The Herpetological Research Team at the USGS Forest and Rangeland Ecosystem Science Center uses innovative tools to investigate the invasion and spread of American bullfrogs in Washington and Oregon and understand how bullfrogs are interacting with native amphibians.
American bullfrogs are native to eastern North America but have been widely introduced around the world. They are frequently linked to population declines of native species, including smaller native amphibians. These large frogs compete with smaller species for food and space. They can also spread disease in areas where they have invaded. Bullfrogs are usually introduced into new habitats through human activities like the pet trade or bait for recreational fishing. After introduction, bullfrogs are capable of thriving and quickly reproducing in a wide range of habitats. To help control the spread of invasive bullfrogs and protect local food webs, land and resource managers need information on when and where bullfrogs are invading and interacting with native species.
In the western United States, bullfrogs have the potential to slow recovery of the Oregon spotted frog, a Threatened species under the Endangered Species Act. Oregon spotted frogs are susceptible to competition and predation by bullfrogs. Bullfrogs are much bigger than Oregon spotted frogs and tend to live in the same habitats. We are involved in several studies aimed at learning more about bullfrog invasion dynamics and whether bullfrog removal at sites where the two species co-occur could benefit Oregon spotted frogs.
Explore the science pages in the tab above to learn more about American bullfrog research at FRESC.
Invader Removal and Recovery of a Threatened Amphibian
Acoustic Surveys to Inform Invasive American Bullfrog Removal Efforts
Oregon Spotted Frog
Herpetological Research Team (FRESC)
- Overview
The Herpetological Research Team at the USGS Forest and Rangeland Ecosystem Science Center uses innovative tools to investigate the invasion and spread of American bullfrogs in Washington and Oregon and understand how bullfrogs are interacting with native amphibians.
American bullfrogs are native to eastern North America but have been widely introduced around the world. They are frequently linked to population declines of native species, including smaller native amphibians. These large frogs compete with smaller species for food and space. They can also spread disease in areas where they have invaded. Bullfrogs are usually introduced into new habitats through human activities like the pet trade or bait for recreational fishing. After introduction, bullfrogs are capable of thriving and quickly reproducing in a wide range of habitats. To help control the spread of invasive bullfrogs and protect local food webs, land and resource managers need information on when and where bullfrogs are invading and interacting with native species.
In the western United States, bullfrogs have the potential to slow recovery of the Oregon spotted frog, a Threatened species under the Endangered Species Act. Oregon spotted frogs are susceptible to competition and predation by bullfrogs. Bullfrogs are much bigger than Oregon spotted frogs and tend to live in the same habitats. We are involved in several studies aimed at learning more about bullfrog invasion dynamics and whether bullfrog removal at sites where the two species co-occur could benefit Oregon spotted frogs.
Explore the science pages in the tab above to learn more about American bullfrog research at FRESC.
- Science
Invader Removal and Recovery of a Threatened Amphibian
The Herpetological Research Team is using acoustic surveys and eDNA methods to evaluate the progress of invasive bullfrog removal and Oregon spotted frog recovery.Acoustic Surveys to Inform Invasive American Bullfrog Removal Efforts
The Herpetological Research Team is recording audio in areas where American bullfrogs have invaded to learn more about where and when they are breeding and inform managers tasked with controlling their spread.Oregon Spotted Frog
The Oregon spotted frog (Rana pretiosa) is a medium-sized anuran native to the northwestern United States. Body coloration ranges from brown or tan to brick red, usually overlaid with dark, ragged spots. Oregon spotted frogs can be distinguished from other native species by their relatively short hind legs, orange or red wash of color on underside of abdomen and legs, and upturned chartreuse eyes...Herpetological Research Team (FRESC)
The Herpetological Research Team focuses on issues related to conservation and management of amphibians and other aquatic and semi-aquatic species. Among our current studies are effects of invasive species, disease, and land use change on the dynamics of amphibian communities to inform conservation and management decision making. - Data
- Publications