Michael L Casazza

Historical methyl mercury in San Francisco Bay

San Francisco Bay, California is considered a mercury-impaired watershed. Elevated concentrations of mercury are found in water and sediment as well as fish and estuarine birds. Sources of mercury to the watershed since 1845 include sediment-associated mercury from mercury mining, mercury losses from gold amalgamation activities in mines of the Sierra Nevada, aerial deposition of mercury from global and regional emissions to air, and the direct discharge of mercury to Bay waters associated with the urbanization and industrialization of the estuary. We assessed historical trends in mercury bioaccumulation by measuring mercury concentrations in feathers of the endangered California Ridgway’s rail (formerly California...

Categories: Data; Tags: California Ridgway's Rail, Feathers, Ice Cores, Lake Tahoe, Mercury, All tags... San Francisco Bay, Sediment, Structural Equation Model, USGS Science Data Catalog (SDC), Wyoming, Fewer tags

Raven Observations near Greater Sage-Grouse Nests in the Great Basin and Bi-State Regions of the Western United States (2009 - 2019)

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...

Categories: Data; Tags: Anthropogenic subsidies, California, Great Basin, Idaho, Nevada, All tags... bi-state, biota, conservation planning, decision support, density surface model, distance sampling, ecology, human impacts, native species, nest survival, population decline, predation, predator-prey, sagebrush, species distribution, species of concern, wildlife, Fewer tags

This USGS data release represents geospatial data for the sage-grouse habitat mapping project. This study provides timely and highly useful information about greater sage-grouse over a large area of the Great Basin. USGS researchers and their colleagues created a template for combining landscape-scale occurrence or abundance data with habitat selection data in order to identify areas most critical to sustaining populations of species of conservation concern. The template also identifies those areas where land use changes have minimal impact. To inform greater sage-grouse conservation planning, the researchers developed greater sage-grouse habitat management categories based on habitat selection indices (HSI) and...

Tags: Biota, Boundaries, Environment, USA, Great Basin, Nevada, USGS Science Data Catalog (SDC), biota, boundaries, All tags... environment, greater sage-grouse, Fewer tags

Tule Greater White-fronted Goose Migration Tracks (2019-2020) and Atmospheric Smoke Concentrations (2020)

April through May (spring) and August through September (fall) locations for tule greater white-fronted geese (Anser albifrons elgasi) marked with GPS collars at Summer Lake Wildlife Area, OR in 2018 and 2019. Locations may include pre-migration and post-migration designations. Locations occurring between September 11, 2020, and arrival at, or within 50 kilometers of the Summer Lake Wildlife Area stopover location also provided with elevation information and smoke concentrations derived from the experimental HRRR-Smoke model. Median predicted smoke concentrations extrapolated from ground level through 5,000 meters also provided. These data supports the following publication: Overton, C.T., Lorenz, A.A., James,...

Categories: Data; Tags: Alaska, Oregon, Pacific Northwest, Pacific Ocean, Summer Lake, Oregon, All tags... USGS Science Data Catalog (SDC), Washington, birds, migratory species, smoke, Fewer tags

Ranked Habitat Classes for Sage-Grouse Brood-Rearing Productivity, Nevada and California

Ranked habitat classes for sage-grouse brood-rearing productivity at each 90 m pixel. Habitat classes represent areas where high brood selection and high brood survival intersected, whereas the lowest ranks represent areas where high brood habitat selection intersected with the low brood survival. Hierarchical models of brood selection and survival were fit to landscape covariates within a Bayesian modeling framework in Nevada and California from 2009 - 2017 to develop spatially explicit information about brood habitat selection and survival.

Tags: Great Basin, adaptive habitat selection, chick survival, ecological trap, ecosystems, All tags... fires, habitat functional response, human impacts, maladaptive habitat selection, native species, resource selection function, shrubland ecosystems, western United States, Fewer tags