Publications

Birds can cause extensive crop damage in the United States. In some regions, depredating species comprise a substantial portion of the total avian population, emphasizing their importance both economically and ecologically. We used the National Audubon Society Christmas Bird Count data from the south-central United States and mixed-effects models to identify habitat factors associated...

Sources of mercury (Hg) in Great Lakes sediments were assessed with stable Hg isotope ratios using multicollector inductively coupled plasma mass spectrometry. An isotopic mixing model based on mass-dependent (MDF) and mass-independent fractionation (MIF) (δ202Hg and Δ199Hg) identified three primary Hg sources for sediments: atmospheric, industrial, and watershed-derived. Results...

Region-specific conservation programs should have objective, reliable metrics for species prioritization and progress evaluation that are customizable to the goals of a program, easy to comprehend and communicate, and standardized across time. Regional programs may have vastly different goals, spatial coverage, or management agendas, and one-size-fits-all schemes may not always be the...

A collection of 24 datasets, including streamflow, well characteristics, groundwater elevations, and discrete water-quality concentrations, is provided to produce a consistent set of example data to demonstrate typical data manipulations or statistical analysis of hydrologic data. These example data are provided in an R package called smwrData. The data in the package have been collected...

Conserving migratory birds is made especially difficult because of movement among spatially disparate locations across the annual cycle. In light of challenges presented by the scale and ecology of migratory birds, successful conservation requires integrating objectives, management, and monitoring across scales, from local management units to ecoregional and flyway administrative...

There is growing need to develop models of spatial patterns in animal abundance, yet comparatively few examples of such models exist. This is especially true in situations where the abundance of one species may inhibit that of another, such as the intensively-farmed landscape of the Prairie Pothole Region (PPR) of the central United States, where waterfowl production is largely...

Managers in the Upper Mississippi River (UMR) are using reductions in the River's water levels during summer to mimic historical water regimes and rehabilitate habitats for vegetation and other species. Concerns for the unintended effects of these actions on mussel populations threatened to halt these projects. Our objective was to characterise the survival and movement of two mussel...

Lake Erie is a large lake straddling the border of the U.S. and Canada that has become increasingly eutrophic in recent years. Eutrophication is particularly focused in the shallow western basin. The western basin of Lake Erie is hydrodynamically similar to a large estuary, with riverine inputs from the Detroit and Maumee Rivers mixing together and creating gradients in chemical and...

Dissolved organic matter (DOM) composition in freshwater ecosystems is influenced by interactions between physical, chemical, and biological processes that are controlled, at one level, by watershed landscape, hydrology, and their connections. Against this environmental template, humans may strongly influence DOM composition. Yet, we lack a comprehensive understanding of DOM composition...

Organic waste compounds (OWCs) are ingredients and by-products of common agricultural, industrial, and household substances that can contaminate our streams through sources like urban runoff, sewage overflows, and leaking septic systems. To better understand how OWCs are affecting Milwaukee-area streams, the U.S. Geological Survey, in cooperation with the Milwaukee Metropolitan Sewerage...

Resource managers lack an effective chemical tool to control the invasive zebra mussel Dreissena polymorpha. Zebra mussels clog water intakes for hydroelectric companies, harm unionid mussel species, and are believed to be a reservoir of avian botulism. Little is known about the digestive physiology of zebra mussels and unionid mussels. The enzymatic profile of the digestive glands of...

The PEST++ Version 1 object-oriented parameter estimation code is here extended to Version 3 to incorporate additional algorithms and tools to further improve support for large and complex environmental modeling problems. PEST++ Version 3 includes the Gauss-Marquardt-Levenberg (GML) algorithm for nonlinear parameter estimation, Tikhonov regularization, integrated linear-based uncertainty