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The USGS provides unbiased, objective, and impartial scientific information upon which our audiences, including resource managers, planners, and other entities, rely.
Browse more than 65,000 articles authored by our scientists over the past 100+ year history of the USGS and refine search by topic, location, year, and advanced search.
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Simple statistical models can be sufficient for testing hypotheses with population time series data Simple statistical models can be sufficient for testing hypotheses with population time series data
Time-series data offer wide-ranging opportunities to test hypotheses about the physical and biological factors that influence species abundances. Although sophisticated models have been developed and applied to analyze abundance time series, they require information about species detectability that is often unavailable. We propose that in many cases, simpler models are adequate for...
Authors
Seth J. Wenger, Edward S. Stowe, Keith B. Gido, Mary Freeman, Yoichiro Kanno, Nathan R. Franssen, Julian Olden, N. LeRoy Poff, Annika W. Walters, Phillip M. Bumpers, Meryl C. Mims, Mevin B. Hooten, Xinyi Lu
Range-wide population projections for Northern Red-Bellied Cooters (Pseudemys rubriventris) Range-wide population projections for Northern Red-Bellied Cooters (Pseudemys rubriventris)
Northern Red-Bellied Cooters (Pseudemys rubriventris) have a disjunct distribution with a relictual population in southeastern Massachusetts and a larger range across the mid-Atlantic United States. The relictual population is currently listed with protections under the U.S. Endangered Species Act but the status of the population in the remainder of the species' range has not been...
Authors
Jillian Elizabeth Fleming, Jennifer F. Moore, Hardin Waddle, Julien Martin, Evan H. Campbell Grant
Genetic analyses provide new insight on the mating strategies of the American Black Swift (Cypseloides niger) Genetic analyses provide new insight on the mating strategies of the American Black Swift (Cypseloides niger)
Avian mating strategies play a vital role in the demographic and genetic dynamics of a species and understanding avian reproductive tactics is important to conservation, population management and restoration. Classifications of avian mating strategies have historically been based on direct physical observations and tend to be rigid population-level generalizations that overlook the...
Authors
Carolyn Gunn, Kim Potter, Jennifer A. Fike, Sara J. Oyler-McCance
Post-fire seed dispersal of a wind-dispersed shrub declined with distance to seed source, yet had high levels of unexplained variation Post-fire seed dispersal of a wind-dispersed shrub declined with distance to seed source, yet had high levels of unexplained variation
Plant-population recovery across large disturbance areas is often seed-limited. An understanding of seed dispersal patterns is fundamental for determining natural-regeneration potential. However, forecasting seed dispersal rates across heterogeneous landscapes remains a challenge. Our objectives were to determine (i) the landscape patterning of post-disturbance seed dispersal, and...
Authors
Cara Applestein, Trevor Caughlin, Matthew J. Germino
Antecedent climatic conditions spanning several years influence multiple land-surface phenology events in semi-arid environments Antecedent climatic conditions spanning several years influence multiple land-surface phenology events in semi-arid environments
Ecological processes are complex, often exhibiting non-linear, interactive, or hierarchical relationships. Furthermore, models identifying drivers of phenology are constrained by uncertainty regarding predictors, interactions across scales, and legacy impacts of prior climate conditions. Nonetheless, measuring and modeling ecosystem processes such as phenology remains critical for...
Authors
David J. A. Wood, Paul C. Stoy, Scott Powell, Erik A. Beever
Multiproxy paleolimnological records provide evidence for a shift to a new ecosystem state in the Northern Great Plains, USA Multiproxy paleolimnological records provide evidence for a shift to a new ecosystem state in the Northern Great Plains, USA
Wetlands in the Prairie Pothole Region of the North American Northern Great Plains perform multiple ecosystem services and are biodiversity hotspots. However, climatological changes can result in sudden shifts in these important ecosystems. For example, marked increases in precipitation in the last few decades have resulted in a widespread shift in wetlands across the Prairie Pothole...
Authors
Kui Hu, David M. Mushet, Jon N. Sweetman
Nonlinear multidecadal trends in organic matter dynamics in Midwest reservoirs are a function of variable hydroclimate Nonlinear multidecadal trends in organic matter dynamics in Midwest reservoirs are a function of variable hydroclimate
Dissolved organic matter (DOM) and particulate organic matter (POM) can influence biogeochemical processes in aquatic systems. An understanding, however, of the source, composition, and processes driving inland reservoir organic matter (OM) cycling at a regional scale over the long term is currently unexplored. Here, we quantify decadal patterns (> 20 yr) of DOM quantity and composition...
Authors
Ruchi Bhattacharya, John R. Jones, Jennifer L. Graham, Daniel V. Obrecht, Anthony P. Thorpe, James D. Harlan, Rebecca L. North
Multi-omics responses in tree swallow (Tachycineta bicolor) nestlings from the Maumee Area of Concern, Maumee River, Ohio Multi-omics responses in tree swallow (Tachycineta bicolor) nestlings from the Maumee Area of Concern, Maumee River, Ohio
A multi-omics approach was utilized to identify altered biological responses and functions, and to prioritize contaminants to assess the risks of chemical mixtures in the Maumee Area of Concern (AOC), Maumee River, OH, USA. The Maumee AOC is designated by the United States Environmental Protection Agency as having significant beneficial use impairments, including degradation of fish and...
Authors
Yen Tseng, Christine M. Custer, Thomas W. Custer, Paul M. Dummer, Natalie Karouna-Renier, Cole W. Matson
Multispecies approaches to status assessments in support of endangered species classifications Multispecies approaches to status assessments in support of endangered species classifications
Multispecies risk assessments have developed within many international conservation programs, reflecting a widespread need for efficiency. Under the United States Endangered Species Act (ESA), multispecies assessments ultimately lead to species-level listing decisions. Although this approach provides opportunities for improved efficiency, it also risks overwhelming or biasing the...
Authors
Daniel Bruce Fitzgerald, Mary Freeman, Kelly O. Maloney, John A. Young, Amanda E. Rosenberger, David C. Kazyak, David R. Smith
Creep rate models for the 2023 US National Seismic Hazard Model: Physically constrained inversions for the distribution of creep on California faults Creep rate models for the 2023 US National Seismic Hazard Model: Physically constrained inversions for the distribution of creep on California faults
Widespread surface creep is observed across a number of active faults included in the United States (US) National Seismic Hazard Model (NSHM). In northern California, creep occurs on the central section of the San Andreas fault, along the Hayward and Calaveras faults through the San Francisco Bay Area, and to the north coast region along the Maacama and Bartlett Springs faults. In...
Authors
K. M. Johnson, Jessica R. Murray, Crystal Wespestad
Genomic divergence, local adaptation, and complex demographic history may inform management of a popular sportfish species complex Genomic divergence, local adaptation, and complex demographic history may inform management of a popular sportfish species complex
The Neosho Bass (Micropterus velox), a former subspecies of the keystone top-predator and globally popular Smallmouth Bass (M. dolomieu), is endemic and narrowly restricted to small, clear streams of the Arkansas River Basin in the Central Interior Highlands (CIH) ecoregion, USA. Previous studies have detected some morphological, genetic, and genomic differentiation between the Neosho...
Authors
J.C. Gunn, L.K. Berkman, J. Kopplelman, A.T. Taylor, Shannon K. Brewer, James M. Long, L.S. Eggert
Next-generation technologies unlock new possibilities to track rangeland productivity and quantify multi-scale conservation outcomes Next-generation technologies unlock new possibilities to track rangeland productivity and quantify multi-scale conservation outcomes
Historically, relying on plot-level inventories impeded our ability to quantify large-scale change in plant biomass, a key indicator of conservation practice outcomes in rangeland systems. Recent technological advances enable assessment at scales appropriate to inform management by providing spatially comprehensive estimates of productivity that are partitioned by plant functional group...
Authors
Caleb Powell Roberts, David Naugle, Brady W. Allred, Victoria M. Donovan, Dillon T. Fogarty, Matthew O. Jones, Jeremy D. Maestas, Andrew C. Olsen, Dirac Twidwell