Publications

Climatic variability and land surface change have a wide range of effects on streamflow and are often difficult to separate. We analyzed long-term records of climate, land use and land cover, and re-constructed the water budget based on precipitation, groundwater levels, and water use from 1950 through 2010 in the Cimarron–Skeleton watershed and a portion of the Cimarron–Eagle Chief...

In many food webs, species in similar trophic positions can interact either by competing for resources or boosting shared predators (apparent competition), but little is known about how the relative strengths of these interactions vary across environmental gradients. Introduced Mysis diluviana shrimp interact with planktivorous fishes such as kokanee salmon (lacustrine Oncorhynchus nerka...

Intrinsic and extrinsic factors affect vital rates and population-level processes, and understanding these factors is paramount to devising successful management plans for wildlife species. For example, birds time migration in response, in part, to local and broadscale climate fluctuations to initiate breeding upon arrival to nesting territories, and prolonged inclement weather early in...

Population size of habitat-specialized butterflies is limited in part by host plant distribution and abundance. Effective conservation for host-specialist species requires knowledge of host-plant habitat conditions and relationships with the specialist species. Clayton’s copper butterfly (Lycaena dorcas claytoni) is a Maine state-endangered species that relies exclusively on shrubby...

Climate often drives ungulate population dynamics, and as climates change, some areas may become unsuitable for species persistence. Unraveling the relationships between climate and population dynamics, and projecting them across time, advances ecological understanding that informs and steers sustainable conservation for species. Using pronghorn (Antilocapra americana) as an ecological...

Freshwater mussels (Bivalvia: Unionoida) are highly imperiled with many species on the verge of local extirpation or global extinction. This study investigates patterns of genetic structure and diversity in six species of freshwater mussels in the central Great Lakes region of Ontario, Canada. These species vary in their conservation status (endangered to not considered at risk), life...

Trends in water quality and quantity were assessed for 11 major reservoirs of the Brazos and Colorado river basins in the southern Great Plains (maximum period of record, 1965–2010). Water quality, major contributing-stream inflow, storage, local precipitation, and basin-wide total water withdrawals were analyzed. Inflow and storage decreased and total phosphorus increased in most...

Baseline survival and mortality data for lesser prairie-chickens (Tympanuchus pallidicinctus) are lacking for shinnery oak (Quercus havardii) prairies. An understanding of the causes and timing of mortalities and breeding season survival in this ecoregion is important because shinnery oak prairies have hotter and drier environmental conditions, as well as different predator communities...

Sampling by spatially replicated counts (point-count) is an increasingly popular method of estimating population size of organisms. Challenges exist when sampling by point-count method, and it is often impractical to sample entire area of interest and impossible to detect every individual present. Ecologists encounter logistical limitations that force them to sample either few large...

Catchment land uses, particularly agriculture and urban uses, have long been recognized as major drivers of nutrient concentrations in surface waters. However, few simple models have been developed that relate the amount of catchment land use to downstream freshwater nutrients. Nor are existing models applicable to large numbers of freshwaters across broad spatial extents such as regions...

Algal blooms in the Great Lakes are a potential food source for silver carp (Hypophthalmichthys molitrix) and bighead carp (H. nobilis; together bigheaded carps). Understanding these blooms thus plays an important role in understanding the invasion potential of bigheaded carps. We used remote sensing imagery, temperatures, and improved species specific bioenergetics models to determine...

Isolation of the Hawaiian archipelago produced a highly endemic and unique avifauna. Avian malaria (Plasmodium relictum), an introduced mosquito-borne pathogen, is a primary cause of extinctions and declines of these endemic honeycreepers. Our research assesses how global climate change will affect future malaria risk and native bird populations. We used an epidemiological model to...