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Person

Craig A Stricker

Research Biologist

Fort Collins Science Center

Email: cstricker@usgs.gov
Office Phone: 303-236-7908
Fax: 303-236-4930
ORCID: 0000-0002-5031-9437

Supervisor: Brian E Reichert
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This dataset includes ovary mass and stable hydrogen isotope compositions of feathers and claws from resident and migratory female dark-eyed juncos (Junco hyemalis) collected during early spring at Mountain Lake Biological Station, Pembroke, Virginia. A total of 18 migrant and 15 resident female dark-eyed juncos, a songbird that exhibits seasonal sympatry, were caught during March-April. Stable hydrogen isotopes were used to infer relative breeding and wintering latitude of migrants. Ovary mass served as a proxy for reproductive development. These data were used to explore whether seasonal sympatry fosters or inhibits genetic divergence between migrants and residents and to the extent that this depends on their...
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This dataset includes stable hydrogen isotope values of the nonexchangeable hydrogen contained in the outer most secondary feathers of dark-eyed juncos (Junco hyemalis thurberi) collected from the University of California San Diego campus in La Jolla, California in 2014. Hydrogen isotope values in feathers have become a powerful tool for inferring the breeding grounds of a wide variety of avian species. In most of these migratory species, feathers are molted prior to departing the breeding grounds for more overwintering regions to the south. These data were used in tandem with morphological and genetic data for the classification of resident and migrant birds. There are two files in this dataset: 1) A tab delimitated...
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This dataset includes the field measurements and laboratory analyses of surface water, seston, and sediment collected from Lake Powell, within Glen Canyon National Recreation area (GLCA), during high flow (May-June 2014) and low flow (August 2015) conditions. The study area includes 12-13 sampling sites that follow a transect spanning the entire length of the reservoir from the Colorado River inflow to the Glen Canyon dam, as well as the San Juan River arm, the Escalante River arm and West Canyon. Bed sediment samples were analyzed for mercury speciation, methylmercury production and degradation rates, total reduced sulfur, iron speciation, organic content, and 16S rRNA gene templates as a proxy for microbial abundances....
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This data release includes sampling location data; field-collected stream attribute data; laboratory-analyzed chemistry concentrations (total mercury, methyl mercury) and isotopic composition (total mercury, carbon, and nitrogen) for stream biota (seston, periphyton, benthic insects, emerging adult insects, riparian spiders, and fish); density, body length, and taxonomic information for benthic insects; and density, biomass, and taxonomic information for emerging adult aquatic insects for biota sampled from stream reaches up and downstream of an historical mercury mine site. Sampling took place during summer low-flow conditions in 2015 and 2016. Stream reaches were located on USFS land near the Cinnabar Mine Site...
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In response to the 2010 Fourmile Canyon fire near Boulder, Colorado, the U.S. Geological Survey collected data to support investigations into the magnitude and critical drivers of water-quality impairment after wildfire. We analyzed chemistry of stream water, sediment, wildfire ash, soil, dust, and mine waste for metals and other parameters in order to evaluate the effects of legacy mining and wildfire on stream chemistry in the Colorado Front Range, USA. This data release includes data that were published earlier (McCleskey et al., 2012; Murphy et al., 2018).
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