In an evolutionary biological sense, mimicry can be defined as a similarity of one species (the mimic) to another (the model) as a protective mechanism for either one or both species, against another species (the signal-receiver or the audience), typically a common predator of both species. The stimulus occurs as appearance, behaviour, sound or scent. The model is usually another organism, with the exception of automimicry. For prey species, mimicry strategies evolved as an adaptation against predators within their environment. The selective action of a signal-receiver drives the evolutionary process. In most circumstances, mimicry is advantageous to the mimic and harmful to the receiver. The effect on the fitness of the model depends entirely …show more content…
One interesting example is the Kermadec petrel. The Great Skua is a dominant parasitic predator species in the Eastern Tropical Pacific, feeding upon other birds and fish. When at sea, the skua usually obtains its nutrition by kleptoparasitism. Skuas search for smaller seabirds that have just caught food, then chase them and force them to regurgitate or drop their fresh catches. If the victim resists, the skua uses terror tactics by knocking its victim out of the air and into the water, grabbing onto its neck and viciously shaking it, or holding its head under water. Through operant conditioning, the victim birds have learnt not to even attempt to flee or resist, but instead to give up their catch as soon as a skua is visibly closing in. This has proven to be a very successful strategy for the skua.
The Kermadec petrel is the skua’s mimic. Other species of petrel are usual victims of the skua, however the Kermadec has learnt to resemble the skua very closely; not only in profile, but they also share the same conspicuous white wing patch, a very distinctive and visible warning sign. Due to their aggressive nature, skuas do not attack their conspecifics as a defensive measure for themselves. Mimicry has proven to be a greatly successful strategy of the Kermadec as it allows the Kermadec to not only deceive its hosts into giving up their food, but also deceives its supposed predator into not attacking