Why are frog and toad populations declining? 

Research suggests that even though amphibians are severely declining worldwide, there is no smoking gun—and thus no simple solution—to halting or reversing these declines.

Though every region in the United States has suffered amphibian declines, threats differ among regions. They include:

  • Human influence from the Mississippi River east, including the metropolitan areas of the Northeast and the agricultural-dominated landscapes of the Midwest
  • Disease, particularly a chytrid fungus in the Upper Midwest and New England
  • Pesticide applications east of the Colorado River
  • Climate changes across the Southern U.S. and the West Coast

Amphibian declines are a global phenomenon that has continued unabated in the United States since at least the 1960's. Declines are occurring even in protected national parks and refuges.

The average decline in overall amphibian populations is 3.79 percent per year, though the decline rate is more severe in some regions of the U.S., such as the West Coast and the Rocky Mountains. If this rate remains unchanged, some species will disappear from half of the habitats they occupy in about 20 years.

Amphibians are good indicators of significant environmental changes. Amphibians, unlike people, breathe at least partly through their skin, which is constantly exposed to everything in their environment. Consequently, their bodies are much more sensitive to environmental factors such as disease, pollution, toxic chemicals, ultraviolet radiation, and habitat destruction. The worldwide occurrences of amphibian declines and deformities could be an early warning that some of our ecosystems, even seemingly pristine ones, are seriously out of balance.

The USGS coordinatess and leads the National Amphibian Research and Monitoring Initiative (ARMI), which was formed to determine the scope, severity, and causes of amphibian declines.

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Date published: September 19, 2017

Emerging Disease Further Jeopardizes North American Frogs

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Filter Total Items: 22
Adult California Red-Legged Frog WERC
January 27, 2017

Adult California Red-Legged Frog

taken in Point Reyes Beach and used for Frogs on the Beach.

Frosted flatwoods salamander
December 31, 2016

Frosted flatwoods salamander

Frosted flatwoods salamander, St. Marks National Wildlife Refuge, Florida

A leopard frog in the wetlands in southeast/central North Dakota.
August 17, 2016

A leopard frog in the wetlands

A frog in the wetlands in southeast/central North Dakota. 

An American bullfrog.
June 30, 2016

American bullfrog close-up

An American bullfrom is native to most eastern states, but considered invasive in the moutain west.

Ornate Chorus Frog, Pseudacris ornata
June 17, 2016

Ornate Chorus Frog, Pseudacris ornata

Ornate Chorus Frog, Pseudacris ornata

Image: Salamander
March 15, 2016


An unknown hybrid species of salamander captured in Olympic National Park, Washington.

Attribution: Ecosystems
Image: Cascades Frog
March 15, 2016

Cascades Frog

A Cascades frog perched on moss.

Attribution: Ecosystems
An invasive American bullfrog with tracking device.
December 31, 2014

An invasive American bullfrog with tracking device.

An invasive American bullfrog with tracking device.  

Image: Weighing a Toad
July 31, 2013

Weighing a Toad

USGS technician weighing a Yosemite toad in the field.

Image: Pacific Chorus Frog
July 1, 2012

Pacific Chorus Frog

A Pacific Chorus frog (Pseudacris regilla) in a meadow located in Yosemite National Park.

Attribution: Ecosystems
Image: Three-lined Salamander
June 18, 2012

Three-lined Salamander

A three-lined salamander (Eurycea guttolineata) discovered in Prince William Forest Park, VA.

Attribution: Ecosystems