Biology of Species of Concern

The Greater Sage-grouse is a small bird found only in the sagebrush steppe of the Great Basin. Invasions of non-native grasses, evolving wildfire patterns, grazing from livestock, and human land uses are changing this unique ecosystem. WERC’s Dr. Pete Coates studies sage-grouse populations to determine how these influences could affect the bird and other wildlife in the future.

WERC wildlife biologist Dr. Kristin Berry has more than forty years of experience studying Agassiz’s desert tortoise. As the lead on several USGS projects, Dr. Berry continues to lend her expertise to investigating the status, genetics, and behavior of Agassiz’s tortoise populations in the Mojave Desert.

Invertebrate communities provide food for several economically and ecologically important fish and waterbird species in coastal estuaries. Scientists at the WERC San Francisco Bay Estuary Field Station specialize in studying foraging ecology of waterbirds and fishes, general food web dynamics across estuaries, and the effects of habitat restoration and other factors on waterbird prey availability.

Deserts in the southwestern United States are experiencing rapid changes due to human activities. The growth of human populations and development of cities and towns affect adjacent rare, threatened, and endangered species and their associated ecosystems in the Mojave and Sonoran deserts of southeastern California, southern Nevada, southwestern Utah, and western Arizona.

USGS scientists sampled grebes in California lakes to compare mercury levels in these predators versus the small fish they prey on—developing a new tool for water quality monitoring.