Program SPACECAP: software for estimating animal density using spatially explicit capture-recapture models
Arjun M. Gopalaswamy, J. Andrew Royle, James E. Hines, Pallavi Singh, Devcharan Jathanna, N. Samba Kumar, K. Ullas Karanth
2012, Methods in Ecology and Evolution (3) 1067-1072
1. The advent of spatially explicit capture-recapture models is changing the way ecologists analyse capture-recapture data. However, the advantages offered by these new models are not fully exploited because they can be difficult to implement. 2. To address this need, we developed a user-friendly software package,...
Mars global digital dune database: MC-30
R.K. Hayward, L.K. Fenton, T.N. Titus, A. Colaprete, P. R. Christensen
2012, Open-File Report 2012-1259
The Mars Global Digital Dune Database (MGD3) provides data and describes the methodology used in creating the global database of moderate- to large-size dune fields on Mars. The database is being released in a series of U.S. Geological Survey Open-File Reports. The first report (Hayward and others, 2007) included dune...
Density estimation in tiger populations: combining information for strong inference
Arjun M. Gopalaswamy, J. Andrew Royle, Mohan Delampady, James D. Nichols, K. Ullas Karanth, David W. Macdonald
2012, Ecology (93) 1741-1751
A productive way forward in studies of animal populations is to efficiently make use of all the information available, either as raw data or as published sources, on critical parameters of interest. In this study, we demonstrate two approaches to the use of multiple sources of information on a parameter...
Balancing precision and risk: should multiple detection methods be analyzed separately in N-mixture models?
Tabitha A. Graves, J. Andrew Royle, Katherine C. Kendall, Paul Beier, Jeffrey B. Stetz, Amy C. Macleod
2012, PLoS ONE (7)
Using multiple detection methods can increase the number, kind, and distribution of individuals sampled, which may increase accuracy and precision and reduce cost of population abundance estimates. However, when variables influencing abundance are of interest, if individuals detected via different methods are influenced by the landscape differently, separate analysis of...
Future scenarios of land-use and land-cover change in the United States--the Marine West Coast Forests Ecoregion
Tamara S. Wilson, Benjamin M. Sleeter, Terry L. Sohl, Glenn Griffith, William Acevedo, Stacie Bennett, Michelle Bouchard, Ryan R. Reker, Christy Ryan, Kristi L. Sayler, Rachel Sleeter, Christopher E. Soulard
2012, Open-File Report 2012-1252
Detecting, quantifying, and projecting historical and future changes in land use and land cover (LULC) has emerged as a core research area for the U.S. Geological Survey (USGS). Changes in LULC are important drivers of changes to biogeochemical cycles, the exchange of energy between the Earth’s surface and atmosphere, biodiversity,...
Species, functional groups, and thresholds in ecological resilience
Shana M. Sundstrom, Craig R. Allen, Chris Barichievy
2012, Conservation Biology (26) 305-314
The cross-scale resilience model states that ecological resilience is generated in part from the distribution of functions within and across scales in a system. Resilience is a measure of a system's ability to remain organized around a particular set of mutually reinforcing processes and structures, known as a regime. We...
Earthquake recurrence models fail when earthquakes fail to reset the stress field
Thessa Tormann, Stefan Wiemer, Jeanne L. Hardebeck
2012, Geophysical Research Letters (39)
Parkfield's regularly occurring M6 mainshocks, about every 25 years, have over two decades stoked seismologists' hopes to successfully predict an earthquake of significant size. However, with the longest known inter-event time of 38 years, the latest M6 in the series (28 Sep 2004) did not conform to any of the...
Northwestern salamanders Ambystoma gracile in mountain lakes: record oviposition depths among salamanders
R. Hoffman Jr., C.A. Pearl, G.L. Larson, B. Samora
2012, Herpetological Review (43) 553-556
Oviposition timing, behaviors, and microhabitats of ambystomatid salamanders vary considerably (Egan and Paton 2004; Figiel and Semlitsch 1995; Howard and Wallace 1985; Mac-Cracken 2007). Regardless of species, however, females typically oviposit using sites conducive to embryo development and survival. For example, the results of an experiment by Figiel and Semlitsch...
Spring onset variations and trends in the continental United States: past and regional assessment using temperature-based indices
Mark D. Schwartz, Toby R. Ault, Julio L. Betancourt
2012, International Journal of Climatology
Phenological data are simple yet sensitive indicators of climate change impacts on ecosystems, but observations have not been made routinely or extensively enough to evaluate spatial and temporal patterns across most continents, including North America. As an alternative, many studies use weather-based algorithms to simulate specific phenological responses. Spring Indices...
Spectral damping scaling factors for shallow crustal earthquakes in active tectonic regions
Sanaz Rezaeian, Yousef Bozorgnia, I.M. Idriss, Kenneth Campbell, Norman Abrahamson, Walter Silva
2012, PEER Report 2012/01
Ground motion prediction equations (GMPEs) for elastic response spectra, including the Next Generation Attenuation (NGA) models, are typically developed at a 5% viscous damping ratio. In reality, however, structural and non-structural systems can have damping ratios other than 5%, depending on various factors such as structural types, construction materials, level...
Associations of benthic macroinvertebrate assemblages with environmental variables in the upper Clear Creek watershed, California
Larry R. Brown, Jason T. May, Marissa Wulff
2012, Western North American Naturalist (72) 473-494
Benthic macroinvertebrates are integral components of stream ecosystems and are often used to assess the ecological integrity of streams. We sampled streams in the upper Clear Creek drainage in the Klamath—Siskiyou Ecoregion of northwestern California in fall 2004 (17 sites) and 2005 (original 17 plus 4 new sites) with the...
Step-changes in the physical, chemical and biological characteristics of the Gulf of Maine, as documented by the GNATS time series
William M. Balch, D.T. Drapeau, B.C. Bowler, Thomas G. Huntington
2012, Marine Ecology Progress Series (450) 11-35
We identify step-changes in the physical, chemical and biological characteristics of the Gulf of Maine (GoM) using the Gulf of Maine North Atlantic Time Series (GNATS), a series of oceanographic measurements obtained between September 1998 and December 2010 along a transect in the GoM running from Portland, ME, to Yarmouth,...
A remote-sensing, GIS-based approach to identify, characterize, and model spawning habitat for fall-run chum salmon in a sub-arctic, glacially fed river
Lisa Wirth, Amanda Rosenberger, Anupma Prakash, Rudiger Gens, F. Joseph Margraf, Toshihide Hamazaki
2012, Transactions of the American Fisheries Society (141) 1349-1363
At northern limits of a species’ distribution, fish habitat requirements are often linked to thermal preferences, and the presence of overwintering habitat. However, logistical challenges and hydrologic processes typical of glacial systems could compromize the identification of these habitats, particularly in large river environments. Our goal was to identify and...
Predator evasion by white-tailed deer fawns
Troy W. Grovenburg, Kevin L. Monteith, Robert W. Klaver, Jonathan A. Jenks
2012, Animal Behaviour (84) 59-65
Despite their importance for understanding predator–prey interactions, factors that affect predator evasion behaviours of offspring of large ungulates are poorly understood. Our objective was to characterize the influence of selection and availability of escape cover and maternal presence on predator evasion by white-tailed deer, Odocoileus virginianus, fawns in the northern...
Gravity fluctuations induced by magma convection at Kilauea Volcano, Hawai'i
Daniele Carbone, Michael P. Poland
2012, Geology (40) 803-806
Convection in magma chambers is thought to play a key role in the activity of persistently active volcanoes, but has only been inferred indirectly from geochemical observations or simulated numerically. Continuous microgravity measurements, which track changes in subsurface mass distribution over time, provide a potential method for characterizing convection in...
On the use of wave parameterizations and a storm impact scaling model in National Weather Service Coastal Flood and decision support operations
Anthony Mignone, H. Stockdon, M. Willis, J.W. Cannon, R. Thompson
2012, Conference Paper, 92nd American Meteorological Society Annual Meeting, January 22-26, 2012
National Weather Service (NWS) Weather Forecast Offices (WFO) are responsible for issuing coastal flood watches, warnings, advisories, and local statements to alert decision makers and the general public when rising water levels may lead to coastal impacts such as inundation, erosion, and wave battery. Both extratropical and tropical cyclones can...
Stable isotopes identify dietary changes associated with beak deformities in Black-Capped Chickadees (Poecile atricapillus)
Caroline R. Van Hemert, Colleen M. Handel, Diane M. O’Brien
2012, The Auk (129) 460-466
A large number of beak deformities of unknown etiology have recently been reported in Black-capped Chickadees (Poecile atricapillus) and other resident avian species in Alaska. We investigated the potential association between diet and beak deformities. We analyzed carbon (δ13C) and nitrogen (δ15N) isotopes in whole blood of Black-capped Chickadees captured...
Data-driven modeling of surface temperature anomaly and solar activity trends
Michael J. Friedel
2012, Environmental Modelling and Software (37) 217-232
A novel two-step modeling scheme is used to reconstruct and analyze surface temperature and solar activity data at global, hemispheric, and regional scales. First, the self-organizing map (SOM) technique is used to extend annual modern climate data from the century to millennial scale. The SOM component planes are used to...
Methods for simulating solute breakthrough curves in pumping groundwater wells
J. Jeffrey Starn, Amvrossios C. Bagtzoglou, Gary A. Robbins
2012, Computers & Geosciences (48) 244-255
In modeling there is always a trade-off between execution time and accuracy. For gradient-based parameter estimation methods, where a simulation model is run repeatedly to populate a Jacobian (sensitivity) matrix, there exists a need for rapid simulation methods of known accuracy that can decrease execution time, and thus make the...
A historical estimate of apparent survival of American oystercatcher (Haematopus palliatus) in Virginia
Erica Nol, Sean P. Murphy, Michael D. Cadman
2012, Waterbirds (35) 631-635
Using mark-recapture models, apparent survival was estimated from older banding and re-sighting data (1978–1983) of American Oystercatchers (Haematopus palliatus) nesting on beaches and in salt marshes of coastal Virginia, USA. Oystercatchers nesting in salt marshes exhibited higher apparent survival (0.94 ±0.03) than birds nesting on beaches (0.81 ±0.06), a difference...
Predicting the geographic distribution of a species from presence-only data subject to detection errors
Robert M. Dorazio
2012, Biometrics (68) 1303-1312
Several models have been developed to predict the geographic distribution of a species by combining measurements of covariates of occurrence at locations where the species is known to be present with measurements of the same covariates at other locations where species occurrence status (presence or absence) is unknown. In the...
Late Quaternary sedimentological and climate changes at Lake Bosumtwi Ghana: new constraints from laminae analysis and radiocarbon age modeling
Timothy M. Shanahan, J. Warren Beck, Jonathan T. Overpeck, Nicholas P. McKay, Jeffrey S. Pigati, John A. Peck, Christopher A. Scholz, Clifford W. Heil Jr., John W. King
2012, Palaeogeography, Palaeoclimatology, Palaeoecology (361-362) 49-60
The Lake Bosumtwi sediment record represents one of the longest and highest-resolution terrestrial records of paleoclimate change available from sub-Saharan Africa. Here we report a new sediment age model framework for the last ~ 45 cal kyr of sedimentation using a combination of high-resolution radiocarbon dating, Bayesian age-depth modeling and...
Modeling responses of large-river fish populations to global climate change through downscaling and incorporation of predictive uncertainty
Mark L. Wildhaber, Christopher K. Wikle, Christopher J. Anderson, Kristie J. Franz, Edward H. Moran, Rima Dey
Helmut Mader, Julia Kraml, editor(s)
2012, Conference Paper, 9th International Symposium on Ecohydraulics 2012 Proceedings
Climate change operates over a broad range of spatial and temporal scales. Understanding its effects on ecosystems requires multi-scale models. For understanding effects on fish populations of riverine ecosystems, climate predicted by coarse-resolution Global Climate Models must be downscaled to Regional Climate Models to watersheds to river hydrology...
Estimating the benefits of land imagery in environmental applications: a case study in nonpoint source pollution of groundwater
Richard L. Bernknopf, William M. Forney, Ronald P. Raunikar, Shruti K. Mishra
Ramanan Laxminarayan, Molly K. Maccauley, editor(s)
2012, Book chapter, The value of information
Moderate-resolution land imagery (MRLI) is crucial to a more complete assessment of the cumulative, landscape-level effect of agricultural land use and land cover on environmental quality. If this improved assessment yields a net social benefit, then that benefit reflects the value of information (VOI) from MRLI. Environmental quality and the...
Exceptional warming in the Western Pacific-Indian Ocean warm pool has contributed to more frequent droughts in eastern Africa
Christopher C. Funk
Thomas C. Peterson, Peter A. Stott, Stephanie Herring, editor(s)
2012, Bulletin of the American Meteorological Society (93) 1049-1051
In 2011, East Africa faced a tragic food crisis that led to famine conditions in parts of Somalia and severe food shortages in parts of Ethiopia and Somalia. While many nonclimatic factors contributed to this crisis (high global food prices, political instability, and chronic poverty, among others) failed rains in...
