Habitat Loss

Dr. Kathleen Longshore’s goal is to understand how predator/prey relationships, disease and human-caused disturbance work separately and synergistically to impact bighorn sheep populations under variable ecological stress. Information from this project will provide managers with an understanding of specific and regional impacting factors that contribute to impact variation in population trends.

The Ridgway’s rail is a federal and state listed endangered species that occurs in wetlands along the Pacific Coast and from the Lower Colorado River drainage to southern Baja California. Three subspecies of Ridgway’s rail are found within the United States: the California Ridgway’s Rail, Yuma Ridgway’s rail, and Light-footed Ridgway’s rail. All three subspecies have declined since 1900 as a...

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...

WERC's sea otter researchers are developing and utilizing a variety of methodological and analytical tools to understand the causes of biological and ecological trends in sea otter populations, and to predict the ecological consequences of management practices on these populations and their ecosystems.

The Suisun Marsh and Central Valley in California offer some of the world’s most important wetland habitats for waterfowl in the Pacific Flyway. Mike Casazza and USGS WERC biologists are providing the science to support and evaluate waterfowl populations and habitat management in North America.

Landscape ecology has only a short history as a recognized discipline, but it has transformed our thinking about the interplay between pattern and process. We now understand that many smaller-scale phenomena are driven by spatial processes, such as the proximity of different habitats to one another, the ability of organisms to move through landscapes, and the dynamics of natural disturbance such...

Environmental stressors such as contaminants and disease can cause physiological imbalance in all types of wildlife. WERC’s Drs. Lizabeth Bowen and A. Keith Miles develop gene transcription profiles to detect organisms’ physiological responses to environmental stressors and provide resource managers with early warnings for potential effects on wildlife and ecosystem health.

Low-elevation Pacific islands are vulnerable to inundation from sea-level rise and sudden flooding events. The largely low-lying islands of Northwestern Hawaiian Islands (NWHI), that extend 1,930 km beyond the main Hawaiian Islands, are a World Heritage Site and part of the Papahānaumokuākea Marine National Monument. The NWHI support the largest tropical seabird rookery in the world, provide...

The Golden-winged Warbler (Vermivora chrysoptera) is a species of considerable conservation concern in North America, primarily due to widespread population declines attributable to habitat loss (Confer et al. 1992, Buehler et al. ) and displacement by the Blue-winged Warbler (V. pinus) in areas of sympatry (Gill 1980, 2004; Will 1986). Recent research highlighted an important mechanism in the...

Bat Research Bats are nocturnal, flying mammals that eat insects or fruits, pollinate flowers, distribute seeds, and are important to many ecosystems. Across North America there are 45 species of bats, many of which are threatened or endangered. One species of federally endangered bat, the Indiana bat (Myotis sodalis), is a medium-sized, gray, black, or chestnut brown bat living primarily in...

The spectaclecase mussel, Cumberlandia monodonta, was effectively listed as federally endangered in April 2012 (https://federalregister.gov/a/2012-5603). It is endemic to the Mississippi, Ohio and Missouri River basins and historically inhabited 44 streams in these basins (USFWS 2014). Currently, the species is known to inhabit 20 of the historical streams, five of which are represented by one or...

The Shenandoah salamander is listed as an endangered salamander that is at risk of extinction due to its small, high-elevation range, competition with the co-occurring red-backed salamander, and the predicted habitat changes in the Appalachian mountain range. We are working with multiple partners to understand the current status of the species, predict future status, and continually engage...