Pub Date : 2022-04-21DOI: 10.1674/0003-0031-187.2.161
Alexandria Medine, J. Hoffman, Eddie K. Lyons, F. LeMieux
Abstract. Baird's pocket gopher (Geomys breviceps) is the only species of pocket gopher in Louisiana. Interest in this species' natural history has increased due to its close association with the Louisiana pine snake (Pituophis ruthveni), which recently was listed as threatened under the Endangered Species Act. Approximately 75% of P. ruthveni's estimated prey biomass consists of G. breviceps, whose burrow systems also provide shelter and hibernacula. Therefore, increasing densities of G. breviceps may assist in the recovery and management of P. ruthveni. Previous studies have identified specific habitat characteristics that are preferred by G. breviceps, but none have assessed how different habitats affect pocket gopher density. Live trapping was conducted at sixteen sites throughout Louisiana to determine relative density of G. breviceps. Vegetation and soil data were collected, and a multi-model selection approach was used to determine which variable(s) best explained variation in relative density. Relative densities of G. breviceps ranged from 0 to 12.5 gophers/ha with an average of 3.44 gophers/ha. Canopy cover best predicted numbers of G. breviceps across the study area. Soil data was not a good predictor; however, all sampling plots possessed sandy loam or loamy sand soils, which is preferred by Geomys spp. Management strategies aimed at increasing density of G. breviceps should focus on continued restoration of longleaf pine forest and supplemented by opening patches of forest, especially in areas with preferred soil textures.
{"title":"Influence of Vegetation and Soil on Relative Density of Baird's Pocket Gopher (Geomys breviceps) in Louisiana","authors":"Alexandria Medine, J. Hoffman, Eddie K. Lyons, F. LeMieux","doi":"10.1674/0003-0031-187.2.161","DOIUrl":"https://doi.org/10.1674/0003-0031-187.2.161","url":null,"abstract":"Abstract. Baird's pocket gopher (Geomys breviceps) is the only species of pocket gopher in Louisiana. Interest in this species' natural history has increased due to its close association with the Louisiana pine snake (Pituophis ruthveni), which recently was listed as threatened under the Endangered Species Act. Approximately 75% of P. ruthveni's estimated prey biomass consists of G. breviceps, whose burrow systems also provide shelter and hibernacula. Therefore, increasing densities of G. breviceps may assist in the recovery and management of P. ruthveni. Previous studies have identified specific habitat characteristics that are preferred by G. breviceps, but none have assessed how different habitats affect pocket gopher density. Live trapping was conducted at sixteen sites throughout Louisiana to determine relative density of G. breviceps. Vegetation and soil data were collected, and a multi-model selection approach was used to determine which variable(s) best explained variation in relative density. Relative densities of G. breviceps ranged from 0 to 12.5 gophers/ha with an average of 3.44 gophers/ha. Canopy cover best predicted numbers of G. breviceps across the study area. Soil data was not a good predictor; however, all sampling plots possessed sandy loam or loamy sand soils, which is preferred by Geomys spp. Management strategies aimed at increasing density of G. breviceps should focus on continued restoration of longleaf pine forest and supplemented by opening patches of forest, especially in areas with preferred soil textures.","PeriodicalId":50802,"journal":{"name":"American Midland Naturalist","volume":null,"pages":null},"PeriodicalIF":0.6,"publicationDate":"2022-04-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43913135","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}
Pub Date : 2022-04-21DOI: 10.1674/0003-0031-187.2.148
Erin M. Hettinger, Benjamin P. Pauli, Moni C. Berg-Binder
Abstract. Nonnative, invasive plant species have been notoriously problematic for many ecosystems by outcompeting native plant species and disrupting habitat for insects and other animal life. Within the last decade, a nonnative orchid, Epipactis helleborine L. Crantz (Orchidaceae), has become increasingly present in Minnesota and is considered invasive in some eastern states, including Wisconsin. This study provides insights into the presence and habitat preferences of E. helleborine in Winona County, in southeastern Minnesota. A large portion of Winona County lies within the Driftless region, which is characterized by bluff land and unique plant communities that have been greatly impacted by invasive species. This study used MaxEnt software to create a habitat suitability model for E. helleborine using six environmental predictors: elevation, slope, aspect, soil type, land cover, and distance to roads. The results were a model with high habitat suitability predictability with elevation and slope being the most important predictors, whereas other variables contributed little to the final model. The final model showed relatively small areas with high suitability, where management efforts should be concentrated. Based on the model, this species does not seem to be a substantial threat to areas of great conservation concern, such as southwestern facing bluff prairies.
{"title":"Examining Suitable Habitat and the Potential for Establishment of Introduced Epipactis helleborine in Southeastern Minnesota","authors":"Erin M. Hettinger, Benjamin P. Pauli, Moni C. Berg-Binder","doi":"10.1674/0003-0031-187.2.148","DOIUrl":"https://doi.org/10.1674/0003-0031-187.2.148","url":null,"abstract":"Abstract. Nonnative, invasive plant species have been notoriously problematic for many ecosystems by outcompeting native plant species and disrupting habitat for insects and other animal life. Within the last decade, a nonnative orchid, Epipactis helleborine L. Crantz (Orchidaceae), has become increasingly present in Minnesota and is considered invasive in some eastern states, including Wisconsin. This study provides insights into the presence and habitat preferences of E. helleborine in Winona County, in southeastern Minnesota. A large portion of Winona County lies within the Driftless region, which is characterized by bluff land and unique plant communities that have been greatly impacted by invasive species. This study used MaxEnt software to create a habitat suitability model for E. helleborine using six environmental predictors: elevation, slope, aspect, soil type, land cover, and distance to roads. The results were a model with high habitat suitability predictability with elevation and slope being the most important predictors, whereas other variables contributed little to the final model. The final model showed relatively small areas with high suitability, where management efforts should be concentrated. Based on the model, this species does not seem to be a substantial threat to areas of great conservation concern, such as southwestern facing bluff prairies.","PeriodicalId":50802,"journal":{"name":"American Midland Naturalist","volume":null,"pages":null},"PeriodicalIF":0.6,"publicationDate":"2022-04-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43608226","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}
Pub Date : 2022-04-21DOI: 10.1674/0003-0031-187.2.258
V. C. Rosas-Espinoza, Mónica Rivas, S. Contreras-Martínez, Jeshael Medina, A. Santiago-Pérez
Abstract. The Mexican Woodnymph (Eupherusa ridgwayi) is endemic to west-central Mexico with a narrow distribution range and relatively small population size. The species nest, nesting activities and nestling's characteristics were unknown until now. We generated a map of this species using data from BirdLife International, the Global Biodiversity Information Fund database, e-Bird, and the Naturalista. We used the Mexican Woodnymph records in Jalisco and projected them on a vegetation map. We documented a female constructing a nest, later nesting, until the nestlings flew out of the nest in the cloud forest in central-western Mexico: Jalisco state. The nest site was characterized and the materials used for the nest construction were determined. In addition, we documented several observations made on territorial and foraging behavior.
{"title":"Notes on Mexican Woodnymph (Eupherusa ridgwayi) Behavior and Nesting in Central-western Mexico","authors":"V. C. Rosas-Espinoza, Mónica Rivas, S. Contreras-Martínez, Jeshael Medina, A. Santiago-Pérez","doi":"10.1674/0003-0031-187.2.258","DOIUrl":"https://doi.org/10.1674/0003-0031-187.2.258","url":null,"abstract":"Abstract. The Mexican Woodnymph (Eupherusa ridgwayi) is endemic to west-central Mexico with a narrow distribution range and relatively small population size. The species nest, nesting activities and nestling's characteristics were unknown until now. We generated a map of this species using data from BirdLife International, the Global Biodiversity Information Fund database, e-Bird, and the Naturalista. We used the Mexican Woodnymph records in Jalisco and projected them on a vegetation map. We documented a female constructing a nest, later nesting, until the nestlings flew out of the nest in the cloud forest in central-western Mexico: Jalisco state. The nest site was characterized and the materials used for the nest construction were determined. In addition, we documented several observations made on territorial and foraging behavior.","PeriodicalId":50802,"journal":{"name":"American Midland Naturalist","volume":null,"pages":null},"PeriodicalIF":0.6,"publicationDate":"2022-04-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47180577","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}
Pub Date : 2022-04-21DOI: 10.1674/0003-0031-187.2.173
Brendan E. Enochs, Jonathan Chong, Miranda A. Kearney
Abstract. Past and current anthropogenic practices have resulted in dramatic alterations to ungulate population densities worldwide. When ungulate populations are overabundant, they can alter the dynamics, structure, and function of ecosystems. White-tailed deer (Odocoileus virginianus), specifically, can occur at densities far greater than their historical records in parts of their native range, which includes forests in the northeastern U.S. They have been shown to alter community structure of native plants, indirectly impact animal communities, and promote the success of invasive species. Despite much research into the effects of overabundant ungulates and deer in particular, less is known about the effects of deer on soil microbial communities. Here, we utilized soil samples from inside and outside of six deer exclosures located in a regional second growth mixed hardwood forest on the Binghamton University campus in Vestal NY, U.S.A. A metagenomic analysis was conducted on DNA extracted from the soil to identify the microbes present. Soil characteristics, including soil organic matter, soil moisture, pH, and electrical conductivity were also measured. Soil samples from inside exclosures had on average lower pH, higher soil moisture and organic matter, and higher electrical conductivity. The microbial communities across all samples were dominated by Proteobacteria, Acidobacteria, and Actinobacteria. However, the structure of the microbial soil community appeared to differ between samples taken inside and outside the exclosures, with those taken outside more closely resembling other outside samples and those sampled inside soils showing more variability in community structure. Overall, our results suggest that overabundant deer may have a homogenization effect on the soil abiotic environment and the soil microbial community.
{"title":"Exclusion of Overabundant White-tailed Deer (Odocoileus virginianus) Results in Shifts in Soil Microbial Communities and Abiotic Soil Condition in a Northeastern Deciduous Forest","authors":"Brendan E. Enochs, Jonathan Chong, Miranda A. Kearney","doi":"10.1674/0003-0031-187.2.173","DOIUrl":"https://doi.org/10.1674/0003-0031-187.2.173","url":null,"abstract":"Abstract. Past and current anthropogenic practices have resulted in dramatic alterations to ungulate population densities worldwide. When ungulate populations are overabundant, they can alter the dynamics, structure, and function of ecosystems. White-tailed deer (Odocoileus virginianus), specifically, can occur at densities far greater than their historical records in parts of their native range, which includes forests in the northeastern U.S. They have been shown to alter community structure of native plants, indirectly impact animal communities, and promote the success of invasive species. Despite much research into the effects of overabundant ungulates and deer in particular, less is known about the effects of deer on soil microbial communities. Here, we utilized soil samples from inside and outside of six deer exclosures located in a regional second growth mixed hardwood forest on the Binghamton University campus in Vestal NY, U.S.A. A metagenomic analysis was conducted on DNA extracted from the soil to identify the microbes present. Soil characteristics, including soil organic matter, soil moisture, pH, and electrical conductivity were also measured. Soil samples from inside exclosures had on average lower pH, higher soil moisture and organic matter, and higher electrical conductivity. The microbial communities across all samples were dominated by Proteobacteria, Acidobacteria, and Actinobacteria. However, the structure of the microbial soil community appeared to differ between samples taken inside and outside the exclosures, with those taken outside more closely resembling other outside samples and those sampled inside soils showing more variability in community structure. Overall, our results suggest that overabundant deer may have a homogenization effect on the soil abiotic environment and the soil microbial community.","PeriodicalId":50802,"journal":{"name":"American Midland Naturalist","volume":null,"pages":null},"PeriodicalIF":0.6,"publicationDate":"2022-04-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41522776","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}
Pub Date : 2022-04-21DOI: 10.1674/0003-0031-187.2.268
E. A. Geest, K. Baum
Abstract. Grassland insect pollinators have undergone population declines due to habitat loss and degradation. Patch-burning is a management method used to reduce woody plant encroachment and maintain grassland habitats. However, the impacts of fire on the quality and quantity of floral resources (nectar volume, total sugar, and sucrose concentration) available to insect pollinators are understudied. Evaluating how time since last fire and season of fire impact nectar quality and quantity is vital to understanding the overall impact of fire on insect pollinator communities. For this study, 10 flowering forb species (Asclepias viridis, Baptisia alba, Cirsium undulatum, Desmodium canadense, Monarda citriodora, Monarda fistulosa, Oenothera speciosa, Penstemon tubaeflorus, Ruellia humilis, Spiranthes cernua) were selected in The Nature Conservancy's Joseph H. William's Tallgrass Prairie Preserve in an area managed with patch-burning and cattle grazing. Study sites were burned in spring 2018, summer 2018, summer 2019, and spring 2020, with three replicates of each treatment (for 12 total burn units). In each unit, we collected nectar from flowering individuals of each plant species with microcapillary tubes to measure standing crop or the nectar in flowers at any given time that is available to insect pollinators. Total volume of nectar and sucrose concentration were recorded, and total mg of sugar was calculated. Desmodium canadense flowering individuals were only located in units burned the previous spring, whereas P. tubaeflorus flowering individuals were only located in units burned the previous summer. For the eight remaining species, total volume of nectar, total mg of sugar, and sucrose concentration varied with different burn regimens for different species. Cirsium undulatum inflorescences with crab spiders (Thomisidae) had higher volumes of nectar and higher amounts of sugar available. This study highlights how a patch-burn approach with different fire return intervals may benefit insect pollinators at the community level by providing a wide range of nectar qualities and quantities to support insect pollinators with different nutritional needs.
{"title":"The Impact of Fire on Nectar Quality and Quantity for Insect Pollinator Communities","authors":"E. A. Geest, K. Baum","doi":"10.1674/0003-0031-187.2.268","DOIUrl":"https://doi.org/10.1674/0003-0031-187.2.268","url":null,"abstract":"Abstract. Grassland insect pollinators have undergone population declines due to habitat loss and degradation. Patch-burning is a management method used to reduce woody plant encroachment and maintain grassland habitats. However, the impacts of fire on the quality and quantity of floral resources (nectar volume, total sugar, and sucrose concentration) available to insect pollinators are understudied. Evaluating how time since last fire and season of fire impact nectar quality and quantity is vital to understanding the overall impact of fire on insect pollinator communities. For this study, 10 flowering forb species (Asclepias viridis, Baptisia alba, Cirsium undulatum, Desmodium canadense, Monarda citriodora, Monarda fistulosa, Oenothera speciosa, Penstemon tubaeflorus, Ruellia humilis, Spiranthes cernua) were selected in The Nature Conservancy's Joseph H. William's Tallgrass Prairie Preserve in an area managed with patch-burning and cattle grazing. Study sites were burned in spring 2018, summer 2018, summer 2019, and spring 2020, with three replicates of each treatment (for 12 total burn units). In each unit, we collected nectar from flowering individuals of each plant species with microcapillary tubes to measure standing crop or the nectar in flowers at any given time that is available to insect pollinators. Total volume of nectar and sucrose concentration were recorded, and total mg of sugar was calculated. Desmodium canadense flowering individuals were only located in units burned the previous spring, whereas P. tubaeflorus flowering individuals were only located in units burned the previous summer. For the eight remaining species, total volume of nectar, total mg of sugar, and sucrose concentration varied with different burn regimens for different species. Cirsium undulatum inflorescences with crab spiders (Thomisidae) had higher volumes of nectar and higher amounts of sugar available. This study highlights how a patch-burn approach with different fire return intervals may benefit insect pollinators at the community level by providing a wide range of nectar qualities and quantities to support insect pollinators with different nutritional needs.","PeriodicalId":50802,"journal":{"name":"American Midland Naturalist","volume":null,"pages":null},"PeriodicalIF":0.6,"publicationDate":"2022-04-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49149767","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}
Pub Date : 2022-01-03DOI: 10.1674/0003-0031-187.1.1
Daniel P. Carlsen, Leah E. Sefton, Chelsea L Butcher, Chelsi P Abbott, J. M. Dannenhoffer, Bradley J. Swanson
Abstract. Small, fragmented populations are at greater risk of extirpation due to reduced genetic diversity from inbreeding and genetic drift. These processes ultimately decrease individual fitness and reduce the ability of a population to adapt. Hill's thistle (Cirsium hillii) is classified as a threatened species throughout much of its range, primarily due to the destruction and fragmentation of its habitat. This study addresses the impact of population size and isolation on the genetic diversity of Hill's thistle. We used microsatellite markers to genotype plants collected from the Lower Peninsula of Michigan in 2001, and from the Lower Peninsula and Drummond Island in 2012, in order to assess genetic differentiation across time and space, as well as to investigate rates of inbreeding in isolated and nonisolated populations. Genetic differentiation between the sample sites in the mainland population of Hill's thistle increased significantly between 2001 and 2012, indicative of increased fragmentation and isolation of the sample sites. However, the 2012 population exhibited lower inbreeding and no difference in heterozygosity or allelic diversity compared to 2001, suggesting the population is stable, or growing, in spite of isolation. Conversely, the population on Drummond Island displayed higher levels of inbreeding and lower number of effective alleles and heterozygosity compared to the mainland, typical of a small, isolated population. Our results indicate that the mainland population of Hill's thistle is persisting but should continue to be monitored demographically due to ongoing habitat loss.
{"title":"Improving Genetic Status Despite Fragmentation and Small Effective Population Size in Hill's Thistle (Cirsium hillii)","authors":"Daniel P. Carlsen, Leah E. Sefton, Chelsea L Butcher, Chelsi P Abbott, J. M. Dannenhoffer, Bradley J. Swanson","doi":"10.1674/0003-0031-187.1.1","DOIUrl":"https://doi.org/10.1674/0003-0031-187.1.1","url":null,"abstract":"Abstract. Small, fragmented populations are at greater risk of extirpation due to reduced genetic diversity from inbreeding and genetic drift. These processes ultimately decrease individual fitness and reduce the ability of a population to adapt. Hill's thistle (Cirsium hillii) is classified as a threatened species throughout much of its range, primarily due to the destruction and fragmentation of its habitat. This study addresses the impact of population size and isolation on the genetic diversity of Hill's thistle. We used microsatellite markers to genotype plants collected from the Lower Peninsula of Michigan in 2001, and from the Lower Peninsula and Drummond Island in 2012, in order to assess genetic differentiation across time and space, as well as to investigate rates of inbreeding in isolated and nonisolated populations. Genetic differentiation between the sample sites in the mainland population of Hill's thistle increased significantly between 2001 and 2012, indicative of increased fragmentation and isolation of the sample sites. However, the 2012 population exhibited lower inbreeding and no difference in heterozygosity or allelic diversity compared to 2001, suggesting the population is stable, or growing, in spite of isolation. Conversely, the population on Drummond Island displayed higher levels of inbreeding and lower number of effective alleles and heterozygosity compared to the mainland, typical of a small, isolated population. Our results indicate that the mainland population of Hill's thistle is persisting but should continue to be monitored demographically due to ongoing habitat loss.","PeriodicalId":50802,"journal":{"name":"American Midland Naturalist","volume":null,"pages":null},"PeriodicalIF":0.6,"publicationDate":"2022-01-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44968139","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}
Pub Date : 2022-01-03DOI: 10.1674/0003-0031-187.1.71
P. L. Arant, M. Lacki, J. Lhotka, J. Stringer
Abstract. Myotis bats have experienced significant population losses due to white-nose syndrome (WNS) throughout large portions of their distributions in eastern North America. As closed-space foragers, these species comprise an important feeding guild within eastern forests. An understanding of where summer populations remain and how their ecology has changed following impact from WNS is needed to assess fully the recovery potential of Myotis bats. We used acoustic sampling, capture surveys, radiotelemetry and roost surveys from 2015 to 2018 to evaluate the status of northern long-eared bat (Myotis septentrionalis) in an eastern Kentucky forest following region-wide impacts from WNS to this species. Acoustic activity of Myotis remained unchanged over the 4 y of sampling, with activity of these bats greatest in mid- to late July. Northern long-eared bats represented 97% of the Myotis captured, indicating activity levels likely reflected patterns for this species. We located 18 roost trees of northern long-eared bats in five tree species, including both live and dead trees. All roost trees were on upper slopes within 100 m of ridge top roads. Maximum exit counts, 24 and 21, at two roosts occurred in late May and early June, suggesting these dates represented the summer maternity period of northern long-eared bats in this forest. Our results demonstrated that post-WNS populations of northern long-eared bats on Robinson Forest formed small colonies, day-roosted in trees near roads on forested ridge tops, were reproductively active, and maintained steady levels of activity across the 4 y of sampling. These data suggest that local populations of northern long-eared bats are surviving WNS and continue to persist during summer months in forests of the Appalachian Mountain region. We hypothesize presence of ridge top roads, often associated with forest logging operations, may be important habitat elements for increasing availability of preferred roosting habitat for summer populations of northern long-eared bats in actively managed forests.
{"title":"Summer Populations of Northern Long-eared Bat in an Eastern Kentucky Forest Following Arrival of White-nose Syndrome","authors":"P. L. Arant, M. Lacki, J. Lhotka, J. Stringer","doi":"10.1674/0003-0031-187.1.71","DOIUrl":"https://doi.org/10.1674/0003-0031-187.1.71","url":null,"abstract":"Abstract. Myotis bats have experienced significant population losses due to white-nose syndrome (WNS) throughout large portions of their distributions in eastern North America. As closed-space foragers, these species comprise an important feeding guild within eastern forests. An understanding of where summer populations remain and how their ecology has changed following impact from WNS is needed to assess fully the recovery potential of Myotis bats. We used acoustic sampling, capture surveys, radiotelemetry and roost surveys from 2015 to 2018 to evaluate the status of northern long-eared bat (Myotis septentrionalis) in an eastern Kentucky forest following region-wide impacts from WNS to this species. Acoustic activity of Myotis remained unchanged over the 4 y of sampling, with activity of these bats greatest in mid- to late July. Northern long-eared bats represented 97% of the Myotis captured, indicating activity levels likely reflected patterns for this species. We located 18 roost trees of northern long-eared bats in five tree species, including both live and dead trees. All roost trees were on upper slopes within 100 m of ridge top roads. Maximum exit counts, 24 and 21, at two roosts occurred in late May and early June, suggesting these dates represented the summer maternity period of northern long-eared bats in this forest. Our results demonstrated that post-WNS populations of northern long-eared bats on Robinson Forest formed small colonies, day-roosted in trees near roads on forested ridge tops, were reproductively active, and maintained steady levels of activity across the 4 y of sampling. These data suggest that local populations of northern long-eared bats are surviving WNS and continue to persist during summer months in forests of the Appalachian Mountain region. We hypothesize presence of ridge top roads, often associated with forest logging operations, may be important habitat elements for increasing availability of preferred roosting habitat for summer populations of northern long-eared bats in actively managed forests.","PeriodicalId":50802,"journal":{"name":"American Midland Naturalist","volume":null,"pages":null},"PeriodicalIF":0.6,"publicationDate":"2022-01-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44020528","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}
Pub Date : 2022-01-03DOI: 10.1674/0003-0031-187.1.84
Virginie Rolland, S. Schratz, Daniel R. Istvanko, S. E. Harrod
Abstract. Forest bats, including evening bats (Nycticeius humeralis), sometimes roost in manmade structures, such as barns and bridges, but here we report the first observations of evening bats using bird nest boxes for roosting on multiple occasions between 2012 and 2019, a few kilometers north of Jonesboro, Arkansas. Most encounters were in August, when the nesting season is almost finished. We discuss timing and factors that may explain use of bird nest boxes for roosting by bats.
{"title":"Evening Bats (Nycticeius humeralis) Use Bird Nest Boxes as Day Roosts in Northeastern Arkansas","authors":"Virginie Rolland, S. Schratz, Daniel R. Istvanko, S. E. Harrod","doi":"10.1674/0003-0031-187.1.84","DOIUrl":"https://doi.org/10.1674/0003-0031-187.1.84","url":null,"abstract":"Abstract. Forest bats, including evening bats (Nycticeius humeralis), sometimes roost in manmade structures, such as barns and bridges, but here we report the first observations of evening bats using bird nest boxes for roosting on multiple occasions between 2012 and 2019, a few kilometers north of Jonesboro, Arkansas. Most encounters were in August, when the nesting season is almost finished. We discuss timing and factors that may explain use of bird nest boxes for roosting by bats.","PeriodicalId":50802,"journal":{"name":"American Midland Naturalist","volume":null,"pages":null},"PeriodicalIF":0.6,"publicationDate":"2022-01-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41992207","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}
Pub Date : 2022-01-03DOI: 10.1674/0003-0031-187.1.51
Karen E. Powers, D. Clore, Georgia M. Davidson, Ryley C. Harris
Abstract. Bird-window collisions (BWCs) constitute a significant source of mortality for both resident and migratory birds. Because windows reflect surrounding landscape components, such as vegetation or sky, birds do not always perceive glass as a barrier. Here we demonstrate a novel technique to classify and quantify reflections in windows on the Radford University campus in southwest Virginia, U.S.A. We deployed a consumer-grade Unmanned Aerial Vehicle, i.e., drone, to photograph 14 contiguous or near-contiguous window columns across five campus buildings in August 2020. For each study aspect, the drone (equipped with an RGB camera) captured images at ca. 5 m altitudinal increments from the ground floor to the roof of each building (three to six images/vertical column). We then manually classified each image in ImageJ to calculate approximate proportions of reflected: (1) vegetation, (2) sky, (3) and artificial structures or impervious surfaces, plus (4) nonreflective glass. We used a generalized linear model to determine how proportional reflections of vegetation, sky, buildings, and nonreflective glass varied across vertical increments. We found the proportion of sky significantly decreased with increasing photo heights, whereas proportion of nonreflective glass significantly increased with increasing heights. This supports previous findings that because birds are drawn to sky reflections, they may collide at relatively lower positions on buildings. Inconsistency in landscape design and building positioning on the campus precluded trends in vegetative or building reflections by height. Our pilot study demonstrates the applicability of a consumer-grade drone for investigating visual characteristics of reflections that influence BWCs from variable observation angles. We suggest the expanded use of drone images as a straightforward technique to measure changes in reflection characteristics from varying degrees of observation. They are a novel method in developing a BWC risk assessment as well as potential mitigation strategies in a suburban or campus environment with buildings of intermediate heights.
{"title":"A Bird's-Eye View: Novel Use of Drone Images to Quantify Differences in Altitudinal Reflections in Bird-window Collision Studies","authors":"Karen E. Powers, D. Clore, Georgia M. Davidson, Ryley C. Harris","doi":"10.1674/0003-0031-187.1.51","DOIUrl":"https://doi.org/10.1674/0003-0031-187.1.51","url":null,"abstract":"Abstract. Bird-window collisions (BWCs) constitute a significant source of mortality for both resident and migratory birds. Because windows reflect surrounding landscape components, such as vegetation or sky, birds do not always perceive glass as a barrier. Here we demonstrate a novel technique to classify and quantify reflections in windows on the Radford University campus in southwest Virginia, U.S.A. We deployed a consumer-grade Unmanned Aerial Vehicle, i.e., drone, to photograph 14 contiguous or near-contiguous window columns across five campus buildings in August 2020. For each study aspect, the drone (equipped with an RGB camera) captured images at ca. 5 m altitudinal increments from the ground floor to the roof of each building (three to six images/vertical column). We then manually classified each image in ImageJ to calculate approximate proportions of reflected: (1) vegetation, (2) sky, (3) and artificial structures or impervious surfaces, plus (4) nonreflective glass. We used a generalized linear model to determine how proportional reflections of vegetation, sky, buildings, and nonreflective glass varied across vertical increments. We found the proportion of sky significantly decreased with increasing photo heights, whereas proportion of nonreflective glass significantly increased with increasing heights. This supports previous findings that because birds are drawn to sky reflections, they may collide at relatively lower positions on buildings. Inconsistency in landscape design and building positioning on the campus precluded trends in vegetative or building reflections by height. Our pilot study demonstrates the applicability of a consumer-grade drone for investigating visual characteristics of reflections that influence BWCs from variable observation angles. We suggest the expanded use of drone images as a straightforward technique to measure changes in reflection characteristics from varying degrees of observation. They are a novel method in developing a BWC risk assessment as well as potential mitigation strategies in a suburban or campus environment with buildings of intermediate heights.","PeriodicalId":50802,"journal":{"name":"American Midland Naturalist","volume":null,"pages":null},"PeriodicalIF":0.6,"publicationDate":"2022-01-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46547613","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}
Pub Date : 2022-01-03DOI: 10.1674/0003-0031-187.1.39
Kate G. Slankard, Michael D. Patton, E. Mojica, B. Watts, Jeffrey L. Hays
Abstract. Immature raptors often travel long distances and move nomadically from the time they leave their natal area to the time they are recruited into the breeding population. Emphasis on identifying the nesting and winter habitat of Bald Eagles (Haliaeetus leucocephalus) has overshadowed the need to understand the habitat and spatial use of young eagles prior to reaching maturity. We used satellite telemetry to track the movements of immature Bald Eagles hatched in western Kentucky during 2010–2016. We analyzed movement data to identify high-use areas for eagles in their first and second years during warm and cool periods. Five out of seven eagles migrated north to the Great Lakes region during their first year. Using Brownian Bridge Movement Modelling, we identified 47 noncontiguous high-use areas during the warm period and 67 during the cool period. Public lands comprised 17% of warm period high-use areas and 43% of cool period high-use areas. High-use areas were located in Illinois, Indiana, Kentucky, Arkansas and Tennessee, and were often near federally-owned dams, rivers with sandbars, or areas with abundant waterfowl. Our small sample of tracked eagles correctly identified known Bald Eagle concentration areas within the study area; thus, we infer that previously unrecognized high-use areas identified by this study are likely to be concentration areas important to the larger population. We further suggest remote sensing data, even in limited datasets, as an efficient way to identify Bald Eagle concentration areas.
{"title":"Satellite Tracking Data Reveals High-Use Areas for Immature Bald Eagles from Kentucky","authors":"Kate G. Slankard, Michael D. Patton, E. Mojica, B. Watts, Jeffrey L. Hays","doi":"10.1674/0003-0031-187.1.39","DOIUrl":"https://doi.org/10.1674/0003-0031-187.1.39","url":null,"abstract":"Abstract. Immature raptors often travel long distances and move nomadically from the time they leave their natal area to the time they are recruited into the breeding population. Emphasis on identifying the nesting and winter habitat of Bald Eagles (Haliaeetus leucocephalus) has overshadowed the need to understand the habitat and spatial use of young eagles prior to reaching maturity. We used satellite telemetry to track the movements of immature Bald Eagles hatched in western Kentucky during 2010–2016. We analyzed movement data to identify high-use areas for eagles in their first and second years during warm and cool periods. Five out of seven eagles migrated north to the Great Lakes region during their first year. Using Brownian Bridge Movement Modelling, we identified 47 noncontiguous high-use areas during the warm period and 67 during the cool period. Public lands comprised 17% of warm period high-use areas and 43% of cool period high-use areas. High-use areas were located in Illinois, Indiana, Kentucky, Arkansas and Tennessee, and were often near federally-owned dams, rivers with sandbars, or areas with abundant waterfowl. Our small sample of tracked eagles correctly identified known Bald Eagle concentration areas within the study area; thus, we infer that previously unrecognized high-use areas identified by this study are likely to be concentration areas important to the larger population. We further suggest remote sensing data, even in limited datasets, as an efficient way to identify Bald Eagle concentration areas.","PeriodicalId":50802,"journal":{"name":"American Midland Naturalist","volume":null,"pages":null},"PeriodicalIF":0.6,"publicationDate":"2022-01-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44272674","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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