We report the occurrence of Lithobates catesbeianus (Shaw, 1802), Bullfrog, in a protected semideciduous forest in the city of Guayaquil, Guayas, Ecuador and in a nearby wildlife management center. Bosqueira Protected Forest is an isolated spot of diversity surrounded by urbanization, quarries, and highways. We found a juvenile Bullfrog in a water canal on the edge of the protected forest, near a private housing complex, and several tadpoles in an artificial pond in a wildlife management center located near the reserve. This is the first sighting of the invasive L. catesbeianus in a native ecosystem in Guayaquil. We also report the this species from, three other provinces of Ecuador, based on observations in iNaturalist. These records reinforce the ability of L. catesbeianus to adapt easily to varied environmental conditions and to disturbed areas. The invasion of L. catesbeianus towards semideciduous forest represents a new threat to biodiversity, particularly the endemic fauna, due to predation or competition. In future studies, it will be important to fully evaluate the Bullfrog diet and population status to estimate its impact on remnant forests of Guayaquil.
