Western North American Naturalist最新文献

{"title":"First Documentation of Least Chub in the Snake River Drainage in Idaho","authors":"E. Billman, Dallin Stokes, Isaac Calderwood, Cody Diehl","doi":"10.3398/064.083.0306","DOIUrl":"https://doi.org/10.3398/064.083.0306","url":null,"abstract":"Abstract. The Least Chub (Iotichthys phlegethontis) is a small minnow endemic to the Bonneville Basin in Utah, where the current distribution of extant populations is limited to a few small spring complexes. We report on the first documentation of Least Chub in the upper Snake River drainage in Idaho. In June 2021, October 2021, and June 2022, we surveyed for small-bodied fishes in off-channel habitat of lower Henrys Fork in Cartier Slough Wildlife Management Area west of Rexburg, Idaho. Small-bodied fishes were sampled at 17 sites in off-channel habitat; 5 baited minnow traps (galvanized steel) were set for approximately 24 h at each site. We captured Least Chub in side-channel habitats during all sampling occasions; we captured 214 Least Chub in June 2021, 34 Least Chub in October 2021, and 41 Least Chub in June 2022. Least Chub were captured at 13 of the 17 sites: 6 sites in June 2021, 6 sites in October 2021, and 12 sites in June 2022. Least Chub ranged in size from 35 mm to 56 mm total length. In both June sampling occasions, female and male Least Chub were mature; females were expressing eggs and males had red/orange breeding coloration laterally. The habitat at sites where Least Chub were captured consisted of muddy or sandy substrate, slow-moving or stagnant water, submerged and emergent macrophytes, and filamentous algae. Additional surveys should be completed to determine the extent of the distribution of Least Chub in Henrys Fork and Snake River. Genetic analyses should also be completed to determine the relationship of this population of Least Chub to populations of Least Chub in the Bonneville Basin. Resumen. El pequeño pez Iotichthys phlegethontis es endémico de la cuenca de Bonneville en Utah, la distribución actual de sus poblaciones se limita a unos cuantos pequeños complejos de manantiales. En este trabajo reportamos el primer registro de peces I. phlegethontis en la corriente superior del río Snake en Idaho. Durante junio y octubre de 2021 y en junio de 2022, muestreamos peces de pequeño tamaño en el hábitat fuera del canal de la parte inferior de Henrys Fork en el Área de Manejo de Vida Silvestre de Cartier Slough al oeste de Rexburg. Se capturaron de peces pequeños en 17 sitios en un hábitat fuera del canal; se colocaron cinco trampas de acero galvanizado con cebo durante aproximadamente 24 horas en cada sitio. Capturamos peces I. phlegethontis dentro de los hábitats del canal en todas las ocasiones de muestreo: 214 I. phlegethontis en junio de 2021, 34 en octubre de 2021 y 41 en junio de 2022. Los peces I. phlegethontis fueron capturados en 13 de los 17 sitios: seis sitios en junio de 2021, seis sitios en octubre de 2021 y en doce sitios en junio de 2022. El tamaño de los peces I. phlegethontis varió entre 35 y 56 mm de longitud total. En ambas ocasiones durante los muestreos de junio, las hembras y los machos de I. phlegethontis fueron adultos; las hembras se encontraban en época de desové y los machos tenían coloración rep","PeriodicalId":49364,"journal":{"name":"Western North American Naturalist","volume":"1 1","pages":"355 - 364"},"PeriodicalIF":0.6,"publicationDate":"2023-08-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139347202","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":"Soil Seed Bank Composition and Spatial Distribution in a Cheatgrass (Bromus tectorum L.)–Dominated Rangeland in Colorado, USA","authors":"Ryan W. R. Schroeder, J. Jonas, M. N. Grant-Hoffman, M. Paschke","doi":"10.3398/064.083.0205","DOIUrl":"https://doi.org/10.3398/064.083.0205","url":null,"abstract":"Abstract. Invasion by nonnative annual plants that form prolific seed banks, including Bromus tectorum L. (cheatgrass), throughout western North America is a major natural resource concern. Even with known economic and ecological implications, soil seed banks and their potential to impact ecological restoration in arid and semiarid ecosystems are poorly understood. Quantifying the regenerative potential of the soil seed bank—the living seeds in the soil profile and on the soil surface—can help natural resource managers make decisions to increase the likelihood of restoration success. We analyzed the germinable soil seed bank composition and distribution of a rangeland site in western Colorado that experienced a wildfire in 1994 and is dominated by cheatgrass. We collected soil seed bank samples from 118 points in a 100 × 110 m grid to a depth of 5 cm. Each sample was split by depth from 0 to 2 cm and from 2 to 5 cm, and the seed bank was quantified using greenhouse emergence methods. We found that seeds of native species were more dense and evenly distributed (3391 seeds ∙ m–2) than seeds of nonnative species were (1880 seeds ∙ m–2) in the 0–5 cm seed bank across the site. We also found that seeds of both native and nonnative species were concentrated in the 0–2 cm layer of the seed bank but that native and nonnative seeds were present in substantive densities in the 2–5 cm layer. These findings suggest that the soil seed bank of the site is resilient, and a targeted approach to specifically deplete the seed bank of nonnative annuals could facilitate restoration by the in situ native seed bank. Resumen. La invasión de plantas anuales no autóctonas que forman prolíficos bancos de semillas, entre ellas Bromus tectorum L. (pasto espiguilla), en todo el oeste de Norteamérica es una preocupación muy importante de recursos naturales. A pesar de sus conocidas implicaciones económicas y ecológicas, los bancos de semillas del suelo y su potencial para influir en la restauración ecológica de los ecosistemas áridos y semiáridos son poco conocidos. Cuantificar el potencial regenerativo del banco de semillas del suelo—las semillas vivas en el perfil y la superficie del suelo—puede ayudar a los gestores de recursos naturales a tomar decisiones para aumentar las probabilidades de éxito de la restauración. Analizamos la composición y distribución del banco de semillas germinables del suelo de un pastizal del oeste de Colorado que sufrió un incendio forestal en 1994 y en el que predomina el pasto espiguilla. Recogimos muestras del banco de semillas del suelo en 118 puntos de una cuadrícula de 100 × 110 metros a una profundidad de 5 cm. Cada muestra se dividió por profundidad de 0–2 cm y 2–5 cm y el banco de semillas se cuantificó utilizando métodos de emergencia en invernadero. Encontramos que las semillas de especies nativas fueron más densas y estaban distribuidas uniformemente (3391 semillas ∙ m–2) que las semillas de especies no nativas (1880 semillas ∙ m–2) ","PeriodicalId":49364,"journal":{"name":"Western North American Naturalist","volume":"51 1","pages":"191 - 206"},"PeriodicalIF":0.6,"publicationDate":"2023-08-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139350203","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":"Effects of Annual Weather Variation on Peak Herbaceous Yield Date in Sagebrush Steppe","authors":"J. Bates, Dustin Johnson, Kirk W. Davies, Tony Svejcar, Stuart Hardegree","doi":"10.3398/064.083.0207","DOIUrl":"https://doi.org/10.3398/064.083.0207","url":null,"abstract":"Abstract. Interannual climate variability impacts forage yield in semiarid rangelands, but it also affects the timing of peak yields. Knowledge of peak standing crop or yield dates would be useful when planning fieldwork for various research or management activities and for developing more accurate models linking herbage production to climatic variables. In this study, herbaceous yield was measured every 2 weeks (April–August) over an 8-year period in a Wyoming big sagebrush (Artemisia tridentata ssp. wyomingensis) community in southeastern Oregon. Date of peak yield (Julian day) was calculated for morphological groups (tall perennial bunchgrasses, perennial forbs, annual forbs), Sandberg bluegrass (Poa secunda J. Pressl), and total herbaceous yield. Linear and multiple regression analyses were used to correlate date of peak yield of herbaceous morphological groups with spring precipitation, reference evapotranspiration (RET), and air temperature. Peak yield dates for the herbaceous response variables were strongly correlated to annual climatic variation, commonly a combination of early growing season precipitation (March to 16 May) and March through May RET. Depending on morphological group, peak yield date varied by 3 to 7 weeks during the growing season. The best regression coefficients for peak yield date of perennial bunchgrasses, perennial forbs, Sandberg bluegrass, annual forbs, and total herbaceous vegetation alone or with various combinations of precipitation, temperature, and RET were 0.97, 0.82, 0.86, 0.90, and 0.98, respectively. For planning fieldwork, estimates of peak yield date can be used to accurately sample for yields of herbaceous morphological groups and community production potentials. Resumen. La variabilidad climática interanual influye en el rendimiento del forraje de los pastizales semiáridos, pero también afecta al momento en que alcanzan su rendimiento máximo. El conocimiento de las fechas de máxima cosecha o rendimiento podría ser útil en el momento de planificar el trabajo de campo para diversas actividades de investigación o gestión y para desarrollar modelos más precisos que relacionen la producción de hierba con las variables climáticas. En este estudio, se midió el rendimiento herbáceo cada dos semanas (abril-agosto), durante un periodo de ocho años, en una comunidad de artemisa de Wyoming (Artemisia tridentata ssp. wyomingensis) en el sureste de Oregón. Se calculó la fecha de máximo rendimiento (en días julianos) para cada grupo morfológico (hierbas altas o pasrtos perennes, hierbas perennes, hierbas anuales), el pasto azul de Sandberg (Poa secunda J. Pressl) y el rendimiento herbáceo total. Se utilizaron análisis de regresión lineal y múltiple para correlacionar la fecha de máximo rendimiento de los grupos morfológicos herbáceos con la precipitación primaveral, la evapotranspiración de referencia (RET) y la temperatura del aire. Las fechas de máximo rendimiento para las variables de respuesta herbáceas se corre","PeriodicalId":49364,"journal":{"name":"Western North American Naturalist","volume":"25 1","pages":"220 - 231"},"PeriodicalIF":0.6,"publicationDate":"2023-08-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139350260","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":"Aquatic Insect Communities Remain Impaired Following Large-Scale River Restoration","authors":"Jared Meek, Jackson Birrell, Teagan Mulford, Dennis K. Shiozawa, C. R. Nelson","doi":"10.3398/064.083.0206","DOIUrl":"https://doi.org/10.3398/064.083.0206","url":null,"abstract":"Abstract. River manipulation and degradation can cause detrimental impacts on aquatic insect communities. River restoration projects seek to mitigate these human disturbances. Assessing the efficacy of river restoration remains an important goal for river managers and conservation biologists so that improved restoration methods can be used in the future. From 1999 to 2008, the Utah Reclamation Mitigation and Conservation Commission restored a 15-km channelized portion of the Provo River (Wasatch County, Utah, USA). Before (1999) and during (2002) the restoration project, macroinvertebrate samples were collected using modified kick nets from 3 sites within the restored area and 1 site outside the restored area. In 2017, we collected macroinvertebrates from these same sites using identical sampling methods to assess the long-term outcomes of the Provo River Restoration Project through a comparison of macroinvertebrate species richness, Shannon diversity, %EPT (Ephemeroptera, Plecoptera, Trichoptera), functional feeding groups, and habit groups. We show that macroinvertebrate richness and diversity have significantly decreased in the restored reaches of the river, despite the restoration project being completed in 2008. Additionally, we found that EPT taxa declined in the restored reaches and that the community remains dominated by collectors. Our results help quantify the efficacy of the Provo River Restoration Project and highlight the need for additional remediation techniques. Significant reductions in richness, Shannon diversity, and functional feeding group diversity at the reference site suggest that factors unaddressed by the restoration such as river damming, lack of riparian vegetation, maintenance of nonnative fish, nutrient pollution, and climate change may be preventing the full rehabilitation of the river. We discuss potential factors that may be contributing to river degradation in this system and advocate for revised and more holistic river restoration approaches, along with the importance of regular monitoring programs for completed restoration projects. Resumen. La manipulación y degradación de los ríos puede tener efectos perjudiciales en las comunidades de insectos acuáticos. Los proyectos de restauración de ríos tratan de mitigar estas perturbaciones humanas. Evaluar la eficacia de la restauración de los ríos sigue siendo un objetivo importante para los gestores de ríos y los biólogos conservacionistas, de modo que en el futuro puedan utilizarse mejores métodos de restauración. Entre 1999 y 2008, la Utah Reclamation Mitigation and Conservation Commission restauró una porción canalizada de 15 km del río Provo (condado de Wasatch, Utah, EE.UU.). Antes (1999) y durante (2002) el proyecto de restauración, se recogieron muestras de macroinvertebrados utilizando redes modificadas en tres sitios dentro del área restaurada y un sitio fuera del área restaurada. En 2017, recogimos macroinvertebrados de estos mismos sitios utilizando métod","PeriodicalId":49364,"journal":{"name":"Western North American Naturalist","volume":"44 1","pages":"207 - 219"},"PeriodicalIF":0.6,"publicationDate":"2023-08-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139351089","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":"Insights on the Distribution of Struthanthus palmeri Kuijt (Loranthaceae), the Northernmost Species of the Genus","authors":"Mónica I. MIGUEL-VÁZQUEZ, Yasser S. López de Olmos-Reyes, Maria Guadalupe Maldonado-Borja, R. Cerros-Tlatilpa","doi":"10.3398/064.083.0215","DOIUrl":"https://doi.org/10.3398/064.083.0215","url":null,"abstract":"Abstract. Struthanthus (Loranthaceae) is native to the Americas, and several species occur in Mexico, some of which are endemic, such as S. palmeri. Within the genus, S. palmeri has the northernmost distribution, inhabiting the arid environments of northwestern Mexico near the border with the United States. In this study, the known distribution of the species was updated. The elevation, hosts, and vegetation types where S. palmeri occurs were compiled to infer its potential distribution, using ecological niche modeling. Based on the results, the endemic status of S. palmeri is reinforced. This taxon occurs in several types of vegetation, from near sea level to 1300 m, and it parasitizes taxa of 12 families. There are records of the species for 1 of the 21 federal Protected Natural Areas that are included in the “M area” employed in the analysis. The potential distribution of S. palmeri shows high probabilities of presence mainly in the North American Terrestrial Ecoregions that include the coastal areas of Sonora and Sinaloa. This study expands our knowledge of mistletoes from arid regions of America as well as our knowledge of Mexican endemic species, providing additional habitat and host information for the management and conservation of this group. Resumen. Struthanthus (Loranthaceae) es nativo de América y varias de sus especies se encuentran en México, algunas de las cuales son endémicas, por ejemplo S. palmeri. Dentro del género, S. palmeri tiene la distribución más septentrional, habitando en los ambientes áridos del noroeste de México, cerca de la frontera con Estados Unidos. En este estudio, se actualizó la distribución conocida de la especie. Se compiló la elevación, hospederos y tipos de vegetación donde S. palmeri se encuentra, para inferir su distribución potencial, usando modelado de nicho ecológico. Con base en los resultados, se reforzó el estatus de endemismo de S. palmeri. Este taxón se presenta en varios tipos de vegetación, desde cerca del nivel del mar hasta los 1300 m y parasitando taxa de 12 familias. Hay registros de la especie para una de las 21 Áreas Naturales Protegidas federales incluidas en el área M empleada en el análisis. Su distribución potencial muestra probabilidades altas de presencia, principalmente en las Ecorregiones Terrestres de Norteamérica que incluyen las áreas costeras de Sonora y Sinaloa. Este estudio expande el conocimiento de muérdagos de regiones áridas de América y de las especies endémicas de México, proporcionando información adicional sobre hábitat y hospederos, para el manejo y conservación de este grupo.","PeriodicalId":49364,"journal":{"name":"Western North American Naturalist","volume":"26 1","pages":"289 - 295"},"PeriodicalIF":0.6,"publicationDate":"2023-08-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139351276","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":"Reproductive Ecology and Bee Associates of Packard's Milkvetch (Astragalus packardiae), a Rare Plant Endemic to Southwestern Idaho","authors":"Justin R Fulkerson, C. L. Kinter","doi":"10.3398/064.083.0209","DOIUrl":"https://doi.org/10.3398/064.083.0209","url":null,"abstract":"Abstract. Conservation of rare plants is dependent on identifying mechanisms that limit their population or persistence. Successful pollination of flowers is one life history trait that is often limiting in plants occurring in fragmented landscapes. We studied pollinator associates and seed production in Astragalus packardiae (= A. cusickii var. packardiae, Packard's milkvetch), a narrow endemic that is imperiled as a result of nonnative annual grasses, increased wildfire, recreational off-highway vehicle use, and livestock use. We used pollinator exclusion bags to examine the breeding system of Packard's milkvetch. We collected and videotaped floral visitors to determine the makeup of the associates and the visitation rate to flowers. Our study demonstrates that Packard's milkvetch is highly dependent on pollinators for reproductive success. Plants that were excluded from pollinator visitation produced a mean of 0.05 seeds/fruit (SD = 0.21), while plants open to pollinator visitation produced 2.44 seeds/fruit (SD = 1.03) (Wilcoxon signed-rank test: n = 23, P < 0.001). We collected a total of 203 floral visitors of A. packardiae. The order Hymenoptera (bees and wasps) made up 86% of the visitors, of which wasps were merely 1% of the collected insects. Lepidoptera (butterflies), Coleoptera (beetles), and Diptera (flies) accounted for the remaining 7%, 4.4%, and 2.5% of visitors, respectively. The bee associates were markedly composed of Osmia bee species. Visitation rate for Packard's milkvetch was 3.8 visits/flower per hour, which is within the range of other studied Astragalus species. Because seed production in Packard's milkvetch is highly dependent on native bees, future conservation of Packard's milkvetch is reliant on the conservation of native bee habitat. Resumen. La conservación de las plantas raras depende de la identificación de los mecanismos que limitan su población o persistencia. La polinización exitosa de las flores es un rasgo de historia de vida vital que suele ser limitante en plantas que se desarrollan en paisajes fragmentados. Estudiamos la asociación de polinizadores y la producción de semillas en Astragalus packardiae (= A. cusickii var. packardiae, milkvetch de Packard), una planta endémica que se encuentra en peligro como consecuencia de la presencia de hierbas anuales no autóctonas, el aumento de los incendios forestales, el uso recreativo de vehículos todoterreno y el uso ganadero. Utilizamos bolsas de exclusión de polinizadores para examinar el sistema de reproducción del milkvetch de Packard. Recogimos y grabamos en video a los visitantes florales para determinar la composición de los asociados y la tasa de visitas a las flores. Nuestro estudio demuestra que el milkvetch de Packard depende en gran medida de los polinizadores para su éxito reproductivo. Las plantas que fueron excluidas de la visita de polinizadores produjeron un promedio 0.05 semillas/fruto (SD = 0.21). Mientras que, las plantas no excluidas produjeron","PeriodicalId":49364,"journal":{"name":"Western North American Naturalist","volume":"121 1","pages":"243 - 253"},"PeriodicalIF":0.6,"publicationDate":"2023-08-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139351659","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":"Reviewers for 2022","authors":"","doi":"10.3398/064.083.0112","DOIUrl":"https://doi.org/10.3398/064.083.0112","url":null,"abstract":"","PeriodicalId":49364,"journal":{"name":"Western North American Naturalist","volume":"84 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-08-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136145406","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":"Insects are Attracted to White Wind Turbine Bases: Evidence from Turbine Mimics","authors":"Madison S. Crawford, Delina E. Dority, Michael E. Dillon, Lusha M. Tronstad","doi":"10.3398/064.083.0208","DOIUrl":"https://doi.org/10.3398/064.083.0208","url":null,"abstract":"Abstract. Wind power is one of the fastest growing forms of renewable energy, but the interactions between wind turbines and insects are largely unknown beyond the observation that the accumulation of dead insects on turbine blades drastically reduces the power produced. Insects may be attracted to wind energy facilities because of topography, the heat that turbines produce, the lighting, or the visual cue of the turbine itself. Turbines can present a striking visual contrast relative to the surrounding landscape, particularly when they are painted bright white and reflect ultraviolet wavelengths. To test the hypothesis that wind turbine color attracts insects, we sampled insects near experimental wind turbine mimics of 9 colors. The mimics were located on a hill with characteristics similar to sites of nearby wind energy facilities. Passive traps painted the same colors and placed next to their corresponding turbine mimic provided an estimate of insect attraction to turbines of different colors. Insect abundance was highest next to the white, violet, and blue turbine mimics, and lowest adjacent to the green, orange, yellow, light gray, and dark gray turbine mimics. Our results suggest that white, the predominant color of wind turbines globally, is one of the most attractive colors to insects. We encourage others to investigate whether painting turbine bases a less attractive color (e.g., gray or green) may drastically reduce the attraction of insects to wind energy facilities. Resumen La energía eólica es una de las formas de energía renovable de más rápido crecimiento, pero se desconocen en gran medida las interacciones entre las turbinas eólicas y los insectos, más allá de la observación de que la acumulación de insectos muertos en las aspas de las turbinas reduce drásticamente la potencia producida. Los insectos pueden sentirse atraídos por las instalaciones de energía eólica debido a la topografía, el calor que producen las turbinas, la iluminación de las instalaciones de energía eólica o la señal visual de la propia turbina. Las turbinas pueden presentar un llamativo contraste visual en relación con el paisaje circundante, en particular cuando están pintadas de blanco brillante y reflejan longitudes de onda ultravioleta. Para probar la hipótesis de que el color de las turbinas eólicas atrae a los insectos, tomamos muestras de insectos de nueve imitaciones de turbinas eólicas experimentales de diferentes colores, situadas en una colina con características similares a las instalaciones de energía eólica cercanas. Las trampas pasivas pintadas de los mismos colores y colocadas junto a su correspondiente turbina de imitación proporcionaron una estimación de la atracción de los insectos hacia las turbinas de diferentes colores. La abundancia de insectos fue más alta junto a las turbinas de imitación blancas, violetas y azules, y más baja junto a las turbinas de imitación verdes, naranjas, amarillas, grises claras y grises oscuras. Nuestros result","PeriodicalId":49364,"journal":{"name":"Western North American Naturalist","volume":"48 1","pages":"232 - 242"},"PeriodicalIF":0.6,"publicationDate":"2023-08-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139351805","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":"Western Pearlshell (Margaritifera falcata) Extirpation in the Smith River, Montana, with a Possible Link to Warming Water Temperatures","authors":"D. Stagliano","doi":"10.3398/064.083.0210","DOIUrl":"https://doi.org/10.3398/064.083.0210","url":null,"abstract":"Abstract. Western pearlshell (Margaritifera falcata) populations are in decline across the species' range in western North America. In 2008, Montana categorized the western pearlshell as an imperiled species of concern (S2) based on reduced detections at historically occupied sites and few viable populations. Between 2004 and 2014, we surveyed 24 Smith River reaches (61 total sites in the watershed) for the presence of western pearlshell populations. Despite historical and anecdotal descriptions of abundant western pearlshell in the Smith River, intensive structured surveys between 2004 and 2007 documented only 4 sections with low-density, nonviable western pearlshell populations (<10 individuals, large size classes [average total length = 70 mm], with no signs of recruitment). In 2014, we revisited these occupied sites to repeat surveys (expending significantly more search time) and observed no live individuals. This was surprising given that, although those populations would certainly die out without recruitment, older individuals can oftentimes persist for decades. Therefore, we consider the western pearlshell mussel extirpated from the Smith River watershed. We reviewed long-term USGS gage discharge and temperature data near the western pearlshell populations to evaluate the potential causal factors for, and timing of, the extirpation. From 3 July to 3 August 2007, water temperatures were at or above the thermal stress levels of the western pearlshell (>25 °C, with maximum daily temperatures of 28 °C) for 23 days. Water temperatures did not reach these threshold levels on any days between 2008 and 2012, and in 2013, only 6 days reached temperatures >25 °C (max. 26 °C). Therefore, we hypothesize that the lack of live individuals reported in 2014 was most likely a result of population losses occurring during the summer of 2007. We could not evaluate viruses or bacterial infections as possible causes of the extirpation, but these factors are being implicated in recent mussel mass mortality events. Such infections may have been additional causal factors in the Smith River extirpations because of already high E. coli loads in conjunction with thermally and/or oxygen-stressed individuals. Two eDNA samples collected in July 2022 downstream of the Hwy. 360 bridge and Fort Logan WMA tested negative for western pearlshell DNA fragments, confirming their continued absence. Resumen. Concha de perla occidental, Margaritifera falcata, las poblaciones de mejillones están en declive en todo el oeste de los Estados Unidos. En 2008, Montana enumeró la concha de perlas como una especie de preocupación en peligro (S2) basada en detecciones severamente reducidas en sitios históricamente ocupados y muy pocas poblaciones viables. Entre 2004 y 2014, examinamos 24 secciones del río Smith (61 sitios totales de cuencas hidrográficas) para la presencia de poblaciones de conchas de perlas occidentales. A pesar de las descripciones históricas y anecdóticas de abundantes c","PeriodicalId":49364,"journal":{"name":"Western North American Naturalist","volume":"26 1","pages":"254 - 263"},"PeriodicalIF":0.6,"publicationDate":"2023-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139352467","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":"Mexican Gartersnakes (Thamnophis eques) along the Gila River in Southwestern New Mexico","authors":"Keith Geluso","doi":"10.3398/064.083.0216","DOIUrl":"https://doi.org/10.3398/064.083.0216","url":null,"abstract":"Abstract. The Mexican gartersnake (Thamnophis eques) is a federally threatened species in the United States, with only a few isolated populations remaining in Arizona and New Mexico. For some populations, only limited knowledge exists regarding their status and natural history; thus, all observations are noteworthy. Along the Gila River in New Mexico, for example, only 2 observations of this species have been published, one in 1883 and one in 1973. Herein, I report on 6 additional observations of Mexican gartersnakes from along the Gila River in southwestern New Mexico. Five individuals were documented in riparian habitats close to or in water, but one was observed in more arid habitats away from riparian habitats. Two individuals were found dead on paved roadways, demonstrating that mortality along roads is a threat to this limited population that generally is associated only with wetland habitats. Further surveys are warranted in the area to better understand the status and habitats used by this rare species in the region. Resumen. La serpiente de jarretera o culebra de agua nómada mexicana (Thamnophis eques) es una especie amenazada a nivel federal en los Estados Unidos, con solo unas pocas poblaciones aisladas en Arizona y Nuevo México. Muy poco se conoce sobre el estado e historia natural de algunas poblaciones, por lo tanto, cualquier observación es novedosa. A lo largo del río Gila en Nuevo México, por ejemplo, solo se publicaron dos observaciones de esta especie han sido publicadas: una en 1883 y otra en 1973. A continuación, se reportan seis observaciones adicionales de las serpientes de jarretera a lo largo del río Gila en el suroeste de Nuevo México. Se documentaron cinco individuos en hábitats ribereños cerca o en el agua, y un individuo se observó en hábitats más áridos lejos de los hábitats ribereños. Adicionalmente, se encontraron dos individuos muertos en carreteras pavimentadas, lo que demuestra que la mortalidad en las carreteras representa una amenaza para esta población limitada que generalmente se asocia únicamente con hábitats de humedales. Por lo anterior, resulta necesario llevar a cabo más estudios en el área para comprender mejor la condición, así como los hábitats utilizados por esta rara especie en la región.","PeriodicalId":49364,"journal":{"name":"Western North American Naturalist","volume":"11 1","pages":"296 - 299"},"PeriodicalIF":0.6,"publicationDate":"2023-07-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139356119","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}