Giant invasive bullfrogs overrun Baden-Württemberg, sparking urgent culls
Invasive North American bullfrogs are spreading through Baden-Württemberg, threatening local wildlife. Conservation teams are taking action by culling adults and removing tadpoles—including draining a pond in Ötigheim last year. Authorities now ask the public to report sightings of unusually large frogs or tadpoles to stop the species from establishing itself further.
The bullfrog problem in Germany likely began in the 1990s when the species was first introduced to Baden-Württemberg. Since then, their spread has remained mostly limited to certain areas, but their impact is severe. A single female can lay up to 50,000 eggs, and tadpoles may take up to three years to develop, even surviving through winter in the water.
These frogs grow up to 25 centimetres long and eat almost anything that fits in their mouths—including fish, other frogs, and small birds. Last year, around 300 adult bullfrogs were shot in the Karlsruhe region as part of ongoing control efforts. In Ötigheim, authorities drained an entire biotope pond to remove tadpoles, suspecting humans had moved the animals there. The issue is partly linked to Germany’s ongoing import of reptiles and amphibians. Over 200,000 such animals still arrive from third countries annually, with many later abandoned. Experts argue that a long-standing import ban could have prevented the bullfrog’s spread entirely.
The Regional Council continues to monitor the situation, urging pond owners to stay vigilant. Reporting large tadpoles or frogs helps prevent further colonization. Without intervention, the bullfrog’s appetite and rapid reproduction could further disrupt native ecosystems in Baden-Württemberg.
