11,306 results match your criteria: "U. S. Geological Survey; MS 926A; National Center; Reston; Virginia 20192. jrepetski@usgs.gov.[Affiliation]"

Comparison of Butorphanol-Azaperone-Medetomidine and Nalbuphine-Medetomidine-Azaperone in Free-Ranging Elk (Cervus canadensis) in Pennsylvania, USA.

J Wildl Dis

October 2024

U.S. Geological Survey, Pennsylvania Cooperative Fish and Wildlife Research Unit, 403 Forest Resources Building, University Park, Pennsylvania 16802, USA.

Chemical immobilization is commonly used to capture and handle free-ranging elk (Cervus canadensis). Butorphanol-azaperone-medetomidine (BAM) and nalbuphine-medetomidine-azaperone (NalMed-A) are compounded drug combinations that are lower-scheduled in the US than drugs historically used for elk immobilizations. We compared BAM and NalMed-A for immobilization of free-ranging elk using free-darting and Clover trapping.

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Social monogamy is the prevalent mating system in birds, but alternative strategies of extra-pair paternity (EPP) and conspecific brood parasitism (CBP) occur in many species. Raptors are virtually absent in discussions of broad taxonomic reviews regarding EPP and CBP likely because these strategies are mostly absent or at low frequency; CBP is unreported in solitary nesting raptors. In contrast, we found high frequencies of EPP (16%-31%) and CBP (15%-26%) nests among three populations of Cooper's Hawks () across the northern breeding range of this solitary nesting, socially monogamous species.

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Wildfire disturbance propagation along fluvial networks remains poorly understood. We use incident, atmospheric, and water-quality data from the largest wildfire in New Mexico's history to quantify how this gigafire affected surface runoff processes and mobilized wildfire disturbances into fluvial networks after burning 1382 km. Surface runoff post-fire increased compared to pre-fire conditions, and precipitation events that are frequently observed in the affected watershed (<2-year recurrence) and fell during the post-fire first rainy season resulted in uncorrelated, less frequently observed runoff events (10-year recurrence).

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With the intensity and frequency of wildfires increasing rapidly, the need to study the ecological effects of these wildfires is also growing. An understudied aspect of fire ecology is the effect fires have on parasite-host interactions, including ectoparasites that might be pathogen vectors. Although some studies have examined the impacts of fire on ticks, studies on other ectoparasites, including pathogen vectors, are rare.

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Spatiotemporal and Multilayer Trade Network Patterns of the Global Cobalt Cycle.

Environ Sci Technol

August 2024

College of Urban and Environmental Sciences, Peking University, Beijing 100871, China.

Recent years have witnessed increasing attempts to track trade flows of critical materials across world regions and along the life cycle for renewable energy and the low carbon transition. Previous studies often had limited spatiotemporal coverage, excluded end-use products, and modeled different life cycle stages as single-layer networks. Here, we integrated material flow analysis and complex network analysis into a multilayer framework to characterize the spatiotemporal and multilayer trade network patterns of the global cobalt cycle from 1988 to 2020.

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Perfluorohexanesulfonic Acid (PFHxS) Impairs Lipid Homeostasis in Zebrafish Larvae through Activation of PPARα.

Environ Sci Technol

September 2024

Guangdong Provincial Key Laboratory of Soil and Groundwater Pollution Control, School of Environmental Science and Engineering, Southern University of Science and Technology, Shenzhen 518055, China.

Perfluorohexanesulfonic acid (PFHxS), an emerging short-chain per- and polyfluoroalkyl substance, has been frequently detected in aquatic environments. Adverse outcome pathway studies have shown that perfluorinated compounds impair lipid homeostasis through peroxisome proliferator activated receptors (PPARs). However, many of these studies were performed at high concentrations and may thus be a result of overt toxicity.

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Characterizing the population density of species is a central interest in ecology. Eastern North America is the global hotspot for biodiversity of plethodontid salamanders, an inconspicuous component of terrestrial vertebrate communities, and among the most widespread is the eastern red-backed salamander, . Previous work suggests population densities are high with significant geographic variation, but comparisons among locations are challenged by lack of standardization of methods and failure to accommodate imperfect detection.

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Size-dependent effects of dams on river ecosystems and implications for dam removal outcomes.

Ecol Appl

September 2024

Senator George J. Mitchell Center for Sustainability Solutions and School of Biology and Ecology, University of Maine, Orono, Maine, USA.

Understanding the relationship between a dam's size and its ecological effects is important for prioritization of river restoration efforts based on dam removal. Although much is known about the effects of large storage dams, this information may not be applicable to small dams, which represent the vast majority of dams being considered for removal. To better understand how dam effects vary with size, we conducted a multidisciplinary study of the downstream effect of dams on a range of ecological characteristics including geomorphology, water chemistry, periphyton, riparian vegetation, benthic macroinvertebrates, and fish.

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Utility of an Instantaneous Salt Dilution Method for Measuring Streamflow in Headwater Streams.

Ground Water

January 2025

U.S. Geological Survey, Earth System Processes Division, Hydrogeophysics Branch, Storrs Mansfield, CT, 06269.

Streamflow records are biased toward large streams and rivers, yet small headwater streams are often the focus of ecological research in response to climate change. Conventional flow measurement instruments such as acoustic Doppler velocimeters (ADVs) do not perform well during low-flow conditions in small streams, truncating the development of rating curves during critical baseflow conditions dominated by groundwater inflow. We revisited an instantaneous solute tracer injection method as an alternative to ADVs based on paired measurements to compare their precision, efficiency, and feasibility within headwater streams across a range of flow conditions.

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Population genetic structure and demographic history reconstruction of introduced flathead catfish (Pylodictis olivaris) in two US Mid-Atlantic rivers.

J Fish Biol

December 2024

U.S. Geological Survey, Pennsylvania Cooperative Fish and Wildlife Research Unit, Pennsylvania State University, University Park, Pennsylvania, USA.

Population genetic analysis of invasive populations can provide valuable insights into the source of introductions, pathways for expansion, and their demographic histories. Flathead catfish (Pylodictis olivaris) are a prolific invasive species with high fecundity, long-distance dispersal, and piscivorous feeding habits that can lead to declines in native fish populations. In this study, we analyse the genetics of invasive P.

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The evolutionary histories of adaptive radiations can be marked by dramatic demographic fluctuations. However, the demographic histories of ecologically-linked co-diversifying lineages remain understudied. The Laurentian Great Lakes provide a unique system of two such radiations that are dispersed across depth gradients with a predator-prey relationship.

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Population genomics can reveal cryptic biological diversity that may impact fitness while simultaneously serving to delineate relevant conservation units. Here, we leverage the power of whole-genome resequencing for conservation by studying 433 individual lesser prairie-chicken (; LEPC, a federally endangered species of conservation concern in the United States) and greater prairie-chicken (; GRPC, a legally huntable species throughout much of its range). The genomic diversity of two formally recognized distinct population segments (DPSs) of LEPCs is similar, but they are genetically distinct.

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Understanding the movement patterns of an invasive species can be a powerful tool in designing effective management and control strategies. Here, we used a Bayesian multistate model to investigate the movement of two invasive carp species, silver carp () and bighead carp (), using acoustic telemetry. The invaded portions of the Illinois and Des Plaines Rivers, USA, are a high priority management zone in the broader efforts to combat the spread of invasive carps from reaching the Laurentian Great Lakes.

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To further refine the use of solid bitumen reflectance (BR in %) as a measurement of thermal maturity in source-rock reservoirs, we examined its relationship to other thermal proxies in the Bakken Formation. Comparisons included criteria from programmed temperature pyrolysis, gas chromatography (GC), and Fourier transform infrared (FTIR) spectroscopy. Thirty-two organic-rich samples from the lower and upper shale members of the Devonian-Lower Carboniferous Bakken Formation were collected from eight cores across the Williston Basin, USA, at depths (∼7575-11,330 ft) representing immature through post peak oil/early condensate thermal maturity conditions based on proximity to current hydrocarbon production.

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Dopaminergic and anti-estrogenic responses in juvenile steelhead (Oncorhynchus mykiss) exposed to bifenthrin.

Comp Biochem Physiol C Toxicol Pharmacol

November 2024

Department of Environmental Sciences, University of California, Riverside, Riverside, CA, USA.

Article Synopsis
  • * Juvenile steelhead exposed to low concentrations of bifenthrin exhibited increased dopamine levels in their brains, alongside decreased expression of key genes linked to dopamine and estrogen signaling.
  • * The study suggests that bifenthrin may disrupt dopaminergic pathways and endocrine functions in juvenile steelhead, underscoring the necessity of understanding how pesticides affect different species and life stages to improve risk assessments.
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qPCR-based phytoplankton abundance and chlorophyll a: A multi-year study in twelve large freshwater rivers across the United States.

Sci Total Environ

December 2024

Office of Research and Development, United States Environmental Protection Agency, Cincinnati, OH 45268, United States. Electronic address:

Phytoplankton overgrowth, which characterizes the eutrophication or trophic status of surface water bodies, threatens ecosystems and public health. Quantitative polymerase chain reaction (qPCR) is promising for assessing the abundance and community composition of phytoplankton. However, applications of qPCR to indicate eutrophication and trophic status, especially in lotic systems, have yet to be comprehensively evaluated.

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Asymmetric mate preference and reproductive interference mediate climate-induced changes in mate availability in a small mammal hybrid zone.

Evolution

October 2024

Department of Natural Resources and Environmental Science; Program in Ecology, Evolution, and Conservation Biology, University of Nevada, Reno, NV, United States.

Range expansion and contraction are among the most common biotic responses to changing environmental conditions, yet much is to be learned about the mechanisms that underlie range-edge population dynamics, especially when those areas are points of secondary contact between closely related species. Here, we present field-measured parentage data that document the reproductive outcomes of changes in mate availability at a secondary contact zone between two species of woodrat in the genus Neotoma. Changes in mate availability resulted from drought-driven differential survival between the species and their hybrids.

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The Arctic is warming four times faster than the rest of the world, threatening the persistence of many Arctic species. It is uncertain if Arctic wildlife will have sufficient time to adapt to such rapidly warming environments. We used genetic forecasting to measure the risk of maladaptation to warming temperatures and sea ice loss in polar bears (Ursus maritimus) sampled across the Canadian Arctic.

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Background: Social network analysis of animal societies allows scientists to test hypotheses about social evolution, behaviour, and dynamic processes. However, the accuracy of estimated metrics depends on data characteristics like sample proportion, sample size, and frequency. A protocol is needed to assess for bias and robustness of social network metrics estimated for the animal populations especially when a limited number of individuals are monitored.

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Using a selection of native grass and forb seeds commonly seeded in local restoration projects, we conducted a field experiment to evaluate the effects of seed species, distance of seed patches from nests, and distance between patches on patterns of seed removal by Owyhee harvester ants, Pogonomyrmex salinus (Olsen) (Hymenoptera: Formicidae). To provide context for ants' seed preferences, we evaluated differences in handling time among seed species. In addition, we assessed the influences of cheatgrass, Bromus tectorum (L.

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For many drylands, both long- and short-term drought conditions can accentuate landscape heterogeneity at both temporal (e.g., role of seasonal patterns) and spatial (e.

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Article Synopsis
  • The Greenland Ice Sheet's (GrIS) persistence during the Pleistocene impacts our understanding of past sea level rise and future climate projections.
  • Researchers studied glacial till from beneath 3 km of ice at Summit, Greenland, revealing a stable land surface with plant and animal remnants.
  • Evidence shows that central Greenland was tundra-covered during the Pleistocene, helping to clarify how the Arctic ecosystem responded to periods of ice melting.
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No current technology can specifically target grass carp (Ctenopharyngodon idella) for control within aquatic ecosystems. Rotenone and Carbon Dioxide-Carp are currently the only available registered pesticides for grass carp; they are nonselective and typically applied throughout the water, equally exposing target and native species. A more selective control tool or pesticide application could be used by resource managers to support mitigation efforts.

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Microplastics are fast-emerging as another potential threat to already globally declining seagrass ecosystems, but there is a paucity of in situ surveys showing their accumulations. Here, we surveyed multiple Zostera marina L. meadows in 2020 and 2021 across Massachusetts, USA, for microplastic contamination, as well as identified factors related to patterns of accumulation.

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Article Synopsis
  • Scientists studied how climate change affects Joshua trees in the Mojave Desert using 15 years of images shared by people online.
  • They created a computer model that can predict when these trees will bloom based on weather data.
  • The study found that while the conditions for flowering are getting more frequent, other factors like higher temperatures and drought could still harm the trees.
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