The Goliath Frog (Conraua goliath) is the largest living frog species on Earth. Native to a small area of West Africa, this amphibian challenges the common perception of what a frog can be. Its existence is an example of specialized evolution, requiring a highly specific and pristine environment. Understanding this frog involves examining its size, the unique environment it inhabits, and the forces that threaten its future.
The Definitive Size Metrics
The Goliath Frog earns its name through physical dimensions that set it apart from all other anurans. A mature adult commonly reaches a snout-to-vent length (SVL) of 32 centimeters (12.6 inches) and can weigh over 3 kilograms (6.6 pounds). The largest verified specimen recorded had an SVL of 35.6 centimeters (14.0 inches) and weighed 3.3 kilograms (7.3 pounds), comparable in size and weight to an average house cat. When its long hind legs are fully extended, the frog can span over 80 centimeters (31 inches), enabling powerful leaps of up to 3 meters (10 feet). Males use this strength to move rocks and gravel, sometimes weighing over 1.5 kilograms (3 pounds), to construct nesting ponds along riverbanks.
Geographic Range and Habitat
The Goliath Frog has a restricted native range, confined almost exclusively to the rainforests of Cameroon and Equatorial Guinea in West Africa. Its existence is tied to a specialized aquatic habitat within the humid rainforests of the Lower Guinean Forest Zone. This species requires rivers that are fast-flowing, clear, and highly oxygenated, often near waterfalls and rapids. The water temperature must remain relatively cool, typically hovering around 19.4 °C (67 °F), maintained by the forest canopy providing shade. This specific habitat requirement means that any disturbance, such as deforestation or pollution, can severely impact the entire population.
The Role of Diet and Longevity
The size of the Goliath Frog demands a substantial caloric intake, supported by its broad, carnivorous diet as an adult. Adult frogs are nocturnal hunters, consuming a wide variety of prey found near the riverbanks and in the water. Their menu includes insects, crustaceans, fish, smaller amphibians, and small mammals like mice or bats. The tadpole stage is a biological bottleneck that restricts the species’ range, as Goliath tadpoles are herbivorous and feed exclusively on the aquatic plant Dicraeia warmingii. This plant, a member of the Podostemaceae family, only grows on rocks in the fast-moving currents of the frog’s specific river habitat. Individuals that survive this vulnerable stage can live for 10 to 15 years or more in the wild.
Conservation and Human Interaction
The Goliath Frog is classified as Endangered on the IUCN Red List, with its population having declined by over 50% in the last three generations. The primary threat is habitat destruction, driven by commercial logging and the conversion of rainforest into agricultural land. This deforestation leads to increased sedimentation and water pollution from pesticides, degrading the pristine river conditions the frog requires. Hunting also contributes to the population decline, as the frog is prized as a local food source, often referred to as bushmeat. The species is also illegally collected for the international pet trade and for use in competitive frog-jumping events. Although Equatorial Guinea has set a legal export limit of 300 frogs per year, poaching and habitat loss continue to pose a serious risk to the species’ survival.