Under the Endangered Species Act (ESA), plant and animal species may be listed as either endangered or threatened. “Endangered” means a species is in danger of extinction throughout all or a significant portion of its range. “Threatened” means a species is likely to become endangered within the foreseeable future.
States have their own ESA-type laws, so species can have different Threatened/Endangered statuses at the federal and state levels. The USGS typically refers to the federal status unless otherwise noted.
"Imperiled" or "at risk" are not legal terms under ESA, but more biological terms. Generally speaking, they are animals and plants that are in decline and may be in danger of extinction. Those terms can include species that are at low populations and near extinction but still not legally protected under ESA.
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Are salmon endangered worldwide?
No, salmon are not endangered worldwide. For example, most populations in Alaska are healthy. Some populations in the Pacific Northwest are much healthier than others. These healthy populations usually occupy protected habitats such as the Hanford Reach on the Columbia River and streams of Olympic National Park. Learn more: Western Fisheries Research Center - Questions and Answers about Salmon
What is the threat from West Nile Virus (WNV) to endangered and threatened bird species?
This is an issue of great concern, as these populations are already struggling to survive in the current environment. If some of these species are more vulnerable to fatal WNV infection, WNV may ultimately lead to their extinction or significantly set back the progress of the recovery programs.
Where are salmon most endangered?
Certain populations of sockeye salmon, coho salmon, chinook salmon, and Atlantic salmon are listed as endangered. Sockeye salmon from the Snake River system are probably the most endangered salmon. Coho salmon in the lower Columbia River may already be extinct. Salmon are not endangered worldwide. For example, most populations in Alaska are healthy. Some populations in the Pacific Northwest are...
Why do animals and plants become endangered?
Although extinctions occur naturally, the current rate of plant and animal extinctions is much higher than the natural or historical rates. Habitat loss is the primary cause of higher extinction rates. Other causes include habitat changes, over-exploitation of wildlife for commercial purposes, the introduction of harmful nonnative species, pollution, and the spread of diseases.Learn more...
What species of bats are affected by White-nose Syndrome?
White-nose Syndrome mostly affects hibernating bats. More than half of the 47 bat species living in the United States and Canada hibernate to survive the winter. Twelve bat species, including two endangered species and one threatened species, have been confirmed with white-nose syndrome in North America. The causative fungus, Pseudogymnoascus destructans (Pd), has been found on an additional six...

U.S. Geological Survey science in support of the North American Bat Monitoring Program (NABat)
Status and threats analysis for the Florida manatee (Trichechus manatus latirostris), 2016
Early action to address an emerging wildlife disease
Using genetic research to inform imperiled and invasive species management
White-nose syndrome in bats: U.S. Geological Survey updates
Lead poisoning in wild birds
Protecting Black-Footed Ferrets and Prairie Dogs against sylvatic plague
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- FAQ
Are salmon endangered worldwide?
No, salmon are not endangered worldwide. For example, most populations in Alaska are healthy. Some populations in the Pacific Northwest are much healthier than others. These healthy populations usually occupy protected habitats such as the Hanford Reach on the Columbia River and streams of Olympic National Park. Learn more: Western Fisheries Research Center - Questions and Answers about Salmon
What is the threat from West Nile Virus (WNV) to endangered and threatened bird species?
This is an issue of great concern, as these populations are already struggling to survive in the current environment. If some of these species are more vulnerable to fatal WNV infection, WNV may ultimately lead to their extinction or significantly set back the progress of the recovery programs.
Where are salmon most endangered?
Certain populations of sockeye salmon, coho salmon, chinook salmon, and Atlantic salmon are listed as endangered. Sockeye salmon from the Snake River system are probably the most endangered salmon. Coho salmon in the lower Columbia River may already be extinct. Salmon are not endangered worldwide. For example, most populations in Alaska are healthy. Some populations in the Pacific Northwest are...
Why do animals and plants become endangered?
Although extinctions occur naturally, the current rate of plant and animal extinctions is much higher than the natural or historical rates. Habitat loss is the primary cause of higher extinction rates. Other causes include habitat changes, over-exploitation of wildlife for commercial purposes, the introduction of harmful nonnative species, pollution, and the spread of diseases.Learn more...
What species of bats are affected by White-nose Syndrome?
White-nose Syndrome mostly affects hibernating bats. More than half of the 47 bat species living in the United States and Canada hibernate to survive the winter. Twelve bat species, including two endangered species and one threatened species, have been confirmed with white-nose syndrome in North America. The causative fungus, Pseudogymnoascus destructans (Pd), has been found on an additional six...
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An Endangered Red Hawksbill Sea Turtle Swims Over a Threatened Elkhorn Coral in Virgin Islands National Park
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U.S. Geological Survey science in support of the North American Bat Monitoring Program (NABat)
Bats make up one-fifth of all mammalian species worldwide and are found on every continent except Antarctica. They contribute to overall ecosystem health by suppressing pest insects and pollinating plants and spreading seeds. Eight North American bat species are listed as federally endangered or threatened, and more than one-half are of current conservation concern in the United States, Canada, orAuthorsBrian Reichert, Suzanna C. SoileauStatus and threats analysis for the Florida manatee (Trichechus manatus latirostris), 2016
Trichechus manatus (West Indian manatee), especially T. m. latirostris, the Florida subspecies, has been the focus of conservation efforts and extensive research since its listing under the Endangered Species Act of 1973. To determine the status of, and severity of threats to, the Florida manatee, a comprehensive revision and update of the manatee Core Biological Model was completed and used to peAuthorsMichael C. Runge, Carol A. Sanders-Reed, Catherine A. Langtimm, Jeffrey A. Hostetler, Julien Martin, Charles J. Deutsch, Leslie I. Ward-Geiger, Gary L. MahonEarly action to address an emerging wildlife disease
A deadly fungal pathogen, Batrachochytrium salamandrivorans (Bsal) that affects amphibian skin was discovered during a die-off of European fire salamanders (Salamandra salamandra) in 2014. This pathogen has the potential to worsen already severe worldwide amphibian declines. Bsal is a close relative to another fungal disease known as Batrachochytrium dendrobatidis (Bd). Many scientists consider BdAuthorsM. J. Adams, M. Camille Harris, Daniel A. GrearUsing genetic research to inform imperiled and invasive species management
The long-term viability of species and populations is related to their potential to migrate, reproduce, and adapt to environmental changes. In the southeast United States, U.S. Geological Survey (USGS) scientists are providing resource managers with genetic information to improve the long-term survival and sustainability of the Nation's aquatic species. Research focused on native and imperiled speAuthorsMargaret E. Hunter, Rachel J. PawlitzWhite-nose syndrome in bats: U.S. Geological Survey updates
White-nose syndrome (WNS) is a devastating disease that has killed millions of hibernating bats since it first appeared in New York in 2007 and has spread at an alarming rate from the northeastern to the central United States and Canada. The disease is named for the white fungus Geomyces destructans that infects the skin of the muzzle, ears, and wings of hibernating bats. The U.S. Geological SurveAuthorsGail Moede Rogall, Michelle VerantLead poisoning in wild birds
Lead in its various forms has been used for thousands of years, originally in cooking utensils and glazes and more recently in many industrial and commercial applications. However, lead is a potent, potentially deadly toxin that damages many organs in the body and can affect all animals, including humans. By the mid 1990s, lead had been removed from many products in the United States, such as painAuthorsLesanna L. Lahner, J. Christian FransonProtecting Black-Footed Ferrets and Prairie Dogs against sylvatic plague
Scientists at the USGS National Wildlife Health Center (NWHC), in collaboration with colleagues at other federal agencies and the University of Wisconsin, are developing and testing vaccines that can be used to protect black-footed ferrets and prairie dogs against plague. The black-footed ferret is commonly regarded as the most endangered mammal in North America, and sylvatic plague is a major impAuthorsTonie E. Rocke - News