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To investigate whether Northern Goshawk textit(Accipiter gentilis) reproduction is food-limited, we evaluated the reproductive output from 401 goshawk breeding opportunities on the Kaibab Plateau, Arizona during 1999-2002. Concurrently, we estimated densities of 10 goshawk prey species (seven birds, three mammals) using distance sampling. We then assessed the relationship between goshawk productivity (number of fledglings produced) and prey density within and among years by relating the contribution of individual prey species and total prey density to goshawk productivity. We also estimated the proportion of total diet and biomass for each species that contributed ?3% of all prey items. Total prey density was highly...
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These tables serve as input data for hierarchical models investigating interactions between raven density and Greater Sage-grouse nest success. Observations were recorded over an 11 year time period, spanning from 2009 through 2019. The model is run in JAGS via R, the code is publicly available via the U.S. Geological Survey's GitLab (O'Neil et al. 2023). We recommend not making any changes or edits to the tables unless the user is experienced with hierarchical modeling. References: O'Neil, S.T., Coates, P.S., Webster, S.C., Brussee, B.E., Dettenmaier, S.J., Tull, J.C., Jackson, P.J., Casazza, M.L., and Espinosa, S.P., 2023, Code for a hierarchical model of raven densities linked with sage-grouse nest survival...
We surveyed a discrete population of Mountain Plovers (Charadrius montanus) in South Park, Park County, Colorado, to determine the size and relative contribution of this geographically isolated area to the global population of plovers. First, we mapped potential plover habitat within South Park based on landform and vegetation descriptors. Second, we identified occupied habitat using observations from a systematic inventory of potential habitat from 1995-1999 and from a study of breeding biology from 2000-2002. Third, we estimated breeding densities within a framework designed specifically for distance sampling. We mapped 82750 ha of potential habitat. We recorded 2516 plover locations from which we estimated 29...
Density estimates of four mammal species in the upper subalpine and alpine zones of the Sierra Nevada range, 2008 - 2012. The estimates were derived from variable distance data collected 3-4 per year along each of 21 transects (10 km in length). The transects were randomly selected from a pool of 53 potential routes. Nine transects were sampled in 2008, 12 were sampled in 2009, 19 were sampled in 2010, 21 were sampled in 2011, and 17 were sampled in 2012. All counts were done in July and August each year. Replicate samples within a given year were done within 2-8 days of each other. All counts were done by single observers. The spreadsheet has six worksheets, including three with density estimates for each species...
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The dataset contains 6 columns of data collected during line transect surveys (Line) that evaluated bait cartridge efficacy for Brown Treesnake control on Guam. Two-person teams recorded all bait cartridges observed while walking the center line of transects in the Habitat Management Unit (HMU). Perpendicular distance (DIST (m)) to cartridges from center line was measured to the nearest 0.005 meters.
Density estimates of four mammal species in the upper subalpine and alpine zones of the Sierra Nevada range, 2008 - 2012. The estimates were derived from variable distance data collected 3-4 times per year at point count stations randomly located along line transects. There were 21 transects (10 km in length) that had been randomly selected from a pool of 53 potential routes, with 10 point count stations along each transect (minimum of 200 m spacing between stations). 45 stations were sampled in 2008 (5 stations on each of 9 transects), 60 stations were sampled in 2009 (5 stations on each of 12 transects),190 stations were sampled in 2010 (10 stations on each of 19 transects), 210 stations were sampled in 2011 (10...
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Rasters representing median raven density estimates, calculated from approximately 28,000 raven point count surveys conducted between 2009 and 2019. Estimates were the result of a Bayesian hierarchical distance sampling model, using environmental covariates on detection and abundance.
This data product contains the quality-controlled, native sampling resolution data from NEON's breeding landbird sampling crosswalked to Darwin Core. Breeding landbirds are defined as “smaller birds (usually exclusive of raptors and upland game birds) not usually associated with aquatic habitats” (Ralph et al. 1993). The breeding landbird point counts product provides records of species identification of all individuals observed during the 6-minute count period, as well as metadata which can be used to model detectability, e.g., weather, distances from observers to birds, and detection methods. The NEON point count method is adapted from the Integrated Monitoring in Bird Conservation Regions (IMBCR): Field protocol...
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We conducted population and habitat assessments for Mountain Plovers in Texas during winters of 2019 and 2020. We used roadside surveys and distance-sampling to estimate bird density and calculate population totals for the study area, which included parts of five ecoregions (Chihuahuan Deserts, High Plains, Central Great Plains, Southern Texas Plains, Texas Blackland Prairies, and Western Gulf Coastal Plain). In 2019, we surveyed 103 transects along 3,032 km (1,884 mi) and, in 2020, we surveyed 152 transects along 4,985 km (3,098 mi). When driving along transects, we stopped every 3.2 km (2 mi) to assess habitat conditions (vegetation height, vegetation density, etc.) and land cover (National Land Cover Database...
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Since 2017, U.S. Geological Survey, Western Ecological Research Center (USGS WERC) partnered with California State Parks to continue long-term, annual at-sea surveys to estimate at-sea abundance and juvenile (i.e. hatch-year) productivity of Marbled Murrelets (Brachyramphus marmoratus) in U.S. Fish and Wildlife Service Conservation Zone 6 (central California: San Francisco Bay to Monterey Bay). Marbled Murrelets have been listed as Endangered by the State of California and Threatened by the U.S. Fish and Wildlife Service since 1992. Marbled Murrelets have been surveyed at sea off central California since 1995 (Becker et al. 1997), and standardized surveys to estimate abundance and productivity have been conducted...
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We combined approximately 28,000 raven point count surveys with data from more than 900 sage-grouse nests between 2009 and 2019 within the Great Basin, USA. We modeled variation in raven density using a Bayesian hierarchical distance sampling approach with environmental covariates on detection and abundance. Concurrently, we modeled sage-grouse nest survival using a hierarchical frailty model as a function of raven density as well as other environmental covariates that influence risk of failure. Raven density commonly exceeded more than 0.5 ravens per square kilometer and increased at low relative elevations with prevalent anthropogenic development and/or agriculture. Reduced sage-grouse nest survival was strongly...
We estimated electrocution rates for raptors and common ravens (Corvus corax) for the Moon Lake Electrical Association in northeastern Utah and northwestern Colorado, USA. From July 2001 to May 2003, we conducted mortality searches at randomly selected distribution line segments and poles within 3 regions, but rate estimates (0.0036–0.0112 deaths/pole/yr) may have been biased by the effects of scavengers and by long sampling intervals (≥3 months), which prevented us from determining the cause of death for most birds because of advanced decay. In 2002–2003, we conducted carcass removal experiments in the Rangely Oil Field (ROF) in northwestern Colorado to estimate scavenging effects, and in 2003–2004, we...
Effective wildlife conservation strategies require an understanding of how fluctuating environmental conditions affect sensitive life stages. As part of a long-term study, we examined post-fledging and post-independence survival of 89 radio-marked juvenile Northern Goshawks (Accipiter gentilis) produced from 48 nests in northern Arizona, USA, during 1998-2001. Information-theoretic methods were used to examine within- and among-year variation in survival relative to environmental (prey abundance, weather), territory (hatching date, brood size), and individual (gender, body mass) sources of variation. The results support age- and cohort-specific differences in survival that were best explained by behaviors occurring...
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These rasters are the result of calculating the difference in Greater Sage-grouse nest survival after a simulated reduction of raven density to 0.1 ravens per square kilometer. The difference in nest survival represents spatial variation in potential to improve nest survival by reducing raven impacts. The extent of each individual raster is the extent of the field site at which sage-grouse nest observations were recorded.
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These data are detections of burros in the Sinbad Herd Management Area in central Utah made during aerial thermal infrared-based distance sampling surveys in December 2015 and May 2016. Burros were detected from a fixed wing aircraft using an infrared camera mounted on the underside of the aircraft. A monitor screen was inside the aircraft, connected to the camera so the observer could look for burros in the monitor. Aircraft flew at 2,000 feet above ground level. These data were collected to estimate the population size of burros in the Sinbad Herd Management Area and to examine effectiveness between helicopter and aerial thermal infrared survey types. To assess performance of the different survey types, data analyses...


    map background search result map search result map Annual Marbled Murrelet Abundance and Productivity Surveys Off Central California (Zone 6), 1999-2021 (ver. 4.0, May 2022) Failed Brown Treesnake bait cartridges from an aerially application in Guam, 2018 Feral burro detections from aerial infrared surveys collected in Sinbad Herd Management Area, Utah, USA, from 2015-2016 Data to Support Hierarchical Models and Decision Support Maps to Guide Management of Subsidized Avian Predator Densities Estimates of Raven Impacts on Greater Sage-Grouse Nest Survival Delineated by Field Site in California, Nevada, and Idaho (2009 - 2019) Median Estimates of Raven Density in California, Nevada, and Idaho (2012 - 2019) Raven Observations near Greater Sage-Grouse Nests in the Great Basin and Bi-State Regions of the Western United States (2009 - 2019) Mountain Plover population and habitat assessments in Texas, 2019–2020 NEON breeding landbird point counts Failed Brown Treesnake bait cartridges from an aerially application in Guam, 2018 Feral burro detections from aerial infrared surveys collected in Sinbad Herd Management Area, Utah, USA, from 2015-2016 Data to Support Hierarchical Models and Decision Support Maps to Guide Management of Subsidized Avian Predator Densities Estimates of Raven Impacts on Greater Sage-Grouse Nest Survival Delineated by Field Site in California, Nevada, and Idaho (2009 - 2019) Median Estimates of Raven Density in California, Nevada, and Idaho (2012 - 2019) Mountain Plover population and habitat assessments in Texas, 2019–2020 Raven Observations near Greater Sage-Grouse Nests in the Great Basin and Bi-State Regions of the Western United States (2009 - 2019) NEON breeding landbird point counts