Publications

Availability of wetlands with low salinities during the breeding season can influence waterfowl reproductive success and population recruitment. Salinities as low as 2 ppt (3.6 mScm–1) can impair duckling growth and influence behavior, with mortality occurring above 9 ppt (14.8 mScm–1). We used satellite imagery to quantify the amount of available water, and sampled surface water...

In south San Francisco Bay, former salt ponds now managed as wildlife habitat support large populations of breeding waterbirds. In 2006, the South Bay Salt Pond Restoration Project began the process of converting 50% to 90% of these managed pond habitats into tidal marsh. We compared American Avocet (Recurvirostra americana) and Black-necked Stilt (Himantopus mexicanus) abundance in...

Gopherus polyphemus has typically high adult survivorship, with some populations reaching a mean annual survivorship of 93.4% (Howell et al. 2019. J. Wildl. Manage. 84:56–65). Instances of adult mortality are not commonly reported outside of large mortality events, and most often result from disease, starvation, dehydration, or chronic stress (Gates et al. 2002. Florida Sci. 65:185– 197...

Phytoplankton provide large quantities of organic carbon and biomolecules that support large river ecosystems. However, when certain groups become overabundant (e.g., cyanobacteria), they can pose a risk to human health and river biota. The purpose of this study was to examine the spatial and temporal dynamics of phytoplankton community composition within the upper Mississippi River...

Tropical forests are expected to experience unprecedented warming and increases in hurricane disturbances in the coming decades; yet, our understanding of how these productive systems, especially their belowground component, will respond to the combined effects of varied environmental changes remains empirically limited. Here we evaluated the responses of root dynamics (production...

The Big Bend region is located within the heart of the Chihuahan Desert of North America. Within this region, the Rio Grande, referred to as the Rio Bravo in Mexico, is the international border between the United States and Mexico. The area known as the Big Bend is named after the large northerly bend that the river makes before flowing southeast to the Gulf of Mexico. This region is

A common impact on riparian ecosystem function following river regulation is the expansion and encroachment of riparian plant species in the active river channels and floodplain, which reduces flow of water and suspended sediment between the river, riparian area, and upland ecosystems. We characterized riparian plant species occurrence and quantified encroachment within the dam-regulated...

Conservation efforts need reliable information concerning the status of a species and their trends to help identify which species are in most need of assistance. We completed a comparative evaluation of the occurrence of breeding for Cascades Frog (Rana cascadae), an amphibian that is being considered for federal protection under the U.S. Endangered Species Act. Specifically, in 2018...

In 2020, a new spill program was implemented to aid the downstream passage of juvenile salmonids at mainstem dams on the Snake and Columbia rivers. Under this program, the total dissolved gas (TDG) cap was increased to 125% and monitoring of native, resident nonsalmonid (NRN) fishes for gas bubble trauma (GBT) became a requirement. The primary objective of this work was to measure the

During summer 2019, we recorded an apparent vocal interaction, lasting just under 4 min, between a pair of Great Horned Owls (Bubo virginianus) and a gray wolf (Canis lupus) in Yellowstone National Park. To our knowledge, this is the first report of such an acoustic interaction in the scientific literature. The increased use of passive acoustic recorders, which record spontaneous...

The tidal freshwater zone near the estuarine head-of-tide is potentially sensitive to both sea-level rise and associated salinity increases as well as changing watershed inputs of freshwater and nutrients. We evaluated the vegetation response of tidal freshwater forested wetlands (TFFW) to changes in nontidal river versus estuarine controls along the longitudinal gradient of the...

Non-native organisms have invaded novel ecosystems for centuries, yet we have only a limited understanding of why their impacts vary widely from minor to severe. Predicting the impact of non-established or newly detected species could help focus biosecurity measures on species with the highest potential to cause widespread damage. However, predictive models require an understanding of...