Species Status Assessments

The Gulf sturgeon, Acipenser oxyrinchus desotoi, has been listed as Threatened since 1991. Beginning in 1986, USGS has been investigating sturgeon population abundance and ecology throughout its range, but mostly in the Suwannee River.

Many of Hawai‘i’s forest birds have shown significant declines in the past 200 years, with many currently listed as endangered species. Multiple threats have been identified as contributing to declines, including disease, invasive species, habitat loss, and decreased survivorship and productivity caused by introduced predators. Through a combination of demographic information, population modeling...

USGS scientists are using innovative combinations of telemetry, genetics, and side-scan Sonar to support conservation of endangered Atlantic sturgeon ( Acipenser o. oxyrinchus).

This web-based mapping tool, released in 2024, enables users to identify which threats are driving the current status of Sagebrush Ecological Integrity (SEI), assess if SEI and associated threats, such as invasive annual grass, conifer encroachment, human modification - have changed over time, and visualize spatial trends in SEI and threats. The Sagebrush Ecosystem Trends Module supports managers...

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 Wildlife 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...

Native freshwater mussels play a critical role in aquatic environments and are considered “ecosystem engineers” and indicators of water quality by constantly filtering water. Populations of native freshwater mussels have declined in recent years, and this decline has been attributed to factors such as habitat degradation, pollution, and invasive species, among others. The importance of these...

WARC researchers are investigating individual movement, growth, and population dynamics of alligator snapping turtles in a southwest Louisiana creek.

Nitrogen and phosphorus are plant essential nutrients that are currently in excess in many aquatic ecosystems due to runoff from urban and agricultural areas. In high amounts, these nutrients are detrimental to aquatic ecosystem health, because elevated nutrients promote excessive growth or “blooms” of algae and other nuisance species. Many species that cause blooms can produce toxins which are...

Conservation and Restoration of Native Freshwater Mussels Clean water is vital to public health, commerce, and recreation in the United States. Despite great efforts to reduce water pollution, many waters in the U.S. remain impaired. Having clean water not only supports considerable economic activity, but it also costs billions annually to maintain and provide. Freshwater mussels are avid filter...

The Challenge: Taxonomic nomenclature relies, in part, upon an accurate taxonomic history in order to establish the correct name for a taxon. Constantine S. Rafinesque (1783–1840), was a knowledgeable North American natural historian who was is responsible for describing and naming such iconic American mammals as the mule deer [Odocoileus hemionus (Rafinesque, 1817)] and the white-footed mouse...

The Challenge: It has been generally considered that a severe injury to a wild mammal that seemingly limits its ability to forage for food or escape predators will almost certainly lead to that individual’s demise. Inspection of skeletons of wild caught small mammals, however, has revealed a surprising number of individuals with healed fractures of the skeletal bones―including the primary...

The Challenge: Treeshrews (order Scandentia) are small-bodied mammals endemic to South and Southeast Asia. Since it was first described in 1820, the Common Treeshrew (Tupaia glis) has had a complex taxonomic history that has led to widely variable estimates of diversity, misidentification of populations, and general confusion regarding it and closely related species. One result is that T. glis has...