlife conservation and species monitoring.
{"title":"Automatic Camera-Trap Classification Using Wildlife-Specific Deep Learning in Nilgai Management","authors":"Matthew Kutugata, Jeremy A. Baumgardt, J. Goolsby, A. Racelis","doi":"10.3996/jfwm-20-076","DOIUrl":"https://doi.org/10.3996/jfwm-20-076","url":null,"abstract":"\u0000 Camera traps provide a low-cost approach to collect data and monitor wildlife across large scales but hand-labeling images at a rate that outpaces accumulation is difficult. Deep learning, a subdiscipline of machine learning and computer science, can address the issue of automatically classifying camera-trap images with a high degree of accuracy. This technique, however, may be less accessible to ecologists or small-scale conservation projects, and has serious limitations. In this study, we trained a simple deep learning model using a dataset of 120,000 images to identify the presence of nilgai Boselaphus tragocamelus, a regionally specific nonnative game animal, in camera-trap images with an overall accuracy of 97%. We trained a second model to identify 20 groups of animals and one group of images without any animals present, labeled as “none,” with an accuracy of 89%. Lastly, we tested the multigroup model on images collected of similar species, but in the southwestern United States, resulting in significantly lower precision and recall for each group. This study highlights the potential of deep learning for automating camera-trap image processing workflows, provides a brief overview of image-based deep learning, and discusses the often-understated limitations and methodological considerations in the context of wildlife conservation and species monitoring.","PeriodicalId":49036,"journal":{"name":"Journal of Fish and Wildlife Management","volume":" ","pages":""},"PeriodicalIF":0.7,"publicationDate":"2021-07-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49567444","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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