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At least 1,603 records · Page 89Linked to original sources
USGS2026

Where will the cat cross the road? Comparing camera and GPS-based models for identifying wildlife corridors

Designing effective wildlife corridors is a critical conservation challenge in fragmented landscapes. GPS-based step selection functions strongly predict dispersal corridors and connectivity, but GPS collaring can be expensive and invasive. Camera-based occupancy models are widely used for connectivity analyses but may involve trade-offs in data resolution. Despite widespread use of both approaches, few studies have directly compared them using concurrent datasets. We developed a stacked single-species, single-season occupancy model and a Circuitscape connectivity surface for mountain lions (Puma concolor) on Washington’s Olympic Peninsula, USA, and compared them with a connectivity surface from an existing integrated step selection function. Both models predicted mountain lion GPS locations well, with binned Spearman rank correlations of 1 for Circuitscape and 0.96 for the step selection function, though step selection better identified habitat use by dispersers. Connectivity predictions were moderately correlated across the landscape ( r = 0.26), but agreement was strongest in human-dominated areas most critical for corridor planning. We conclude that GPS-based approaches are advantageous when data collection is feasible and the focus is on dispersal or fine-scale movement. However, camera-based approaches may be preferable for multi-species monitoring, large spatial and temporal scales, noninvasive sampling, when resources are limited, or when fine-scale or dispersal-specific inference is not required.

Washington↗
USGS2026

Experimentally quantifying how long recreation noise displaces mammals: Recovery over weeks to months varies by disturbance type and species tolerance

Outdoor recreation is expanding across public lands, yet managers lack evidence for how long wildlife responses to recreation persist and whether response duration depends on disturbance type and frequency. Using a field-based acoustic playback experiment in the Bridger–Teton National Forest, Wyoming, USA, we isolated recreation noise from other components of human presence and quantified how long mammal detections took to return to baseline. Across 12 sites over two field seasons, we broadcast motorized and non-motorized recreation sounds at rates mimicking high- and low-use trails, paired with nature-sound controls. We quantified treatment effects as deviations from expected weekly detections at our control sites, defining time-to-return as the first week when deviations overlapped zero. Response duration differed between disturbance types. High-rate motorized playbacks produced the longest suppression: all species except mule deer did not return to baseline within our 15-week season, whereas mule deer recovered by six weeks. For high-rate non-motorized playbacks, all species except for mule deer had suppressed detections until seven weeks while mule deer detections were not different from baseline. For low-rate non-motorized playbacks, mule deer detections returned to baseline at nine weeks while all other species returned to baseline at seven weeks. Species differences indicate that apparent overall recovery can mask prolonged avoidance by less tolerant taxa. Recreation effects persisted for weeks to months and varied with disturbance type and exposure frequency, highlighting how temporal patterns of use influence wildlife responses and where recreational planning of spatial refugia or seasonal restrictions could reduce impacts on sensitive species.

Wyoming↗
USGS2026

Flying under the radar: The demographic importance of immatures in long-lived seabird populations

Demographic assessments are essential for effective biological conservation management, allowing early detection of population declines and timely allocation of resources to avoid possible crises. For species with slow life-history strategies like seabirds, only the breeding adults are monitored routinely. The dynamics of immatures, often unobservable from fledging to recruitment, are less well understood and typically not accounted for in conservation status assessments. Here, we quantify the importance of changes in the survival and abundance of immatures in shaping the past and forecasted dynamics of a long-lived marine top-predator. We use integrated population models (IPM) incorporating the dynamics of immatures, based on multi-decadal demographic monitoring of the black-browed albatross ( Thalassarche melanophris ) at three globally important breeding sites. The populations showed differences in breeding and survival rates, highlighting a degree of life history flexibility in response to the environment. Using a retrospective sensitivity analysis, we consistently identified immature survival as the key contributor to population growth rate. At all sites, even those with increasing or stable breeding populations, the total population has been declining, largely due to decreases in immature survival. Although not directly apparent from counts, this decline is already underway and is projected to emerge at the level of the breeding population over the coming three generations. This contrasts with a model focusing solely on counts of breeding adults, which mostly indicate an overall population increase. Collectively, our findings highlight that conservation assessments must account for the dynamics of subadult stages, or risk providing an inaccurate picture of population status.

Biological Conservation↗
USGS2026

Spatial ecology and recovery patterns of a translocated mammal community in southern Africa

Conservation translocations are an increasingly common tool to restore wildlife populations within protected areas. Along with identifying and mitigating threats, post-release monitoring allows managers to evaluate recovery effectiveness and improve success rates. Multispecies translocations present challenges in monitoring design, data processing, and analysis. Camera traps coupled with computer-vision-assisted workflows, environmental data, and spatially explicit occupancy models show promise for efficient multispecies monitoring over broad spatiotemporal scales. We applied this approach to a large translocation program in Nkhotakota Wildlife Reserve, Malawi, using a six-year camera-trap dataset to assess recovery patterns of nine large herbivore species. We fit spatial occupancy models to estimate species distributions and trends in landscape use while incorporating environmental covariates and accounting for spatial autocorrelation. African bush elephants ( Loxodonta africana ) and cape buffalo ( Syncerus caffer ) showed the strongest evidence of establishment and expansion, while common eland ( Taurotragus oryx ), greater kudu ( Tragelaphus strepsiceros ), plains zebra ( Equus quagga ), and impala ( Aepyceros melampus ) showed positive but weaker or uneven trends. Sable antelope ( Hippotragus niger ) showed evidence of establishment without expansion, whereas waterbuck ( Kobus ellipsiprymnus ) and warthog ( Phacochoerus africanus ) exhibited negative trends, although support for waterbuck declines was weak. Species exhibited variable and seasonally specific relationships with tree density, proximity to water, elevation, slope, and the reserve boundary, indicating that a range of environmental conditions support this mammal community. Our results demonstrate how spatial occupancy models can provide interpretable recovery indicators for multispecies translocations while highlighting how long-term monitoring can distinguish early recovery, behavioral shifts, and interannual variation from long-term population responses.

Nkhotakota Wildlife Reserve↗
USGS2026

Rhyolitic and basaltic reference materials for TC/EA analysis: Investigation of water extraction and D/H ratios

Increasingly, water and D/H ratios of silicic and basaltic glasses are used to investigate magmatic degassing and secondary hydration, as well as for study these parameters in the mantle and crustal magmas. The advent of the High Temperature Conversion Element Analyzer (TC/EA) continuous flow mass spectrometry made the determination of hydrogen isotopes relatively quick and precise (±0.04 wt% H 2 O and 1–3‰ δ 2 H). Many labs around the world have such systems, thus there is a need to develop both silicic and basaltic volcanic glass reference materials (RMs) that can be used for interlaboratory comparison by bulk and microanalytical methods. Here, we report results of such investigation run against solid RMs (USGS micas) and water RMs (including VSMOW) in three different labs and describe analytical protocols. We report on the effects of glass size fraction, the mass of aliquots measured, and yield dependency for two glasses: UOR (drill cutting of IDDP-1 rhyolite, Iceland) and UOB (an E -MORB basalt from the East Pacific Rise). Proposed RM values are: UOB rhyolitic glass ( n = 31): H 2 O = 1.84 ± 0.06 wt% (1 s.d.), and δ 2 H = −115.5 ± 2.6‰ (1 s.d.). UOB basaltic glass ( n = 60): H 2 O = 0.37 ± 0.03 wt% (1 s.d.), and δ 2 H = −82.1 ± 5.7‰ (1 s.d.). Glass reference materials are available in 100 mg quantities from the Stable Isotope Laboratory at the University of Oregon for a nominal fee.

Chemical Geology↗
USGS2026

Utilization of multiple geochronology techniques to constrain the age of laterization and mineralization of the world-class Mount Weld rare earth element deposit, Western Australia

Pervasive chemical weathering on stable cratons may form thick regoliths and elemental enrichment, but constraining the age of regolith formation is challenging. In this study we utilize multiple geochronological techniques on different minerals from the world-class Mount Weld rare earth element (REE) deposit, formed by lateritic weathering of a carbonatite, to constrain the age of formation and provide insight into landscape evolution. The oldest dates, ca. 100 to 38 Ma, are from Lu-Hf dating of churchite [HREE(PO 4 )·2(H 2 O)], a heavy REE phosphate mineral. Growth bands on individual minerals show a younging outwards. 40 Ar/ 39 Ar geochronology of cryptomelane [K(Mn 4+ ,Mn 2+ )₈O₁₆] yielded dates from ca. 40 to 27 Ma. Similarly, (U-Th)/He geochronology of goethite [FeO(OH)] yielded dates ranging from ca. 45 to 19 Ma. Integrating results into regional constraints, suggests 1) churchite formed by mineral saturation in a karst-like setting below the water table from ca. 100 to 40 Ma, 2) with minor uplift and erosion, cryptomelane and goethite formed at or near the water table between ca. 45 and 19 Ma, 3) after ca. 15 to 10 Ma chemical weathering within the profile had ended. Other studies document that the region experienced minimal uplift and a wet, warm climate from ca. 100 Ma to 15 Ma. These conditions and the high carbonate content of the carbonatite promote extensive chemical weathering, a deep weathering profile, and the preservation of the weathered section. This study highlights the use of multiple geochronological techniques utilizing different minerals to provide insight into how laterites form and to constrain the timing and history of the formation of this important mineral deposit.

Western Australia↗
USGS2026

Integrating detrital magnetite geochemistry and (U-Th)/He chronometry as a sediment provenance tool in geologic and metallogenic terranes

Magnetite is ubiquitous in porphyry Cu systems and in sediment sourcing both barren and mineralized regions, with potential as an indicator mineral in concealed and coarsely-mapped terranes. We develop and test a workflow for integrated geochemistry and (U–Th)/He (He) dating for inferring detrital magnetite (DMt) provenance in these settings. The ca. 70 Ma Taurus porphyry Cu–Mo(–Au) district in eastern interior Alaska serves as a test case. DMt from streams draining porphyry-related mineralization was characterized by geochemistry and mineral inclusion and microstructure observations, complemented by similar data for potential porphyry and host rock sources. Principal component analysis and clustering of DMt geochemical data resolve multiple populations in our samples geochemically and texturally compatible with derivation from metamorphic, porphyry-related hydrothermal, and igneous sources. Hydrothermal magnetite comprises ∼16–50% of DMt nearest porphyry mineralization but diminishes to ∼4% ∼15 km downstream. Subsampled grains within populations yield ∼160–110 Ma, ∼70 Ma, ∼55 Ma, and ∼20 Ma magnetite He date modes. Combined with provenance, He dates capture Early Cretaceous regional exhumation of metamorphic host rock and Late Cretaceous porphyry Cu mineralization. DMt grains showing partial hematite replacement yield ca. 55–20 Ma dates regardless of source, overlapping regional warm/wet climatic intervals. We interpret Cenozoic dates to reflect exhumation to near-surface oxidizing conditions and(or) supergene weathering. Magnetite is thus a promising target phase for (1) tracking the spatiotemporal distribution of porphyry systems, and (2) linking the formation and exhumation of these systems to a regional geologic history, both in Alaska and globally.

Alaska, Yukon↗
USGS2026

Release and recapture: Limited carbon mobilization in sediment adjacent to Central Atlantic Magmatic Province sills, Florida, USA

Large Igneous Provinces (LIPs) are associated with dramatic changes to the Earth system; their rapid release of carbon may initiate catastrophic climatic changes causing mass extinction. This carbon release is often associated with volcanic emissions, yet metamorphic carbon production is poorly constrained. Metamorphic carbon devolatilization occurs as intrusions interact with host sediment, potentially releasing substantial sedimentary carbon. While this process has been modeled, few studies use an observational approach. Here, we apply geochemical analysis, petrographic analysis, Raman spectroscopy, vitrinite reflectance, and thermodynamic modeling to understand carbon devolatilization in sediment adjacent to Central Atlantic Magmatic Province basaltic intrusions using two boreholes that penetrate the Florida basement. We find geochemical and petrographic evidence for CO 2 release from carbonates below a 10 m thick sill, with upward fluid transport and recapture of mobilized CO 2 at the top of the sill. Ultimately, we estimate 220 mols/m 2 to 9900 mols/m 2 of carbon were mobilized from sedimentary carbonate. Uncertainties in the extent of re‑carbonation suggest that anywhere from 0 mols/m 2 to 7100 mols/m 2 may have escaped to the surface. We find little evidence of organic carbon mobility, due partly to the increased activity of CO 2 from carbonate devolatilization. Discrepancies between measured temperatures and 1D thermal models suggest complexities in heat transport through aqueous pore fluid flow and short (hundred to thousand year) heating timescales. These results highlight that further field-based study can help clarify the roles that heating timescales, fluid flow, sediment chemistry, and other factors play in releasing and capturing carbon during LIP emplacement.

Florida↗
USGS2026

Characterisation of bituminite and testing reproducibility of vitrinite and bituminite reflectance measurements in organic‑carbon-rich intervals of the Kimmeridge Clay Formation: ICCP Identification of Dispersed Organic Matter Working Group round robin exercises

Three round robin exercises (RRE) aimed at characterizing bituminite and testing the reproducibility of random vitrinite (VR o %) and bituminite (BitR o %) reflectance measurements on samples of dispersed organic matter from organic‑carbon rich shale intervals of Kimmeridge Clay Formation were conducted in 2016, 2018, and 2020. This work was conducted by the Identification of Dispersed Organic Matter Working Group (IDOM WG) of the International Committee for Coal and Organic Petrology (ICCP). The Kimmeridge Clay Formation represents the major marine source rock for the North Sea hydrocarbon province. Samples collected from Kimmeridge Bay, Dorset, England, United Kingdom and Filey Bay, North Yorkshire, England, United Kingdom outcrops and the 16/17–14 well in the Tiffany oil field, Viking Graben, North Sea, were analyzed by 19 to 23 participants in 15 to 17 laboratories from 14 to 15 countries. Samples contain moderate to high organic matter content [5.32 to 12.10 wt% total organic carbon (TOC) content] with thermal maturity ranging from immature to thermally mature (T max 418 to 445 °C). Participants used a standard description sheet to record bituminite morphological characteristics, including its form, size, mode of appearance, and impurities, for use in the revision of the bituminite definition. The usage of previously published classifications of bituminite types (e.g., bituminite I sensu Teichmüller and Ottenjann, 1977 ) in the RRE was not found to be helpful. The indistinct, amorphous character of boundaries of bituminite, and the poor preparation of whole rock pellets for the 2018 and 2020 RRE hampered identification of bituminite. Mean random BitR o %, including outlying values, varied in all three RRE from 0.19 to 0.35% and is reported here for the first time. Application of the criterion standard deviation (SD) < 0.15 × BitR o % to exclude outlying BitR o % values showed virtually no change in modified BitR o % in immature samples (2016 and 2018 RRE) and an unexpected increase to 0.43% BitR o in the thermally mature sample (2020 RRE). Mean VR o values, including outliers in the three RRE, range from 0.47 to 0.71%, confirming the immature to thermally mature nature of samples of the Kimmeridge Clay Formation used in this study. Application of the criterion SD < 0.15 × VR o to exclude outlying values results in a comparable range of modified VR o values and a decrease in group standard deviation. Precision of VR o values (including outlying values) evaluated via the averaged unsigned multiple of the standard deviation rule (< 1.5) showed moderate to high precision comparable to historical values from similar RRE. An average reproducibility limit (RL) of 0.29% (including outlying values) showed an improvement in reproducibility relative to similar historical RRE (0.35%), which was attributed to the application of a common methodology (ASTM D7708, 2014b, 2023) to enhance the quality of data from the reflectance test method.

Kimmeridge Bay↗
USGS2026

HyFlood: A surrogate-model-based framework for compound coastal flooding

Compound coastal flooding is a major threat to low-lying coastal regions and is expected to intensify under future climate change projections. However, modeling the joint interaction of waves, storm surge, tides, and rainfall remains computationally demanding, limiting the development of fast and reliable forecast tools. Here we present HyFlood, a hybrid statistical-numerical downscaling framework capable of computing and mapping high-resolution compound flood hazards while substantially reducing the computational cost compared with fully process-based hydrodynamic modeling. HyFlood combines statistical sampling and selection algorithms with a cascade of reduced-complexity surrogate models that emulate nearshore wave transformation, surf-zone hydrodynamics, and coastal, fluvial, and pluvial flooding. The surrogate models employ machine-learning and regression algorithms applied to a low-dimensional representation of the flooding outputs, obtained through statistical dimensionality reduction. The framework is demonstrated in southern O'ahu, Hawai'i, a region exposed to elevated sea levels driven by tides, waves, and storm surge along with frequent precipitation-driven flash flooding. Validation of the surrogates against the physics-based model outputs demonstrates that HyFlood accurately reproduces daily maxima of spatially distributed flooding depths. This hybrid approach offers a scalable and efficient tool to better quantify how changes in flooding drivers translate into hazard and impact assessments, and to support compound-flood risk assessments and climate-change adaptation planning.

Hawaii↗
USGS2026

Foraging benefits promote fitness in migratory mule deer

Although migration is widespread among ungulates, the fitness benefits associated with different migratory tactics have rarely been documented. Here, we evaluated a 9-year dataset on a migratory population of mule deer to test the hypothesis that long-distance migration provides access to seasonal forage which translates into demographic benefits. Mule deer that migrated long (>130 km) and medium distances (50–130 km) accessed higher forage quality and thus gained 1.3–2.7 times more fat over the growing season compared to mule deer that remained year-round as residents within a desert ecosystem. Elevated levels of fat translated to ∼20% higher probability of adult annual survival than residents. Mule deer that remained year-round in the desert portion of the study area were so resource-limited that they raised fawns at the expense of their own survival. Due to their higher levels of fat, annual survival, and fetal rates, migrants showed more robust population growth (λ = 1.03) compared to residents, which exhibited projected declines in population size over time (λ = 0.95). These results support the notion that migration translates into demographic benefits and highlight the urgent conservation work necessary to sustain diverse ungulate migrations amid habitat alteration due to climate change and an expanding web of linear barriers to movement.

Wyoming↗
USGS2026

Guidelines for producing integrated 210Pb and 14C age-models

Accurate reconstructions of past environmental changes are crucial in paleoecological research and require reliable chronologies of sedimentary archives. Establishing robust age-models and obtaining the most appropriate proxies for analysis is a complex scientific endeavor, requiring extensive resources and collaboration among specialists, including radiochronologists. Radiometric dating methods, such as 210 Pb and radiocarbon ( 14 C), are frequently employed to establish chronologies in aquatic sedimentary deposits and peat bogs. In this study, we review key aspects of sampling, analysis, and the principles underlying 210 Pb and 14 C age-models, focusing on methods for developing robust joint chronologies for paleoenvironmental research. Drawing largely from the authors' experiences and group discussions during and after a scientific workshop in 2022, we discuss important considerations for site selection, sampling strategies, and radiometric dating to construct integrated 210 Pb and 14 C age-models. Using expert consensus, this group – called Paleostats – aims to provide a set of best practices for other geochronologists with this methods paper. Among our conclusions, we emphasize the importance of accounting for site-specific factors such as prior information on sedimentation rates to establish appropriate sampling and analytical strategies. The use of appropriate coring devices can minimize disturbance to sediments and ensure the core surface remains intact and preserved until sectioning. Where excess 210 Pb is expected, sectioning at intervals of ≤1 cm provides an adequate sampling resolution for 210 Pb dating. Exceptions are possible, allowing for ~2–3 cm sections in areas with confirmed high sedimentation rates (e.g., > 1 cm yr −1 ). Recovering deeper core sections for 14 C dating with sufficient overlap allows for accounting errors in depth estimates made in the field. Special attention is advised during time intervals where validation proxies, such as the human-made radionuclides 137 Cs or post-bomb 14 C, are expected, and to determine the depth of secular equilibrium between 210 Pb and 226 Ra. Radiocarbon analyses are commonly performed by accelerator mass spectrometry, and age models are constructed mainly using Bayesian statistics with Markov Chain Monte Carlo techniques (e.g., Bacon ). A Bayesian approach ( Plum ) is now available for producing 210 Pb age-models, which infers the 210 Pb ex flux, eliminates the need for selecting an equilibrium depth, and allows dating cores with incomplete 210 Pb ex inventory. Plum offers improved chronologies by integrating raw 210 Pb and 14 C data, and these age-models can be enriched with other dating methodologies, such as identifying tephras and other well-recorded historical events. Harmonized reporting would contribute to making radiometric age-models reproducible, which would benefit from an international effort. Using 210 Pb and 14 C to produce integrated age-models may yield better insights into the interplay between natural and recent anthropogenic forcings on ecosystems. This can enhance our understanding of environmental processes and their impacts on climate change, ultimately supporting science-based assessments and decisions.

Earth-Science Reviews↗
USGS2026

Understanding the resource potential of natural hydrogen on Earth: Scientific gaps, uncertainties and recommendations

A comprehensive scientific research roadmap is essential to bridge knowledge gaps and deepen the understanding of key geological, geochemical, and geophysical aspects of natural hydrogen (H 2 ) as a potential new energy resource. This paper reviews major scientific uncertainties on natural H 2 , suggesting research priorities, as a guide for defining exploration strategies, techniques, and data interpretation. The uncertainties concern all phases of the natural H 2 cycle, from generation (source rocks) through migration (advection and diffusion) and accumulation (reservoir and cap rocks) to the application and interpretation of subsurface and surface geochemical and geophysical exploration techniques. Understanding H 2 sources and generation rates (the amount of H 2 generated by a given volume of rock over time) is crucial for determining whether a geological H 2 system operates as a short-term dynamic system with rapid H 2 production and release, or as a conventional gas system with long-term accumulations, analogous to petroleum reservoirs. Preliminary estimates for serpentinisation, radiolysis, and organic matter degradation suggest that H 2 generation is not inherently fast, especially for non-hydrothermal continental systems (crystalline basement of shields, ophiolites, peridotite massifs, sedimentary basins), and long-term accumulations, like those of fossil natural gas systems, represent the most likely scenario. The mechanisms of H 2 migration through geological formations require application of fundamental principles of fluid-flow physics, distinguishing advection and diffusion, as well as their forms (from gas-phase, bubble flows to aqueous solutions). Additional studies of H 2 accumulation and retention in subsurface reservoirs could improve understanding of mechanisms of H 2 migration by focusing on the rock fluid-bearing properties and the factors affecting H 2 preservation, such as the presence of cap rocks impermeable to H 2 , pressure conditions, residence times, and microbial or abiotic consumption. Advanced techniques, including reservoir modelling, flow simulations, 3D imaging (micro-CT) of H 2 -bearing rocks, and extraction and analysis of gas occluded in rocks, can provide insights into the stability and potential recoverability of H 2 accumulations. The interpretation of surface exploration techniques, including gas geochemistry, geophysics, and remote sensing, long employed in mineral and energy resource exploration, is now being adapted for natural H 2 studies, but challenges remain in the data interpretation. Distinguishing H 2 seepage due to geological degassing from H 2 produced near the surface by modern microbial processes or artificial sources, such as hammering or drilling for soil-gas sampling, drilling into aquifers, and corrosion in boreholes, is an essential step in exploration. The simple detection of H 2 in soils, even in morphological structures like sub-circular depressions or “fairy circles”, cannot be cursorily interpreted as a signal of natural H 2 seepage from a deep source. A holistic geochemical approach, including isotopic analyses of gases associated with H 2 , is recommended to distinguish among the variety of possible H 2 origins. Observations of H 2 in wells should be interrogated to rule out possible artifacts such as corrosion and drill bit metamorphism. The integration of multiple geophysical methods, including seismic, gravimetric, magnetic, and electro-magnetic surveys, is recommended to mitigate interpretation ambiguities regarding the structure of a subsurface H 2 system (source and reservoir rocks, including fluid and gas storage), due to the non-uniqueness of rock-specific physical properties.

Earth-Science Reviews↗
USGS2026

Estimating paleotemperature using stable isotopes of soil-formed phyllosilicates from paleosols: A review

Fossilized soils, or paleosols, contain soil-formed phyllosilicates whose stable isotopic compositions may be used to calculate paleotemperature and thus reconstruct ancient terrestrial environments. Though paleosols are common in the geologic record, the use of phyllosilicates as paleotemperature proxies is limited in the literature owing to difficulties with selecting optimal paleosols, isolation from non-clay minerals and organic materials, mixtures of phyllosilicates in natural samples, wide variations of chemical compositions for phyllosilicates, and limited to undefined equilibrium fractionation factors between phyllosilicates-water. Here, we address these challenges by examining and comparing methods used for sample selection, mineral isolation, pretreatments, mineral identification, conventional and developing methods for oxygen and hydrogen isotopic analyses, and determination of phyllosilicate-water equilibrium fractionation factors, concluding with recommendations for best approaches for paleotemperature estimation. Additionally, we discuss how to identify and avoid detrital phyllosilicates, the impacts of diagenesis, comparison of stable isotope and non-isotope paleosol paleotemperature proxies, and challenges and opportunities for broadly using paleosols as paleoclimate archives. With ongoing efforts to refine this multi-faceted paleotemperature approach, the stable isotope geochemistry of soil-formed phyllosilicates continues to be an invaluable proxy system, enhancing our understanding of terrestrial paleoenvironments and paleoclimate.

Kansas↗
USGS2026

Hierarchical mixture models and high-resolution monitoring data can inform siting and operational strategies to mitigate bat fatalities at wind turbines

Bats provide critical ecosystem services, but bat fatalities due to wind energy development may imperil some bat populations. Statistical models are used to estimate the total fatalities that occur based on carcasses observed during monitoring surveys. Current models often estimate fatalities aggregated across species, time, and/or turbines, but fall short of reliably informing siting and operational collision mitigation strategies that account for species-specific fatality patterns on a fine spatiotemporal scale. We developed a hierarchical mixture model for estimating species-specific covariate effects and total fatalities per species at each turbine on weekly intervals. We applied the model to a high-resolution dataset of bat carcasses found during turbine searches across nineteen wind facilities in Iowa over two years. Our model explains species-specific variation in bat fatalities at individual wind turbines according to turbine proximity to bat habitat, turbine design specifications, seasonal trends, and weather conditions such as nightly air temperature, air pressure, and wind speed. Turbines located on the edge of wind facilities had higher fatalities, and proximity to roosting and foraging habitat accounted for variation in species-specific fatality estimates. These insights into turbine placement effects can inform siting strategies. We also discovered species-specific relationships with average nightly wind speed and air temperature, among other weather conditions, that could inform operational mitigation strategies such as smart curtailment. Our model can transform observations of carcasses found during turbine searches across multiple facilities, years, and variable search efforts into estimates of total fatalities per species associated with species-specific spatial, temporal, and environmental covariate effects.

Ecological Informatics↗
USGS2026

Two-stage approach to automatic detection with machine learning for improved surveillance of the invasive Cuban treefrog

The Cuban treefrog ( Osteopilus septentrionalis ), as an invasive species in the southern United States, presents a need for effective surveillance. Automated detection expedites processing of audio data for large-scale surveillance and monitoring programs. However, current available methods commonly used for anuran species have not been sufficient to detect Cuban treefrogs. Here, we present results from a two-stage method for automated detection that employs both cross-correlation template matching and secondary supervised learning classifiers. In the first stage, audio data are screened for initial detections using template matching, in which the detections contain both true and false positives. In the second stage, the false positives are screened out using classifier algorithms. We used this method to process 139,985 audio recordings, consisting of 596,046 total minutes, collected at 13 locations in Louisiana and Florida from 2014 to 2022. From the stage 1 template matching, we detected 83,191 Cuban treefrog signals across recordings. The stage 2 machine learning model was able to identify stage 1 false positive detections with a testing accuracy of 98.46% and a testing false positive rate of 1.116%. After pruning false positive detections, a total of 20,271 individual Cuban treefrog detections remained, distributed mainly across 3 sites in an area with known presence. Locations with presumed absence had an easily verifiable number of false positive detections ( n = 109 across all other sites). The two-stage methodology utilizing both template matching and machine learning algorithms can be integrated into wildlife surveillance or monitoring programs for species with distinctive, conserved calls as an effective way to achieve sensitive species detection with a low incidence of false positives.

Florida, Louisiana↗
USGS2026

A site prioritization tool for invasive species management: Integrating diverse spatial data to improve decision making

Resource managers are tasked with protecting natural areas from invasive species with limited resources. Further, invasive management goals can vary greatly based on different management priorities specific to management agencies or taxa of interest. The site prioritization tool for invasive species management addresses these challenges by creating a platform to view and combine diverse spatial data layers to estimate cumulative invasion risk based on user-specific needs. For this tool, we developed a human transport risk layer, estimating invasion risk based on proximity to human population centers and transportation corridors, and created maps of non-native species richness across the conterminous United States. The tool also includes spatial layers showing projected changes in key climate variables through the end of the century to identify areas where invasion risk may shift. Users can explore these layers to prioritize sites based on the invasive taxa of interest, likely invasion pathways, and disturbances that may elevate invasion risk. This interactive tool will allow managers to make the spatial comparisons needed to focus efforts on areas that are highly susceptible to invasion and efficiently target monitoring and suppression efforts.

Ecological Informatics↗
USGS2026

Environmental tradeoffs of urban stream restoration in Fairfax County, Virginia

Regulatory mandates to improve water quality and stream health have driven substantial investment in stream restoration. Most projects aim to improve channel-floodplain connectivity, reduce sediment erosion, and enhance habitat for aquatic organisms, yet few include adequate pre- and post-restoration monitoring to assess outcomes. Since 2007, Fairfax County, Virginia, and the U.S. Geological Survey have partnered to monitor and evaluate water-quality conditions in Flatlick Branch. In 2018, a 1.72-km reach of stream above the monitoring station was restored using a Natural Channel Design approach. This study applied the Stream Functions Pyramid (SFP) framework to evaluate restoration tradeoffs. Post-restoration, watershed hydrology remained largely unchanged, but channel modifications increased flow capacity, reduced velocity, and further disconnected the channel from the floodplain. Nutrient and sediment reductions exceeded expected amounts, but the removal of over 20 % of riparian tree canopy increased physicochemical variability and the frequency and magnitude of water temperature heatwaves. Post-restoration, state standards for low dissolved oxygen and elevated pH were exceeded 2.5 and 7.5 times more often, respectively. Gross primary production and ecosystem respiration increased and organic matter sources supporting metabolism shifted from allochthonous to autochthonous. Trends in several benthic macroinvertebrate metrics, which were improving prior to construction, have since plateaued or declined, and the fish assemblage shifted from a native minnow dominated community to non-native, warmwater tolerant taxa. This study highlights the need for comprehensive assessments of stream restoration and benefits of using the SFP to understand the consequences and possible tradeoffs of different ecosystem management decisions.

Virginia↗