SACRAMENTO, Calif. December 7, 2016 – The Center for Biological Diversity and Save the Frogs today petitioned the California Fish and Game Commission to add the North American bullfrog to California’s list of “restricted animals.” The addition would help prevent future introductions of this destructive non-native, invasive amphibian. Bullfrogs prey upon, and compete with, California’s native wildlife and play a role in the spread of disease.
“Bullfrogs have already inflicted significant damage on California’s wildlife populations, including many that are threatened with extinction,” said Jenny Loda, a biologist and attorney with the Center. “Every new shipment of live bullfrogs into California presents the threat of further introductions of this highly invasive frog. We simply can’t take the risk.”
The American bullfrog is included in the Global Invasive Species Database’s list of “One Hundred of the World’s Worst Invasive Alien Species.” In 1997 the European Union banned the importation of live American bullfrogs due to their invasiveness, yet about 2 million live bullfrogs are currently imported into California every year. The California Department of Fish and Wildlife recognizes they pose a significant threat to California’s wildlife and are likely to continue to spread within the state through both accidental and intentional releases associated with live importation and trade.
Bullfrogs are voracious, opportunistic predators and will eat virtually anything that fits in their mouths, including fish, frogs, birds, bats, snakes and turtles. This makes the bullfrog a strong competitor for food with native wildlife — especially California amphibians, with whom they often share habitats. Bullfrogs also act as disease vectors and have been implicated in the spread of new wildlife pathogens like chytrid fungus and ranaviruses. While these frogs can affect a wide variety of animals, their impact is most devastating on those already threatened with extinction, such as the California tiger salamander, California red-legged frog and mountain yellow-legged frog.
“Bullfrogs have played a role in the spread of the killer chytrid fungus Batrachochytrium dendrobatidis (Bd), one of the major drivers of amphibian declines and extinctions throughout the world. Bd is a primary factor in the rapid decline of mountain yellow-legged frog populations in California,” said Kerry Kriger, executive director of Save the Frogs. “If live bullfrogs continue to be imported into California they may spread new strains of this disease as well as other emerging pathogens that can devastate amphibians and other wildlife populations.”
An animal can be added to the “restricted animals” list by the California Fish and Game Commission when it “is proven to be undesirable and a menace to native wildlife.” The commission has previously used its authority to restrict live imports of other non-native, invasive animals that pose similar threats as bullfrogs, including carp, water snakes and some species of abalone.