page_title: Mimicry
section_title: Batesian mimicry
hierarchical_section_title: Mimicry / Signalling / Batesian mimicry
caption_attribution_description: Plate from Bates (1862) illustrating Batesian mimicry between Dismorphia species (top row, third row) and various Ithomiini (Nymphalidae) (second row, bottom row)
context_page_description: In biology, mimicry is when a species evolves features similar to another. Either one or both are protected when a third species cannot tell them apart. Often, these features are visual; one species looks like another; but similarities of sound, smell and behaviour may also make the fraud seem more real.
  Mimicry is related to camouflage, and to warning signals, in which species manipulate or deceive other species which might do them harm. Although mimicry is mainly a defence against predators, sometimes predators also use mimicry, and fool their prey into feeling safe.
  Mimicry happens in both animal and plant species. The mimic is the species which looks like the model. The model may be living, or not. Whole groups of animals go in for mimicry as a life style, such as mantids, leaf insects or stick insects. Camouflage, in which a species looks similar to its surroundings, is a form of visual mimicry.
  There are far more insect mimics than any other class of animal, but then there are far more insects than other types of animals. Indeed, 75% of all animals which have been described and named, are insects.
context_section_description: In Batesian mimicry, the mimic is a sheep in wolf's clothing: it looks like something dangerous or which tastes disgusting, but in reality it is good to eat. As he was exploring the Amazon valley in the 1850s, Bates collected butterflies. He saw how some harmless butterflies looked like other species which were toxic. Birds avoided them, so the mimics survived even though they were good food. This was the first scientific account of mimicry.
  Hoverflies often visit flowers to feed on nectar. They are harmless insects which often mimic wasps and bees. They also fly in a slow, erratic fashion, rather like wasps and bees. Often their mimicry is not perfect, and you can easily tell them apart once they have settled. However, even an imperfect mimic might cause a bird to hesitate, and that may save their life.
  Biologists still do research on Batesian and Müllerian mimicry. They study how the models differ in their foul taste; and what happens when the ratio of mimics to models varies. Quite often, it is only the female which is a mimic; the male carries the normal appearance of its genus. The females need more protection, while the males need to mate. A more subtle reason is that it halves the number of mimics, and so bolsters the effectiveness of the mimicry. Batesian mimicry might damage the warning effect if the frequency of mimics became high, because more young birds would taste them and be encouraged to try again. The benefit of warning declines if there are more mimics. 
  This may explain cases such as Papilio dardanus, an African swallowtail, whose females mimic a number of unpalatable species from the Danaidae: survival is higher when each mimetic form is rare relative to its model. The advantage is probably greater for the females, because males do not show the mimetic patterns; sexual selection probably helps to maintain this difference. These, and other issues, have been researched for many years.  
  With this type of insect the life is split into stages (see complete metamorphosis). The larva is the growth stage, the adult is the reproductive stage. The larvae, too, show camouflage, aposematic colour and mimicry. It is the larvae that pick up the offensive chemicals from the plants they feed on. However, larvae do not show differences between male and female, because reproduction is not their function.
caption: Shows Batesian mimicry between Dismorphia species (top row, third row) and various Ithomiini (Nymphalidae) (second row, bottom row) Bates 1862
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