Publications

Mercury (Hg), a potent neurotoxic element, can biomagnify through food webs once converted into methylmercury (MeHg). Some studies have found that selenium (Se) exposure may reduce MeHg bioaccumulation and toxicity, though this pattern is not universal. Se itself can also be toxic at elevated levels. We experimentally manipulated the relative concentrations of dietary MeHg and Se (as

Scavengers likely play an important role in ecosystem energy flow as well as disease transmission, but whether they facilitate or reduce disease transmission is often unknown. In the Greater Yellowstone Ecosystem, scavengers are likely to reduce the transmission and subsequent spread of brucellosis within and between livestock and elk by consuming infectious abortion materials, thereby...

Scientists collect fleas (Siphonaptera) to survey for Yersinia pestis, the bacterial agent of plague. When studying fleas parasitizing prairie dogs (Cynomys spp.), two primary methods are used: (1) combing fleas from live-trapped prairie dogs and (2) swabbing fleas from burrows with cloth swabs attached to metal cables. Ideally, burrow swabbing, the cheaper and easier method, would...

Extreme climatic events are likely to intensify under climate change and can have different effects on ecosystems depending on their timing and magnitude. Understanding how productivity responds to extreme precipitation patterns requires assessing stability and vulnerability during critical growing periods at the plant community level. In this study, we experimentally imposed two...

Most invasive species are not studied during their initial colonization of ecosystems to which they were recently introduced. Rather, research is typically performed after invasive species are well established and causing harm to the native biodiversity. Thus, novel adaptations of invasive species during their initial invasions are rarely identified. The California kingsnake...

Biodiversity projections with uncertainty estimates under different climate, land-use, and policy scenarios are essential to setting and achieving international targets to mitigate biodiversity loss. Evaluating and improving biodiversity predictions to better inform policy decisions remains a central conservation goal and challenge. A comprehensive strategy to evaluate and reduce...

Nitrate concentrations in high-elevation lakes of the Colorado Front Range remain elevated despite declining trends in atmospherically deposited nitrate since 2000. The current source of this elevated nitrate in surface waters remains elusive, given shifts in additional nitrogen sources via glacial inputs and atmospheric ammonium deposition. We present the complete isotopic composition...

Public concern regarding per- and polyfluoroalkyl substances (PFAS) has grown substantially in recent years. In addition, research has documented multiple potential agriculture-related release pathways for PFAS (e.g., biosolids and livestock manure). Nevertheless, little research on the environmental prevalence of PFAS has been conducted in agricultural regions of the United States. To...

We show that for some foragers the form that a functional response takes depends on the temporal and spatial scales considered. In representing the consumption rate of an organism, it may be necessary to use a hierarchy of functional responses. Consider, for example, a wading bird foraging in wetland landscape characterized by a spatial distribution of potential foraging sites, such as...

Haemosporidian parasites may impact avian health and are subject to shifts in distribution and abundance with changing ecologic conditions. Therefore, understanding variation in parasite prevalence is important for evaluating biologically meaningful changes in infection patterns and associated population level impacts. Previous research in western Alaska, US, indicated a possible...

We develop a spatio-temporal geostatistical interpolation framework to estimate hypoxia extent (dissolved oxygen [DO] concentrations below 2 mg/L) with data from a network of DO loggers. The framework uses empirical orthogonal functions and Bayesian kriging to identify the spatially varying temporal pattern and estimate the distribution of hypoxia, including estimation uncertainty. A...

Understanding habitat needs and patch utilization of wild and managed bees has been identified as a national research priority in the United States. We used occupancy models to investigate patterns of bee use across 1030 transects spanning a gradient of floral resource abundance and richness and distance from apiaries in the Prairie Pothole Region (PPR) of the United States. Estimates of...