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USGS2022

Abundance and productivity of Marbled Murrelets ( Brachyramphus marmoratus ) off central California during the 2020 and 2021 breeding seasons

Marbled murrelets ( Brachyramphus marmoratus ) have been listed as “endangered” by the State of California and “threatened” by the U.S. Fish and Wildlife Service since 1992 in California, Oregon, and Washington. Information regarding marbled murrelet abundance, distribution, population trends, and habitat associations is critical for risk assessment, effective management, evaluation of conservation efficacy, and ultimately, to meet federal- and state-mandated recovery efforts for this species. During June–August 2020 and 2021, the U.S. Geological Survey Western Ecological Research Center continued previously established, long-term (1999–present), at-sea surveys to estimate abundance and productivity of marbled murrelets in U.S. Fish and Wildlife Service Conservation Zone 6 (San Francisco Bay to Point Sur in central California). The abundance estimated for the entire study area was 470 birds (95-percent confidence interval, 313–707 birds) in 2020 and 402 birds (95-percent confidence interval, 219–737 birds) in 2021. Estimated abundances for both years are comparable with most prior years of study. We estimated reproductive productivity (calculated as the hatch-year to after-hatch-year ratio) after date-correcting hatch-year and after-hatch-year counts to account for birds expected to be absent from the water while inland at nests. The date-corrected juvenile ratio was 0.018±0.011 standard error in 2020 and 0.041±0.024 standard error in 2021. We updated a comprehensive database of all Zone 6 marbled murrelet survey data since 1999 with 2020–21 data to allow scientists and managers to evaluate established survey methods and assess trends in abundance and productivity estimates.

California↗
USGS2022

Distribution and abundance of Southwestern Willow Flycatchers (Empidonax traillii extimus) on the Upper San Luis Rey River, San Diego County, California—2021 data summary

We surveyed for Southwestern Willow Flycatchers ( Empidonax traillii extimus ; flycatcher) along the upper San Luis Rey River near Lake Henshaw in Santa Ysabel, California, in 2021. Surveys were completed at four locations: three downstream from Lake Henshaw, where surveys occurred from 2015 to 2020 (Rey River Ranch [RRR], Cleveland National Forest [CNF], Vista Irrigation District [VID]), and one at VID Lake Henshaw (VLH) that has been surveyed annually since 2018. There were 78 territorial flycatchers detected at 3 locations (RRR, CNF, VLH), and 1 transient flycatcher of unknown subspecies was detected at VID. Downstream from Lake Henshaw, five flycatchers, including three males and two females, were detected at RRR and CNF. In total, three territories were established, consisting of two pairs and one male of undetermined breeding status. At VLH, we detected 73 flycatchers, including 32 males, 38 females, and 3 flycatchers of unknown sex. In total, 43 territories were established, containing 38 pairs (22 monogamous pairings, 7 confirmed polygynous groups consisting of 7 males each pairing with 2 different females, and 1 suspected polygynous group consisting of 1 male and 2 females), and 5 flycatchers of undetermined breeding status (2 males and 3 flycatchers of unknown sex). Brown-headed cowbirds ( Molothrus ater ; cowbird) were detected at all four survey locations. Flycatchers used five habitat types in the survey area: (1) mixed willow riparian, (2) willow-cottonwood, (3) willow-oak, (4) willow-ash, and (5) sycamore-oak. Eighty-seven percent of the flycatchers were detected in habitat characterized as mixed willow riparian, and 94 percent of the flycatchers were detected in habitat with greater than 95-percent native plant cover. Exotic vegetation was not prevalent in the survey area. There were 15 nests incidentally located during surveys: 1 was successful, 2 were seen with eggs or nestlings on the last visit, 9 failed, and the outcome of the remaining 3 nests was unknown. Three of these nests were parasitized by cowbirds. There were 13 juveniles detected at VLH during surveys; no juveniles were detected at RRR or CNF. Of the 10 banded flycatchers detected during surveys, 7 were resighted and confirmed to be adults that held territories in previous years. Three flycatchers with a single dark blue federal band, indicating that they were banded as nestlings in the former demographic study area downstream from Lake Henshaw, were resighted during surveys. In 2021, we documented both adult and natal flycatchers moving from the former demographic study area downstream from Lake Henshaw upstream to the habitat surrounding Lake Henshaw. Three natal flycatchers that were originally banded as nestlings and three adults that previously held territories downstream dispersed to Lake Henshaw in 2021.

California↗
USGS2022

Distribution and demography of coastal Cactus Wrens (Campylorhynchus brunneicapillus) in southern San Diego County, California — 2021 Data summary

We surveyed for coastal Cactus Wren ( Campylorhynchus brunneicapillus ) in 378 established plots in southern San Diego County in 2021, encompassing 3 genetic clusters (Otay, Lake Jennings, and Sweetwater/Encanto). Two surveys were completed at each plot between March 1 and July 31. Cactus Wrens were detected in 130 plots (34 percent of plots), remaining virtually the same as the percentage of plots occupied in 2020 (35 percent). There were 113 Cactus Wren territories detected across all survey plots in 2021, an increase from 109 in 2020. At least 86 percent of Cactus Wren territories were occupied by pairs, and 50 fledglings were observed in 2021. We observed 48 color-banded Cactus Wrens in 2021, 44 of which we could identify to individual. Adults of known age ranged from 2 to at least 7 years old. Adult Cactus Wrens moved, on average, 0.1 kilometers (maximum 0.5 kilometers) from their 2020 territories to their 2021 territories. No known-identity Cactus Wrens moved between genetic clusters from 2020 to 2021. Vegetation at Cactus Wren plots typically was dominated by coastal sage scrub shrubs, such as California sagebrush ( Artemisia californica ), California buckwheat ( Eriogonum fasciculatum ), lemonadeberry ( Rhus integrifolia ), and San Diego sunflower ( Bahiopsis laciniata ). Twenty-nine percent of plots contained blue elderberry ( Sambucus nigra ssp. caerulea ), 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 the plots that were occupied by Cactus Wrens were likely to contain more healthy cactus than plots that were not occupied by Cactus Wrens. Thirteen percent of plots had 5 percent or less of the cactus crowded or overtopped by vines and shrubs. Although in 2020, Cactus Wrens occupied proportionally more plots with 5 percent or less of cactus crowded or overtopped by vines and shrubs, this pattern was not found in 2021. Non-native annual cover was 5 percent or less at 29 percent of plots and, unlike in 2020, Cactus Wrens appeared to occupy proportionally more plots with less non-native annual cover than plots with more than 5-percent annual cover.

California↗
USGS2022

Aerial counts for surface-nesting seabirds at Lehua Island and Moku Manu Islet and Ulupaʻu Crater, Oʻahu, in 2019

Among important seabird breeding sites in the main Hawaiian Islands, Lehua Island offshore Niʻihau and Moku Manu Islets offshore Oʻahu support diverse and abundant seabird breeding populations. Both offshore islands provide excellent nesting habitat for surface-nesting boobies ( Sula spp .) and terns but, of the two, only Moku Manu supports relatively large breeding populations of Sooty Tern ( Onychoprion fuscatus ) and Brown Noddy ( Anous stolidus ). Additionally, Ulupaʻu Crater, near Moku Manu on Oʻahu, is one of only a few sites within the eight main Hawaiian islands and the only site on the main island of Oʻahu that supports a nesting population of Red-footed Boobies ( Sula sula ). Despite their importance for informing renewable offshore energy planning off Hawaiʻi, robust and accurate seabird population survey data exist and are available for some locations (Lehua; Raine and others, 2021), but at Moku Manu and Ulupa‘u Crater, recent information are not yet available (E. VanderWerf, written commun. 2021). In this study, we completed comprehensive aerial photographic counts at these three sites for six surface-nesting seabird species present during the 2019 breeding season: Brown Booby ( Sula leucogaster ), Red-footed Booby, Masked Booby ( S. dactylatra ), Great Frigatebird ( Fregata minor ), Sooty Tern, and Brown Noddy. We estimated 5,782, 102, and 1,446 nesting pairs of Red-footed Boobies at Lehua, Ulupaʻu Crater, and Moku Manu, respectively. At Lehua and Moku Manu, we estimated 692 and 65 nesting pairs of Brown Boobies, respectively. At Moku Manu, we estimated 95 nesting pairs of Masked Boobies, one of only three nesting locales for this species in the main Hawaiian Islands. Based on digital photograph counts of sampled areas and area-based extrapolation, we estimated 17,938 terns (mostly Sooty Tern with fewer Brown Noddy) on Moku Manu. We observed Great Frigatebirds roosting at the two island sites, but we did not detect any sign of nesting for this species. We found that inter-observer counts for behavioral classifications (nesting, roosting, unknown) ranged in precision (D=0.13–0.31), but generally, counts among photographs accounting for all seabird targets (D=0.10–0.22) and for boobies classified as nesting (D=0.13–0.18) were more precise than for roosting and unknown categories (D=0.13–0.31), indicating that at least some of the variation in count precision relates to differences in how independent counters identified behavioral classifications. The nesting population sizes (and number of terns present on Moku Manu) present during aerial counts likely are minimum estimates because individuals among these species can exhibit asynchronous nesting phenologies, and not all members of the nesting populations would be expected to be attending the sites when we surveyed. The results of these counts provide current and accurate abundance estimates for these species that can serve as benchmarks for future management and monitoring and as important components of population-level assessments aimed at quantifying seabird vulnerability to potential offshore wind energy development in the main Hawaiian Islands.

Hawaii↗
USGS2022

Materials flow in the United States—A global context, 1900–2020

Introduction During the last 12 decades (1900–2020), the amounts of raw materials used in the United States have increased significantly due to economic development, technological innovations, and population growth. Data on materials are presented here to provide an overview of the annual quantities (measured in physical terms) required for the standard of living in the United States and to provide insights into the consumption trajectory that developing countries may follow. The consumption patterns driving the use of raw materials were analyzed through the lens of economic disruptions and expansions during this period, illustrating the linkages between the selected materials and economic development. These annual material inputs to the U.S. economy (excluding food or fuel) were also analyzed in a global context. The data used were gathered by various agencies and compiled by the U.S. Geological Survey.

Data Report↗
USGS2022

Range-wide population trend analysis for greater sage-grouse (Centrocercus urophasianus)—Updated 1960–2021

Greater sage-grouse ( Centrocercus urophasianus ) are at the center of state and national land use policies largely because of their unique life-history traits as an ecological indicator for health of sagebrush ecosystems. This updated population trend analysis provides state and federal land and wildlife managers with best-available science to help guide current management and conservation plans aimed at benefitting sage-grouse populations. This analysis relied on previously published population trend modeling methodology from Coates and others (2021) and includes the addition of three analytical updates: (1) identification of population nadirs (lowest points within cycles) at the lek (breeding ground) and neighborhood cluster (group of leks) spatial scales, (2) truncation of prior distributions on rate of change in apparent abundance values to more realistic boundaries for leks with missing data, and (3) addition of 2 years of population lek count data (2020 and 2021) to the current dataset (1953–2021). Bayesian state-space models estimated 2.9 percent average annual decline in sage-grouse populations across their geographical range, which varied among subpopulations at the largest scale of analysis, termed climate clusters (2.2–4.6). Cumulative declines were 42.5, 65.6, and 80.1 percent range-wide across short (19 years), medium (35 years), and long (55 years) temporal periods, respectively. These results indicate that range-wide populations continued to decline during 2020 and 2021, although two climate clusters (eastern area and Bi-State area) have shown growth in population abundance in recent years, indicating they have surpassed a recent population abundance nadir.

Data Report↗
USGS2023

Evaluating water-quality conditions in the mainstem and tidal reaches of the Merrimack River in Massachusetts, June to September 2020

In summer and early fall (June to September) 2020, water-quality data were collected at 13 stations along the mainstem of the Merrimack River and into the Merrimack River estuary. The data are allocated among three different datasets: discrete water sample data, discrete vertical profile data, and continuous data. The collective purpose of these datasets is to enable assessment of the overall water-quality conditions in the Merrimack River and estuary and to identify areas for potentially more targeted water-quality monitoring in the future. The highest concentrations of nutrients—nitrogen and phosphorus—were found at the stations downstream from wastewater treatment plants in Lowell, Lawrence, and Haverhill. Nutrient concentrations measured in the Merrimack River estuary were not as high as those measured in the Merrimack River, indicating that other processes are affecting nutrient concentrations in the system. These data were collected coincident with a severe flash drought in New England. Analysis of the vertical profile and continuous data indicated that, for intermittent periods up to 5 days, water quality in some sections of the Merrimack River may not support designated uses for the waterbody as established in the Massachusetts surface water quality standards.

Massachusetts↗
USGS2023

Distribution and abundance of Least Bell’s Vireos (Vireo bellii pusillus), Southwestern Willow Flycatchers (Empidonax traillii extimus), and Coastal California Gnatcatchers (Polioptila californica californica) at the Santa Fe Dam, Los Angeles County, California—2022 data summary

In 2022, we surveyed for Least Bell’s Vireos ( Vireo bellii pusillus ; vireo), Southwestern Willow Flycatchers ( Empidonax traillii extimus ; flycatcher), and Coastal California Gnatcatchers ( Polioptila californica californica ; gnatcatcher) in the Santa Fe Dam detention basin and along the San Gabriel River upstream from the Santa Fe Dam near Irwindale, California. Four vireo surveys were completed between April 21 and July 13, 2022; three flycatcher surveys were completed between May 18 and July 13, 2022; and four gnatcatcher surveys were completed between April 21 and July 13, 2022. We detected seven territorial male vireos, including four that were paired and three with undetermined breeding status. We also detected one transient vireo. Two juvenile vireos were observed during surveys. Vireo territories were found in riparian scrub, willow ( Salix spp.)-cottonwood ( Populus spp.), and mixed willow habitat, with mixed willow the most commonly-recorded habitat type. Black willow ( S. gooddingii ) was the dominant plant species in most vireo territories. We detected 10 transient flycatchers in riparian scrub (5 individuals), mixed willow (4 individuals), and non-native vegetation (1 individual). Black willow and mule fat ( Baccharis salicifolia ) were the predominant plant species in flycatcher locations. We detected four territorial male gnatcatchers, two of which were paired and two of undetermined breeding status. We also detected one territorial female gnatcatcher. One juvenile gnatcatcher was observed during surveys. All gnatcatchers were detected in coastal sage scrub. The dominant shrub species at gnatcatcher locations were California sagebrush ( Artemisia californica ) and scale broom ( Lepidospartum squamatum ).

California↗
USGS2023

Southwestern Willow Flycatcher (Empidonax traillii extimus) surveys at the city of Carlsbad Preserve, San Diego County, California—2022 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 2022. Three flycatcher surveys were completed between May 18 and June 29, 2022. Territorial or transient flycatchers were not observed at the City of Carlsbad Preserve in 2022.

California↗
USGS2023

Distribution and abundance of Southwestern Willow Flycatchers (Empidonax traillii extimus) on the upper San Luis Rey River, San Diego County, California—2022 data summary

Executive Summary We surveyed for Southwestern Willow Flycatchers ( Empidonax traillii extimus ; flycatcher) along the upper San Luis Rey River near Lake Henshaw in Santa Ysabel, California, in 2022. Surveys were completed at four locations: three downstream from Lake Henshaw, where surveys occurred from 2015 to 2021 (Rey River Ranch [RRR], Cleveland National Forest [CNF], Vista Irrigation District [VID]), and one at VID Lake Henshaw (VLH) that has been surveyed annually since 2018. There were 71 territorial flycatchers detected at 3 locations (RRR, CNF, VLH), and 6 transient flycatchers of unknown subspecies detected at VID and VLH. Downstream from Lake Henshaw, four territorial flycatchers, including two males and two females, were detected at RRR and CNF. In total, two territories were established consisting of two pairs at these locations. At VLH, we detected 67 territorial flycatchers, including 30 males, 34 females, and 3 flycatchers of unknown sex. In total, 40 territories were established, containing 35 pairs (24 monogamous pairings and 5 polygynous groups consisting of 4 males each pairing with 2 different females, and 1 male pairing with 3 different females), and 5 flycatchers of undetermined breeding status (3 males and 2 flycatchers of unknown sex). Brown-headed cowbirds ( Molothrus ater ; cowbird) were detected at all four survey locations. Flycatchers used five habitat types in the survey area: (1) mixed willow riparian, (2) willow-cottonwood, (3) willow-oak, (4) willow-ash, and (5) oak-sycamore. Of the flycatcher locations, 83 percent were located in habitat characterized as mixed willow riparian, and 92 percent were in habitat with greater than 95-percent native plant cover. Exotic vegetation was not prevalent in the survey area. There were 22 nests incidentally located during surveys: 5 were successful, 1 was seen with eggs on the last visit, 10 failed, and the outcome of the remaining 6 nests was unknown. Three of these nests were parasitized by cowbirds. There were 13 juveniles detected at VLH; no juveniles were detected at RRR or CNF. Five banded flycatchers were detected during surveys, three of which were confirmed to be adults that held territories in previous years. In addition, two flycatchers with a single dark blue federal band, indicating that they were banded as nestlings in a previous demographic study downstream from Lake Henshaw (Howell and others, 2022), were resighted during surveys.

California↗
USGS2023

Distribution and demography of coastal Cactus Wrens ( Campylorhynchus brunneicapillus ) in San Diego County, California—2022 data summary

We surveyed for coastal Cactus Wren ( Campylorhynchus brunneicapillus ) in 507 established plots in San Diego County in 2022, 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 214 plots (42 percent of plots). Cactus Wrens were detected in 31 percent of plots that have been consistently surveyed since 2020, indicating less plot occupancy than in 2021 (34 percent) and 2020 (35 percent). There were 202 Cactus Wren territories detected across all survey plots in 2022. In plots that have been consistently surveyed since 2020, we documented 94 territories, which is a decrease from 113 territories in 2021 and 109 in 2020. The number of territories declined from 2021 to 2022 in the Lake Jennings and Otay genetic clusters but remained virtually the same in the Sweetwater/Encanto genetic cluster. At least 78 percent of Cactus Wren territories were occupied by pairs, and 134 fledglings were observed in 2022. We observed 24 banded Cactus Wrens in 2022, 20 of which we could identify individually by band combination. Adults of known age ranged from 3 to at least 7 years old. All individually identifiable adult Cactus Wrens remained on the same territory in 2022 that they occupied in 2021, 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 ), lemonadeberry ( Rhus integrifolia ), jojoba ( Simmondsia chinensis ), and San Diego sunflower ( Bahiopsis laciniata ). No definitive signs of fungal pathogens were observed on cactus within and around survey plots. Blue elderberry ( Sambucus nigra ssp. caerulea ) was detected at 39 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 the plots that were occupied by Cactus Wrens were likely to contain fewer dead cactus than plots that were not occupied by Cactus Wrens. Almost 80 percent of plots had more than 5 percent of cactus crowded or overtopped by vines and shrubs. Similar to 2020, Cactus Wrens occupied proportionally more plots with 5 percent or less of cactus crowded or overtopped by vines and shrubs, although this pattern was not observed in 2021. Non-native annual cover was less prevalent in survey plots in 2022 than in 2021, and Cactus Wrens did not preferentially occupy survey plots with 5 percent or less non-native annual cover than plots with more non-native cover.

California↗
USGS2023

Range-wide population trend analysis for greater sage-grouse (Centrocercus urophasianus)—Updated 1960–2022

Greater sage-grouse ( Centrocercus urophasianus ) are at the center of state and national land-use policies largely because of their unique life-history traits as an ecological indicator for health of sagebrush ecosystems. This updated population trend analysis provides state and federal land and wildlife managers with best-available science to help guide current management and conservation plans aimed at benefitting sage-grouse populations. This analysis relied on previously published population trend modeling methodology from Coates and others (2021, 2022a) and incorporated population lek count data through 2022. Bayesian state-space models estimated 2.9 percent average annual decline in sage-grouse populations across their geographical range, which varied among subpopulations at the largest scale of analysis, termed climate clusters (2.2–4.7). Cumulative declines were 40.9, 65.0, and 79.6 percent range-wide across short (19 years), medium (35 years), and long (55 years) temporal periods, respectively. These results indicate that the most recent nadir for range-wide populations occurred during 2021. However, growth during 2022 was modest, making 2021 a tentative final nadir at this point.

Data Report↗
USGS2023

Bedrock-surface elevation and overburden thickness maps of the five boroughs, New York City, New York

Digital maps of bedrock elevation and overburden thickness (depth to bedrock) were constructed for the five boroughs of New York City by the U.S. Geological Survey, in cooperation with the New York City Department of Design and Construction, from a compilation of historical and newly acquired data. Raster surfaces were interpolated from a point database containing data from more than 14,000 locations collected from a variety of sources. These data were collected between 1905 and 2021. These maps were constructed to supplement existing tools for the evaluation of potential construction of geothermal heat pump technology for buildings in New York City. The bedrock underlying the study area ranges from easily weathered to very resistant to weathering. This differential susceptibility to erosion, along with numerous north-northwest-trending faults, is believed to control the shape of the bedrock surface. Glacial scouring of the bedrock during the Pleistocene Epoch is the most recent control on the topography of bedrock surfaces. Overburden thickness is an important consideration for evaluation and construction of geothermal systems. Bedrock-surface elevation ranges from about 360 feet above sea level (in central Staten Island and northern Bronx) to 1,200 feet below sea level (in southern Queens) (North American Vertical Datum of 1988). The overburden thickness ranges from 0 foot thick at surface outcrops on Staten Island, Manhattan, and the Bronx, to 1,280 feet thick in southeastern Queens.

Data Report↗
USGS2023

Least Bell’s Vireo (Vireo bellii pusillus) and Southwestern Willow Flycatcher (Empidonax traillii extimus) surveys in the Sepulveda Dam Basin, Los Angeles County, California—2022 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 2022. Four vireo surveys were completed from April 26 to July 14, and three flycatcher surveys were completed from May 19 to July 14. We detected 10 territorial male vireos, 5 of which were confirmed as paired, and 2 transient vireos. Of the 10 territorial vireos, 70 percent were detected along the Los Angeles River, 20 percent along Bull Creek, and 10 percent along Haskell Creek. Of the vireos detected, 80 percent were in habitats characterized as mixed willow, and most vireos were detected in habitats with greater than 50-percent native plant cover. One transient flycatcher was observed in the survey area in 2022.

California↗
USGS2023

Distribution of large boulders on the deposit of the West Salt Creek rock avalanche, western Colorado

On May 25, 2014, a 54.5-million cubic meter rock avalanche in the West Salt Creek valley, Mesa County, Colorado, traveled 4.6 kilometers, leaving a deposit that covers about 2.2 square kilometers. To check the particle-size distribution of the deposit for information about the high mobility of the avalanche, we estimated boulder distribution density for the entire deposit by counting 1-meter (m) or larger diameter boulders of sedimentary rock derived from the Green River Formation that are visible in high-resolution imagery collected from the area in July 2014. Basalt boulders were excluded from the count because field observations indicated that they generally stayed intact as the avalanche moved downslope, whereas sedimentary boulders showed evidence of fragmentation during downslope movement. Variable clarity, contrast, and resolution of the imagery precluded mapping smaller boulders. Experimentation with 5-, 10-, and 20-m resolution grids indicated that a 20-m resolution grid showed the spatial pattern of boulder density across the deposit at a scale that allowed statistically meaningful variations to be determined. In addition to counting the boulders in each 20×20-m grid cell, six categories of successively increasing boulder distribution density were created to help visualize variations in the distribution of 1 meter or larger boulders across the avalanche deposit. Analysis indicates that boulder distribution density gradually decreases with increasing distance from the avalanche source.

Colorado↗
USGS2024

Land-use and land-cover change in the Lower Rio Grande Ecoregions, Texas, 2001–2011

Urban growth and other land-use changes were examined in the Lower Rio Grande Valley and Alluvial Floodplain ecoregions in Texas, along the U.S.-Mexico border. The analysis focused on understanding the types and causes of land change as well as the recovery of natural land-cover types between years 2001 and 2011. The purpose was to develop improved capabilities for understanding land change dynamics in urbanizing ecoregions and to provide data for further analyses. The spatial data, including metadata, allows further exploration and characterization of changes affecting this dynamic region.

Texas↗
USGS2024

Range-wide population trend analysis for greater sage-grouse (Centrocercus urophasianus)—Updated 1960–2023

Greater sage-grouse ( Centrocercus urophasianus ) are at the center of state and national land-use policies largely because of their unique life-history traits as an ecological indicator for health of sagebrush ecosystems. This updated population trend analysis provides state and federal land and wildlife managers with best-available science to help guide management and conservation plans aimed at benefitting sage-grouse populations. This analysis relied on previously published population trend modeling methodology from Coates and others (2021, 2022a) and incorporates population lek count data for 1960–2023. Included in this update are changes in terminology. Specifically, we now use the terms Period 1 (previously Long), Period 2 (previously Medium/Long), Period 3 (previously Medium), Period 4 (previously Short/Medium), Period 5 (previously Short), and Period 6 (previously Recent) to identify specific trends. State-space models estimated 2.8-percent average annual decline in sage-grouse populations between 1966 and 2021 (Period 1, six population oscillations) across their geographical range. Average annual decline among climate clusters for the same number of oscillations ranged between 2.1 and 3.1 percent. Cumulative declines were 41.1, 64.5, and 78.4 percent range-wide during Period 5 (19 years), Period 3 (35 years), and Period 1 (55 years), respectively. Population growth during 2022 and 2023 continue to point to 2021 as the most recent range-wide nadir.

Data Report↗
USGS2024

Distribution and abundance of Southwestern Willow Flycatchers ( Empidonax traillii extimus ) on the Upper San Luis Rey River, San Diego County, California—2023 data summary

Executive Summary We surveyed for Southwestern Willow Flycatchers ( Empidonax traillii extimus ; flycatcher) along the upper San Luis Rey River near Lake Henshaw in Santa Ysabel, California, in 2023. Surveys were completed at four locations: three downstream from Lake Henshaw, where surveys previously occurred from 2015 to 2022 (Rey River Ranch [RRR], Cleveland National Forest [CNF], Vista Irrigation District [VID]), and one at VID Lake Henshaw (VLH) that has been surveyed annually since 2018. There were a minimum of 74 territorial flycatchers detected at 1 location (VLH), and 12 transient flycatchers of unknown subspecies detected at 2 locations (CNF and VLH). At VLH, we detected a minimum of 31 males, 40 females, and 3 flycatchers of unknown sex. In total, 51 territories were established, containing 40 pairs and 11 flycatchers of undetermined breeding status (8 males and 3 flycatchers of unknown sex). Of the 40 pairs, 9–11 pairs were monogamous (1 male and 1 female), and 29–31 pairs were polygynous (1 male paired with more than 1 female). For the first time since annual surveys began in 2015, no territorial flycatchers were detected downstream from Lake Henshaw. Brown-headed cowbirds ( Molothrus ater ; cowbird) were detected at all four survey locations. No banded flycatchers were detected during surveys. Flycatchers used three habitat types in the survey area: (1) mixed willow riparian, (2) willow-cottonwood, and (3) oak-sycamore. Of the flycatcher locations, 86 percent were in habitat characterized as mixed willow riparian, and 95 percent were in habitat with greater than 95-percent native plant cover. Exotic vegetation was not prevalent in the survey area. There were five nests incidentally located during surveys: one failed, one was seen with eggs on the last visit, and the outcome of the remaining three nests was unknown. One of these nests was parasitized by cowbirds, and a second nest was suspected to contain a cowbird nestling. Adult flycatchers in two territories were observed feeding cowbird fledglings. No juvenile flycatchers were detected during surveys.

California↗