Publications

Many species living in deeper lentic ecosystems exhibit daily movements that cycle through the water column, generally referred to as diel vertical migration (DVM). In this study, we applied bioenergetics modelling to evaluate growth as a hypothesis to explain DVM by bull trout (Salvelinus confluentus) in a thermally stratified reservoir (Ross Lake, WA, USA) during the peak of thermal

Nest box programs are frequently implemented for conservation of cavity-nesting birds, but their effectiveness is rarely evaluated in comparison to birds not using nest boxes. In the European Palearctic, Red-Footed Falcon (Falco vespertinus) populations are both of high conservation concern and are strongly associated with nest box programs in heavily managed landscapes. We used a 21...

Mariana Swiftlets (Aerodramus bartschi) are federally listed as endangered, with populations currently limited to just three islands in the Mariana Islands plus an introduced population on the Hawaiian island of O'ahu. Before efforts are made to reintroduce Mariana Swiftlets to other islands in the Mariana archipelago, additional information is needed concerning their breeding biology...

It is generally accepted that climate change will stress coldwater species such as Pacific salmon. However, it is unclear what aspect of altered thermal regimes (e.g., warmer winters, springs, summers, or increased variability) will have the greatest effect, and what role the spatial properties of river networks play. Thermally diverse habitats may afford protection from climate change...

The pervasive and unabated nature of global amphibian declines suggests common demographic responses to a given driver, and quantification of major drivers and responses could inform broad-scale conservation actions. We explored the influence of climate on demographic parameters (i.e., changes in the probabilities of survival and recruitment) using 31 datasets from temperate zone...

Intermittent and ephemeral streams represent more than half of the length of the global river network. Dryland freshwater ecosystems are especially vulnerable to changes in human-related water uses as well as shifts in terrestrial climates. Yet, the description and quantification of patterns of flow permanence in these systems is challenging mostly due to difficulties in instrumentation...

Organic matter is of emerging interest as a control on molybdenum (Mo) biogeochemistry, and information on isotope fractionation during adsorption to organic matter can improve interpretations of Mo isotope variations in natural settings. Molybdenum isotope fractionation was investigated during adsorption onto insolubilized humic acid (IHA), a surrogate for organic matter, as a function...

Structured decision making allows reintroduction decisions to be made despite uncertainty by linking reintroduction goals with alternative management actions through predictive models of ecological processes. We developed a decision model to evaluate the trade-offs between six bull trout (Salvelinus confluentus) reintroduction decisions with the goal of maximizing the number of adults in...

Although poisoning from anthropogenically derived lead threatens wildlife of many species, routes of lead exposure are unclear and rarely empirically tested. We used blood lead concentration and isotope ratio (207Pb/206Pb) data from populations of four species of raptors from across North America to test hypotheses associated with lead exposure via inhalation versus ingestion. Mean...

Lead poisoning is an important conservation concern for wildlife, and scavenging birds are especially at risk from consumption of carcasses of animals killed with lead ammunition. Because current methods to identify lead exposure require animal capture and blood collection, management would benefit from the development of a less costly and noninvasive behavioral test for illness in wild...

Movement behavior and its relationship to habitat provide critical information toward understanding the effects of changing environments on birds. The eastern North American population of Golden Eagles (Aquila chrysaetos) is a genetically distinct and small population of conservation concern. To evaluate the potential responses of this population to changing landscapes, we calculated the...

Conserving wide-ranging animals requires knowledge about their year-round movements and resource use. Golden Eagles (Aquila chrysaetos) exhibit a wide range of movement patterns across North America. We combined tracking data from 571 Golden Eagles from multiple independent satellite-telemetry projects from North America to provide a comprehensive look at the magnitude and extent of...