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Publications

Browse more than 160,000 publications authored by our scientists over the past 100+ year history of the USGS.  Publications available are: USGS-authored journal articles, series reports, book chapters, other government publications, and more.

Filter Total Items: 175531

Iguanas rafted more than 8,000 km from North America to Fiji Iguanas rafted more than 8,000 km from North America to Fiji

Founder-event speciation can occur when one or more organisms colonize a distant, unoccupied area via long-distance dispersal, leading to the evolution of a new species lineage. Species radiations established by long-distance, and especially transoceanic, dispersal can cause substantial shifts in regional biodiversity. Here, we investigate the occurrence and timing of the greatest known...
Authors
Simon G. Scarpetta, Robert D. Fisher, Benjamin R. Karin, Jone B. Niukula, Ammon Corl, Todd R. Jackman, Jimmy A. McGuire

Optimizing sampling across transect-based methods improves the power of agroecological monitoring data Optimizing sampling across transect-based methods improves the power of agroecological monitoring data

Transect-based monitoring has long been a valuable tool in ecosystem monitoring to measure multiple ecosystem attributes. The line-point intercept (LPI), vegetation height, and canopy gap intercept methods comprise a set of core methods, which provide indicators of ecosystem condition. However, users often struggle to design a sampling strategy that optimizes the ability to detect...
Authors
Sarah E. McCord, Nicholas P. Webb, Justin W. Van Zee, Ericha M. Courtright, Benjamin J Billings, Michael C. Duniway, Brandon L. Edwards, Emily Kachergis, Daniel N Moriasi, Brian Morra, Aleta Nafus, Beth A. Newingham, Drew A. Scott, David Toledo

Stratigraphy, structure, and geomorphology of the central Appalachians across the North Mountain fault zone near Harrisonburg, Virginia, USA Stratigraphy, structure, and geomorphology of the central Appalachians across the North Mountain fault zone near Harrisonburg, Virginia, USA

This field trip focuses on the geology of the central Appalachian Valley and Ridge province near Harrisonburg, Virginia, USA. Recent geologic mapping utilizing 1-m resolution lidar data has revealed new insights into the Paleozoic stratigraphy, structural geology, and Neogene landscape evolution of the region. The detailed mapping reveals the presence of the Big Spring Station Member and...
Authors
Daniel H. Doctor, Alexander Addison Gray, William E. Odom

Ordovician stratigraphy, structure, and karst of the Falling Spring Valley, Alleghany County, Virginia, USA Ordovician stratigraphy, structure, and karst of the Falling Spring Valley, Alleghany County, Virginia, USA

This one-day trip highlights new findings on a preliminary bedrock geologic map that shows results from ongoing geologic mapping in the Falling Spring Valley of Alleghany County, Virginia, USA, which is the southern end of the larger Warm Springs Valley, an elongated anticlinal valley rimmed by Ordovician and Silurian siliciclastic rocks, and which is famous for its thermal springs. This...
Authors
John T. Haynes, Richard A. Lambert, Delbert C. Martin, Randall C. Orndorff, Mercer Parker

Being loud to find a quiet bird: Surveying a secretive tropical avian species Being loud to find a quiet bird: Surveying a secretive tropical avian species

Secretive birds are hard to detect, and thus, likely underestimated when surveyed, potentially preventing measures to protect them. We identified a sampling period and method that would yield the most reliable estimates of population numbers of the secretive Puerto Rican Lizard-Cuckoo (Coccyzus vieilloti). We addressed these objectives by comparing point counts (passive) and playback...
Authors
Kenneth X. Rodriquez-Rivera, Alberto R. Puente Rolon, Jaime A. Collazo

Evaluating the potential to quantify salmon habitat via UAS-based particle image velocimetry Evaluating the potential to quantify salmon habitat via UAS-based particle image velocimetry

Continuous, high-resolution data for characterizing freshwater habitat conditions can support successful management of endangered salmonids. Uncrewed aircraft systems (UAS) make acquiring such fine-scale data along river channels more feasible, but workflows for quantifying reach-scale salmon habitats are lacking. We evaluated the potential for UAS-based mapping of hydraulic habitats...
Authors
Lee R. Harrison, Carl J. Legleiter, Brandon Overstreet, James White
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