Batesian mimicry is a form of mimicry typified by a situation where a harmless species has evolved to imitate the warning signals of a harmful species directed at a common predator. It is named after the English naturalist Henry Walter Bates, after his work in the rainforests of Brazil.

Batesian mimicry is the most commonly known and widely studied of mimicry complexes, such that the word mimicry is often treated as synonymous with Batesian mimicry.

The organism imitating the protected species is referred to as the mimic, while the imitated organism is known as the model. The receiver mediating indirect interactions between these two parties is variously known as the signal receiver, dupe or operator. By parasitizing the honest warning signal of the protected species, the Batesian mimic gains the same advantage, without having to go to the expense of arming themselves. The model, on the other hand, is disadvantaged, along with the dupe. If imposters appear in high numbers, positive experiences with the mimic may result in the model being treated as harmless. Additionally, in higher frequency there is a stronger selective advantage for the predator to distinguish mimic from model. For this reason, mimics are usually less numerous than models. However, some mimetic populations have evolved multiple forms (polymorphism), enabling them to mimic several different models. This affords them greater protection, a concept in evolutionary biology known as frequency dependent selection.

Example: Coral snake and King snake (mimic). Coral snakes are quite venomous, and their bite is very dangerous to humans and animals alike. King snakes, on the other hand, are harmless.

Biological Interactions