Pub Date : 2022-01-03DOI: 10.1674/0003-0031-187.1.97
D. Hernández, J. Bump
Abstract. Wolf predation of beaver is common in boreal ecosystems, but predation events are thought to be rare in winter. We describe the encounter of a recent wolf predation event of a beaver during conditions of ice cover. The beaver had a broken upper incisor, which may have contributed to it foraging on land during the winter. While it is common for injured animals to have increased vulnerability to predation, injuries can also influence foraging decisions that may indirectly increase vulnerability to predation.
{"title":"Predation of a Beaver (Castor canadensis) by a Gray Wolf (Canis lupus) during Winter","authors":"D. Hernández, J. Bump","doi":"10.1674/0003-0031-187.1.97","DOIUrl":"https://doi.org/10.1674/0003-0031-187.1.97","url":null,"abstract":"Abstract. Wolf predation of beaver is common in boreal ecosystems, but predation events are thought to be rare in winter. We describe the encounter of a recent wolf predation event of a beaver during conditions of ice cover. The beaver had a broken upper incisor, which may have contributed to it foraging on land during the winter. While it is common for injured animals to have increased vulnerability to predation, injuries can also influence foraging decisions that may indirectly increase vulnerability to predation.","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":"48139452","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: 10.1674/0003-0031-187.1.29
B. B. Tumolo, B. Richardson, D. Lebeda, M. Flinn
Abstract. The ability of organisms to survive ingestion and digestion by their predators, or endozoochory, is a fascinating ecological phenomenon that can facilitate predator-mediated dispersal of prey and alter interaction strengths within ecological networks. However, the role of endozoochory in the context of invasive species is considered less often. Throughout the United States, Silver Carp (Hypophthalmichthys molitrix) are prolific invaders that often alter food web structure of recipient ecosystems through the consumption of basal resources. Despite the biogeochemical and food web effects of Silver Carp, there is limited understanding of plankton prey survival after Silver Carp consumption and digestion, and even less known about the ecological effects of selective diets and potential survival. In this study, we quantify hindgut contents of Silver Carp collected from Kentucky Lake, Kentucky, Tennessee River Valley, United States. We found the majority (83%) of phytoplankters within hindguts of Silver Carp showed little digestion prior to egestion. Our study suggests digestion limitations of Silver Carp may have important ecological implications for invaded environments. These results may be applicable in understanding how this rapidly spreading invasive fish can influence food web dynamics and biogeochemical cycles pertinent to toxic algal blooms within recently invaded ecosystems, and forecasting invasion in the near future.
{"title":"Phytoplankton Survival in Hindgut of Invasive Silver Carp (Hypophthalmichthys molitrix)","authors":"B. B. Tumolo, B. Richardson, D. Lebeda, M. Flinn","doi":"10.1674/0003-0031-187.1.29","DOIUrl":"https://doi.org/10.1674/0003-0031-187.1.29","url":null,"abstract":"Abstract. The ability of organisms to survive ingestion and digestion by their predators, or endozoochory, is a fascinating ecological phenomenon that can facilitate predator-mediated dispersal of prey and alter interaction strengths within ecological networks. However, the role of endozoochory in the context of invasive species is considered less often. Throughout the United States, Silver Carp (Hypophthalmichthys molitrix) are prolific invaders that often alter food web structure of recipient ecosystems through the consumption of basal resources. Despite the biogeochemical and food web effects of Silver Carp, there is limited understanding of plankton prey survival after Silver Carp consumption and digestion, and even less known about the ecological effects of selective diets and potential survival. In this study, we quantify hindgut contents of Silver Carp collected from Kentucky Lake, Kentucky, Tennessee River Valley, United States. We found the majority (83%) of phytoplankters within hindguts of Silver Carp showed little digestion prior to egestion. Our study suggests digestion limitations of Silver Carp may have important ecological implications for invaded environments. These results may be applicable in understanding how this rapidly spreading invasive fish can influence food web dynamics and biogeochemical cycles pertinent to toxic algal blooms within recently invaded ecosystems, and forecasting invasion in the near future.","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":"49405872","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: 10.1674/0003-0031-187.1.14
N. Lemoine, M. Budny
Abstract. Overcompensation to herbivory is prevalent among plant species. However, we do not yet fully understand why plant species vary in their compensatory abilities. It is highly likely that overcompensation is determined by the ability of plants to elevate photosynthesis in response to herbivory, which is dictated by evolutionary exposure to grazing. Here, we tested the hypothesis that photosynthetic overcompensation should be predictable based on plant life form by simulating herbivore damage on four plant species: two common range grasses with long evolutionary exposure to grazing (Andropogon gerardii, Bouteloua curtipendula) and two common understory forbs that are resistant to, and therefore experience little, grazing (Alliaria petiolata, Symplocarpus foetidus). We measured leaf-level gas exchange in a high-resolution time series that extended throughout the growing season. We found no evidence of photosynthetic compensation for three of the four plant species. Interestingly, only A. petiolata, a highly invasive species, demonstrated increased photosynthesis and stomatal conductance following clipping. Further, the effects were short-lived, as both photosynthesis and stomatal conductance returned to baseline levels within 24 h. Our results suggest that elevated photosynthesis to herbivory might not be a general mechanism by which plants either resist or tolerate herbivory.
{"title":"Impacts of Herbivory on Photosynthesis of Four Common Wisconsin Plant Species","authors":"N. Lemoine, M. Budny","doi":"10.1674/0003-0031-187.1.14","DOIUrl":"https://doi.org/10.1674/0003-0031-187.1.14","url":null,"abstract":"Abstract. Overcompensation to herbivory is prevalent among plant species. However, we do not yet fully understand why plant species vary in their compensatory abilities. It is highly likely that overcompensation is determined by the ability of plants to elevate photosynthesis in response to herbivory, which is dictated by evolutionary exposure to grazing. Here, we tested the hypothesis that photosynthetic overcompensation should be predictable based on plant life form by simulating herbivore damage on four plant species: two common range grasses with long evolutionary exposure to grazing (Andropogon gerardii, Bouteloua curtipendula) and two common understory forbs that are resistant to, and therefore experience little, grazing (Alliaria petiolata, Symplocarpus foetidus). We measured leaf-level gas exchange in a high-resolution time series that extended throughout the growing season. We found no evidence of photosynthetic compensation for three of the four plant species. Interestingly, only A. petiolata, a highly invasive species, demonstrated increased photosynthesis and stomatal conductance following clipping. Further, the effects were short-lived, as both photosynthesis and stomatal conductance returned to baseline levels within 24 h. Our results suggest that elevated photosynthesis to herbivory might not be a general mechanism by which plants either resist or tolerate herbivory.","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":"45614424","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: 10.1674/0003-0031-187.1.62
M. Hayes
Abstract. I describe the phenology of territorial Greater Sandhill Cranes (Grus canadensis tabida) from a long-term (20+ y) marked population near Briggsville, Wisconsin. Territorial adults typically arrived in mid-March (average = 27 Mar., median = 25 Mar.) and egg-laying commenced a median date of 2 wk post-arrival. Chicks typically hatched in mid-May (average and median = 12 May). Renesting occurred from 3-14 d after the first clutch failed and renests hatched from late May to early July (95% CI: 23 May–8 Jul.). Known territorial birds began congregating in mid-Sept, and fall migration typically occurred in late Nov. Territory use by adults occurred at all stages of the annual cycle and may be a way to ensure reclamation of the territory in subsequent years.
{"title":"Phenology of Territorial Sandhill Cranes on the Breeding Grounds in South-Central Wisconsin","authors":"M. Hayes","doi":"10.1674/0003-0031-187.1.62","DOIUrl":"https://doi.org/10.1674/0003-0031-187.1.62","url":null,"abstract":"Abstract. I describe the phenology of territorial Greater Sandhill Cranes (Grus canadensis tabida) from a long-term (20+ y) marked population near Briggsville, Wisconsin. Territorial adults typically arrived in mid-March (average = 27 Mar., median = 25 Mar.) and egg-laying commenced a median date of 2 wk post-arrival. Chicks typically hatched in mid-May (average and median = 12 May). Renesting occurred from 3-14 d after the first clutch failed and renests hatched from late May to early July (95% CI: 23 May–8 Jul.). Known territorial birds began congregating in mid-Sept, and fall migration typically occurred in late Nov. Territory use by adults occurred at all stages of the annual cycle and may be a way to ensure reclamation of the territory in subsequent years.","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":"47091322","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: 10.1674/0003-0031-187.1.104
S. Jacquemin, M. Cubberley
Abstract. We assessed a large-scale fish die off event resultant of prolonged anoxic conditions on Grand Lake St. Marys in west central Ohio, U.S., during the summer of 2020, and used this as the basis for comparing long-term species diversity in the lake over the past century. Fish collections were made along a series of shoreline and open water transects, totaling approximately 1.5% of the entire 5220 ha lake area (majority of surveys were shoreline), wherein we identified a total of 12,351 fish comprised of 25 taxa. We used this die off event, combined with recent near shore seine survey data, as an opportunity to assess the modern assemblage structure and to serve as a reference point to prior collected data over the past century. Combining these recent data with historical records, we found that although 57 species have been recorded from the lake dating back to the mid-1800s, only 30 taxa are known to inhabit the lake today. Some of the lost taxa predictably include more intolerant species from the Darter (Percidae), Minnow (Cyprinidae), and Sucker (Catostomidae) families; however, there were also instances of increases in taxa resulting from both state stocking efforts (e.g. Flathead Catfish, Pylodictis olivaris) and natural distribution expansions (e.g. Freshwater Drum, Aplodinotus grunniens). Overall, we attribute the changes to the fish assemblage as negative, given no intolerant taxa currently inhabit the lake. We attribute these long-term changes to watershed wide destruction of natural forest, wetland, and prairie habitats that once typified the region.
{"title":"Documentation of a Massive Fish Die Off on Grand Lake St. Marys, with Notes on Long-term Changes in Fish Assemblage and Watershed Habitat Over the Past Century","authors":"S. Jacquemin, M. Cubberley","doi":"10.1674/0003-0031-187.1.104","DOIUrl":"https://doi.org/10.1674/0003-0031-187.1.104","url":null,"abstract":"Abstract. We assessed a large-scale fish die off event resultant of prolonged anoxic conditions on Grand Lake St. Marys in west central Ohio, U.S., during the summer of 2020, and used this as the basis for comparing long-term species diversity in the lake over the past century. Fish collections were made along a series of shoreline and open water transects, totaling approximately 1.5% of the entire 5220 ha lake area (majority of surveys were shoreline), wherein we identified a total of 12,351 fish comprised of 25 taxa. We used this die off event, combined with recent near shore seine survey data, as an opportunity to assess the modern assemblage structure and to serve as a reference point to prior collected data over the past century. Combining these recent data with historical records, we found that although 57 species have been recorded from the lake dating back to the mid-1800s, only 30 taxa are known to inhabit the lake today. Some of the lost taxa predictably include more intolerant species from the Darter (Percidae), Minnow (Cyprinidae), and Sucker (Catostomidae) families; however, there were also instances of increases in taxa resulting from both state stocking efforts (e.g. Flathead Catfish, Pylodictis olivaris) and natural distribution expansions (e.g. Freshwater Drum, Aplodinotus grunniens). Overall, we attribute the changes to the fish assemblage as negative, given no intolerant taxa currently inhabit the lake. We attribute these long-term changes to watershed wide destruction of natural forest, wetland, and prairie habitats that once typified the region.","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":"47362962","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: 10.1674/0003-0031-187.1.90
Eryn M. Watson, Bradley S. Cohen, D. Osborn, James M. Brown, K. Miller
Abstract. The visual capabilities of prey species such as white-tailed deer (Odocoileus virginianus) must be specialized to enhance predator detection and traverse a complex physical environment. Although aspects of the visual system of deer have been investigated, there has been no evaluation of the species' spatial resolution abilities. We used a behavioral assay to estimate visual acuity of three adult female deer using operant conditioning techniques. We estimated the spatial resolution is between four and six cycles/degree. Our results suggest the white-tailed deer eye allows relatively low spatial resolution, consistent with prior studies that reported high temporal resolution. The combination of low spatial resolution and high temporal resolution allows for efficient detection of movement and enhanced capability to transverse a complex environment.
{"title":"Estimation of Visual Discrimination in the White-tailed Deer by Behavioral Assay","authors":"Eryn M. Watson, Bradley S. Cohen, D. Osborn, James M. Brown, K. Miller","doi":"10.1674/0003-0031-187.1.90","DOIUrl":"https://doi.org/10.1674/0003-0031-187.1.90","url":null,"abstract":"Abstract. The visual capabilities of prey species such as white-tailed deer (Odocoileus virginianus) must be specialized to enhance predator detection and traverse a complex physical environment. Although aspects of the visual system of deer have been investigated, there has been no evaluation of the species' spatial resolution abilities. We used a behavioral assay to estimate visual acuity of three adult female deer using operant conditioning techniques. We estimated the spatial resolution is between four and six cycles/degree. Our results suggest the white-tailed deer eye allows relatively low spatial resolution, consistent with prior studies that reported high temporal resolution. The combination of low spatial resolution and high temporal resolution allows for efficient detection of movement and enhanced capability to transverse a complex environment.","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":"48718551","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 : 2021-10-18DOI: 10.1674/0003-0031-186.2.231
Emily A. Sinnott, M. D. Weegman, F. Thompson, T. R. Thompson
Abstract. Precocial young leave their nest immediately after hatch to move and forage as a group during a rapid period of development. Growth and body condition are correlated with survival; young are better able to thermoregulate as they become larger, and they are better able to escape predators as they become more mobile. Environmental conditions can influence development and ultimately survival. We evaluated weather, cover type, and temporal factors affecting northern bobwhite juvenile body condition. We captured 216 individuals from 33 broods >16 d old on five conservation areas in southwest Missouri in 2017 and 2018. Brood hatch dates ranged from 26 May through 19 September. Body condition was measured as the residuals from a linear regression of juvenile tarsus length and body mass on capture. We found some support for improved body condition earlier in the breeding season and in native grasslands that were burned and grazed within the previous 2 y. However, models representing these effects had similar support to the null model (i.e., ΔWAIC<2), indicating weak support. Limited support for these effects may have been due to limited data or the influence of other environmental factors not considered in our competing model set. Our top model supported negative effects of later hatching date and agricultural crop cover on juvenile body condition. The early breeding season is an important period for successful bobwhite productivity, and native grasslands managed with rotational fire and grazing may create higher quality brood rearing habitat for improved juvenile body condition.
{"title":"Early Hatch and Managed Native Grasslands Minorly Improve Bobwhite Juvenile Body Condition","authors":"Emily A. Sinnott, M. D. Weegman, F. Thompson, T. R. Thompson","doi":"10.1674/0003-0031-186.2.231","DOIUrl":"https://doi.org/10.1674/0003-0031-186.2.231","url":null,"abstract":"Abstract. Precocial young leave their nest immediately after hatch to move and forage as a group during a rapid period of development. Growth and body condition are correlated with survival; young are better able to thermoregulate as they become larger, and they are better able to escape predators as they become more mobile. Environmental conditions can influence development and ultimately survival. We evaluated weather, cover type, and temporal factors affecting northern bobwhite juvenile body condition. We captured 216 individuals from 33 broods >16 d old on five conservation areas in southwest Missouri in 2017 and 2018. Brood hatch dates ranged from 26 May through 19 September. Body condition was measured as the residuals from a linear regression of juvenile tarsus length and body mass on capture. We found some support for improved body condition earlier in the breeding season and in native grasslands that were burned and grazed within the previous 2 y. However, models representing these effects had similar support to the null model (i.e., ΔWAIC<2), indicating weak support. Limited support for these effects may have been due to limited data or the influence of other environmental factors not considered in our competing model set. Our top model supported negative effects of later hatching date and agricultural crop cover on juvenile body condition. The early breeding season is an important period for successful bobwhite productivity, and native grasslands managed with rotational fire and grazing may create higher quality brood rearing habitat for improved juvenile body condition.","PeriodicalId":50802,"journal":{"name":"American Midland Naturalist","volume":null,"pages":null},"PeriodicalIF":0.6,"publicationDate":"2021-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45044233","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 : 2021-10-18DOI: 10.1674/0003-0031-186.2.299
Zaavian S. Espinoza, F. Weckerly
Abstract. An inverse density-dependent relationship between abundance and adult sex ratio (ASR, males:female) occurs in some populations of polygynous mammals due to life history differences between the sexes. Male fecundity and survival is dictated by attempts to obtain as many copulations as possible, whereas female fecundity and survival is dictated by resource acquisition. Therefore, females usually acquire forage before males as a result of interspecific scramble competition, particularly when forage becomes more limited at K carrying capacity. This leads to the passive displacement of males in a given area. The common belief is that most monogamous mammal populations exhibit balanced adult sex ratios. The coupling of sexually mature males and females in a population result in this pattern for this mating system. Present literature focuses on primary or secondary sex ratios in mammals or on ASR patterns within individual species. Our goal was to test if expected ASR patterns would be visible across numerous species in both mating systems. We hypothesized we would see an inverse relationship between abundance and ASR across polygynous populations, and no relationship between abundance and ASR across monogamous populations. We extracted time series population data from published literature for 43 populations of 15 different mammal species. Results from our analysis of a linear mixed-effects model were consistent with our hypothesis for polygynous populations, as we found a significant inverse relationship between abundance and ASR. However, our analysis also revealed a significant inverse relationship between abundance and ASR in monogamous populations that was not consistent with our hypothesis. Our findings provide quantitative support for a theoretical model explaining the evolutionary and ecological mechanisms driving a density-dependent relationship between abundance and ASR in polygynous mammals. An investigation into monogamous mammals is needed to assess why some species with this mating system display a density-dependent response in ASR as well.
{"title":"A Comparative Analysis of Adult Sex Ratios in Polygynous and Monogamous Mammal Populations","authors":"Zaavian S. Espinoza, F. Weckerly","doi":"10.1674/0003-0031-186.2.299","DOIUrl":"https://doi.org/10.1674/0003-0031-186.2.299","url":null,"abstract":"Abstract. An inverse density-dependent relationship between abundance and adult sex ratio (ASR, males:female) occurs in some populations of polygynous mammals due to life history differences between the sexes. Male fecundity and survival is dictated by attempts to obtain as many copulations as possible, whereas female fecundity and survival is dictated by resource acquisition. Therefore, females usually acquire forage before males as a result of interspecific scramble competition, particularly when forage becomes more limited at K carrying capacity. This leads to the passive displacement of males in a given area. The common belief is that most monogamous mammal populations exhibit balanced adult sex ratios. The coupling of sexually mature males and females in a population result in this pattern for this mating system. Present literature focuses on primary or secondary sex ratios in mammals or on ASR patterns within individual species. Our goal was to test if expected ASR patterns would be visible across numerous species in both mating systems. We hypothesized we would see an inverse relationship between abundance and ASR across polygynous populations, and no relationship between abundance and ASR across monogamous populations. We extracted time series population data from published literature for 43 populations of 15 different mammal species. Results from our analysis of a linear mixed-effects model were consistent with our hypothesis for polygynous populations, as we found a significant inverse relationship between abundance and ASR. However, our analysis also revealed a significant inverse relationship between abundance and ASR in monogamous populations that was not consistent with our hypothesis. Our findings provide quantitative support for a theoretical model explaining the evolutionary and ecological mechanisms driving a density-dependent relationship between abundance and ASR in polygynous mammals. An investigation into monogamous mammals is needed to assess why some species with this mating system display a density-dependent response in ASR as well.","PeriodicalId":50802,"journal":{"name":"American Midland Naturalist","volume":null,"pages":null},"PeriodicalIF":0.6,"publicationDate":"2021-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42812805","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 : 2021-10-18DOI: 10.1674/0003-0031-186.2.263
P. Yaukey
Abstract. Northern Mockingbirds (Mimus polyglottus) were studied between 1995 and 2015 on a university campus in New Orleans, U.S.A., spanning the 2005 landfall of Hurricane Katrina. The storm subjected the city to high winds and a prolonged flood. Nesting success showed a spike for 3 y after the storm, after which it gradually sank back to near pre-storm levels. Number of broods detected jumped from the first to the second year after the storm on campus and at two nearby residential sites. Success of males in acquiring mates improved from the first nesting season after the storm to the second across the three sites. Results draw attention to the importance of considering top-down effects in analyzing the recovery of storm-impacted birds.
{"title":"Demographic Dynamics of a Population of Northern Mockingbirds (Mimus polyglottus) in New Orleans, U.S.A., before and after Hurricane Katrina","authors":"P. Yaukey","doi":"10.1674/0003-0031-186.2.263","DOIUrl":"https://doi.org/10.1674/0003-0031-186.2.263","url":null,"abstract":"Abstract. Northern Mockingbirds (Mimus polyglottus) were studied between 1995 and 2015 on a university campus in New Orleans, U.S.A., spanning the 2005 landfall of Hurricane Katrina. The storm subjected the city to high winds and a prolonged flood. Nesting success showed a spike for 3 y after the storm, after which it gradually sank back to near pre-storm levels. Number of broods detected jumped from the first to the second year after the storm on campus and at two nearby residential sites. Success of males in acquiring mates improved from the first nesting season after the storm to the second across the three sites. Results draw attention to the importance of considering top-down effects in analyzing the recovery of storm-impacted birds.","PeriodicalId":50802,"journal":{"name":"American Midland Naturalist","volume":null,"pages":null},"PeriodicalIF":0.6,"publicationDate":"2021-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43547580","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 : 2021-10-18DOI: 10.1674/0003-0031-186.2.274
Elizabeth M. Barnes, A. Burton
Abstract. This case study seeks to fill a critical knowledge gap regarding how natural wind disturbance affects stand and seedling bank diversity in mixed northern hardwood forests managed by single tree selection harvest methods. Contemporary timber harvests on state managed lands in Michigan's Upper Peninsula employ single tree selection cutting methods to promote more complex age structure in second growth stands dominated by sugar maple (Acer saccharum). However, concern exists that single tree selection harvest may result in lowered compositional diversity of seedlings as the low light conditions of small dispersed gaps exclude less shade tolerant species from gap regeneration. In July 2016 severe thunderstorms with winds in excess of 145 km/h (90 mph) caused extensive tree fall and canopy gap creation in second growth mixed northern hardwood forests in the southern Keweenaw Peninsula. We measured the species composition of overstory tree mortality and understory seedling regeneration in 14 storm gaps created in stands with and without previous single tree selection harvest. Storm gaps ranged in size from 125 to 1100 m2. American basswood (Tilia americana) was disproportionately wind-thrown. Robust seedling regeneration was released in all storm gaps, with sugar maple comprising more than 75% of mean seedling abundance, regardless of previous single tree selection harvest. Sugar maple and ironwood (Ostrya virginiana) comprised 80% of sapling abundance. Results indicate single tree selection of mixed northern hardwood stands does not exacerbate, but rather emulates, dense sugar maple regeneration found on unmanaged second growth sites.
{"title":"Sugar maple (Acer saccharum) Seedling Bank Response to Storm Disturbance and Single Tree Selection Harvest in the Southern Keweenaw Peninsula, Michigan","authors":"Elizabeth M. Barnes, A. Burton","doi":"10.1674/0003-0031-186.2.274","DOIUrl":"https://doi.org/10.1674/0003-0031-186.2.274","url":null,"abstract":"Abstract. This case study seeks to fill a critical knowledge gap regarding how natural wind disturbance affects stand and seedling bank diversity in mixed northern hardwood forests managed by single tree selection harvest methods. Contemporary timber harvests on state managed lands in Michigan's Upper Peninsula employ single tree selection cutting methods to promote more complex age structure in second growth stands dominated by sugar maple (Acer saccharum). However, concern exists that single tree selection harvest may result in lowered compositional diversity of seedlings as the low light conditions of small dispersed gaps exclude less shade tolerant species from gap regeneration. In July 2016 severe thunderstorms with winds in excess of 145 km/h (90 mph) caused extensive tree fall and canopy gap creation in second growth mixed northern hardwood forests in the southern Keweenaw Peninsula. We measured the species composition of overstory tree mortality and understory seedling regeneration in 14 storm gaps created in stands with and without previous single tree selection harvest. Storm gaps ranged in size from 125 to 1100 m2. American basswood (Tilia americana) was disproportionately wind-thrown. Robust seedling regeneration was released in all storm gaps, with sugar maple comprising more than 75% of mean seedling abundance, regardless of previous single tree selection harvest. Sugar maple and ironwood (Ostrya virginiana) comprised 80% of sapling abundance. Results indicate single tree selection of mixed northern hardwood stands does not exacerbate, but rather emulates, dense sugar maple regeneration found on unmanaged second growth sites.","PeriodicalId":50802,"journal":{"name":"American Midland Naturalist","volume":null,"pages":null},"PeriodicalIF":0.6,"publicationDate":"2021-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43870646","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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