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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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Chitinozoan biostratigraphy through the Aeronian – Telychian boundary interval on Anticosti Island, Canada Chitinozoan biostratigraphy through the Aeronian – Telychian boundary interval on Anticosti Island, Canada
The well-preserved Llandovery (lower Silurian) succession of Anticosti Island (Quebec, eastern Canada) contains an expanded Aeronian–Telychian boundary interval when compared to other coeval basins. This boundary interval on Anticosti Island also includes two of the most important Llandovery biogeochemical events, the late Aeronian and Valgu events. These two events were previously...
Authors
Carolina Klock, André Desrochers, Patrick I. McLaughlin, Poul Emsbo, Tim De Backer, Fien M. Jonckheere, Cristiana J.P. Esteves, Thijs R.A. Vandenbroucke
Retention of T‐bar anchor tags by adult steelhead during their upstream migration Retention of T‐bar anchor tags by adult steelhead during their upstream migration
Objective: T-bar anchor tags can be used to obtain recapture data from anglers, directly estimate exploitation, and evaluate population dynamics. Unfortunately, their use by biologists to study anadromous salmonid fisheries is limited. Two hurdles to adoption include the functional difficulty of tagging large anadromous salmonids using conventional tagging equipment and a lack of...
Authors
Nicholas S. Voss, Joshua L. McCormick, William J. Lubenau, Brett J. Bowersox, Timothy Copeland, Michael C. Quist
Smectite-rich horizons in Inceptisols trigger shallow landslides in tropical granitic terranes Smectite-rich horizons in Inceptisols trigger shallow landslides in tropical granitic terranes
Puerto Rico was affected by >70,000 landslides in the wake of 2017 Hurricane Maria, and landslide prevalence was especially high in the Utuado region in the Cordillera Central. Landslide density was highest where soil parent material is granodiorite; landslide slip surfaces tended to be shallow (
Authors
Peter C. Ryan, D. Mahmud, K. L. Derenoncourt, L. F. Nerbonne, I. L. Perez-Martin, J. Reyes Collovati, M. Junaid, Corina Cerovski-Darriau
Applying mark-resight, count, and telemetry data to estimate effective sampling area and fish density with stationary underwater cameras Applying mark-resight, count, and telemetry data to estimate effective sampling area and fish density with stationary underwater cameras
Accurate estimates of abundance and density for geographically open populations must account for the effective sampling area (ESA) of sampling gears. We describe a Marked N-Mixture model to estimate ESA and density (number of individuals/unit area) from repeated counts of unmarked and marked individuals, integrating mark-resight, camera counts, and telemetry data of red snapper (Lutjanus
Authors
Viviane Zulian, Krishna Pacifici, Nathan M. Bacheler, Jeffrey A. Buckel, William F. Patterson III, Brian J. Reich, Kyle W. Shertzer, Nathan J. Hostetter
Distinguishing natural sources from anthropogenic events in seismic data Distinguishing natural sources from anthropogenic events in seismic data
As seismic data are increasingly used to investigate a diverse range of subsurface phenomena beyond regular fast-rupturing earthquakes (Peng and Gomberg, 2010; Beroza and Ide, 2011), it is important to acknowledge that human-generated ground vibrations may be mistaken for naturally generated subsurface processes (Larose et al., 2015; Li et al., 2018). Correct discrimination of natural...
Authors
Sean Maher, Margaret Elizabeth Glasgow, Elizabeth S. Cochran, Zhigang Peng
Roles of host and environment in shift of primary anthrax host species in Kruger National Park Roles of host and environment in shift of primary anthrax host species in Kruger National Park
Environmental and climatic factors, as well as host demographics and behaviour, significantly influence the exposure of herbivorous mammalian hosts to pathogens such as Bacillus anthracis, the causative agent of anthrax. Until the early 1990s in Kruger National Park (KNP), kudu (Tragelaphus strepsiceros) was the host species most affected by anthrax, with outbreaks occurring...
Authors
Sunday O. Ochai, Lourens Snyman, Amelie C. Dolfi, Abel Ramoelo, Brian K. Reilly, Judith M. Botha, Edgar H. Dekker, O. Louis van Schalkwyk, Pauline L. Kamath, Emma Archer, Wendy Christine Turner, Henriette van Heerden
Bayesian networks facilitate updating of species distribution and habitat suitability models Bayesian networks facilitate updating of species distribution and habitat suitability models
Managers often rely on predictions of species distributions and habitat suitability to inform conservation and management decisions. Although numerous approaches are available to develop models to make these predictions, few approaches exist to update existing models as new data accumulate. There is a need for updatable models to ensure good modeling practices in an aim to keep pace with...
Authors
Adam Duarte, Robert S. Spaan, James T. Peterson, Christopher Pearl, Michael J. Adams
Evolutionary perspectives on thiamine supplementation of managed Pacific salmonid populations Evolutionary perspectives on thiamine supplementation of managed Pacific salmonid populations
Thiamine deficiency complex (TDC) has been identified in an ever-expanding list of species and populations. In many documented occurrences of TDC in fishes, juvenile mortality can be high—up to 90% at the population level. Such sweeping demographic losses and concomitant decreases in genetic diversity due to TDC can be prevented by treating pre-spawn females or fertilized eggs with...
Authors
Avril M. Harder, Aimee N. Reed, Freya Elizabeth Rowland
Using remote sensing to identify habitat for wintering Henslow's Sparrows (Centronyx henslowii) Using remote sensing to identify habitat for wintering Henslow's Sparrows (Centronyx henslowii)
The Henslow's Sparrow (Centronyx henslowii) is a grassland bird species that overwinters in the southeastern United States and is a species of conservation concern due to population declines primarily caused by habitat loss. Henslow's Sparrows often overwinter in marginal habitats, such as powerline rights-of-way (ROWs), clear cuts, and field edges that provide some of their desired...
Authors
Sierra A. Moore, Abigail W. Dwire, Thomas J. Prebyl, Todd M. Schneider, Elizabeth Ann Hunter
A meta-analysis highlights the idiosyncratic nature of tradeoffs in laboratory models of virus evolution A meta-analysis highlights the idiosyncratic nature of tradeoffs in laboratory models of virus evolution
Different theoretical frameworks have been invoked to guide the study of virus evolution. Three of the more prominent ones are (i) the evolution of virulence, (ii) life history theory, and (iii) the generalism–specialism dichotomy. All involve purported tradeoffs between traits that define the evolvability and constraint of virus-associated phenotypes. However, as popular as these...
Authors
Ketty Kabengele, Wendy Christine Turner, Paul E. Turner, C. Brandon Ogbunugafor
Disparities in Perimyotis subflavus body mass between cave and culvert hibernacula in Georgia, USA Disparities in Perimyotis subflavus body mass between cave and culvert hibernacula in Georgia, USA
The tricolored bat (Perimyotis subflavus), once common in the eastern United States, has experienced significant mortality due to white-nose syndrome (WNS), a fungal disease that primarily affects bats hibernating in caves and mines. In coastal regions of the southeastern United States, where caves and mines are scarce, tricolored bats often use roadway culverts as hibernacula. However...
Authors
Emily Ferrall, S. Perea, K.M. Morris, P.E. Pattavina, Brian J. Irwin, J. Hepinstall-Cymerman, S.B. Castleberry
An audience segmentation study of native plant gardening behaviors in the United States An audience segmentation study of native plant gardening behaviors in the United States
Audience segmentation can be used to identify target audiences in environmental public engagement and communication, but few studies have used segmentation to study biodiversity conservation behavior. This study used segmentation to better understand perceptions and behaviors around different types of actions related to native plant gardening. With a United States representative survey...
Authors
Veronica M. Champine, Kaiya Tamlyn, Megan Siobhan Jones, Meena M. Balgopal, Brett Bruyere, Jennifer N. Solomon, Rebecca M. Niemiec