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: Endangered Species Act

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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...

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: Questions and Answers...

What are the differences between endangered, threatened, imperiled, and at-risk species?

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...

What is an invasive species and why are they a problem?

An invasive species is an introduced, nonnative organism (disease, parasite, plant, or animal) that begins to spread or expand its range from the site of its original introduction and that has the potential to cause harm to the environment, the economy, or to human health. A few well-known examples include the unintentional introduction of the...
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Date published: February 2, 2017

A Century of Habitat Loss Affects Genetics of Endangered Bird

A new study analyzes the genetic diversity and population structure of the California Ridgway’s rail, Rallus obsoletus, a state and federally-listed endangered bird. The results demonstrate that the so-called “rails” are experiencing negative genetic effects following more than a century of salt marsh habitat loss from agriculture, commercial salt production and urban development.

Date published: December 21, 2016

Declining Male Offspring Further Imperil Endangered Flycatchers in Southern California

A new study in The Condor: Ornithological Applications documents the steep decline of a population of endangered Southwestern Willow Flycatchers over 16 years—and the change in the sex ratio that has left the birds’ future hanging on a dwindling number of males.

Date published: August 20, 2016

Drought and Wildfires Threaten the Endangered Mountain Yellow-Legged Frog (Los Angeles Times)

SOUTHERN CALIFORNIA — Wildfires are affecting endangered Mountain yellow-legged frogs in San Diego and other counties.

Date published: April 20, 2016

Community flood protection may also help endangered salmon to thrive

Building a river setback levee to reduce the risk of flood for a community may also help endangered fish species to thrive, according to the results of a novel computer model reported by the U.S. Geological Survey. 

Date published: January 23, 2015

Culprit Identified in Decline of Endangered Missouri River Pallid Sturgeon

BOZEMAN – Pallid sturgeon come from a genetic line that has lived on this planet for tens of millions of years; yet it has been decades since anyone has documented any of the enormous fish successfully producing young that survive to adulthood in the upper Missouri River basin.

Date published: July 24, 2009

Biologists Rediscover Endangered Frog Population

For the first time in nearly 50 years, a population of a nearly extinct frog has been rediscovered in the San Bernardino National Forest's San Jacinto Wilderness.

Date published: June 29, 2007

Endangered Desert Pupfish found in Research Ponds near the Salton Sea, Calif.

Researchers from the U.S. Geological Survey (USGS) have discovered a population of the endangered desert pupfish (Cyprinodon macularius)in constructed ponds along the southeastern shore of the Salton Sea, in south-central California.

Date published: July 9, 1999

A First: Endangered Puaiohi Birds Fledge Four Chicks in the Wild

A highly endangered native Hawaiian bird species has taken a small but significant step back from the brink of extinction. USGS biologists monitoring 14 captive-reared puaiohi released into the wild earlier this year by The Peregrine Fund say the birds are nesting and have already fledged four young.

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Close-up of a small Pima pineapple cactus in coarse-textured soil in the desert.
December 14, 2016

Pima pineapple cactus

Pima pineapple cactus and vegetative offshoot, commonly called a pup, in the Altar Valley of south-central Arizona (November 2014).

an Indiana bat hanging on to a tree trunk
October 21, 2016

Indiana Bat (Myotis sodalis)

An Indiana bat hanging on to a tree. (Myotis sodalis)

A green and black endangered Sonoran tiger salamander on a tree branch
August 18, 2016

Endangered Sonoran Tiger Salamander (Ambystoma mavortium stebbinsi)

A green and black endangered Sonoran tiger salamander (Ambystoma mavortium stebbinsi) on a tree branch

Green Sea Turtle Swimming in Dry Tortugas National Park
April 13, 2016

Green Sea Turtle Swimming in Dry Tortugas National Park

Green Sea Turtle Swimming in Dry Tortugas National Park

Image: An Endangered Puaiohi (Small Mountain Thrush) in Hawaii
March 14, 2016

An Endangered Puaiohi (Small Mountain Thrush) in Hawaii

Many species of Hawaiian honeycreepers have persisted into the 20th century because high elevation rain forests on the islands of Kaua’i, Maui, and Hawai'i are cool enough to limit transmission of introduced avian malaria (Plasmodium relictum). Malaria transmission is tied closely to the effects of temperature on development of malarial parasites within their mosquito

Image: Female Pallid Sturgeon
March 20, 2013

Female Pallid Sturgeon

CSRP Biologist Sabrina Davenport holding reproductive feamle pallid sturgeon, PLS11-020.

Image: An Endangered Yellow-Legged Frog
May 19, 2011

An Endangered Yellow-Legged Frog

USGS biologists are leading the monitoring and reintroduction effort of the Southern California mountain yellow-legged frog -- federally listed as endangered with only 200 wild adults remaining in the mountains surrounding Los Angeles County.

Image: An Endangered Humpback Chub
May 19, 2011

An Endangered Humpback Chub

The Colorado River basin supports one of the most distinctive fish communities in North America, including the federally endangered humpback chub (Gila cypha). One of only six remaining populations of this fish is found in Grand Canyon National Park, Arizona. USGS scientists and their cooperators are responsible for monitoring the Grand Canyon population. The number Grand

Attribution: Ecosystems
May 20, 2010

Big Invaders and Tiny Fish: Endangered Species Day

Kids! Listen up—it's Endangered Species Day, and we have two podcasts for you: giant, invasive predators that eat endangered animals, and the tiny Devil's Hole pupfish, which lives on a watery shelf no bigger than a walk-in closet.

Shaken, Not Stirred—Watch Devils Hole pupfish deal with a large earthquake that causes