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At least 1,387 records · Page 77Linked to original sources
USGS2024

Pesticide concentrations of surface water and suspended sediment in Yolo By-Pass and Cache Slough Complex, California, 2019–2021

Managed flow pulses in the north Sacramento-San Joaquin Delta are an adaptive management tool used in efforts to enhance food availability in delta smelt ( Hypomesus transpacificus ) habitat as part of the North Delta Food Subsidies Action. The California Department of Water Resources (DWR) monitors non-managed seasonal and local flow pulses and managed flow pulses from agricultural drainage or main stem Sacramento River water redirected through Yolo By-Pass. Augmented flow pulses are hypothesized to improve net positive flow during summer and fall in Yolo By-Pass and enhance plankton availability in delta smelt habitat in Cache Slough complex. However, flow pulses may also result in unintended negative effects of increased pesticides that are transported through Yolo By-Pass. Here, we evaluate pesticides in surface water and suspended sediment correlated with flow pulses in Yolo By-Pass during the 2019–21 calendar years. Surface-water and suspended-sediment samples were collected by DWR personnel. Water samples were analyzed at the U.S. Geological Survey Organic Chemistry Research Laboratory in Sacramento, California, for a suite of as many as 178 current-use pesticides and pesticide degradates using gas chromatography with mass spectrometry (GC/MS), gas chromatography with tandem mass spectrometry, and liquid chromatography with tandem mass spectrometry. Suspended sediments filtered from water samples were analyzed for a suite of as many as 173 current-use pesticides and pesticide degradates. There were 52 different current-use pesticides and pesticide degradates detected in water samples collected throughout the study. Concentrations ranged from below method detection limits to 4,070 nanograms per liter. Five different compounds in water samples were detected with concentrations above U.S. Environmental Protection Agency aquatic life benchmarks. In suspended-sediment samples collected throughout the study, eight different current-use pesticides and pesticide degradates were detected. Total pesticide concentrations were highest at surface-water sites in the northern end of Yolo By-Pass and decreased farther downstream during the same sampling events. Total pesticide concentrations generally were higher for most surface-water sites immediately before or during the managed flow pulse in 2019 versus after the flow pulse. Finally, mean total pesticide concentrations for each surface-water site generally were higher during all of 2019 than 2021, regardless of sampling period.

California↗
USGS2024

Distribution, abundance, and habitat characteristics of Coastal Cactus Wrens (Campylorhynchus brunneicapillus) in San Diego County, California—2023 Data Summary

Executive Summary We surveyed for coastal Cactus Wren ( Campylorhynchus brunneicapillus ) in 507 established plots in San Diego County in 2023, encompassing 4 genetic clusters (Otay, Lake Jennings, Sweetwater/Encanto, and San Pasqual). Two surveys were completed at each plot between March 1 and July 31. Cactus Wrens were detected in 181 plots (36 percent of plots). Cactus Wrens were detected in 26 percent of plots that have been consistently surveyed since 2020, indicating lower plot occupancy than in 2022 (31 percent), 2021 (34 percent), and 2020 (35 percent). There were 158 Cactus Wren territories detected across all survey plots in 2023. In plots that have been consistently surveyed since 2020, we documented 85 territories, which is a decrease from 94 territories in 2022, 113 territories in 2021, and 109 territories in 2020. The number of territories declined from 2022 to 2023 in the Lake Jennings, Sweetwater/Encanto, and San Pasqual genetic clusters but remained virtually the same in the Otay genetic cluster. At least 80 percent of Cactus Wren territories were occupied by pairs, and 125 fledglings were observed in 2023. We observed 14 banded Cactus Wrens in 2023, 9 of which we could identify individually by color band combination. Adults of known age ranged from 4 to 7 years old. All individually identifiable adult Cactus Wrens occupied the same territory in 2023 that they occupied in 2022, and we detected no movement of banded Cactus Wrens between genetic clusters. Vegetation at Cactus Wren survey plots was dominated by coastal sage scrub shrubs, such as California sagebrush ( Artemisia californica ), California buckwheat ( Eriogonum fasciculatum ), lemonade berry ( Rhus integrifolia ), jojoba ( Simmondsia chinensis ), and San Diego viguiera ( Bahiopsis laciniata ). No definitive signs of fungal pathogens were observed on cactus within and around survey plots. Blue elderberry ( Sambucus mexicana ) was detected at 41 percent of plots, and Cactus Wrens occupied proportionally more plots with elderberry than plots without elderberry. Very little dead or unhealthy cactus was observed within all survey plots, and Cactus Wren occupancy did not differ between plots with high or low amounts of dead or unhealthy cactus. Almost 90 percent of plots had more than 5 percent of cactus crowded or overtopped by vines and shrubs, and Cactus Wren occupancy did not differ between plots with high or low amounts of cactus crowded or overtopped by vines and shrubs. Non-native annual cover was more prevalent in survey plots in 2023 than in 2022. Cactus Wrens did not select or avoid plots with more non-native cover.

California↗
USGS2024

Hydrodynamic model of the Colorado River, Glen Canyon Dam to Lees Ferry in Glen Canyon National Recreation Area, Arizona

The U.S. Geological Survey constructed a two-dimensional hydrodynamic model that was applied to a 15.8-mile tailwater reach of the Colorado River in Glen Canyon that begins 0.25 mile downstream from Glen Canyon Dam and extends to Lees Ferry in Glen Canyon National Recreation Area, Arizona. The model used the Flow and Sediment Transport with Morphological Evolution of Channels (FaSTMECH) solver in the International River Interface Cooperative (iRIC) modeling interface. The model grid was developed from a full channel digital elevation model derived by combining bathymetric and topographic data collected from March 2013 to February 2016. The model was used to predict water-surface elevations, depths, depth-averaged flow velocities, and bed shear stresses for discharges ranging from 1,000 to 70,000 cubic feet per second. Modeled water-surface elevations matched well with measured values at cross sections throughout the reach, with a mean absolute error of 0.14 meter over the range of typical discharge releases from Glen Canyon Dam. The mean error on discharge, a measure of how well the model solution converged, averaged 0.6 percent and did not exceed 2 percent over the range of discharges modeled. These results indicate that model predictions of hydraulic parameters are reasonably accurate and suitable for use for a variety of purposes, such as ecological and geomorphic modeling.

Arizona↗
USGS2025

Critical minerals in orogenic (gold) and Coeur d’Alene-type mineral systems of the United States

Orogenic and Coeur d’Alene-type mineral systems are produced by metamorphic devolatilization of thick volcanic or siliciclastic sedimentary rock sequences and the focused flow of hydrothermal fluids upwards along crustal-scale faults. Most orogenic systems are found along the Cordilleran orogen, stretching from California northwards into Alaska, whereas most Coeur d’Alene-type systems occur in the Proterozoic Belt Basin in Idaho and Montana. Although the deposit types in these systems are exploited for precious and base metals, potential exists for the production of critical minerals necessary for current (2025) societal needs in the United States. Publicly available geochemical data compiled for these mineral systems, coupled with mineralogical characteristics, indicate that several critical minerals could potentially be recovered from unmined resources and processed mine waste: arsenic, antimony, tellurium, cobalt, and tungsten from orogenic gold deposits and zinc, antimony, arsenic, and manganese from Coeur d’Alene-type systems. These critical minerals reside primarily in arsenopyrite (arsenic), scheelite (tungsten), siderite (manganese), sphalerite (zinc), tetrahedrite (antimony and arsenic), stibnite (antimony), and telluride (tellurium) minerals.

continental United States↗
USGS2024

Streamflow, water quality, and constituent loads and yields, Scituate Reservoir drainage area, Rhode Island, water year 2021

As part of a long-term cooperative program to monitor water quality within the Scituate Reservoir drainage area, the U.S. Geological Survey in cooperation with Providence Water (formerly Providence Water Supply Board) collected streamflow and water-quality data in tributaries to the Scituate Reservoir, Rhode Island. Streamflow and concentrations of chloride and sodium estimated from records of specific conductance for 16 tributaries were used to calculate loads of chloride and sodium during water year 2021 (October 1, 2020, through September 30, 2021). Water-quality samples were collected by Providence Water at 36 sampling stations on tributaries to the Scituate Reservoir during water year 2021. These water-quality data are summarized by using values of central tendency and are used, in combination with measured (or estimated) streamflows, to calculate loads and yields of selected water-quality constituents for water year 2021. Annual mean streamflows for monitoring stations in this study ranged from 0.37 to 32.4 cubic feet per second during water year 2021. At the 16 continuous-record streamgages, tributaries transported about 2,900 metric tons (t) of chloride and 1,800 t of sodium to the Scituate Reservoir; annual chloride yields for the tributaries ranged from 15 to 110 metric tons per square mile (t/mi 2 ), and annual sodium yields ranged from 10 to 68 t/mi 2 . At the stations where water-quality samples were collected by Providence Water, the medians of the median daily loads were 180 kilograms per day for chloride, 12 grams per day as nitrogen for nitrite, less than 700 grams per day as nitrogen for nitrate, 410 grams per day as orthophosphate for phosphate, 71,000 million colony forming units per day for coliform bacteria, and less than 2,000 million colony forming units per day for Escherichia coli . The medians of the median yields were 67 kilograms per day per square mile for chloride, 4.2 grams per day per square mile as nitrogen for nitrite, 400 grams per day per square mile as nitrogen for nitrate, 180 grams per day per square mile as orthophosphate as phosphate, 46,000 million colony forming units per day per square mile for coliform bacteria, and 1,000 million colony forming units per day per square mile for Escherichia coli .

Rhode Island↗
USGS2025

Parentage and sibship relationships among captive snakes at the Phoenix Zoo—2024 data summary

Introduction The narrow-headed gartersnake ( Thamnophis rufipunctatus ) is listed as threatened under the Endangered Species Act (U.S. Fish and Wildlife Service, 2014). This species has a strong association with aquatic habitats, and these habitats have been highly altered by impoundments, land-use changes, and the introduction and spread of non-native aquatic species, which contributed to declines in Arizona and New Mexico for the last 30–40 years. Captive breeding programs can be used for genetic rescue and conservation of threatened and endangered species (Frankham, 2010). Often based on pedigree analyses, captive management plans aim to retain genetic diversity, limit inbreeding, and avoid adaptation to captivity (Foose and Ballou, 1988; Hedrick and Miller, 1992; Ivy and others, 2009; Frankham, 2010). In 2011, the Arizona Center for Nature Conservation/Phoenix Zoo (hereafter Phoenix Zoo) developed an ex-situ captive breeding management plan for T. rufipunctatus , with the aim to propagate and release individual T. rufipunctatus back into their native range (Blais and others, 2022). We sequenced 125 microsatellite loci to generate genetic toolsets to track pedigree and assess paternity and sibship relationships for this captive breeding program. Specifically, we used microsatellite loci to assign paternity and relatedness among eight litters composed of multiple female and male snakes born between 2014 and 2023 at the Phoenix Zoo breeding facility. We also completed sibship analysis for six wild gartersnakes collected from Canyon Creek, Arizona, that were brought into the Phoenix Zoo breeding facility in 2017 and 2018.

Arizona↗
USGS2025

Streamflow, water quality, and constituent loads and yields, Scituate Reservoir drainage area, Rhode Island, water year 2022

As part of a long-term cooperative program to monitor water quality within the Scituate Reservoir drainage area, the U.S. Geological Survey, in cooperation with Providence Water (formerly the Providence Water Supply Board), collected streamflow and water-quality data in tributaries to the Scituate Reservoir, Rhode Island. Streamflow and concentrations of chloride and sodium estimated from records of specific conductance for 16 tributaries were used to calculate loads of chloride and sodium during water year 2022 (October 1, 2021, through September 30, 2022). Water-quality samples were collected by Providence Water at 37 sampling stations on tributaries to the Scituate Reservoir during water year 2022. These water-quality data are summarized by using values of central tendency and are used, in combination with measured (or estimated) streamflows, to calculate loads and yields of selected water-quality constituents for water year 2022. Annual mean streamflows for monitoring stations in this study ranged from about 0.31 to 28.0 cubic feet per second during water year 2022. At the 16 continuous-record streamgages, tributaries transported about 2,600 metric tons of chloride and 1,600 metric tons of sodium to the Scituate Reservoir; annual chloride yields for the tributaries ranged from 15 to 100 metric tons per square mile, and annual sodium yields ranged from 10 to 59 metric tons per square mile. At the stations where water-quality samples were collected by Providence Water, the medians of the median daily loads were 55,000 million colony forming units per day for coliform bacteria, 1,300 million colony forming units per day for Escherichia coli , 230 kilograms per day for chloride, 11 grams per day as nitrogen for nitrite, 620 grams per day as nitrogen for nitrate, and 440 grams per day as orthophosphate for phosphate, The medians of the median yields were 25,000 million colony forming units per day per square mile for coliform bacteria, 810 million colony forming units per day per square mile for Escherichia coli , 110 kilograms per day per square mile for chloride, 5.1 grams per day per square mile as nitrogen for nitrite, less than 300 grams per day per square mile as nitrogen for nitrate, and 230 grams per day per square mile as orthophosphate for phosphate.

Rhode Island↗
USGS2025

Base-flow sampling to enhance understanding of the groundwater flow component of nitrogen loading in small watersheds draining into Long Island Sound

Excessive nitrogen discharge is a major concern for the Long Island Sound. Programs have been implemented to reduce point sources of nitrogen to the sound, but little is known about the nonpoint sources. This study aims to better understand the current groundwater contributions of nitrogen from nonpoint sources in the Long Island Sound watershed. During the spring and summer of 2022, the U.S. Geological Survey, in cooperation with the U.S. Environmental Protection Agency, collected water-quality samples to analyze nutrients (nitrogen and phosphorus), chloride, and bromide at 45 stations in the Long Island Sound watershed in Connecticut, New York, and Rhode Island. The stations were in small drainage watersheds (5 to 30 square kilometers) in the southern part of the Long Island Sound watershed. During two separate synoptic sampling events, water-quality samples and instantaneous streamflow measurements were collected under base-flow conditions (where the streamflow is dominated by groundwater inputs rather than overland flow or runoff flow). One sampling event was in the nongrowing season (April 24–25, 2022), and the other was in the growing season (June 30–July 1, 2022). To calculate instantaneous nitrogen loads and yields, streamflow was measured at the time of sample collection. Nitrogen concentrations, loads, and yields varied among sampling stations and by season. Total filtered nitrogen concentrations were generally lower in the nongrowing season (from less than 0.14 to 1.9 milligrams per liter) than in the growing season (from less than 0.23 to 3.0 milligrams per liter). Nitrate plus nitrite concentrations showed little variation between the nongrowing and growing seasons. Unfiltered ammonia plus organic nitrogen concentrations were generally lower in the nongrowing season (from less than 0.07 to 0.83 milligram per liter) than in the growing season (from 0.11 to 0.98 milligram per liter). In contrast, total filtered and unfiltered nitrogen loads and yields were higher in the nongrowing season than during the growing season, likely because streamflows were higher during the nongrowing season. Total unfiltered nitrogen yields during the nongrowing season ranged from less than 0.15 to 5.0 kilograms per square kilometer per day. Total unfiltered nitrogen yields during the growing season ranged from less than 0.12 to 2.5 kilograms per square kilometer per day. Total filtered nitrogen yields during the nongrowing season ranged from less than 0.13 to 5.2 kilograms per square kilometer per day. Total filtered nitrogen yields during the growing season ranged from less than 0.06 to 2.5 kilograms per square kilometer per day.

Connecticut, New York, Rhode Island↗
USGS2025

Bedrock fracture characterization of the New Hampshire State Route 111 bypass, Windham, New Hampshire

Bedrock roadcuts developed with blasting along the New Hampshire State Route 111 bypass in Windham expose the metasedimentary Silurian Berwick Formation and intrusions of multiple phases of foliated to nonfoliated granite to granitic pegmatite of the Devonian New Hampshire Plutonic Suite. Fracture characterization at two roadway rock cuts (roadcuts) included measurement of fractures over a distance of approximately 225 and 85 meters. The Berwick Formation consists of medium-gray biotite-plagioclase-quartz granofels, biotite schist, and lesser calc-silicate rock. The Berwick Formation is locally sulfidic. Fresh, unweathered roadcuts are mostly gray but exhibit locally rusty weathering. The most conspicuous foliation in the region around the studied roadcuts is steeply northwest dipping to subvertical and northeast-southwest striking. Regionally, the strike of the foliation is consistently to the northeast-southwest, but the dip is locally variable to both the southeast and northwest. About 8 percent of the observed foliation surfaces exhibit limited fracture parting. The limited degree of parting agrees with observations for rocks within the garnet zone of metamorphism elsewhere in the Windham 7.5-minute quadrangle. The most prominent fracture trend is subvertical to steeply northeast-dipping and northwest-southeast striking (strike and dip of about 295°, 80°). The peak trend of steeply dipping fractures at the two exposures is 295°±12° and 289°±6°. Veins observed in the granite occur parallel to the peak fracture trend and consist primarily of quartz, tourmaline, and ankerite with minor amounts of sulfides (arsenopyrite, galena, and rare sphalerite), and trace amounts of apatite and rutile. The observed peak fracture trend at these roadcuts closely agrees with the most prominent fracture trend recognized within the Windham quadrangle. Gently south- to southeast-dipping and east- to northeast-striking fractures occur as joints and as parting fractures along a weak S 3 cleavage. Water-bearing fractures at one exposure occur along joints and gently dipping contacts between the Berwick Formation and the granite to granitic pegmatite of the New Hampshire Plutonic Suite. About 8 percent of the fractures are water-bearing and most water-bearing fractures are gently dipping to the southeast. Fracture data separated by rock type shows a similar distribution for steeply dipping northwest-striking trends, but with much fewer observed steeply north-dipping fractures in the granitic rocks. Both rock types show a cluster of gently south-dipping fractures. The granites show far fewer steeply dipping northeast-striking fractures, which reflects a greater degree of parting along the foliation in the metasedimentary rocks than in the granites. No foliation-parallel fractures were observed in the granites, but some contacts between granites and the Berwick Formation do exhibit parting. Fracture termination classification yields 3 percent abutting, 76 percent dead end, and 21 percent crossing (or throughgoing) fractures. Six brittle faults were observed, which strike northeast and most dip steeply to the northwest. Calculated paleostress tensors for the faults show an average stress field that is consistent with Late Triassic to Early Jurassic northwest-southeast extension associated with rifting of the New England crust during the initial opening of the Atlantic Basin. Fault data are consistent with brittle reactivation of the northeast striking and northwest dipping dominant foliation.

New Hampshire↗
USGS2025

Distribution, abundance, and breeding activities of Southwestern Willow Flycatchers (Empidonax traillii extimus) at select locations on the San Luis Rey River, San Diego County, California—2024 data summary

We surveyed for Southwestern Willow Flycatchers ( Empidonax traillii extimus ; flycatcher) at select locations along the San Luis Rey River, including along the middle San Luis Rey River near Bonsall and the upper San Luis Rey River near Santa Ysabel, California, in 2024. Surveys were completed at six locations: two along the middle San Luis Rey River (Bonsall [BO] and Rincon), which were last surveyed in 2021, and four along the upper San Luis Rey River, including three downstream from Lake Henshaw that have been surveyed annually since 2015 (Rey River Ranch, Cleveland National Forest [CNF] , Vista Irrigation District [VID] ), and one upstream at VID Lake Henshaw (VLH) that has been surveyed annually since 2018. There were a minimum of 47 territorial flycatchers (26 male, 21 female) detected at 1 location (VLH) and 6 transient flycatchers of unknown subspecies detected at 3 locations (BO, CNF, and VLH). In total, 30 territories were established, containing 21 pairs and 9 flycatchers of undetermined breeding status. Of the 21 pairs, 13 pairs were monogamous (1 male and 1 female), and 8 pairs were polygynous (1 male paired with more than 1 female). No territorial flycatchers were detected downstream from Lake Henshaw or along the middle San Luis Rey River. Brown-headed Cowbirds ( Molothrus ater ; cowbird) were detected at all six survey locations. No banded flycatchers were detected during surveys. Flycatchers used four habitat types in the survey area: (1) mixed willow riparian, (2) willow-cottonwood, (3) willow-oak, and (4) willow-sycamore. Of the flycatcher locations, 86 percent were in habitat characterized as mixed willow riparian, and 97 percent were in habitat with greater than 95-percent native plant cover. We monitored flycatcher nests at VLH to collect baseline data on nest success, productivity, and parasitism rate. There were 22 nests monitored in 13 territories; 9 were successful. Of the 13 failed nests, 8 were depredated, 3 failed for unknown reasons, and 2 failed because of cowbird parasitism. We confirmed 26 juvenile flycatchers in 2024, which included 22 from monitored nests, and an additional 4 juveniles detected in unmonitored territories. Based on 19 nests in which the contents were observed during the egg stage, 16 percent of nests in 2024 were parasitized.

California↗
USGS2025

Revised marine bird collision and displacement vulnerability index for U.S. Pacific Outer Continental Shelf offshore wind energy development

The installation of offshore wind energy infrastructure (OWEI) at sea may affect marine birds by increasing the risk of mortality from collision with OWEI (Collision Vulnerability) and causing disturbance and displacement from important habitats (Displacement Vulnerability). In 2017, we published the first comprehensive database quantifying marine bird Collision Vulnerability and Displacement Vulnerability to potential OWEI in the region of the U.S. Pacific Outer Continental Shelf (POCS; waters within the Exclusive Economic Zone of California, Oregon, and Washington). We have updated this Vulnerability Index with new research and data, additional species present in the POCS, and an evolved understanding of the application and utility of the Index. Of the species assessed, phalaropes and Red-billed Tropicbird have the highest Collision Vulnerability, and gulls, terns, jaegers, skuas, and pelicans have moderately high Collision Vulnerability. Boobies, sea ducks, and pelicans have the greatest Displacement Vulnerability. The overall trends in ranked Vulnerability among marine birds in the POCS were consistent between Version 1 and Version 2 although new data and revised calculations updated the outcomes. Alcids, loons, storm-petrels, Brant, and phalaropes ranked higher for Collision Vulnerability in Version 2 compared to Version 1; sea ducks, cormorants, skua, and jaegers ranked lower for Collision Vulnerability in Version 2 compared to Version 1. Displacement Vulnerability ranks were higher in Version 2 for gulls, pelicans, sea ducks, and alcids and lower for albatrosses, terns, and loons. Vulnerability Index Version 2 is an up-to-date, representative, and transparent assessment of marine bird vulnerability to potential offshore wind energy development. This updated Vulnerability Index can assist resource managers and others in understanding and addressing potential interactions between OWEI and marine bird species that inhabit the POCS.

Data Report↗
USGS2025

Framework developed for geomorphic mapping of Fern Ridge Lake, Oregon, 2023

The construction and operation of large reservoirs in the Willamette River Basin, Oregon, influences important cultural, biological, and other natural or economic resources in affected river corridors. The present-day landforms and cover within the reservoirs have been shaped by a variety of processes, including the pre-dam valley setting and geomorphic processes related to dam operations. Maps of reservoir geomorphic process domains, landforms, and cover provide a foundation for understanding how erosion and deposition processes in or near the reservoirs may affect cultural resources. Detailed geomorphic mapping of Fern Ridge Lake in 2023 provides a basis for evaluating geomorphic processes and patterns of sediment transfer within the reservoir. These processes are related to geomorphic and hydroclimatic conditions as well as annual lake level fluctuation for seasonal flood-control operations. This geomorphic mapping also provides an inventory of existing landforms from which to evaluate the spatial and temporal geomorphic change over time. Digital maps based on high-resolution digital surface models and orthophotographs acquired during low-pool conditions in 2023 extend over an area of about 30 square kilometers (km) upstream of the Fern Ridge Dam. The mapping framework has 3 main components consisting of several subtypes: 5 process domains, 18 landforms, and 7 cover categories. The overarching classification structure is tied to the process domains, which correspond to dissimilar regions of the reservoir that have distinct landforms and broadly similar suites of geomorphic processes. This document describes the geomorphic mapping framework for the reservoir at Fern Ridge Lake and provides mapping unit descriptions including delineation criteria, hypothesized formation processes inferred from remote-sensing and field observations and the literature, and relevance during drawdown operations.

Oregon↗
USGS2025

Distribution, abundance, and habitat characteristics of Coastal Cactus Wrens (Campylorhynchus brunneicapillus) in San Diego County, California—2024 data summary

Executive Summary We surveyed for coastal Cactus Wren ( Campylorhynchus brunneicapillus ) in 507 established plots in San Diego County in 2024, encompassing four genetic clusters (Otay, Lake Jennings, Sweetwater/Encanto, and San Pasqual). Of the 507 plots, 376 have been surveyed every year starting in 2020. Two surveys were completed at each plot between March 1 and July 31, 2024. Cactus Wrens were detected in 216 plots (43 percent of plots). Cactus Wrens were detected in 34 percent of the plots that have been consistently surveyed since 2020, indicating a higher plot occupancy rate than in 2023 (26 percent) and a similar plot occupancy rate to 2022 (31 percent), 2021 (34 percent), and 2020 (35 percent). There were 175 Cactus Wren territories detected across all survey plots in 2024. We documented 111 territories in the plots that have been consistently surveyed since 2020, which is an increase from 85 territories in 2023 and from 94 territories in 2022, and similar to the number of territories documented in 2021 (113) and 2020 (109). The number of territories declined from 2023 to 2024 in the San Pasqual genetic cluster but increased in the Otay, Lake Jennings, and Sweetwater/Encanto genetic clusters. At least 86 percent of Cactus Wren territories were occupied by pairs, and 176 fledglings were observed in 2024. We observed six banded Cactus Wrens in 2024, all of which we could identify individually by color band combination. Adults of known age ranged from 5 to 8 years old. All individually identifiable adult Cactus Wrens occupied the same territory in 2024 that they occupied during 2022 or 2023. We detected no movement of banded Cactus Wrens between genetic clusters during 2024. Vegetation at Cactus Wren survey plots was dominated by coastal sage scrub shrubs, such as California sagebrush ( Artemisia californica ), California buckwheat ( Eriogonum fasciculatum ), lemonade berry ( Rhus integrifolia ), San Diego County sunflower ( Bahiopsis laciniata ), and laurel sumac ( Malosma laurina ). Cactus Wrens preferentially occupied plots dominated by California buckwheat in the Otay genetic cluster and avoided plots dominated by lemonade berry (results of this test were marginally significant). Cactus Wrens also appeared to prefer plots dominated by broom baccharis ( Baccharis sarothroides ) in the Sweetwater/Encanto cluster and plots dominated by California buckwheat in the San Pasqual genetic cluster, although these preferences were marginally statistically significant. No definitive signs of fungal pathogens were observed on cactus within and around survey plots. Blue elderberry ( Sambucus mexicana ) was detected at 43 percent of plots, and Cactus Wrens preferentially occupied more plots with elderberry than were available. Very little dead or unhealthy cactus was observed within all survey plots, and Cactus Wrens preferentially occupied plots with lower amounts of dead and unhealthy cactus than were available. Over 80 percent of plots had more than 5 percent of cactus crowded or overtopped by vines and shrubs, and Cactus Wren occupied plots in proportion to the degree of shrub and vine crowding or overtopping. Non-native annual cover was less prevalent in survey plots in 2024 than in 2023, and Cactus Wrens preferentially occupied plots with less non-native cover.

California↗
USGS2026

Distribution and Abundance of Least Bell’s Vireo ( Vireo bellii pusillus ) and Southwestern Willow Flycatcher ( Empidonax traillii extimus ) at the Sepulveda Dam Basin, Los Angeles County, California—2025 Data Summary

Executive Summary We surveyed for Least Bell’s Vireos ( Vireo bellii pusillus ; vireo) and Southwestern Willow Flycatchers ( Empidonax traillii extimus ; flycatcher) along Bull Creek, Haskell Creek, and the Los Angeles River (Sepulveda Dam project area) in Los Angeles County, California, in 2025. Four vireo surveys were completed between April 16 and July 2, 2025, and three flycatcher surveys were completed between May 21 and July 2, 2025. We found 11 territorial male vireos, 4 of which were confirmed as paired, and 3 transient vireos. Of the 11 territorial vireos, 6 were detected along the Los Angeles River, 3 along Haskell Creek, and 2 along Bull Creek. Forty-three percent of vireos were detected in habitat characterized as mixed willow riparian, and most vireos were detected in habitat with greater than 50-percent native plant cover. No flycatchers were observed in the Sepulveda Dam project area in 2025.

California↗
USGS2026

Distribution and abundance of Least Bell’s Vireo ( Vireo bellii pusillus ) and Southwestern Willow Flycatcher ( Empidonax traillii extimus ) at the Hansen Dam Basin, Los Angeles County, California—2025 data summary

Executive Summary We surveyed for Least Bell’s Vireos ( Vireo bellii pusillus ; vireo) and Southwestern Willow Flycatchers ( Empidonax traillii extimus ; flycatcher) along Big Tujunga Creek in the Hansen Dam Basin in Los Angeles County, California, in 2025. Four vireo surveys were completed between April 17 and July 2, 2025, and three flycatcher surveys were completed between May 20 and July 2, 2025. We detected 62 territorial male vireos, 51 of which were confirmed as paired, and 2 transient vireos. Additionally, we detected 32 juvenile vireos during surveys. Seventy-seven percent of vireos were detected in habitat characterized as mixed willow, and 95 percent of vireos were detected in habitat with greater than 50-percent native plant cover. Most vireo territories were dominated by Goodding’s black willow ( Salix gooddingii ). On May 20, 2025, we detected 18 transient Willow Flycatchers of unknown subspecies, none of which were confirmed to be paired, and no juveniles were detected. Mixed willow habitat was used by 78 percent of Willow Flycatchers, and all Willow Flycatchers were detected in habitat with greater than 50-percent native plant cover. Most Willow Flycatchers were detected in locations dominated by Goodding’s black willow.

California↗
USGS2026

Southwestern Willow Flycatcher ( Empidonax traillii extimus ) surveys at the city of Carlsbad Preserve, San Diego County, California—2025 data summary

Executive Summary We surveyed for Southwestern Willow Flycatchers ( Empidonax traillii extimus ; flycatcher) at five survey areas within the City of Carlsbad Preserve, Carlsbad, California, in 2025. Three flycatcher surveys were completed between May 16 and June 30, 2025. One transient flycatcher was observed at the Lake Calavera survey area in the City of Carlsbad Preserve in 2025.

California↗
USGS2026

Distribution, abundance, and breeding activities of Southwestern Willow Flycatchers ( Empidonax traillii extimus ) on the San Dieguito River and upper San Luis Rey River, San Diego County, California—2025 data summary

Executive Summary We surveyed for Southwestern Willow Flycatchers ( Empidonax traillii extimus ; flycatcher) at the San Dieguito River and the upper San Luis Rey River in 2025. Surveys were completed at five locations: one along the San Dieguito River (San Dieguito [SD]), which was last surveyed in 2016, and four along the upper San Luis Rey River, including three downstream from Lake Henshaw that have been surveyed annually since 2015 (Rey River Ranch [RRR], Cleveland National Forest [CNF], Vista Irrigation District [VID]), and one upstream at VID Lake Henshaw (VLH) that has been surveyed annually since 2018. There was a minimum of 57 territorial flycatchers (22 male, 35 female) and 3 transient flycatchers of unknown subspecies detected at 1 location (VLH). In total, 37 territories were established, containing 35 pairs (20 males and 35 females) and 2 male flycatchers of undetermined breeding status. Of the 35 pairs, 12 were monogamous pairings, and 23 were polygynous pairings consisting of 3 males each pairing with 2 different females [6 pairs], 3 males each pairing with 3 different females [9 pairs], and 2 males each pairing with 4 different females [8 pairs]). No territorial flycatchers were detected downstream from Lake Henshaw or along the San Dieguito River. Brown-headed Cowbirds ( Molothrus ater ; cowbird) were detected at all five survey locations. No banded flycatchers were detected during surveys. Flycatchers used only one habitat type at VLH, mixed willow riparian. All flycatcher locations were in habitat characterized as mixed willow riparian dominated by Goodding’s black willow ( Salix gooddingii ), and 93 percent were in habitat with greater than 95-percent native plant cover. We monitored flycatcher nests at VLH to collect baseline data on nest success, productivity, and cowbird parasitism rate. There were 33 completed nests monitored in 26 territories; 10 were successful (30 percent). Of the 23 failed nests, 14 were depredated, 5 failed for unknown reasons, and 4 failed because of cowbird parasitism. There were 33 fledglings confirmed in monitored territories, yielding a seasonal productivity of 1.3 young/pair (33 young/26 monitored pairs). One additional fledgling was confirmed in an unmonitored territory during surveys at VLH. Based on 31 nests in which the contents were observed during the egg stage, 23 percent of nests in 2025 were parasitized. In two additional territories where nests were not located, adult flycatchers were observed feeding a cowbird fledgling.

California↗
USGS2026

Streamflow, water quality, and constituent loads and yields, Scituate Reservoir drainage area, Rhode Island, water year 2023

As part of a long-term cooperative program to monitor water quality within the Scituate Reservoir drainage area, the U.S. Geological Survey, in cooperation with Providence Water (formerly the Providence Water Supply Board), collected streamflow and water-quality data in tributaries to the Scituate Reservoir, Rhode Island. Streamflow and concentrations of chloride and sodium estimated from records of specific conductance for 16 tributaries were used to calculate loads of chloride and sodium during water year 2023 (October 1, 2022, through September 30, 2023). Water-quality samples were collected by Providence Water at 38 sampling stations on tributaries to the Scituate Reservoir during water year 2023. These water-quality data are summarized by using values of central tendency and are used, in combination with measured (or estimated) streamflows, to calculate loads and yields of selected water-quality constituents for water year 2023. Annual mean streamflows for monitoring stations in this study ranged from 0.47 to 34.4 cubic feet per second during water year 2023. At the 16 continuous-record streamgages, tributaries transported about 3,000 metric tons of chloride and 1,900 metric tons of sodium to the Scituate Reservoir; annual chloride yields for the tributaries ranged from 19 to 200 metric tons per square mile, and annual sodium yields ranged from 13 to 120 metric tons per square mile. At the stations where water-quality samples were collected by Providence Water, the medians of the median daily loads were 65,000 million colony forming units per day for coliform bacteria, 870 million colony forming units per day for Escherichia coli , 200 kilograms per day for chloride, 8.2 grams per day as nitrogen for nitrite, 520 grams per day as nitrogen for nitrate, and 300 grams per day as orthophosphate for phosphate. The medians of the median yields were 25,000 million colony forming units per day per square mile for coliform bacteria, 600 million colony forming units per day per square mile for Escherichia coli , 65 kilograms per day per square mile for chloride, 4.6 grams per day per square mile as nitrogen for nitrite, 180 grams per day per square mile as nitrogen for nitrate, and 180 grams per day per square mile as orthophosphate for phosphate.

Rhode Island↗