Pub Date : 2021-07-19DOI: 10.1674/0003-0031-186.1.51
D. Hornbach, K. Shea, Jerald J. Dosch, Carolyn L. Thomas, T. B. Gartner, A. Aguilera, L. J. Anderson, Kevin Geedey, C. Mankiewicz, B. Pohlad, Rachel Schultz
Abstract. Leaf litter decomposition plays an important role in nutrient cycling in both terrestrial and aquatic systems. Decay rates vary based on species, habitat, climate, and local environmental conditions. Invasive plants alter decomposition processes; however, there is a lack of research exploring patterns at regional and continental scales. In this study we examined the decomposition of both native and nonnative, invasive woody plant leaf litter and mixtures of the two, in both terrestrial and aquatic habitats at nine locations in the eastern and midwestern U.S.A. There was significant variation among locations, which was not clearly related to either average air temperature or precipitation. Unexpectedly, in locations with multiple years of data, there were higher rates of decomposition in years with lower temperatures and precipitation in both terrestrial and aquatic habitats. We found decay rates were generally higher in aquatic than terrestrial habitats and leaf litter from nonnative invasive species generally decayed faster than that of native species in both terrestrial and aquatic systems. Differences in litter decay rates among invasive species were significant in both terrestrial and aquatic habitats; whereas no differences were found among native species in either habitat. In mixed litter bags, decay rates were lower than what was predicted based on the relative amounts of native and invasive litter in each bag, possibly indicating the presence of native leaf litter slows the decomposition of invasive leaf litter. Additionally, there may have been threshold effects in the mixed litter bags, especially in aquatic systems. While this study supported several generalizations about leaf decomposition rates (invasive > native, aquatic > terrestrial), the variability in the decay rates from different locations and habitats indicates combinations of different species and local conditions may overshadow other general trends related to litter decomposition.
{"title":"Decomposition of Leaf Litter from Native and Nonnative Woody Plants in Terrestrial and Aquatic Systems in the Eastern and Upper Midwestern U.S.A.","authors":"D. Hornbach, K. Shea, Jerald J. Dosch, Carolyn L. Thomas, T. B. Gartner, A. Aguilera, L. J. Anderson, Kevin Geedey, C. Mankiewicz, B. Pohlad, Rachel Schultz","doi":"10.1674/0003-0031-186.1.51","DOIUrl":"https://doi.org/10.1674/0003-0031-186.1.51","url":null,"abstract":"Abstract. Leaf litter decomposition plays an important role in nutrient cycling in both terrestrial and aquatic systems. Decay rates vary based on species, habitat, climate, and local environmental conditions. Invasive plants alter decomposition processes; however, there is a lack of research exploring patterns at regional and continental scales. In this study we examined the decomposition of both native and nonnative, invasive woody plant leaf litter and mixtures of the two, in both terrestrial and aquatic habitats at nine locations in the eastern and midwestern U.S.A. There was significant variation among locations, which was not clearly related to either average air temperature or precipitation. Unexpectedly, in locations with multiple years of data, there were higher rates of decomposition in years with lower temperatures and precipitation in both terrestrial and aquatic habitats. We found decay rates were generally higher in aquatic than terrestrial habitats and leaf litter from nonnative invasive species generally decayed faster than that of native species in both terrestrial and aquatic systems. Differences in litter decay rates among invasive species were significant in both terrestrial and aquatic habitats; whereas no differences were found among native species in either habitat. In mixed litter bags, decay rates were lower than what was predicted based on the relative amounts of native and invasive litter in each bag, possibly indicating the presence of native leaf litter slows the decomposition of invasive leaf litter. Additionally, there may have been threshold effects in the mixed litter bags, especially in aquatic systems. While this study supported several generalizations about leaf decomposition rates (invasive > native, aquatic > terrestrial), the variability in the decay rates from different locations and habitats indicates combinations of different species and local conditions may overshadow other general trends related to litter decomposition.","PeriodicalId":50802,"journal":{"name":"American Midland Naturalist","volume":null,"pages":null},"PeriodicalIF":0.6,"publicationDate":"2021-07-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46870943","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 : 2021-07-19DOI: 10.1674/0003-0031-186.1.150
J. Pynne, S. Castleberry, L. Conner, Colleen W. Piper, Elizabeth I. Parsons, Robert A. Gitzen, Sarah I. Duncan, J. D. Austin, R. McCleery
Abstract. Biofluorescence in mammal pelage is considered rare, but has been documented in multiple taxa in recent years. Herein, we provide the first observations of biofluorescence in fossorial mammals. We documented biofluorescence in live Geomys pinetis (southeastern pocket gopher) and in museum specimens of four additional geomyid species. Although unknown, the adaptive significance of biofluorescence in pocket gophers is likely similar to that documented in terrestrial and arboreal species previously, including communication or predator evasion.
{"title":"Ultraviolet Biofluorescence in Pocket Gophers","authors":"J. Pynne, S. Castleberry, L. Conner, Colleen W. Piper, Elizabeth I. Parsons, Robert A. Gitzen, Sarah I. Duncan, J. D. Austin, R. McCleery","doi":"10.1674/0003-0031-186.1.150","DOIUrl":"https://doi.org/10.1674/0003-0031-186.1.150","url":null,"abstract":"Abstract. Biofluorescence in mammal pelage is considered rare, but has been documented in multiple taxa in recent years. Herein, we provide the first observations of biofluorescence in fossorial mammals. We documented biofluorescence in live Geomys pinetis (southeastern pocket gopher) and in museum specimens of four additional geomyid species. Although unknown, the adaptive significance of biofluorescence in pocket gophers is likely similar to that documented in terrestrial and arboreal species previously, including communication or predator evasion.","PeriodicalId":50802,"journal":{"name":"American Midland Naturalist","volume":null,"pages":null},"PeriodicalIF":0.6,"publicationDate":"2021-07-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43467077","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 : 2021-07-19DOI: 10.1674/0003-0031-186.1.122
Firas A. Houssein, Katherine E. O’Reilly, B. Peters, Michael A. Brueseke, G. Lamberti
Abstract. Bald eagles (Haliaeetus leucocephalus) were formerly endangered in the contiguous United States, but have since recolonized much of their past range. Maintaining bald eagle populations following recovery requires knowledge of factors that influence nesting success, including food habits during the brood-rearing period. We examined over 26,000 images from a high-resolution, above-nest digital camera to document the diet of a nesting bald eagle pair in north-central Indiana, U.S.A., during the 2018 brood-rearing period. After the hatch of two eaglets in April 2018, the camera was programmed to take still photos of the nest every 20 min, in addition to live-streaming video to YouTube for public audiences. Still images were used to quantify and identify all prey deliveries to the lowest taxonomic level possible, typically species. A total of 135 prey items and at least 26 prey taxa were recorded during the 75 d of the study, although daily prey count became uncertain in the final 20 d as fledglings began to move out of camera view. The majority of recorded prey items (73%) were fish, with redhorse suckers (Moxostoma spp.) representing the most numerous of the 13 fish taxa observed. Smaller numbers of birds (13%), mammals (10%), and reptiles (4%) were also observed. Although our results represent one nest across a single brood-rearing season, we gained novel insights through the analysis of high-frequency, high-definition images that provided increased temporal and taxonomic resolution of prey deliveries. The use of a camera not only avoided historical biases in bald eagle diet analysis, but also provided a valuable tool to engage public audiences.
{"title":"High-Frequency Photographic Imaging Provides Novel Insights into Nesting Bald Eagle Diet and Opportunities for Public Engagement","authors":"Firas A. Houssein, Katherine E. O’Reilly, B. Peters, Michael A. Brueseke, G. Lamberti","doi":"10.1674/0003-0031-186.1.122","DOIUrl":"https://doi.org/10.1674/0003-0031-186.1.122","url":null,"abstract":"Abstract. Bald eagles (Haliaeetus leucocephalus) were formerly endangered in the contiguous United States, but have since recolonized much of their past range. Maintaining bald eagle populations following recovery requires knowledge of factors that influence nesting success, including food habits during the brood-rearing period. We examined over 26,000 images from a high-resolution, above-nest digital camera to document the diet of a nesting bald eagle pair in north-central Indiana, U.S.A., during the 2018 brood-rearing period. After the hatch of two eaglets in April 2018, the camera was programmed to take still photos of the nest every 20 min, in addition to live-streaming video to YouTube for public audiences. Still images were used to quantify and identify all prey deliveries to the lowest taxonomic level possible, typically species. A total of 135 prey items and at least 26 prey taxa were recorded during the 75 d of the study, although daily prey count became uncertain in the final 20 d as fledglings began to move out of camera view. The majority of recorded prey items (73%) were fish, with redhorse suckers (Moxostoma spp.) representing the most numerous of the 13 fish taxa observed. Smaller numbers of birds (13%), mammals (10%), and reptiles (4%) were also observed. Although our results represent one nest across a single brood-rearing season, we gained novel insights through the analysis of high-frequency, high-definition images that provided increased temporal and taxonomic resolution of prey deliveries. The use of a camera not only avoided historical biases in bald eagle diet analysis, but also provided a valuable tool to engage public audiences.","PeriodicalId":50802,"journal":{"name":"American Midland Naturalist","volume":null,"pages":null},"PeriodicalIF":0.6,"publicationDate":"2021-07-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43506990","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 : 2021-07-19DOI: 10.1674/0003-0031-186.1.16
Kathryn E. Caruso, J. Horton, A. Hove
Abstract. Eastern hemlock (Tsuga canadensis (L.) Carrière) is a foundation species in eastern North American forests, providing critical habitats for a number of species. These trees are experiencing widespread decline due to the spread of hemlock woolly adelgid (HWA: Adelges tsugae Annand Order Hemiptera) into their range, potentially resulting in the disappearance of hemlocks from eastern forests. Hemlock dieback can lead to cascading effects on associated ecosystems, including belowground, mycorrhizal fungal communities. Ectomycorrhizal fungi (EM), which are mutualistic with many tree species and provide nutrients to plant hosts, are known to colonize hemlock as well as neighboring tree species at lower levels following HWA infection. This study investigated the effect of hemlock decline from HWA infestation on mycorrhizal communities, as inferred from colonization on northern red oak (Quercus rubra L.) “bait” seedlings grown near “host” hemlock trees. Hemlock health surveys were conducted in healthy (Carl Sandburg Home National Historic Site – CARL) and declining (Warren Wilson College – WWC) stands in western North Carolina, and host trees were paired between stands based on diameter. In each stand, northern red oak seedlings were planted within a meter of host hemlocks in early summer and allowed to grow for 8 w, when they were harvested. Seedling growth and dry biomass were recorded at harvest and roots were sampled for mycorrhizal colonization frequencies. Different mycorrhizal morphotypes were collected from seedling roots for subsequent DNA barcoding analyses to characterize EM taxonomic richness to compare mycorrhizal community assemblages between the two stands. Mycorrhizal colonization frequencies (percentage of the total number of EM-colonized root tips per seedling) and growth in seedling height were significantly greater at CARL than WWC, suggesting healthy hemlock stands are more favorable for oak seedling growth than declining stands. Moreover, a greater proportion of seedlings grown in the healthy stand were colonized by EM, indicating EM assemblages differ between a healthy and a declining hemlock stand. Differences between EM communities corresponded with altered seedling growth allocation, as seedlings in the declining stand had higher root to shoot ratios with reduced stem height, but showed greater investment in root biomass and stem diameter growth. We conclude EM communities differ between a healthy and declining hemlock stands, and changes in EM communities following hemlock dieback may affect the growth of replacement species.
摘要东铁杉(Tsuga canadensis, L.)carririre)是北美东部森林的基础物种，为许多物种提供了重要的栖息地。这些树木正经历着广泛的衰退，因为铁杉毛杉(HWA: Adelges tsugae Annand目半翅目)进入了它们的活动范围，可能导致铁杉从东部森林中消失。铁杉枯死会导致相关生态系统的级联效应，包括地下菌根真菌群落。外生菌根真菌(EM)与许多树种共生，并为植物宿主提供营养，已知在HWA感染后，其在铁杉和邻近树种中的定殖水平较低。本研究通过北红橡树(Quercus rubra L.)“诱饵”幼苗在“寄主”铁杉附近的定殖，研究了HWA侵染铁杉对菌根群落的影响。在北卡罗来纳州西部的健康(Carl Sandburg Home National Historic Site - Carl)和衰退(Warren Wilson College - WWC)林分中进行了铁杉健康调查，并根据林分直径对宿主树进行配对。在每个林分中，在初夏将北红橡树幼苗种植在距离宿主铁杉1米的地方，并在收获时让它们生长8周。在收获时记录幼苗生长和干生物量，并对根系进行菌根定植频率取样。从幼苗根系中收集不同的菌根形态，随后进行DNA条形码分析，表征EM分类丰富度，比较两种林分之间的菌根群落组合。菌根定植频率(占每株幼苗根尖总数量的百分比)和幼苗高的生长均显著高于WWC，说明健康的铁杉林分比衰败的铁杉林分更有利于橡树幼苗生长。此外，在健康林分生长的幼苗中，EM定域的比例更大，这表明健康和衰退铁杉林分的EM组合存在差异。EM群落间的差异与幼苗生长分配的变化相对应，衰败林分的幼苗根冠比较高，茎高降低，但根系生物量和茎粗的生长投入较大。我们得出结论，在健康和衰退的铁杉林分中，EM群落存在差异，铁杉枯死后EM群落的变化可能会影响替代物种的生长。
{"title":"Assessing the Effect of Eastern Hemlock (Tsuga canadensis) Decline from Hemlock Woolly Adelgid (Adelges tsugae) Infestation on Ectomycorrhizal Colonization and Growth of Red Oak (Quercus rubra) Seedlings","authors":"Kathryn E. Caruso, J. Horton, A. Hove","doi":"10.1674/0003-0031-186.1.16","DOIUrl":"https://doi.org/10.1674/0003-0031-186.1.16","url":null,"abstract":"Abstract. Eastern hemlock (Tsuga canadensis (L.) Carrière) is a foundation species in eastern North American forests, providing critical habitats for a number of species. These trees are experiencing widespread decline due to the spread of hemlock woolly adelgid (HWA: Adelges tsugae Annand Order Hemiptera) into their range, potentially resulting in the disappearance of hemlocks from eastern forests. Hemlock dieback can lead to cascading effects on associated ecosystems, including belowground, mycorrhizal fungal communities. Ectomycorrhizal fungi (EM), which are mutualistic with many tree species and provide nutrients to plant hosts, are known to colonize hemlock as well as neighboring tree species at lower levels following HWA infection. This study investigated the effect of hemlock decline from HWA infestation on mycorrhizal communities, as inferred from colonization on northern red oak (Quercus rubra L.) “bait” seedlings grown near “host” hemlock trees. Hemlock health surveys were conducted in healthy (Carl Sandburg Home National Historic Site – CARL) and declining (Warren Wilson College – WWC) stands in western North Carolina, and host trees were paired between stands based on diameter. In each stand, northern red oak seedlings were planted within a meter of host hemlocks in early summer and allowed to grow for 8 w, when they were harvested. Seedling growth and dry biomass were recorded at harvest and roots were sampled for mycorrhizal colonization frequencies. Different mycorrhizal morphotypes were collected from seedling roots for subsequent DNA barcoding analyses to characterize EM taxonomic richness to compare mycorrhizal community assemblages between the two stands. Mycorrhizal colonization frequencies (percentage of the total number of EM-colonized root tips per seedling) and growth in seedling height were significantly greater at CARL than WWC, suggesting healthy hemlock stands are more favorable for oak seedling growth than declining stands. Moreover, a greater proportion of seedlings grown in the healthy stand were colonized by EM, indicating EM assemblages differ between a healthy and a declining hemlock stand. Differences between EM communities corresponded with altered seedling growth allocation, as seedlings in the declining stand had higher root to shoot ratios with reduced stem height, but showed greater investment in root biomass and stem diameter growth. We conclude EM communities differ between a healthy and declining hemlock stands, and changes in EM communities following hemlock dieback may affect the growth of replacement species.","PeriodicalId":50802,"journal":{"name":"American Midland Naturalist","volume":null,"pages":null},"PeriodicalIF":0.6,"publicationDate":"2021-07-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44115574","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 : 2021-07-19DOI: 10.1674/0003-0031-186.1.76
Andrea L. Myers, J. Marshall
Abstract. Habitat fragmentation is the process of reducing habitat area while increasing the number and isolation of habitat patches. Although much of Indiana's land area was historically covered with contiguous forests, remaining forests are now heavily fragmented. This is especially true in northeastern Indiana where agriculture is the dominant land use cover type. Loss of functional forests in northeast Indiana could lead to a loss of biodiversity at a regional scale. Ground-dwelling arthropods have been used frequently as biological indicator taxa of forest health. We characterized 10 typical northeast Indiana forest plant communities and inventoried ground-dwelling arthropod communities within those forests. Plant community and environmental heterogeneity within forests were used to assess forest complexity, and ground-dwelling arthropod communities were compared to forest environmental characteristics. Our forest comparisons revealed plant community and structural heterogeneity differences. While overstory and understory diversity, compositional heterogeneity, and litter depth did have influence on arthropod communities' relative dissimilarities in nonmetric multidimensional scaling ordination plots, those communities were similar across all forest patches. However, those same environmental variables did not have direct influence on overall arthropod abundance, richness, or diversity. Even though differences did occur in forest structure and composition, arthropod communities had high similarity values, especially in August. As the forests in the region are similar in type and structure, between-forest comparisons of arthropod communities showed corresponding similarities in composition, abundance, richness, and diversity.
{"title":"Influence of Forest Fragment Composition and Structure on Ground-Dwelling Arthropod Communities","authors":"Andrea L. Myers, J. Marshall","doi":"10.1674/0003-0031-186.1.76","DOIUrl":"https://doi.org/10.1674/0003-0031-186.1.76","url":null,"abstract":"Abstract. Habitat fragmentation is the process of reducing habitat area while increasing the number and isolation of habitat patches. Although much of Indiana's land area was historically covered with contiguous forests, remaining forests are now heavily fragmented. This is especially true in northeastern Indiana where agriculture is the dominant land use cover type. Loss of functional forests in northeast Indiana could lead to a loss of biodiversity at a regional scale. Ground-dwelling arthropods have been used frequently as biological indicator taxa of forest health. We characterized 10 typical northeast Indiana forest plant communities and inventoried ground-dwelling arthropod communities within those forests. Plant community and environmental heterogeneity within forests were used to assess forest complexity, and ground-dwelling arthropod communities were compared to forest environmental characteristics. Our forest comparisons revealed plant community and structural heterogeneity differences. While overstory and understory diversity, compositional heterogeneity, and litter depth did have influence on arthropod communities' relative dissimilarities in nonmetric multidimensional scaling ordination plots, those communities were similar across all forest patches. However, those same environmental variables did not have direct influence on overall arthropod abundance, richness, or diversity. Even though differences did occur in forest structure and composition, arthropod communities had high similarity values, especially in August. As the forests in the region are similar in type and structure, between-forest comparisons of arthropod communities showed corresponding similarities in composition, abundance, richness, and diversity.","PeriodicalId":50802,"journal":{"name":"American Midland Naturalist","volume":null,"pages":null},"PeriodicalIF":0.6,"publicationDate":"2021-07-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42042124","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 : 2021-07-19DOI: 10.1674/0003-0031-186.1.136
T. M. Gehring, Ellisif E. Cline, R. Swihart
Abstract. Long-tailed weasels (Mustela frenata) have an extensive North American geographic range and tolerate a wide range of life zones, excluding some desert ecosystems. However, little is known of their habitat use in landscapes fragmented by agriculture, despite the fact that long-tailed weasel populations may be declining in these landscapes. During late winter-spring and late summer-autumn 1998–2000, we monitored 11 long-tailed weasels (seven males, four females) via radio telemetry to examine patterns of habitat use in an Indiana landscape fragmented by agriculture. Long-tailed weasels exhibited scale-dependent patterns of habitat selection (i.e., habitat selection within a landscape and selection of habitats within home ranges). Weasels selected forest patches, fencerows, and drainage ditches, whereas agricultural fields were avoided. Forest patches and fencerows provided suitable den sites and refuge cover from other predators and exhibited an abundant and diverse prey community. Drainage ditches provided movement corridors and access to free-standing, drinking water. The resource selection patterns and limited dispersal ability of long-tailed weasels compared to other carnivores are consistent with the notion that long-tailed weasels appear sensitive to agriculturally induced fragmentation of habitat.
{"title":"Habitat use by Long-tailed Weasels in a Fragmented Agricultural Landscape","authors":"T. M. Gehring, Ellisif E. Cline, R. Swihart","doi":"10.1674/0003-0031-186.1.136","DOIUrl":"https://doi.org/10.1674/0003-0031-186.1.136","url":null,"abstract":"Abstract. Long-tailed weasels (Mustela frenata) have an extensive North American geographic range and tolerate a wide range of life zones, excluding some desert ecosystems. However, little is known of their habitat use in landscapes fragmented by agriculture, despite the fact that long-tailed weasel populations may be declining in these landscapes. During late winter-spring and late summer-autumn 1998–2000, we monitored 11 long-tailed weasels (seven males, four females) via radio telemetry to examine patterns of habitat use in an Indiana landscape fragmented by agriculture. Long-tailed weasels exhibited scale-dependent patterns of habitat selection (i.e., habitat selection within a landscape and selection of habitats within home ranges). Weasels selected forest patches, fencerows, and drainage ditches, whereas agricultural fields were avoided. Forest patches and fencerows provided suitable den sites and refuge cover from other predators and exhibited an abundant and diverse prey community. Drainage ditches provided movement corridors and access to free-standing, drinking water. The resource selection patterns and limited dispersal ability of long-tailed weasels compared to other carnivores are consistent with the notion that long-tailed weasels appear sensitive to agriculturally induced fragmentation of habitat.","PeriodicalId":50802,"journal":{"name":"American Midland Naturalist","volume":null,"pages":null},"PeriodicalIF":0.6,"publicationDate":"2021-07-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44881509","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 : 2021-04-28DOI: 10.1674/0003-0031-185.2.241
C. Fill, C. Allen, J. F. Benson, D. Twidwell
Abstract. Bats are important bio-indicators of ecosystem health and provide a number of ecosystem services. White-nose Syndrome and habitat loss have led to the decline of many bat species in eastern North America, including the federally threatened northern long-eared bat, Myotis septentrionalis. White-nose Syndrome was only recently found in Nebraska, which lies on the western extent of this species geographic range. To better understand how this forest-dependent species persists in an agriculturally dominated landscape amid a growing number of pressures, we investigated the roosting habits of this bat at the Homestead National Monument of America, located in southeast Nebraska. We mist-netted bats on eight nights in 2019 (16 August–26 August) and caught 55 bats across five species, including five juvenile northern long-eared bats. We located five unique roosts between two juvenile radio-tracked bats; most of the female roosts were in anthropogenic structures and tree cavities within 0.23 km of capture, while most of the male roosts were in snags and tree cavities as far as 2.73 km from the capture site. Fence cavities were also used by other undocumented northern long-eared bats. We recorded three radio-tagged bats that commuted between roosting sites and capture sites within hours after sunset. Our results provide evidence that at the distributional edge for this species, wooded areas, riparian zones, and human-built structures in an intensively managed agricultural landscape are used by this imperiled species.
{"title":"Roost Use and Movements of Northern Long-Eared Bats in a Southeast Nebraska Agricultural Landscape","authors":"C. Fill, C. Allen, J. F. Benson, D. Twidwell","doi":"10.1674/0003-0031-185.2.241","DOIUrl":"https://doi.org/10.1674/0003-0031-185.2.241","url":null,"abstract":"Abstract. Bats are important bio-indicators of ecosystem health and provide a number of ecosystem services. White-nose Syndrome and habitat loss have led to the decline of many bat species in eastern North America, including the federally threatened northern long-eared bat, Myotis septentrionalis. White-nose Syndrome was only recently found in Nebraska, which lies on the western extent of this species geographic range. To better understand how this forest-dependent species persists in an agriculturally dominated landscape amid a growing number of pressures, we investigated the roosting habits of this bat at the Homestead National Monument of America, located in southeast Nebraska. We mist-netted bats on eight nights in 2019 (16 August–26 August) and caught 55 bats across five species, including five juvenile northern long-eared bats. We located five unique roosts between two juvenile radio-tracked bats; most of the female roosts were in anthropogenic structures and tree cavities within 0.23 km of capture, while most of the male roosts were in snags and tree cavities as far as 2.73 km from the capture site. Fence cavities were also used by other undocumented northern long-eared bats. We recorded three radio-tagged bats that commuted between roosting sites and capture sites within hours after sunset. Our results provide evidence that at the distributional edge for this species, wooded areas, riparian zones, and human-built structures in an intensively managed agricultural landscape are used by this imperiled species.","PeriodicalId":50802,"journal":{"name":"American Midland Naturalist","volume":null,"pages":null},"PeriodicalIF":0.6,"publicationDate":"2021-04-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47588428","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 : 2021-04-28DOI: 10.1674/0003-0031-185.2.149
Bram H. F. Verheijen, Reid T. Plumb, Chris K. Gulick, C. Hagen, Samantha G. Robinson, Daniel S. Sullins, D. Haukos
Abstract. Large-scale declines of grassland ecosystems in the conterminous United States since European settlement have led to substantial loss and fragmentation of lesser prairie-chicken (Tympanuchus pallidicinctus) habitat and decreased their occupied range and population numbers by ∼85%. Breeding season space use is an important component of lesser prairie-chicken conservation, because it could affect both local carrying capacity and population dynamics. Previous estimates of breeding season space use are largely limited to one of the four currently occupied ecoregions, but potential extrinsic drivers of breeding space use, such as landscape fragmentation, vegetation structure and composition, and density of anthropogenic structures, can show large spatial variation. Moreover, habitat needs vary greatly among the lekking/prelaying, nesting, brood-rearing, and postbreeding stages of the breeding season, but space use by female lesser prairie-chickens during these stages remain relatively unclear. We tested whether home range area and daily displacement (the net distance between the first and last location of each day) of female lesser prairie-chickens varied among ecoregions and breeding stages at four study sites in Kansas and Colorado, U.S.A., representing three of the four currently occupied ecoregions. We equipped females with very-high-frequency (VHF) or Global Positioning System (GPS) transmitters, and estimated home range area with kernel density estimators or biased random bridge models, respectively. Across all ecoregions, breeding season home range area averaged 190.4 ha (±19.1 ha se) for birds with VHF and 283.6 ha (±23.1 ha) for birds with GPS transmitters, whereas daily displacement averaged 374.8 m (±14.3 m). Average home range area and daily displacement of bird with GPS transmitters were greater in the Short-Grass Prairie/ Conservation Reserve Program Mosaic and Sand Sagebrush Prairie Ecoregions compared to sites in the Mixed-Grass Prairie Ecoregion. Home range area and daily displacement were greatest during lekking/prelaying and smallest during the brood-rearing stage, when female movements were restricted by mobility of chicks. Ecoregion- and breeding stage-specific estimates of space use by lesser prairie-chickens will help managers determine the spatial configuration of breeding stage-specific habitat on the landscape. Furthermore, ecoregion- and breeding stage-specific estimates are crucial when estimating the amount of breeding habitat needed for lesser prairie-chicken populations to persist.
{"title":"Breeding Season Space Use by Lesser Prairie-Chickens (Tympanuchus Pallidicinctus) Varies Among Ecoregions and Breeding Stages","authors":"Bram H. F. Verheijen, Reid T. Plumb, Chris K. Gulick, C. Hagen, Samantha G. Robinson, Daniel S. Sullins, D. Haukos","doi":"10.1674/0003-0031-185.2.149","DOIUrl":"https://doi.org/10.1674/0003-0031-185.2.149","url":null,"abstract":"Abstract. Large-scale declines of grassland ecosystems in the conterminous United States since European settlement have led to substantial loss and fragmentation of lesser prairie-chicken (Tympanuchus pallidicinctus) habitat and decreased their occupied range and population numbers by ∼85%. Breeding season space use is an important component of lesser prairie-chicken conservation, because it could affect both local carrying capacity and population dynamics. Previous estimates of breeding season space use are largely limited to one of the four currently occupied ecoregions, but potential extrinsic drivers of breeding space use, such as landscape fragmentation, vegetation structure and composition, and density of anthropogenic structures, can show large spatial variation. Moreover, habitat needs vary greatly among the lekking/prelaying, nesting, brood-rearing, and postbreeding stages of the breeding season, but space use by female lesser prairie-chickens during these stages remain relatively unclear. We tested whether home range area and daily displacement (the net distance between the first and last location of each day) of female lesser prairie-chickens varied among ecoregions and breeding stages at four study sites in Kansas and Colorado, U.S.A., representing three of the four currently occupied ecoregions. We equipped females with very-high-frequency (VHF) or Global Positioning System (GPS) transmitters, and estimated home range area with kernel density estimators or biased random bridge models, respectively. Across all ecoregions, breeding season home range area averaged 190.4 ha (±19.1 ha se) for birds with VHF and 283.6 ha (±23.1 ha) for birds with GPS transmitters, whereas daily displacement averaged 374.8 m (±14.3 m). Average home range area and daily displacement of bird with GPS transmitters were greater in the Short-Grass Prairie/ Conservation Reserve Program Mosaic and Sand Sagebrush Prairie Ecoregions compared to sites in the Mixed-Grass Prairie Ecoregion. Home range area and daily displacement were greatest during lekking/prelaying and smallest during the brood-rearing stage, when female movements were restricted by mobility of chicks. Ecoregion- and breeding stage-specific estimates of space use by lesser prairie-chickens will help managers determine the spatial configuration of breeding stage-specific habitat on the landscape. Furthermore, ecoregion- and breeding stage-specific estimates are crucial when estimating the amount of breeding habitat needed for lesser prairie-chicken populations to persist.","PeriodicalId":50802,"journal":{"name":"American Midland Naturalist","volume":null,"pages":null},"PeriodicalIF":0.6,"publicationDate":"2021-04-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44517989","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 : 2021-04-28DOI: 10.1674/0003-0031-185.2.249
A. McLaren, B. Patterson
Abstract. Data on movement of grey wolves (Canis lupus) in island systems is largely restricted to coastal environments and little is known about their space use and movement in freshwater archipelagos. We used data from a GPS-collared wolf in a protected archipelago in Lake Superior, Ontario to examine broad seasonal patterns in space use, movement, and activity. Over approximately 1 y of monitoring, the wolf made 190 crossings between islands and showed more extensive use of the archipelago during the nonwinter season. When ice was present in the archipelago, the mean weekly inter-island crossing rate of the wolf (± se) was 6.08 ± 1.31, with crossings largely restricted to the interior islands bounded by ice, compared to 2.85 ± 0.45 during the open water season. Mean wolf activity was highest in the nonwinter season, but movement rates were comparable across seasons. Our study is the first to document wolf movements in a freshwater archipelago with seasonal ice cover and supports data collection at fine temporal scales to better understand trends in wolf space use and movement at small spatial scales.
{"title":"Seasonal Space Use and Movement of a Grey Wolf (Canis lupus) in a Protected Archipelago in Lake Superior, Ontario","authors":"A. McLaren, B. Patterson","doi":"10.1674/0003-0031-185.2.249","DOIUrl":"https://doi.org/10.1674/0003-0031-185.2.249","url":null,"abstract":"Abstract. Data on movement of grey wolves (Canis lupus) in island systems is largely restricted to coastal environments and little is known about their space use and movement in freshwater archipelagos. We used data from a GPS-collared wolf in a protected archipelago in Lake Superior, Ontario to examine broad seasonal patterns in space use, movement, and activity. Over approximately 1 y of monitoring, the wolf made 190 crossings between islands and showed more extensive use of the archipelago during the nonwinter season. When ice was present in the archipelago, the mean weekly inter-island crossing rate of the wolf (± se) was 6.08 ± 1.31, with crossings largely restricted to the interior islands bounded by ice, compared to 2.85 ± 0.45 during the open water season. Mean wolf activity was highest in the nonwinter season, but movement rates were comparable across seasons. Our study is the first to document wolf movements in a freshwater archipelago with seasonal ice cover and supports data collection at fine temporal scales to better understand trends in wolf space use and movement at small spatial scales.","PeriodicalId":50802,"journal":{"name":"American Midland Naturalist","volume":null,"pages":null},"PeriodicalIF":0.6,"publicationDate":"2021-04-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46725829","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 : 2021-04-28DOI: 10.1674/0003-0031-185.2.267
Justin L. Pitschmann, J. Conard, Elaina M. Hubbell
Abstract. We analyzed the relationship between landscape context and the vigilance and foraging patterns of the black-tailed prairie dog (Cynomys ludovicianus) in urban and rural areas. We observed five colonies, two in urban areas and three in rural areas from 23 March–20 April 2016, 31 August–19 September 2016, 26 March–12 April 2017, and 7 September–17 October 2017. We measured vigilance by observing individual prairie dogs for 5 min and recording the amount of time the individual spent vigilant or foraging. In addition, the total number of individuals in the colony that were actively vigilant or foraging were counted every 10 min for 1 h. Prairie dogs in rural colonies were more vigilant than those in urban colonies and displayed a lower proportion of individuals that were non-vigilant in both the spring and summer. Because prairie dogs in urban colonies might be habituated to disturbance and have a relatively low risk of predation, individuals spent much less time vigilant. Our findings could be used to better understand behavioral changes in black-tailed prairie dogs caused by encroaching urban development.
{"title":"Vigilance Patterns of Black-Tailed Prairie Dogs (Cynomys ludovicianus) in Urban and Rural Areas","authors":"Justin L. Pitschmann, J. Conard, Elaina M. Hubbell","doi":"10.1674/0003-0031-185.2.267","DOIUrl":"https://doi.org/10.1674/0003-0031-185.2.267","url":null,"abstract":"Abstract. We analyzed the relationship between landscape context and the vigilance and foraging patterns of the black-tailed prairie dog (Cynomys ludovicianus) in urban and rural areas. We observed five colonies, two in urban areas and three in rural areas from 23 March–20 April 2016, 31 August–19 September 2016, 26 March–12 April 2017, and 7 September–17 October 2017. We measured vigilance by observing individual prairie dogs for 5 min and recording the amount of time the individual spent vigilant or foraging. In addition, the total number of individuals in the colony that were actively vigilant or foraging were counted every 10 min for 1 h. Prairie dogs in rural colonies were more vigilant than those in urban colonies and displayed a lower proportion of individuals that were non-vigilant in both the spring and summer. Because prairie dogs in urban colonies might be habituated to disturbance and have a relatively low risk of predation, individuals spent much less time vigilant. Our findings could be used to better understand behavioral changes in black-tailed prairie dogs caused by encroaching urban development.","PeriodicalId":50802,"journal":{"name":"American Midland Naturalist","volume":null,"pages":null},"PeriodicalIF":0.6,"publicationDate":"2021-04-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44783918","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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