American Midland Naturalist最新文献

{"title":"Mercury Contamination of Fish and Their Prey Across a Riverine Food Web","authors":"Beth N. Tweedy, B. Sansom, C. Vaughn","doi":"10.1674/0003-0031-188.2.234","DOIUrl":"https://doi.org/10.1674/0003-0031-188.2.234","url":null,"abstract":"Abstract. Lakes and reservoirs are frequently monitored by researchers for elevated mercury concentrations in sportfish. Rivers and streams, especially those of smaller orders, are less frequently monitored for mercury contamination and nonsport fishes and invertebrates, although important components of the food web, are rarely examined. We addressed this gap by surveying mercury levels in a stream community in the Kiamichi River in southeastern Oklahoma, U.S., by sampling fish and macroinvertebrates at ten sites in the river. We found elevated levels of mercury across taxa within the river including individuals of smallmouth bass populations 10–25 cm in length having concentrations (2986 ± 1053 ng/g dry weight) above the U.S. Environmental Protection Agency human limit. Furthermore, we observed high concentrations in darters and logperch (1133 ± 464 ng/g dry weight), nonsport fishes found predominantly in rivers and streams. Our results indicate mercury contamination can reach elevated concentrations in rivers and stream food webs, posing risks to both humans and wildlife.","PeriodicalId":50802,"journal":{"name":"American Midland Naturalist","volume":null,"pages":null},"PeriodicalIF":0.6,"publicationDate":"2022-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48070253","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}

{"title":"Biological Correlates with Degree of Introgressive Hybridization between Coyotes Canis latrans and Wolves Canis sp. in Pennsylvania, U.S.A.","authors":"Erin Pfeffer, Kelsey Barth, Lucas Bitsko, Natalie Gibson, Kim Roth, Eric M. Butler, U. Ramakrishnan, V. Buonaccorsi","doi":"10.1674/0003-0031-188.2.199","DOIUrl":"https://doi.org/10.1674/0003-0031-188.2.199","url":null,"abstract":"Abstract. Descendants of introgressive hybridization between species may have evolutionary advantages over their parental species. Prior studies have documented evidence of introgressive hybridization between coyotes, dogs, grey wolves and eastern wolves. This study attempts to attribute morphology and pelage patterns of Pennsylvania coyotes to sex, ecoregion, and the degree of coyote-wolf introgressive hybridization. A total of 192 coyotes were genotyped at 63 ancestry informative SNPS to determine the percent of coyote genome attributable to wolf origin (percent wolf). Females had higher percent wolf than males, which could be the result of lower survivorship in hybrid males. Percent wolf, sex, and ecoregion each were found to independently influence size using general linear model analysis, and the effect of sex was most pronounced. Coyotes from Northeastern and northcentral ecoregions of Pennsylvania were larger in size and possessed a higher percent wolf. Moreover, coyotes with higher percent wolf were larger, less red in some parts of their pelage, and had a different pelage patchiness composition. This correlates with previous studies that showed ecoregions with increased deer density correlated to coyotes with higher percent wolf. Size and percent wolf may be adaptively advantageous in Northeastern Pennsylvania where there is a relatively high deer population abundance. Furthermore, the degree of redness within coyotes may be used as an indicator for introgression levels for population managers, aiding in understanding the shifting ecological role of coyotes.","PeriodicalId":50802,"journal":{"name":"American Midland Naturalist","volume":null,"pages":null},"PeriodicalIF":0.6,"publicationDate":"2022-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44004631","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}

{"title":"Seasonal Amphibian Species Richness and Population Fluctuations at Powdermill Nature Reserve, Pennsylvania, U.S.A.","authors":"Amanda K. Martin, J. Sheridan","doi":"10.1674/0003-0031-188.2.212","DOIUrl":"https://doi.org/10.1674/0003-0031-188.2.212","url":null,"abstract":"Abstract. Amphibians are a highly vulnerable taxonomic group that have suffered population declines worldwide. As amphibians serve critical links between trophic levels and facilitate nutrient recycling, it is critical to understand how their species richness, abundance, and phenology shift over time. Because amphibian populations naturally fluctuate, short-term monitoring can provide insight into how amphibian communities respond to proximate changes in weather conditions, which is helpful for predicting long-term responses to climate change. We used pitfall traps to examine interannual variation of the amphibian community at Powdermill Nature Reserve (PNR) in Pennsylvania during 2020–2021 to provide critical details for future long-term monitoring. Mean monthly temperature and precipitation did not vary significantly between years, but monthly captures per sampling effort declined and monthly biomass per sampling effort increased from 2020 to 2021. Despite a lack of significant relationships between total amphibian captures and temperature and precipitation, peak abundance shifted earlier, and individuals were larger in 2021 compared to 2020. Interestingly, individual species biomass was predicted by an interaction between temperature and precipitation, suggesting individual species will vary in vulnerability to climate change, but the amphibian community as a whole at PNR is resilient to minor fluctuations in temperature and precipitation.","PeriodicalId":50802,"journal":{"name":"American Midland Naturalist","volume":null,"pages":null},"PeriodicalIF":0.6,"publicationDate":"2022-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49281487","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}

{"title":"A Multi-year Adult Emergence Study of the Cicada Neotibicen canicularis (Harris) (Hemiptera: Cicadidae) in Wisconsin","authors":"A. Young, Aiden S. Mahoney, Jason Canfield","doi":"10.1674/0003-0031-188.2.250","DOIUrl":"https://doi.org/10.1674/0003-0031-188.2.250","url":null,"abstract":"Abstract. Based on daily collections of final instar exuviae, the widespread annual cicada adult emergence of Neotibicen canicularis (Harris) (Hemiptera: Cicadidae) was studied in southeastern Wisconsin in a combined plot containing 15 mature trees and suburban lawns for seven successive years and in a separate plot of two trees for four years. The daily numbers of males and females were recorded. Over the entire seven years of the 15-tree plot, total female and male exuviae were equal, a summative 50:50 ratio. However, there was considerable deviation from this ratio three of the seven years. More females than males eclosed in the first two years and more males eclosed in the final year, yet the overall trend was for females to eclose later than males for the entire seven-year study of the 15-tree plot, with many more females emerging in the last twenty plus days. Although ambient temperatures varied over the study (cooler in the first two years and warmer later), they did not have any discernible effect on the timing of female and male eclosions. The overall annual emergence period was 56.7 (se 4.48) d for a seven-year total of 2967 exuviae, with the annual average emergence being 437.6 (se 34.6) per year. The average density of exuviae, an estimate of the emerging adult population, was 1.3 ± 0.09 (se) per m2. In the separate two-tree plot, a greater number of males emerged than females for all four years. ARISTOTLE ADVISES: “Male cicadas are tastier when young, but the females are preferable later when they are full of eggs.”","PeriodicalId":50802,"journal":{"name":"American Midland Naturalist","volume":null,"pages":null},"PeriodicalIF":0.6,"publicationDate":"2022-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42655684","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}

{"title":"Five-Year Effects of Introduced Mountain Goats and Recreation on Plant Communities and Species of Conservation Concern in an Alpine Sky Island","authors":"J. Chambers, Barb Smith, L. Baggett","doi":"10.1674/0003-0031-188.2.177","DOIUrl":"https://doi.org/10.1674/0003-0031-188.2.177","url":null,"abstract":"Abstract. Alpine ecosystems in the arid southwestern United States are vulnerable to climate change. Many of these ecosystems are experiencing increased recreational use and introductions of nonindigenous ungulates. In the La Sal Mountains of southeastern Utah, alpine plant communities support an endemic plant species, Erigeron mancus, 11 plant and two animal species of conservation concern, and a United States Department of Agriculture (USDA) Forest Service Research Natural Area. Nonindigenous mountain goats (Oreamnos americanus) were introduced by the Utah Division of Wildlife Resources (UDWR) in 2013 and 2014, and recreational use has increased in the intervening period. To evaluate potential effects of mountain goat and recreational use, vegetation monitoring was initiated by the USDA Forest Service in 2016. We used 5 y monitoring data (2016–2020) and generalized linear mixed models to analyze the separate and interacting effects of year, recreational use, and mountain goat use on: (1) populations of plant species of conservation concern; (2) vascular and nonvascular plant cover; and (3) ground cover. Our analyses revealed decreases in proportional frequency of E. mancus at the end of the monitoring. Proportional cover of dominant plant growth forms, especially forbs, declined, while proportional cover of litter and ineffective ground cover (bare soil and pavement) increased. Recreational or goat use were a factor in several of the observed changes, although weather and climate likely also influenced the results. Management complexity arises because of the different missions of USDA Forest Service and UDWR, but adjustments in mountain goat numbers and recreational use may be needed to maintain ecologically resilient ecosystems. Continued monitoring can provide the basis for adaptive management.","PeriodicalId":50802,"journal":{"name":"American Midland Naturalist","volume":null,"pages":null},"PeriodicalIF":0.6,"publicationDate":"2022-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44237980","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}

{"title":"Observations on the Fall Movements of Isabella Moth Larvae (Lepidoptera: Erebidae: Arctiinae) in Northwest Missouri","authors":"Kurt A. Haberyan","doi":"10.1674/0003-0031-188.2.244","DOIUrl":"https://doi.org/10.1674/0003-0031-188.2.244","url":null,"abstract":"Abstract. Despite their visibility, abundance, and widespread distribution, the movements of Isabella moth larvae (a.k.a “woolly worms:” Pyrrharctia isabella (J.E. Smith); Lepidoptera: Erebidae: Arctiinae) have been poorly studied. We observed these larvae to assess the relationship between their movement and local environmental conditions. Twice each day for 83 d, nearly 52 km of highway were observed in northwest Missouri. A total of 264 larvae were encountered during 664 total visits to four road sections, peaking in the first week of October. Analyses revealed increased larva abundance (n ≥ 159 road-section visits) associated with temperature, wind speed, pale pavement tint, and afternoon time-of-day. The best overall model to explain larval movement patterns, based on 163 visits and all measured conditions, incorporated temperature, north wind speed, west wind speed, and humidity (P = 0.015), but no other factors. In addition, larvae showed a significant tendency to travel in the same direction as the wind, and to travel eastward in the afternoons. These observations provide insights into the fall movements of a common larva, and provide directions for future research.","PeriodicalId":50802,"journal":{"name":"American Midland Naturalist","volume":null,"pages":null},"PeriodicalIF":0.6,"publicationDate":"2022-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49638729","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}

{"title":"Drivers of Southern Flying Squirrel (Glaucomys volans) Aggregation Size in South Carolina, U.S.A.","authors":"Anna C. Doty, M. Connior, T. Risch","doi":"10.1674/0003-0031-188.1.20","DOIUrl":"https://doi.org/10.1674/0003-0031-188.1.20","url":null,"abstract":"Abstract. Although it is known that southern flying squirrels (Glaucomys volans) nest in larger groups to offset the energetic costs of low temperatures, the influence of other variables on aggregation size remains relatively unknown. Therefore, the influence of environmental variables and individual characteristics of G. volans on nest box aggregation size was studied from 1992–1998 at the Savannah River Site in South Carolina. Over the study period, 5859 occupied boxes were observed, representing 11,238 captures and 2671 unique individuals. The majority of occupied boxes (60.3%) contained solitary individuals, while 26.1% contained aggregations (≥2 individuals) of adult and/or subadult individuals and 13.6% contained litters. Although ambient temperature is widely believed to be the most important variable influencing aggregation size of G. volans, the final model explaining nest aggregation size for G. volans included not only minimum daily ambient temperature, but also Julian date and individual G. volans characteristics of sex, age, and reproductive status. Minimum ambient temperature was inversely related to aggregation size, with larger aggregation sizes associated with winter months, although aggregation size sharply increased between the months of Aug.–Sept. The retention of Julian date in the final model, in addition to minimum ambient temperature, indicates that behavioral shifts due to seasonal changes, independent of temperature, should be considered. Nestlings were associated with larger aggregation sizes, as were inactive and lactating females and inactive males. However, sex alone did not significantly contribute to the final model. This study demonstrates that in addition to temperature, there are a suite of predictors of nest aggregation size for G. volans that should be considered when evaluating nest box occupancy for this species.","PeriodicalId":50802,"journal":{"name":"American Midland Naturalist","volume":null,"pages":null},"PeriodicalIF":0.6,"publicationDate":"2022-08-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41796501","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}

{"title":"Oxbow Restorations for Topeka Shiner (Notropis topeka) Recovery: Defining Success","authors":"Dylan M. Osterhaus, S. S. Leberg, C. L. Pierce, T. W. Stewart, Audrey L. McCombs","doi":"10.1674/0003-0031-188.1.56","DOIUrl":"https://doi.org/10.1674/0003-0031-188.1.56","url":null,"abstract":"Abstract. Within the Great Plains region of North America, oxbow wetlands were lost as streams were channelized and straightened to allow for agricultural use of the landscape. Topeka Shiner, which rely on these oxbow wetlands, have declined in abundance, currently occupy 20% of their historical geographic range, and are now an endangered species. A large emphasis has been placed on restoring oxbow wetlands to recover Topeka Shiner populations. As the number of oxbow restorations has increased, so has the number of monitoring projects focused on these habitats. Currently, conservation practitioners rely on the presence of Topeka Shiner to determine the success of an oxbow restoration. Given the rarity of the species, this method is likely ineffective. Within this study we attempt to create a model that can be used to determine the success of an oxbow restoration that will benefit the Topeka Shiner without relying on the presence of the species in the wetland. We used multiple fish community metrics and modelling strategies to determine the best model for predicting Topeka Shiner CPUE and presence/absence within oxbows. We determined that the top models were ineffective at predicting Topeka Shiner CPUE and presence/absence. Our findings illustrate the random nature by which fish communities become established within oxbows, and the island-like nature of oxbows in terms of how fish communities may become established and change over time. These findings indicate that the success of oxbow restoration for Topeka Shiner needs to be defined at a larger scale than for individual oxbows. Furthermore, our findings corroborate the inability of previous studies to determine reproducible associations of Topeka Shiner with various fish community metrics.","PeriodicalId":50802,"journal":{"name":"American Midland Naturalist","volume":null,"pages":null},"PeriodicalIF":0.6,"publicationDate":"2022-08-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46979439","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}

{"title":"An Assessment of Prairie Management Practices for Maintaining Habitat Quality for the Endangered Poweshiek Skipperling Butterfly in Canada","authors":"Jaimée Dupont-Morozoff, R. Westwood, Justis Henault","doi":"10.1674/0003-0031-188.1.74","DOIUrl":"https://doi.org/10.1674/0003-0031-188.1.74","url":null,"abstract":"Abstract. The Poweshiek skipperling (Oarisma poweshiek) was once a common prairie butterfly in central North America, but is now critically endangered in Canada and the United States. The Poweshiek skipperling is confined to the largest remaining tall grass prairie in Canada, which is currently managed using grazing and fire to maintain prairie habitat and prevent forest and shrub encroachment. To support re-introduction, restocking, and recovery of this critically endangered species, it is necessary to understand the habitat conditions preferred by skipperlings. By surveying prairie sites with Poweshiek skipperling across age and treatment categories (1–2 y since burn, 4–6 y since burn, >15 y since burn, and grazing), we identified commonly-used nectar plants and recorded physical variables known to influence plant diversity. We measured soil variables, including macronutrients, compaction, pH, texture, and moisture content, and used multivariate statistics to test for significant differences in site characteristics and plant community across treatments. For each site, we captured plant diversity, abundance, and cover, as well as total plant biomass. We found the oldest burn sites had the fewest skipperlings. Intermediate burn sites and lightly grazed sites contained the most skipperlings. In 95% of nectaring observations, adult skipperlings were feeding on Black-eyed Susan (Rudbeckia hirta), upland white aster (Solidago ptarmicoides), and Self-heal (Prunella vulgaris). Characteristics in the physical components of sites and plant communities did not significantly differ across treatment types for most variables with the exception of the oldest burns, which showed significantly higher levels of soil compaction, live biomass, bare ground, less flowering species during the flight period, less flowering stems, and increased presence of nonnative and invasive species. Poweshiek skipperling is at high risk of imminent extirpation, and we recommend that the management regimes be adjusted to plan for a consistent supply of habitat conditions and plant species composition exemplified by our intermediate burn sites. We suggest fire return intervals of 4–6 y using patch burns in combination with grazing, permitted at times that minimize the impact on immature stages of Poweshiek skipperling. This management is needed to provide suitable habitat conditions to maintain the current population and allow for successful restocking and recovery.","PeriodicalId":50802,"journal":{"name":"American Midland Naturalist","volume":null,"pages":null},"PeriodicalIF":0.6,"publicationDate":"2022-08-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45708133","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}

{"title":"Eastern Spotted Skunks Alter Nightly Activity and Movement in Response to Environmental Conditions","authors":"Kassandra J. Arts, M. K. Hudson, Nicholas W. Sharp, A. Edelman","doi":"10.1674/0003-0031-188.1.33","DOIUrl":"https://doi.org/10.1674/0003-0031-188.1.33","url":null,"abstract":"Abstract. Daily and seasonal fluctuations in environmental conditions can significantly impact the survivorship and reproductive success of animals by altering energetic costs and predation risks. Behaviorally, animals often respond to changes in their environment through regulation of activity and associated movement patterns. We used accelerometer-informed GPS telemetry to assess nightly activity and movement patterns in response to environmental conditions in a small endotherm, the eastern spotted skunk (Spilogale putorius). Nightly movements and activity of skunks were monitored in association with ambient temperature, precipitation, and moon illumination during late winter through summer in Alabama. Eastern spotted skunks were strictly nocturnal, exhibiting almost no daytime activity. Total time active and total distance moved each night increased with ambient temperature and rainfall. Variation in moon illumination, which may affect predation risk, did not impact skunk nightly activity or movement. Eastern spotted skunks likely reduce predation risk by being active between sunset and sunrise when they are less visible to predators. Lower activity and movement at cooler temperatures significantly reduces thermoregulatory costs for small endotherms. Increased activity of skunks during or shortly after precipitation may be driven by increased prey availability. Our findings indicate that small endotherms, like the eastern spotted skunk, rely extensively on behavioral thermoregulation, instead of physiological adaptation, to buffer themselves against changing environmental conditions. Behavioral flexibility may promote species persistence as climate changes, and should be considered in conservation strategies of vulnerable species, such as eastern spotted skunks.","PeriodicalId":50802,"journal":{"name":"American Midland Naturalist","volume":null,"pages":null},"PeriodicalIF":0.6,"publicationDate":"2022-08-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42868914","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}