Toad pretends to be a cobra to scare the enemy

The Congolese giant toad mimics the shape and behavior of the poisonous Gaboon cobra in order to avoid being eaten by predators.

Dr. Eli Greenbaum at the University of Texas at El Paso and colleagues observed the behavior of the Congo giant toad (Sclerophrys channingi) for 10 years and discovered they relied on a Bates-style imitation to survive. Bates-like imitation is how a harmless species avoids being eaten by mimicking dangerous or venomous animals.

Congo giant toad (left) and Gaboon cobra (right).(Photo: New Scientist).

The team found many similarities in the shape between the toads living in the rain forests of central Africa and the cobra, which is widely distributed in the east and south of the continent. Using field-caught specimens and museum specimens, they found the color and shape of the toad's body resembled that of a cobra's head. The most prominent features are two dark brown dots and long stripes running along the back of the toad, triangle body and brown lines on the flanks. The Congolese giant toad also has a smooth leather like snake skin. Since the Gaboon cobra has a fatal bite, predators will avoid the snake-shaped toad to ensure safety.

If the Gaboon cobra feels threatened, it will lower its head and let out a long squeak before attacking. Reptilian Chifundera Kusamba in Congo once observed the giant Congo toad make similar sounds.

The researchers also discovered that the Congolese giant toad does not seem to live in the absence of Gaboon cobra. They identified 11 locations in the eastern rainforest of the Democratic Republic of Congo, where the habitats of the two species overlap. The team suggested that they first evolved at the same time in the early Upper Tan 4 to 5 million years ago, leading to mimicking behavior in toads.