Threats

Riparian woodlands are highly productive ecosystems that support a disproportionately high fraction of regional biodiversity. They are also one of the most endangered terrestrial systems in temperate North America, and have been reduced to just 5% of their former extent in California and throughout the American southwest. These losses have been accompanied by steep declines in numerous plant and...

Dr. Robert Fisher and his colleagues have teamed up with the U.S. Fish and Wildlife, The Nature Conservancy and multiple universities to conduct several types of studies that will address high priority issues related to reptiles in the Pacific Basin Islands. These studies will provide new information about species diversity, endemicity, biology and demography of reptile fauna and will lay the...

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.

Over the past 20 years, Alaskans have witnessed a startling increase of beak deformities among Black-capped Chickadees and other species of resident birds. This disease, called avian keratin disorder (AKD), is characterized by debilitating beak overgrowth and other abnormalities of keratinized tissues. Affected birds have difficulty feeding and preening, and may suffer high rates of mortality.

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

The Hawaiian Hoary Bat ( Lasiurus cinereus semotus ) is the only extant land mammal native to the Hawaiian archipelago. It is listed as endangered due to apparent population declines, and a lack of knowledge concerning its distribution, abundance, and habitat needs. Agencies and landowners in Hawai‘i seek to assist in the creation of sustainable uses for managed lands while also protecting bat...

Mesic forests of Hawai‘i island provide an ideal system for the study of forest restoration because they have a similar history to other tropical and subtropical forests globally, while maintaining a relatively simple species assemblage. Many of these forests were cleared for grazing, and then later abandoned, to become dominated by pasture grasses that form competitive layers such that native...

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 Upper Midwest Environmental Sciences Center (UMESC) in La Crosse, Wisconsin is studying the distribution and foraging patterns of sentinel fish-eating waterbirds through aerial surveys, and by tracking migration movements coupled with foraging depth profiles of common loons equipped with archival geo-locator tags and satellite transmitters. The results of this work are expected to elucidate...

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...