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.
Bullfrogs negatively affect many native species including the Oregon spotted frog. Oregon spotted frogs have declined markedly and are now listed as Threatened across their range. Losses include key genetic units and populations such as in Conboy Lake National Wildlife Refuge, where Oregon spotted frogs counts are less than 20 percent of what they were 20 years ago. In 2019, Conboy Lake National Wildlife Refuge began efforts to eradicate bullfrogs from the Glenwood Valley in Washington State. The project is focused on eradicating invaders in areas where removal is likely to benefit a key native population of Oregon spotted frogs. The strategic eradication plan identifies needs for monitoring bullfrog removal and Oregon spotted frog responses, as well as developing an early detection-rapid response approach (EDRR). Information on surveillance and removal will enable new colonist detection and efficient responses where bullfrogs expand on DOI-partner lands in western Washington and central Oregon. The USGS is assisting the U.S. Fish and Wildlife Service with this eradication effort by using environmental DNA (eDNA) and acoustic sampling to evaluate the progress of bullfrog eradication, inform adaptive removals, and assess Oregon spotted frog recovery.
We are also partnering with federal natural resource agencies, state partners, and private landowners to monitor the recovery of an Oregon spotted frog population during and after removal of American bullfrogs in Klamath County, Oregon. Our team is collecting pre- and post-removal data on abundance, distribution, and habitat use by Oregon spotted frogs and bullfrogs in wetlands near Fort Klamath. This will help researchers and managers to determine if bullfrog removal is benefitting Oregon spotted frog populations.
Acoustic Surveys to Inform Invasive American Bullfrog Removal Efforts
American Bullfrog Invasion and Impacts on Native Species in the Pacific Northwest
Oregon Spotted Frog
Herpetological Research Team (FRESC)
The Herpetological Research Team is using acoustic surveys and eDNA methods to evaluate the progress of invasive bullfrog removal and Oregon spotted frog recovery.
Bullfrogs negatively affect many native species including the Oregon spotted frog. Oregon spotted frogs have declined markedly and are now listed as Threatened across their range. Losses include key genetic units and populations such as in Conboy Lake National Wildlife Refuge, where Oregon spotted frogs counts are less than 20 percent of what they were 20 years ago. In 2019, Conboy Lake National Wildlife Refuge began efforts to eradicate bullfrogs from the Glenwood Valley in Washington State. The project is focused on eradicating invaders in areas where removal is likely to benefit a key native population of Oregon spotted frogs. The strategic eradication plan identifies needs for monitoring bullfrog removal and Oregon spotted frog responses, as well as developing an early detection-rapid response approach (EDRR). Information on surveillance and removal will enable new colonist detection and efficient responses where bullfrogs expand on DOI-partner lands in western Washington and central Oregon. The USGS is assisting the U.S. Fish and Wildlife Service with this eradication effort by using environmental DNA (eDNA) and acoustic sampling to evaluate the progress of bullfrog eradication, inform adaptive removals, and assess Oregon spotted frog recovery.
We are also partnering with federal natural resource agencies, state partners, and private landowners to monitor the recovery of an Oregon spotted frog population during and after removal of American bullfrogs in Klamath County, Oregon. Our team is collecting pre- and post-removal data on abundance, distribution, and habitat use by Oregon spotted frogs and bullfrogs in wetlands near Fort Klamath. This will help researchers and managers to determine if bullfrog removal is benefitting Oregon spotted frog populations.