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We know little about the breeding behavior of most nocturnal raptors. Nest attendance and prey delivery rates can be used as indices of relative habitat quality or extent of parental care. We used video cameras to document and observe prey delivery rates, nest attendance and bout durations at two northern...

Species with a long evolutionary history of sympatry often have mechanisms for resource partitioning that reduce competition. However, introduced non-native ungulates often compete with native ungulates and competitive effects can be exacerbated in arid regions due to low primary productivity. Our objectives were to characterize diet composition, quality, and overlap...

Understanding the speciation of divalent mercury (Hg(II)) in aquatic systems containing dissolved organic matter (DOM) and sulfide is necessary to predict the conversion of Hg(II) to bioavailable methylmercury. We used X-ray absorption spectroscopy to characterize the structural order of mercury in Hg(II)–DOM–sulfide systems for a range of sulfide concentration (1–100...

Ultra-high-resolution (1 m * 1 m * 0.25 m) bathymetry was acquired with an autonomous underwater vehicle (AUV) over a sector of the Navy Fan offshore Baja California. The survey specifically targeted an area where the former interpretation of the fan showed a channel–lobe transition; however, the lobe and the...

Deformed wing virus (DWV) is a major pathogen of concern to apiculture, and recent reports have indicated the local predominance and potential virulence of recombinants between DWV and a related virus, Varroa destructor virus 1 (VDV). However, little is known about the frequency and titer of VDV and recombinants relative...

We investigate spatial and temporal relations between an ongoing and prolific seismicity cluster in central Washington, near Entiat, and the 14 December 1872 Entiat earthquake, the largest historic crustal earthquake in Washington. A fault scarp produced by the 1872 earthquake lies within the Entiat cluster; the locations and areas of...

Freshwater littoral zones harbor diverse ecological communities and serve numerous ecosystem functions that are controlled, in part, by natural water level fluctuations. However, human alteration of lake hydrologic regimes beyond natural fluctuations threaten littoral zone ecological integrity. One type of hydrologic alteration in lakes is winter water level drawdowns, which...

Managing an invasive species is particularly challenging as little is generally known about the species’ biological characteristics in its new habitat. In practice, removal of individuals often starts before the species is studied to provide the information that will later improve control. Therefore, the locations and the amount of control...

The spread of Aquatic Invasive Species (AIS) between the Great Lakes and Mississippi River Basin by way of the Chicago Area Waterway System (CAWS) is a pressing concern to resource managers in the Midwest region. Augmenting this spread are watercrafts traveling through the CAWS locks and dams. AIS are able...

The increasing use of pharmaceuticals has led to their subsequent input into and release from wastewater treatment plants, with corresponding discharge into surface waters that may subsequently exert adverse effects upon aquatic organisms. Although the distribution of pharmaceuticals in surface water has been extensively studied, the details of uptake, internal...

Several caves in the Shenandoah Valley in Virginia show evidence for early hypogenic conduit development with later-enhanced solution under partly confined phreatic conditions guided by geologic structures. Many (but not all) of these caves have been subsequently invaded by surface waters as a result of erosion and exhumation. Those not...

ge estimates of Lake Superior Kiyis Coregonus kiyi from scales and otoliths were compared and 12 years (2003–2014) of length frequency data were examined to assess year‐class strength and validate age estimates. Ages estimated from otoliths were precise and were consistently older than ages estimated from scales. Maximum otolith‐derived ages were 20...

Nutritional ecology forms the interface between environmental variability and large herbivore behaviour, life history characteristics, and population dynamics. Forage conditions in arid and semi-arid regions are driven by unpredictable spatial and temporal patterns in rainfall. Diet selection by herbivores should be directed towards overcoming the most pressing nutritional limitation (i.e....

Quantifying the frequency, duration, and elevation range of fog or cloud immersion is essential to estimate cloud water deposition in water budgets and to understand the ecohydrology of cloud forests. The goal of this study was to develop a low-cost and high spatial-coverage method to detect occurrence of cloud immersion...

Here we explore the potential of spring-related, surface and subsurface carbonates as an archive of paleoenvironmental change at Barrancas Blancas, located in the broadest and driest sector of the Atacama Desert at 24.5°S. From these deposits we present a new stable isotopic record of paleoenvironmental conditions over portions of the...

Multibeam acoustic backscatter has considerable utility for remote characterization of spatially heterogeneous bed sediment composition over vegetated and unvegetated riverbeds of mixed sand and gravel. However, the use of high-frequency, decimeter-resolution acoustic backscatter for sediment classification in shallow water is hampered by significant topographic contamination of the signal. In mixed...

Examination of food webs and trophic niches provide insights into organisms' functional ecology, yet few studies have examined trophodynamics within submarine canyons, where the interaction of canyon morphology and oceanography influences habitat provision and food deposition. Using stable isotope analysis and Bayesian ellipses, we documented deep-sea food-web structure and trophic...

In January 2014, approximately 37 800 L of crude 4-methylcyclohexanemethanol (crude MCHM) spilled into the Elk River, West Virginia. To understand the long-term fate of 4-MCHM, we conducted experiments under environmentally relevant conditions to assess the potential for the 2 primary compounds in crude MCHM (1) to undergo biodegradation and (2)...

In 2013 to 2015, 833 public supply wells in 15 Principal aquifers in the U.S. were sampled to identify which aquifers contained high methane concentrations (>1 mg/L) and determine the geologic, hydrologic, and geochemical conditions associated with high concentrations. This study represents the first national assessment of methane in aquifers used...

Agricultural watersheds are globally pervasive, supporting fundamentally different organic matter source, composition, and concentration profiles in comparison to natural systems. Similar to natural systems, agricultural storm runoff exports large amounts of organic carbon from agricultural land into waterways. But intense management of upper soil layers, waterway channelization,...

Large rivers carry terrestrial sediment, contaminants, and other materials to the coastal zone where they can affect marine biogeochemical cycles and ecosystems. This U.S. Geological Survey study combined river and marine sediment geochemistry and organic contaminant analyses to identify riverborne sediment and associated contaminants at shoreline sites in Commencement Bay,...

Two sets of digital flood-inundation map libraries that spanned a combined 16.7-mile reach of the Meramec River that extends upstream from Valley Park, Missouri, to downstream from Fenton, Mo., were created by the U.S. Geological Survey (USGS) in cooperation with the U.S. Army Corps of Engineers, St. Louis Metropolitan Sewer District, Missouri...

The 2017 census of southern sea otters (Enhydra lutris nereis) was conducted between late April and early July along the mainland coast of central California and in April at San Nicolas Island in southern California. The 3-year average of combined counts from the mainland range and San Nicolas Island...

Natural resource management is conducted in the context of multiple anthropogenic stressors and is further challenged owing to changing climate. Experiments to determine the effects of climate change on complex ecological systems are nearly impossible. However, using a simulation model to synthesize current understanding of key ecological processes through...

Climate change and habitat loss are projected to be the two greatest drivers of biodiversity loss over the coming century. While public lands have the potential to increase regional resilience of bird populations to these threats, long-term data are necessary to document species responses to changes in climate and habitat...