Successful Bullfrog Eradication at a Landscape Scale in Yosemite National Park

To protect native aquatic species, National Park Service (NPS) biologists have conducted bullfrog control in Yosemite Valley since the 1990s. Bullfrog removal continued regularly through 2015, with successful eradication achieved in 2019. Bullfrogs were removed using mechanical techniques such as backpack electrofishing, dip and seine nets, hook and line, and rifle shooting. Detection of bullfrogs and their breeding sites was conducted through visual encounter surveys (VES) and eDNA sampling. Project biologists focused on removing breeding adults in breeding areas during breeding seasons, while removal efforts for sub-adults and tadpoles were more opportunistic. By 2019, native red-legged frogs were successfully reintroduced.