A comparison of artificial incubation and natural incubation hatching success of gopher tortoise (Gopherus polyphemus) eggs in southern Mississippi
Krista M. Noel, Carl P. Qualls, Joshua R. Ennen
2012, Herpetologica (68) 324-333
Recent studies have found that Gopher Tortoise, Gopherus polyphemus, populations in southern Mississippi exhibit low recruitment, due in part to very low hatching success of their eggs. We sought to determine if the cause(s) of this low hatching success was related to egg quality (intrinsic factors), unsuitability of the nest...
Century-scale perspective on water quality in selected river basins of the conterminous United States
Edward G. Stets, Valerie J. Kelly, Whitney P. Broussard III, Thor E. Smith, Charles G. Crawford
2012, Scientific Investigations Report 2012-5225
Nutrient pollution in the form of excess nitrogen and phosphorus inputs is a well-known cause of water-quality degradation that has affected water bodies across the Nation throughout the 20th century. The recognition of excess nutrients as pollution developed later than the recognition of other water-quality problems, such as waterborne illness,...
Consequences of declining snow accumulation for water balance of mid-latitude dry regions
Daniel R. Schlaepfer, William K. Lauenroth, John B. Bradford
2012, Global Change Biology (18) 1988-1997
Widespread documentation of positive winter temperature anomalies, declining snowpack and earlier snow melt in the Northern Hemisphere have raised concerns about the consequences for regional water resources as well as wildfire. A topic that has not been addressed with respect to declining snowpack is effects on ecosystem water balance. Changes...
Palynological composition of a Lower Cretaceous South American tropical sequence: Climatic implications and diversity comparisons with other latitudes.
Paula J. Mejia-Velasquez, David L. Dilcher, Carlos A. Jaramillo, Lucas B. Fortini, Steven R. Manchester
2012, American Journal of Botany (99) 1819-1827
Premise of the study: Reconstruction of floristic patterns during the early diversification of angiosperms is impeded by the scarce fossil record, especially in tropical latitudes. Here we collected quantitative palynological data from a stratigraphic sequence in tropical South America to provide floristic and climatic insights into such tropical environments during...
Elucidating spatially explicit behavioral landscapes in the Willow Flycatcher
Amanda V. Bakian, Kimberly A. Sullivan, Eben H. Paxton
2012, Ecological Modelling (232) 119-132
Animal resource selection is a complex, hierarchical decision-making process, yet resource selection studies often focus on the presence and absence of an animal rather than the animal's behavior at resource use locations. In this study, we investigate foraging and vocalization resource selection in a population of Willow Flycatchers, Empidonax traillii...
Female Agassiz’s desert tortoise activity at a wind energy facility in southern California: The influence of an El Niño event
Josh R. Ennen, Kathie Meyer-Wilkins, Jeffrey Lovich
2012, Natural Science (4) 30-37
We compared spring-summer activity of adult female Agassiz’s Desert Tortoises (Gopherus agassizii) among three consecutive years (1997, 1998, and 1999) that differed dramatically in winter rainfall and annual plant production at a wind energy facility in the Sonoran Desert of southern California. Winter rainfall was approximately 71%, 190%, and 17%...
Geomorphic analysis of the river response to sedimentation downstream of Mount Rainier, Washington
Jonathan A. Czuba, Christopher S. Magirl, Christiana R. Czuba, Christopher A. Curran, Kenneth H. Johnson, Theresa D. Olsen, Halley K. Kimball, Casey C. Gish
2012, Open-File Report 2012-1242
A study of the geomorphology of rivers draining Mount Rainier, Washington, was completed to identify sources of sediment to the river network; to identify important processes in the sediment delivery system; to assess current sediment loads in rivers draining Mount Rainier; to evaluate if there were trends in streamflow or...
Determination and uncertainty of moment tensors for microearthquakes at Okmok Volcano, Alaska
J. D. Pesicek, J. Sileny, S. G. Prejean, C.H. Thurber
2012, Geophysical Journal International (190) 1689-1709
Efforts to determine general moment tensors (MTs) for microearthquakes in volcanic areas are often hampered by small seismic networks, which can lead to poorly constrained hypocentres and inadequate modelling of seismic velocity heterogeneity. In addition, noisy seismic signals can make it difficult to identify phase arrivals correctly for small magnitude...
Flood-inundation maps for a nine-mile reach of the Des Plaines River from Riverwoods to Mettawa, Illinois
Elizabeth A. Murphy, David T. Soong, Jennifer B. Sharpe
2012, Scientific Investigations Report 2012-5227
Digital flood-inundation maps for a 9-mile reach of the Des Plaines River from Riverwoods to Mettawa, Illinois, were created by the U.S. Geological Survey (USGS) in cooperation with the Lake County Stormwater Management Commission and the Villages of Lincolnshire and Riverwoods. The inundation maps, which can be accessed through the...
Characterization of Atlantic cod spawning habitat and behavior in Icelandic coastal waters
Timothy B. Grabowski, Kevin M. Boswell, Bruce J. McAdam, R. J. David Wells, Gudrun Marteinsdottir
2012, PLoS ONE (7)
The physical habitat used during spawning may potentially be an important factor affecting reproductive output of broadcast spawning marine fishes, particularly for species with complex, substrate-oriented mating systems and behaviors, such as Atlantic cod Gadus morhua. We characterized the habitat use and behavior of spawning Atlantic cod at two locations...
Do bioclimate variables improve performance of climate envelope models?
James I. Watling, Stephanie S. Romañach, David N. Bucklin, Carolina Speroterra, Laura A. Brandt, Leonard G. Pearlstine, Frank J. Mazzotti
2012, Ecological Modelling (246) 79-85
Climate envelope models are widely used to forecast potential effects of climate change on species distributions. A key issue in climate envelope modeling is the selection of predictor variables that most directly influence species. To determine whether model performance and spatial predictions were related to the selection of predictor variables,...
Body condition of Morelet’s Crocodiles (Crocodylus moreletii) from northern Belize
Frank J. Mazzotti, Michael S. Cherkiss, Laura A. Brandt, Ikuko Fujisaki, Kristen Hart, Brian Jeffery, Scott T. McMurry, Steven G. Platt, Thomas R. Rainwater, Joy Vinci
2012, Journal of Herpetology (46) 356-362
Body condition factors have been used as an indicator of health and well-being of crocodilians. We evaluated body condition of Morelet's Crocodiles (Crocodylus moreletii) in northern Belize in relation to biotic (size, sex, and habitat) and abiotic (location, water level, and air temperature) factors. We also tested the hypothesis that...
Status and trends of land change in the United States--1973 to 2000
Water Resources Division, U.S. Geological Survey
2012, Professional Paper 1794
Summary U.S. Geological Survey (USGS) Professional Paper 1794 is a four-volume series on the status and trends of the Nation’s land use and land cover, providing an assessment of the rates and causes of land-use and land-cover change in the United States between 1973 and 2000. Volumes A, B, C, and...
Temporal analysis of mtDNA variation reveals decreased genetic diversity in least terns
Hope M. Draheim, Patricia Baird, Susan M. Haig
2012, The Condor (114) 145-154
The Least Tern (Sternula antillarum) has undergone large population declines over the last century as a result of direct and indirect anthropogenic factors. The genetic implications of these declines are unknown. We used historical museum specimens (pre-1960) and contemporary (2001–2005) samples to examine range-wide phylogeographic patterns and investigate potential loss...
Along-shelf current variability on the Catalan inner-shelf (NW Mediterranean)
Manel Grifoll, Alfredo L. Aretxabaleta, Manuel Espino, John C. Warner
2012, Journal of Geophysical Research (117)
We examine the circulation over the inner shelf of the Catalan Sea using observations of currents obtained from three ADCPs within the inner-shelf (24 and 50 m depth) during March-April 2011. The along-shelf current fluctuations during that period are mainly controlled by the local wind stress on short time scales...
Estimating rates of decompression from textures of erupted ash particles produced by 1999-2006 eruptions of Tungurahua volcano, Ecuador
Heather M.N. Wright, Katharine V. Cashman, Patricia A. Mothes, Minard L. Hall, Andres Gorki Ruiz, Jean-Luc Le Pennec
2012, Geology (40) 619-622
Persistent low- to moderate-level eruptive activity of andesitic volcanoes is difficult to monitor because small changes in magma supply rates may cause abrupt transitions in eruptive style. As direct measurement of magma supply is not possible, robust techniques for indirect measurements must be developed. Here we demonstrate that crystal textures...
Extension of the spatial autocorrelation (SPAC) method to mixed-component correlations of surface waves
Matthew M. Haney, T. Dylan Mikesell, Kasper van Wijk, Hisashi Nakahara
2012, Geophysical Journal International (191) 189-206
Using ambient seismic noise for imaging subsurface structure dates back to the development of the spatial autocorrelation (SPAC) method in the 1950s. We present a theoretical analysis of the SPAC method for multicomponent recordings of surface waves to determine the complete 3 × 3 matrix of correlations between all pairs...
Ash3d: A finite-volume, conservative numerical model for ash transport and tephra deposition
Hans F. Schwaiger, Roger P. Denlinger, Larry G. Mastin
2012, Journal of Geophysical Research (117)
We develop a transient, 3-D Eulerian model (Ash3d) to predict airborne volcanic ash concentration and tephra deposition during volcanic eruptions. This model simulates downwind advection, turbulent diffusion, and settling of ash injected into the atmosphere by a volcanic eruption column. Ash advection is calculated using time-varying pre-existing wind data and...
Carbon stocks across a chronosequence of thinned and unmanaged red pine (Pinus resinosa) stands
Matthew D. Powers, Randall K. Kolka, John B. Bradford, Brian J. Palik, Shawn Fraver, Martin F. Jurgensen
2012, Ecological Applications (22) 1297-1307
Forests function as a major global C sink, and forest management strategies that maximize C stocks offer one possible means of mitigating the impacts of increasing anthropogenic CO2 emissions. We studied the effects of thinning, a common management technique in many forest types, on age-related trends in C stocks using...
Ballistic blocks around Kīlauea Caldera: Their vent locations and number of eruptions in the late 18th century
Donald A. Swanson, Scott P. Zolkos, Ben Haravitch
2012, Journal of Volcanology and Geothermal Research (231-232) 1-11
Thousands of ballistic blocks occur around Kīlauea Caldera and record part of the latest major period of explosive activity on the volcano, in late 1790 or within a few years thereafter. The sizes of the blocks – the largest of which is more than 2 m in nominal diameter –...
Simulation of groundwater flow in the shallow aquifer system of the Delmarva Peninsula, Maryland and Delaware
Ward E. Sanford, Jason P. Pope, David L. Selnick, Ryan F. Stumvoll
2012, Open-File Report 2012-1140
Estimating future loadings of nitrogen to the Chesapeake Bay requires knowledge about the groundwater flow system and the traveltime of water and chemicals between recharge at the water table and the discharge to streams and directly to the bay. The Delmarva Peninsula has a relatively large proportion of its land...
Downstream movement of fall Chinook salmon juveniles in the lower Snake River reservoirs during winter and early spring
Kenneth F. Tiffan, Tobias J. Kock, William P. Connor, Frank Mullins, R. Kirk Steinhorst
2012, Transactions of the American Fisheries Society (141) 285-293
We conducted a 3-year radiotelemetry study in the lower Snake River to (1) determine whether juvenile fall Chinook salmon Oncorhynchus tshawytscha pass dams during winter, when bypass systems and structures designed to prevent mortality are not operated; (2) determine whether downstream movement rate varies annually, seasonally, and from reservoir to...
Effect of brook trout removal from a spawning stream on an adfluvial population of Lahontan cutthroat trout
G. Gary Scoppettone, Peter H. Rissler, Sean P. Shea, William Somer
2012, North American Journal of Fisheries Management (32) 586-596
Independence Lake (Nevada and Sierra counties, California) harbors the only extant native population of Lahontan cutthroat trout Oncorhynchus clarkii henshawi in the Truckee River system and one of two extant adfluvial populations in the Lahontan basin. The persistence of this population has been precarious for more than 50 years, with...
Wetland fire remote sensing research--The Greater Everglades example
John Jones
2012, Fact Sheet 2012-3133
Fire is a major factor in the Everglades ecosystem. For thousands of years, lightning-strike fires from summer thunderstorms have helped create and maintain a dynamic landscape suited both to withstand fire and recover quickly in the wake of frequent fires. Today, managers in the Everglades National Park are implementing controlled...
The state of amphibians in the United States
E. Muths, M.J. Adams, E.H.C. Grant, Dick Miller, P.S. Corn, L.C. Ball
2012, Fact Sheet 2012-3092
More than 25 years ago, scientists began to identify unexplained declines in amphibian populations around the world. Much has been learned since then, but amphibian declines have not abated and the interactions among the various threats to amphibians are not clear. Amphibian decline is a problem of local, national, and...
