Wildlife Health

The Challenge: The health of the abundant waterfowl species of Chesapeake Bay has become a major concern due to the spread of Avian Influenza (AI) across North America and the role of waterfowl as a vector of AI. For decades, the health of the Bay’s waterfowl has been affected by the degradation of water quality and food supply due to industrial contaminants,agricultural run-off, pollution from...

Remote locations, rugged topography, extreme weather conditions, high numbers of threatened and endangered taxa, and widespread degradation of native ecosystems by invasive species makes routine monitoring to determine status and trends of ecosystems and native and invasive taxa difficult and expensive in the Hawaiian Islands. There is a need to supplement existing monitoring protocols with more...

The Oregon spotted frog ( Rana pretiosa ) is a medium-sized anuran native to the northwestern United States. Body coloration ranges from brown or tan to brick red, usually overlaid with dark, ragged spots. Oregon spotted frogs can be distinguished from other native species by their relatively short hind legs, orange or red wash of color on underside of abdomen and legs, and upturned chartreuse...

This work provides basic information for managing golden eagles in the context of the Bald and Golden Eagle Protection Act (16 U.S.C. 668-668d). The recent development of energy resources, such as wind, oil, gas, and solar, can potentially affect landscapes in ways that require changes in golden eagle management practices. Our work emphasizes priority information needs identified by the USGS and U...

Many species of amphibians and reptiles are declining or facing population threats in the West related to habitat loss, habitat alteration, introduction of non-native species, and other factors. Our work focuses on the status and trends of resident herpetofauna and how to better manage their habitats. Much of the effort is undertaken with cooperators, particularly with other agencies in the...

In 2012, scientists noticed that nearly a third of polar bears sampled in a study in Alaska were suffering from hair loss and poor health. Drs. Lizabeth Bowen and A. Keith Miles of WERC used new technology to track down and identify the factors responsible for driving disease in Alaskan polar bears.

This project improves our understanding of the ecology of reptiles in California and evaluates methods of managing landscapes and these imperiled species. In particular, Dr. Brian Halstead examines the distribution and demography of reptiles to understand factors that affect where they are found and how populations change. He further explores the relationships of reptiles with their abiotic and...

WERC collaborates with other research scientists to conduct annual population surveys of the southern sea otter -- a federally listed threatened species. In coordination with the California Department of Fish and Game and other institutions, ongoing surveys and research continues to inform the southern sea otter recovery plan for the U.S. Fish and Wildlife Service, and contributes to our...

California’s Central Valley and San Francisco Bay Estuary have a long history of mercury contamination from past mercury mining and gold extraction. Waterbirds are particularly susceptible to mercury because of their use of wetland habitats where methylmercury (the most toxic and biologically available form) is produced and relatively low methylmercury exposure can reduce reproductive success...

Sea otters are crucial indicators of the health of our nearshore waters and coastal resources, from kelp forests to fisheries. What clues does the sea otter's decline hold for our knowledge of ecosystem and global change? WERC's sea otter team and U.S. and Canadian researchers have teamed together to investigate. Relevance to USGS Missions: This research project has direct relevance for the...

USGS research on sea ducks is designed to anticipate and address priority information needs of management agencies. Additionally, work is focused on individual species biology, migration and population status and trends because until just recently, very little was known about sea ducks in Alaska.

The Habitat Dynamics Project examines how short and long-term changes in the environment affect the distribution and survival of wildlife populations.