Abstract. Scavenging appears to be a conserved but flexible characteristic among spiders. Although scavenging behavior is well documented in captivity, observations in the wild are rarely witnessed. During a road ecology survey on 6 September 2021, I observed an adult male desert blonde tarantula (Aphonopelma chalcodes) scavenging upon a roadkilled neonate western diamond-backed rattlesnake (Crotalus atrox). The tarantula did not react defensively to my slow approach, and I observed its chelicerae working into the snake's soft tissue. Observations of theraphosids scavenging are quite rare, and this may be the first reported instance of tarantula scavenging upon a reptilian carcass.
{"title":"Scavenging of Western Diamond-Backed Rattlesnake (Crotalus atrox) by Desert Blonde Tarantula (Aphonopelma chalcodes) in Arizona","authors":"Brian R. Blais","doi":"10.3398/064.082.0123","DOIUrl":"https://doi.org/10.3398/064.082.0123","url":null,"abstract":"Abstract. Scavenging appears to be a conserved but flexible characteristic among spiders. Although scavenging behavior is well documented in captivity, observations in the wild are rarely witnessed. During a road ecology survey on 6 September 2021, I observed an adult male desert blonde tarantula (Aphonopelma chalcodes) scavenging upon a roadkilled neonate western diamond-backed rattlesnake (Crotalus atrox). The tarantula did not react defensively to my slow approach, and I observed its chelicerae working into the snake's soft tissue. Observations of theraphosids scavenging are quite rare, and this may be the first reported instance of tarantula scavenging upon a reptilian carcass.","PeriodicalId":49364,"journal":{"name":"Western North American Naturalist","volume":"1 1","pages":"208 - 210"},"PeriodicalIF":0.6,"publicationDate":"2022-03-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75976880","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}
J. P. Esparza-Carlos, P. C. Hernández-Romero, Jaime Antonio Escoto Moreno
Abstract. The neotropical otter (Lontra longicaudis) is associated with freshwater systems and is generally found at elevations lower than 1500 masl. Its diet is based on fish and crustaceans. We present 3 photorecords of the neotropical otter at the divide between 2 hydrological basins in the Sierra de Manantlán Biosphere Reserve, Jalisco, México. The photos were taken at an altitude near 2000 masl, and one of them was >600 m from a water source. The area does not present optimal conditions for the presence of otter since water flows are low, fish are absent, and crustaceans are scarce. These records are evidence of the neotropical otter at high altitude in environments where conditions are suboptimal for the species. In addition, the importance of conserving the basin headwaters is discussed, since the headwaters can support movement or occasional stays of the neotropical otter in marginal habitat and thereby maintain the connectivity between basins and facilitate genetic exchange between otter populations.
{"title":"Presence of Neotropical Otter (Lontra longicaudis) at High Elevation between Watersheds","authors":"J. P. Esparza-Carlos, P. C. Hernández-Romero, Jaime Antonio Escoto Moreno","doi":"10.3398/064.082.0116","DOIUrl":"https://doi.org/10.3398/064.082.0116","url":null,"abstract":"Abstract. The neotropical otter (Lontra longicaudis) is associated with freshwater systems and is generally found at elevations lower than 1500 masl. Its diet is based on fish and crustaceans. We present 3 photorecords of the neotropical otter at the divide between 2 hydrological basins in the Sierra de Manantlán Biosphere Reserve, Jalisco, México. The photos were taken at an altitude near 2000 masl, and one of them was >600 m from a water source. The area does not present optimal conditions for the presence of otter since water flows are low, fish are absent, and crustaceans are scarce. These records are evidence of the neotropical otter at high altitude in environments where conditions are suboptimal for the species. In addition, the importance of conserving the basin headwaters is discussed, since the headwaters can support movement or occasional stays of the neotropical otter in marginal habitat and thereby maintain the connectivity between basins and facilitate genetic exchange between otter populations.","PeriodicalId":49364,"journal":{"name":"Western North American Naturalist","volume":"44 1","pages":"167 - 173"},"PeriodicalIF":0.6,"publicationDate":"2022-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87321968","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}
Nicole A. Deatherage, B. Cypher, Tory L. Westall, Erica C. Kelly
Abstract. The federally endangered and California State–threatened San Joaquin kit fox (Vulpes macrotis mutica) forms an ecological guild with coyotes (Canis latrans), red foxes (V. vulpes), gray foxes (Urocyon cinereoargenteus), and domestic dogs (C. familiaris) in the city of Bakersfield, California, USA. Where these species are sympatric in natural environments, interference competition occurs, resulting in spatiotemporal avoidance or changes in behavior to avoid conflict. We analyzed camera survey data from 2015 to 2019 from 111 1-km2 grid cells throughout Bakersfield to investigate spatial associations between San Joaquin kit foxes and canid competitors, as well as differences in temporal activity of kit foxes in the presence of a canid competitor. We found that kit foxes typically did not occur with other canids on a daily, yearly, or 5-year scale. In cells where other canids were immediately present, kit foxes altered their temporal activity to avoid other canids by appearing 3 h later and exhibited less variance in the amount of time spent at a camera trap. Thus, although kit foxes share the urban habitat with multiple larger competitors, they likely use spatial and temporal partitioning to reduce risk and facilitate coexistence.
{"title":"Spatiotemporal Patterns of San Joaquin Kit Foxes and an Urban Canid Guild","authors":"Nicole A. Deatherage, B. Cypher, Tory L. Westall, Erica C. Kelly","doi":"10.3398/064.082.0103","DOIUrl":"https://doi.org/10.3398/064.082.0103","url":null,"abstract":"Abstract. The federally endangered and California State–threatened San Joaquin kit fox (Vulpes macrotis mutica) forms an ecological guild with coyotes (Canis latrans), red foxes (V. vulpes), gray foxes (Urocyon cinereoargenteus), and domestic dogs (C. familiaris) in the city of Bakersfield, California, USA. Where these species are sympatric in natural environments, interference competition occurs, resulting in spatiotemporal avoidance or changes in behavior to avoid conflict. We analyzed camera survey data from 2015 to 2019 from 111 1-km2 grid cells throughout Bakersfield to investigate spatial associations between San Joaquin kit foxes and canid competitors, as well as differences in temporal activity of kit foxes in the presence of a canid competitor. We found that kit foxes typically did not occur with other canids on a daily, yearly, or 5-year scale. In cells where other canids were immediately present, kit foxes altered their temporal activity to avoid other canids by appearing 3 h later and exhibited less variance in the amount of time spent at a camera trap. Thus, although kit foxes share the urban habitat with multiple larger competitors, they likely use spatial and temporal partitioning to reduce risk and facilitate coexistence.","PeriodicalId":49364,"journal":{"name":"Western North American Naturalist","volume":"20 1","pages":"24 - 35"},"PeriodicalIF":0.6,"publicationDate":"2022-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89928316","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}
Abstract. Cutthroat trout Oncorhynchus clarkii × rainbow trout O. mykiss hybrids (hereafter hybrids) are difficult to visually distinguish from parental taxa, yet identifying phenotypic traits to separate hybrids from cutthroat trout is needed for conservation and management purposes. We compared phenotypic characteristics against genotype (using 34 species-diagnostic single nucleotide polymorphism loci) for 316 Bonneville cutthroat trout O. clarkii utah, rainbow trout and hybrids in Bear River tributaries. Our phenotypic classifications of fish were 91% accurate for Bonneville cutthroat trout but only 68% accurate for rainbow trout and hybrids combined. Classification errors based on phenotype were observed between parental taxa and hybrids but not between cutthroat trout and rainbow trout. The most useful phenotypic traits for distinguishing Bonneville cutthroat trout from hybrids were the absence of a white leading edge on the pelvic fin, the presence of fewer than 7 spots on the top of the head, and the presence of a prominent throat slash. The degree of hybridization in individual hybrids was associated with the number of spots on the top of their head. However, 16% of >F1 hybrids with a higher proportion of cutthroat trout ancestry and 6% of F1 hybrids exhibited all the phenotypic characteristics of cutthroat trout. The ability to visually detect admixture in hybrids was not related to fish length but was related to admixture level, with logistic regression model results predicting that, for individual hybrids when the proportion of alleles assigned to rainbow trout was >18% (95% CI, 11% to 26%), biologists were more than 50% likely to visually detect O. mykiss traits. While we encourage the use of genetic-based assessments for Bonneville cutthroat trout populations when feasible, our results suggest that phenotypic traits can assist in identifying hybridized populations and hybrid individuals, which will benefit the management and conservation of this species. However, our study included Bonneville cutthroat trout from only the Bear River basin, and further work is needed from the southern portion of the subspecies' range to support or refute our findings.
摘要克拉氏Oncorhynchus clarkii × O. mykiss虹鳟鱼杂种(以下简称杂种)很难从亲本分类群中进行视觉区分，但为了保护和管理，需要通过表型性状的鉴定来区分杂种。利用34个物种诊断性单核苷酸多态性位点，对熊河支流316条犹他州克拉基博纳维尔切喉鳟鱼、虹鳟鱼和杂交鳟鱼的表型特征与基因型进行了比较。我们的鱼类表型分类对博纳维尔切喉鳟鱼的准确率为91%，但对虹鳟和杂交鳟鱼的准确率仅为68%。在亲本分类群和杂交分类群之间存在基于表型的分类误差，而在切喉鳟鱼和虹鳟之间没有基于表型的分类误差。区分博纳维尔切喉鳟鱼和杂交种最有用的表型特征是腹鳍上没有白色前缘，头顶上有少于7个斑点，喉咙上有明显的切口。杂交个体的杂交程度与它们头顶上的斑点数量有关。然而，16%具有较高切喉鳟鱼血统的>F1杂交种和6%的F1杂交种表现出切喉鳟鱼的所有表型特征。在杂交品种中，视觉检测外源性的能力与鱼的长度无关，而与外源性水平有关，逻辑回归模型结果预测，当分配给虹鳟的等位基因比例为0.18% (95% CI, 11%至26%)时，生物学家视觉检测O. mykiss性状的可能性超过50%。虽然我们鼓励在可行的情况下对博纳维尔切喉鳟鱼种群进行基于遗传的评估，但我们的研究结果表明，表型性状可以帮助鉴定杂交种群和杂交个体，这将有利于该物种的管理和保护。然而，我们的研究只包括了熊河流域的博纳维尔切喉鳟鱼，需要在亚种范围的南部进行进一步的工作来支持或反驳我们的发现。
{"title":"Detecting Rainbow Trout Introgression in Bonneville Cutthroat Trout of the Bear River Basin Using Field-Based Phenotypic Characteristics","authors":"K. Meyer, Ryan W. Hillyard, M. Campbell","doi":"10.3398/064.082.0111","DOIUrl":"https://doi.org/10.3398/064.082.0111","url":null,"abstract":"Abstract. Cutthroat trout Oncorhynchus clarkii × rainbow trout O. mykiss hybrids (hereafter hybrids) are difficult to visually distinguish from parental taxa, yet identifying phenotypic traits to separate hybrids from cutthroat trout is needed for conservation and management purposes. We compared phenotypic characteristics against genotype (using 34 species-diagnostic single nucleotide polymorphism loci) for 316 Bonneville cutthroat trout O. clarkii utah, rainbow trout and hybrids in Bear River tributaries. Our phenotypic classifications of fish were 91% accurate for Bonneville cutthroat trout but only 68% accurate for rainbow trout and hybrids combined. Classification errors based on phenotype were observed between parental taxa and hybrids but not between cutthroat trout and rainbow trout. The most useful phenotypic traits for distinguishing Bonneville cutthroat trout from hybrids were the absence of a white leading edge on the pelvic fin, the presence of fewer than 7 spots on the top of the head, and the presence of a prominent throat slash. The degree of hybridization in individual hybrids was associated with the number of spots on the top of their head. However, 16% of >F1 hybrids with a higher proportion of cutthroat trout ancestry and 6% of F1 hybrids exhibited all the phenotypic characteristics of cutthroat trout. The ability to visually detect admixture in hybrids was not related to fish length but was related to admixture level, with logistic regression model results predicting that, for individual hybrids when the proportion of alleles assigned to rainbow trout was >18% (95% CI, 11% to 26%), biologists were more than 50% likely to visually detect O. mykiss traits. While we encourage the use of genetic-based assessments for Bonneville cutthroat trout populations when feasible, our results suggest that phenotypic traits can assist in identifying hybridized populations and hybrid individuals, which will benefit the management and conservation of this species. However, our study included Bonneville cutthroat trout from only the Bear River basin, and further work is needed from the southern portion of the subspecies' range to support or refute our findings.","PeriodicalId":49364,"journal":{"name":"Western North American Naturalist","volume":"40 1","pages":"117 - 127"},"PeriodicalIF":0.6,"publicationDate":"2022-03-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90079248","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}
Jeff Clerc, Elizabeth J. Rogers, Emma L Kunkel, Nathan W. Fuller
Abstract. The mating behavior of North American tree bats (Lasiurus spp. and Lasionycteris noctivagans) is not well understood. The majority of records suggest that this group of species mates during the autumn migratory period and that females store sperm throughout the winter before resuming the reproductive cycle in spring. On 16 May 2019, while mist-netting in Bernalillo County, New Mexico, USA, we observed a male and female silver-haired bat (Lasionycteris noctivagans) copulating on the ground. Both individuals were captured and processed to obtain further details on reproductive status. To our knowledge this is the first published record of a silver-haired bat copulation event, and its occurrence during the spring migratory period challenges long-held assumptions about the reproductive cycle of the species and tree bats in general.
{"title":"An Observation of Spring Mating in Silver-Haired Bats (Lasionycteris noctivagans)","authors":"Jeff Clerc, Elizabeth J. Rogers, Emma L Kunkel, Nathan W. Fuller","doi":"10.3398/064.082.0117","DOIUrl":"https://doi.org/10.3398/064.082.0117","url":null,"abstract":"Abstract. The mating behavior of North American tree bats (Lasiurus spp. and Lasionycteris noctivagans) is not well understood. The majority of records suggest that this group of species mates during the autumn migratory period and that females store sperm throughout the winter before resuming the reproductive cycle in spring. On 16 May 2019, while mist-netting in Bernalillo County, New Mexico, USA, we observed a male and female silver-haired bat (Lasionycteris noctivagans) copulating on the ground. Both individuals were captured and processed to obtain further details on reproductive status. To our knowledge this is the first published record of a silver-haired bat copulation event, and its occurrence during the spring migratory period challenges long-held assumptions about the reproductive cycle of the species and tree bats in general.","PeriodicalId":49364,"journal":{"name":"Western North American Naturalist","volume":"15 1","pages":"174 - 176"},"PeriodicalIF":0.6,"publicationDate":"2022-03-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80239545","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}
Abstract. Desert rodents in the western USA cache enormous numbers of seeds. Seed caches represent a reliable, although highly variable, source of seedling recruitment for numerous desert plants. Prefire caching of refractory seeds (i.e., those capable of forming persistent seed banks) is an important source of postfire seedling recruitment, but it is likely that prefire caches of short-lived seeds also may contribute to postfire regeneration. The primary objective of this study was to quantify seedling recruitment from artificial caches of 2 species with short-lived seeds planted after a stand-replacing wildfire in a singleleaf pinyon (Pinus monophylla) forest. I investigated the survival of 180 artificial caches of Yucca brevifolia and Prunus fasciculata. Caches were composed of 2, 4, or 8 seeds. Also, because soils of the burned area have unusually high coarse fragment volumes (59%), I examined, in greenhouse trials, how soil coarse fragment volumes (CFVs) impacted seedling establishment of these 2 species from caches. In greenhouse trials, the number of P. fasciculata seedlings increased with increasing CFVs. In contrast, Y. brevifolia seedling numbers decreased with increasing CFVs. In field transects, 17% of cached P. fasciculata seeds produced seedlings, whereas 12% of Y. brevifolia seeds recruited seedlings in the first year postfire. The advantage of P. fasciculata in greenhouse CFV trials was not replicated in field seedling recruitment. Seedling mortality over the first 3 years postfire was not statistically different among the 3 cache sizes for either species, nor did seedling sizes differ significantly by cache size and survey date. I conclude that, although the overall recruitment from postfire caches was low (12%–17%), prefire caches of short-lived seeds probably recruit postfire seedlings, but only in specific circumstances.
{"title":"Postfire Seedling Establishment of Desert Peach (Prunus fasciculata) and Joshua Tree (Yucca brevifolia) from Simulated Seed Caches in the Mojave Desert","authors":"M. Borchert","doi":"10.3398/064.082.0110","DOIUrl":"https://doi.org/10.3398/064.082.0110","url":null,"abstract":"Abstract. Desert rodents in the western USA cache enormous numbers of seeds. Seed caches represent a reliable, although highly variable, source of seedling recruitment for numerous desert plants. Prefire caching of refractory seeds (i.e., those capable of forming persistent seed banks) is an important source of postfire seedling recruitment, but it is likely that prefire caches of short-lived seeds also may contribute to postfire regeneration. The primary objective of this study was to quantify seedling recruitment from artificial caches of 2 species with short-lived seeds planted after a stand-replacing wildfire in a singleleaf pinyon (Pinus monophylla) forest. I investigated the survival of 180 artificial caches of Yucca brevifolia and Prunus fasciculata. Caches were composed of 2, 4, or 8 seeds. Also, because soils of the burned area have unusually high coarse fragment volumes (59%), I examined, in greenhouse trials, how soil coarse fragment volumes (CFVs) impacted seedling establishment of these 2 species from caches. In greenhouse trials, the number of P. fasciculata seedlings increased with increasing CFVs. In contrast, Y. brevifolia seedling numbers decreased with increasing CFVs. In field transects, 17% of cached P. fasciculata seeds produced seedlings, whereas 12% of Y. brevifolia seeds recruited seedlings in the first year postfire. The advantage of P. fasciculata in greenhouse CFV trials was not replicated in field seedling recruitment. Seedling mortality over the first 3 years postfire was not statistically different among the 3 cache sizes for either species, nor did seedling sizes differ significantly by cache size and survey date. I conclude that, although the overall recruitment from postfire caches was low (12%–17%), prefire caches of short-lived seeds probably recruit postfire seedlings, but only in specific circumstances.","PeriodicalId":49364,"journal":{"name":"Western North American Naturalist","volume":"26 1","pages":"107 - 116"},"PeriodicalIF":0.6,"publicationDate":"2022-03-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77812939","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}
Abstract. Social wasps play critical ecological roles in an ecosystem, providing a diversity of services and some disservices. Yellowjacket wasps (Vespula spp.) in particular are well known for shaping arthropod communities via predation and competition for resources. In part due to their sociality and large colony sizes, Vespula can have a profound ecological impact on local communities. Such effects can be magnified when colonies exhibit a perennial life history, in which a colony will overwinter, persist for more than one year, and become orders of magnitude larger in size compared to typical annual colonies. Despite growing interest in the factors that influence colony success, we currently lack the ability to predict when yellowjackets may have a high-abundance or outbreak year. This highlights the need for a critical understanding of the phenological patterns of foraging activity, colony distribution, and senescence. Here, we quantify the seasonal activity and foraging rates of 123 colonies of the western yellowjacket, V. pensylvanica, in its native range over 4 consecutive years. Average colony longevity was about 1 month longer than previously reported for this species, and colonies with later peaks in activity and higher average traffic rates persisted longer into the winter. Longer-lived colonies tended to cluster together within a year, but not between years. We found 3 perennial colonies (2.4% of all colonies), and they exhibited tenfold higher peak traffic rates compared to annual colonies. By identifying temporal and spatial patterns in survivorship and colony longevity, we gain insight into the factors associated with prolonged survival time and increased likelihood of overwintering in yellowjacket wasps.
{"title":"Seasonal Phenology and Colony Longevity Patterns in a Predatory Social Wasp","authors":"David T. Rankin, K. Loope, E. Wilson-Rankin","doi":"10.3398/064.082.0113","DOIUrl":"https://doi.org/10.3398/064.082.0113","url":null,"abstract":"Abstract. Social wasps play critical ecological roles in an ecosystem, providing a diversity of services and some disservices. Yellowjacket wasps (Vespula spp.) in particular are well known for shaping arthropod communities via predation and competition for resources. In part due to their sociality and large colony sizes, Vespula can have a profound ecological impact on local communities. Such effects can be magnified when colonies exhibit a perennial life history, in which a colony will overwinter, persist for more than one year, and become orders of magnitude larger in size compared to typical annual colonies. Despite growing interest in the factors that influence colony success, we currently lack the ability to predict when yellowjackets may have a high-abundance or outbreak year. This highlights the need for a critical understanding of the phenological patterns of foraging activity, colony distribution, and senescence. Here, we quantify the seasonal activity and foraging rates of 123 colonies of the western yellowjacket, V. pensylvanica, in its native range over 4 consecutive years. Average colony longevity was about 1 month longer than previously reported for this species, and colonies with later peaks in activity and higher average traffic rates persisted longer into the winter. Longer-lived colonies tended to cluster together within a year, but not between years. We found 3 perennial colonies (2.4% of all colonies), and they exhibited tenfold higher peak traffic rates compared to annual colonies. By identifying temporal and spatial patterns in survivorship and colony longevity, we gain insight into the factors associated with prolonged survival time and increased likelihood of overwintering in yellowjacket wasps.","PeriodicalId":49364,"journal":{"name":"Western North American Naturalist","volume":"1 1","pages":"146 - 154"},"PeriodicalIF":0.6,"publicationDate":"2022-03-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90960287","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}
Abstract. The larval stage of the California newt (Taricha torosa) has been little studied despite the presence and abundance of the species throughout much of California. During the 2017–2018 time period, the diet and life history characteristics of this cohort of stream-dwelling newt larvae were examined, using gut contents and stable isotopes, in order to better understand the ecological niche and trophic relationships of the life stage. Our results suggest that the newt larvae consume Chironomidae as a major part of their diet and that this reliance decreases as the larvae age. Newt larvae also feed more widely and abundantly as they age. The isotopic data suggest that as larvae get larger, they alter their diet but that the relationships to both carbon source (δC) and trophic level (δN) are complex.
{"title":"Trophic Relationships in Larval California Newts (Taricha torosa)","authors":"M. P. Marchetti, K. Dunkel, Charlotte L Moxley","doi":"10.3398/064.082.0107","DOIUrl":"https://doi.org/10.3398/064.082.0107","url":null,"abstract":"Abstract. The larval stage of the California newt (Taricha torosa) has been little studied despite the presence and abundance of the species throughout much of California. During the 2017–2018 time period, the diet and life history characteristics of this cohort of stream-dwelling newt larvae were examined, using gut contents and stable isotopes, in order to better understand the ecological niche and trophic relationships of the life stage. Our results suggest that the newt larvae consume Chironomidae as a major part of their diet and that this reliance decreases as the larvae age. Newt larvae also feed more widely and abundantly as they age. The isotopic data suggest that as larvae get larger, they alter their diet but that the relationships to both carbon source (δC) and trophic level (δN) are complex.","PeriodicalId":49364,"journal":{"name":"Western North American Naturalist","volume":"14 1","pages":"77 - 85"},"PeriodicalIF":0.6,"publicationDate":"2022-02-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78412245","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}
J. White, Patricia W. Freeman, Madelene Shehan, Cliff A. Lemen
Abstract. The northern long-eared myotis (Myotis septentrionalis) has declined sharply in the eastern United States due to the disease white-nose syndrome (WNS), which is caused by the fungus Pseudogymnoascus destructans (Pd). However, less is known about the species' status in the central and western parts of its range where WNS has arrived more recently. Here we report the timing of the arrival of Pd and WNS to eastern Nebraska and examine acoustic and capture data of M. septentrionalis to determine the initial impact of the disease on this species. We sampled bats for the presence of Pd and WNS at several mines and one rock crevice in eastern Nebraska from 2014 to 2017. We also recorded bats with acoustic detectors and captured bats with mist nets in spring and summer from 2014 to 2019 at 2 forested sites along the Missouri River near areas of sampling for Pd/WNS. Both acoustic and capture data suggested that M. septentrionalis went from a common species in forests of eastern Nebraska to one that is encountered rarely after the arrival of WNS. Similar to the population declines in the eastern United States, our observations indicate that M. septentrionalis has also declined steeply in the eastern Great Plains and should be closely monitored in western parts of its distribution as WNS continues to spread.
{"title":"Decline of the Northern Long-Eared Myotis (Myotis septentrionalis) in the Eastern Great Plains After the Arrival of White-Nose Syndrome","authors":"J. White, Patricia W. Freeman, Madelene Shehan, Cliff A. Lemen","doi":"10.3398/064.082.0108","DOIUrl":"https://doi.org/10.3398/064.082.0108","url":null,"abstract":"Abstract. The northern long-eared myotis (Myotis septentrionalis) has declined sharply in the eastern United States due to the disease white-nose syndrome (WNS), which is caused by the fungus Pseudogymnoascus destructans (Pd). However, less is known about the species' status in the central and western parts of its range where WNS has arrived more recently. Here we report the timing of the arrival of Pd and WNS to eastern Nebraska and examine acoustic and capture data of M. septentrionalis to determine the initial impact of the disease on this species. We sampled bats for the presence of Pd and WNS at several mines and one rock crevice in eastern Nebraska from 2014 to 2017. We also recorded bats with acoustic detectors and captured bats with mist nets in spring and summer from 2014 to 2019 at 2 forested sites along the Missouri River near areas of sampling for Pd/WNS. Both acoustic and capture data suggested that M. septentrionalis went from a common species in forests of eastern Nebraska to one that is encountered rarely after the arrival of WNS. Similar to the population declines in the eastern United States, our observations indicate that M. septentrionalis has also declined steeply in the eastern Great Plains and should be closely monitored in western parts of its distribution as WNS continues to spread.","PeriodicalId":49364,"journal":{"name":"Western North American Naturalist","volume":"39 1","pages":"86 - 93"},"PeriodicalIF":0.6,"publicationDate":"2022-02-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82433658","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}
Abstract. Rhamnus ilicifolia (Rhamnaceae) is a large shrub found in a range of habitats from southern Oregon south to Baja California and east into Arizona. During spring, the plant produces clusters of unisexual flowers, each with a 5–6-mm-diameter, open perianth of green or yellowish-green sepals. I investigated the pollination of R. ilicifolia in western Arizona during 27 April to 21 May 2020 by examining the distribution and phenology of male and female flowers on shrubs, collecting insects from female flowers, and determining the proportions of conspecific pollen on insects to estimate floral constancy. Shrubs were dioecious, and individual male and female plants flowered for 11–15 d, with male flowers preceding female flowers by 2 d. Pollen grains from male flowers viewed in brightfield microscopy are tricolporate in structure and suboblate in shape, with a polar-axis length of 15 µm and equatorial diameter of 18 µm. Insects on female flowers comprised flies (Diptera) in 6 families and less abundant bees (Hymenoptera: Apoidea) in 3 families. The most abundant insects were the flies Allophorocera sp. (Tachinidae) and Phormia regina (Calliphoridae) and the bees Lasioglossum spp. (Halictidae) and Andrena cerasifolii (Andrenidae). Bees appeared more specific to R. ilicifolia flowers by transporting a higher mean proportion of conspecific pollen (0.57) compared with flies (0.36). The large bee A. cerasifolii carried the highest mean proportion of conspecific pollen (0.93). Proportions of conspecific pollen on the saprophytic P. regina were moderately high (0.48) and higher than on most other flies. Dioecious R. ilicifolia shrubs appear to be pollinated by a diversity of flies and bees that are generally not specific to the plant's flowers. Similar pollination of European Rhamnus by generalist insects suggests that plants in the genus and their pollinators have evolved independently.
{"title":"Flowering by Dioecious Rhamnus ilicifolia (Rhamnaceae) and Pollen Transport to Female Flowers by Flies and Bees","authors":"W. Wiesenborn","doi":"10.3398/064.082.0106","DOIUrl":"https://doi.org/10.3398/064.082.0106","url":null,"abstract":"Abstract. Rhamnus ilicifolia (Rhamnaceae) is a large shrub found in a range of habitats from southern Oregon south to Baja California and east into Arizona. During spring, the plant produces clusters of unisexual flowers, each with a 5–6-mm-diameter, open perianth of green or yellowish-green sepals. I investigated the pollination of R. ilicifolia in western Arizona during 27 April to 21 May 2020 by examining the distribution and phenology of male and female flowers on shrubs, collecting insects from female flowers, and determining the proportions of conspecific pollen on insects to estimate floral constancy. Shrubs were dioecious, and individual male and female plants flowered for 11–15 d, with male flowers preceding female flowers by 2 d. Pollen grains from male flowers viewed in brightfield microscopy are tricolporate in structure and suboblate in shape, with a polar-axis length of 15 µm and equatorial diameter of 18 µm. Insects on female flowers comprised flies (Diptera) in 6 families and less abundant bees (Hymenoptera: Apoidea) in 3 families. The most abundant insects were the flies Allophorocera sp. (Tachinidae) and Phormia regina (Calliphoridae) and the bees Lasioglossum spp. (Halictidae) and Andrena cerasifolii (Andrenidae). Bees appeared more specific to R. ilicifolia flowers by transporting a higher mean proportion of conspecific pollen (0.57) compared with flies (0.36). The large bee A. cerasifolii carried the highest mean proportion of conspecific pollen (0.93). Proportions of conspecific pollen on the saprophytic P. regina were moderately high (0.48) and higher than on most other flies. Dioecious R. ilicifolia shrubs appear to be pollinated by a diversity of flies and bees that are generally not specific to the plant's flowers. Similar pollination of European Rhamnus by generalist insects suggests that plants in the genus and their pollinators have evolved independently.","PeriodicalId":49364,"journal":{"name":"Western North American Naturalist","volume":"63 1","pages":"67 - 76"},"PeriodicalIF":0.6,"publicationDate":"2022-02-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73642298","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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