Emsleyan mimicry, also called Mertensian mimicry, describes an unusual type of mimicry where a deadly prey mimics a less dangerous species. [1]
Emsleyan mimicry, also called Mertensian mimicry, describes an unusual type of mimicry where a deadly prey mimics a less dangerous species. [1]
Emsleyan mimicry was first proposed by M. G. Emsley [2] as a possible explanation for how a predator species could learn to avoid an aposematic phenotype of potentially dangerous animals, such as the coral snake, when the predator is likely to die on its first encounter. The theory was developed by the German biologist Wolfgang Wickler in a chapter of Mimicry in Plants and Animals, [3] who named it after the German herpetologist Robert Mertens. [4] Sheppard points out that Hecht and Marien had put forward a similar hypothesis ten years earlier. [5] [6]
The scenario for Emsleyan mimicry is a little more difficult to understand than for other types of mimicry, since in other types of mimicry it is usually the most harmful species that is the model. But if a predator dies, it cannot learn to recognize a warning signal, e.g., bright colours in a certain pattern. In other words, there is no advantage in being aposematic for an organism that is likely to kill any predator it succeeds in poisoning; such an animal is better off being camouflaged, to avoid attacks altogether. If, however, there were some other species that were harmful but not deadly as well as aposematic, the predator could learn to recognize its particular warning colours and avoid such animals. A deadly species could then profit by mimicking the less dangerous aposematic organism if this reduces the number of attacks. [5] [6]
Non-Emsleyan mechanisms that achieve the observed result, namely that predators avoid extremely deadly prey, are possible. Proposed alternatives include observational learning and innate avoidance. [8] [7] These provide alternative explanations to Emsleyan mimicry: if predators innately avoid a pattern then there is no need to suppose that the more deadly snake is mimicking the less deadly species in these cases. [9]
One mechanism is observational learning, for example through watching a conspecific die. The observing predator then remembers that the prey is deadly and avoids it. Jouventin and colleagues conducted exploratory tests on baboons in 1977 that suggested this was possible. [8]
Another possible mechanism is that a predator might not have to learn that a certain prey is harmful in the first place: it could have instinctive genetic programming to avoid certain signals. In this case, other organisms could benefit from this programming, and Batesian or Müllerian mimics of it could potentially evolve. [7] Some species indeed do innately recognize certain aposematic patterns. Hand-reared turquoise-browed motmots (Eumomota superciliosa), avian predators, instinctively avoid snakes with red and yellow rings. [7] [10] Other colours with the same pattern, and even red and yellow stripes with the same width as rings, were tolerated. However, models with red and yellow rings were feared, with the birds flying away and giving alarm calls in some cases. [9]
The models would not have to be other snakes. Large red and black millipedes are common and foul-tasting; various species of these millipedes form Müllerian mimicry rings, and some are the models for mimicry in lizards. [10]
Some harmless milk snake (Lampropeltis triangulum) subspecies, the moderately toxic false coral snakes (genus Erythrolamprus ), and the deadly coral snakes (genus Micrurus ) all have a red background color with black and either white or yellow rings. Over 115 species or some 18% of snakes in the New World are within this mimicry system. [10] In this system, Emsley stated that both the milk snakes and the deadly coral snakes are the mimics, whereas the false coral snakes are the models. [2]
It has been suggested that this system could be an instance of pseudomimicry, the similar colour patterns having evolved independently in similar habitats. [11]
In evolutionary biology, mimicry is an evolved resemblance between an organism and another object, often an organism of another species. Mimicry may evolve between different species, or between individuals of the same species. In the simplest case, as in Batesian mimicry, a mimic resembles a model, so as to deceive a dupe, all three being of different species. A Batesian mimic, such as a hoverfly, is harmless, while its model, such as a wasp, is harmful, and is avoided by the dupe, such as an insect-eating bird. Birds hunt by sight, so the mimicry in that case is visual, but in other cases mimicry may make use of any of the senses. Most types of mimicry, including Batesian, are deceptive, as the mimics are not harmful, but Müllerian mimicry, where different harmful species resemble each other, is honest, as when species of wasps and of bees all have genuinely aposematic warning coloration. More complex types may be bipolar, involving only two species, such as when the model and the dupe are the same; this occurs for example in aggressive mimicry, where a predator in wolf-in-sheep's-clothing style resembles its prey, allowing it to hunt undetected. Mimicry is not limited to animals; in Pouyannian mimicry, an orchid flower is the mimic, resembling a female bee, its model; the dupe is the male bee of the same species, which tries to copulate with the flower, enabling it to transfer pollen, so the mimicry is again bipolar. In automimicry, another bipolar system, model and mimic are the same, as when blue lycaenid butterflies have 'tails' or eyespots on their wings that mimic their own heads, misdirecting predator dupes to strike harmlessly. Many other types of mimicry exist.
Frequency-dependent selection is an evolutionary process by which the fitness of a phenotype or genotype depends on the phenotype or genotype composition of a given population.
Batesian mimicry is a form of mimicry where a harmless species has evolved to imitate the warning signals of a harmful species directed at a predator of them both. It is named after the English naturalist Henry Walter Bates, who worked on butterflies in the rainforests of Brazil.
Anti-predator adaptations are mechanisms developed through evolution that assist prey organisms in their constant struggle against predators. Throughout the animal kingdom, adaptations have evolved for every stage of this struggle, namely by avoiding detection, warding off attack, fighting back, or escaping when caught.
The mimic octopus is a species of octopus from the Indo-Pacific region. Like other octopuses, it uses its chromatophores to disguise itself. It is noteworthy for being able to impersonate a wide variety of other marine animals. While many animals mimic either their environment or other animals to avoid predation, the mimic octopus and its close relative the wunderpus are the only ones known to actively imitate several animals in order to elude predators.
Erythrolamprus aesculapii, also known commonly as the Aesculapian false coral snake, the South American false coral snake, and in Portuguese as bacorá, or falsa-coral, is a species of mildly venomous snake in the family Colubridae. The species is endemic to South America.
Müllerian mimicry is a natural phenomenon in which two or more well-defended species, often foul-tasting and sharing common predators, have come to mimic each other's honest warning signals, to their mutual benefit. The benefit to Müllerian mimics is that predators only need one unpleasant encounter with one member of a set of Müllerian mimics, and thereafter avoid all similar coloration, whether or not it belongs to the same species as the initial encounter. It is named after the German naturalist Fritz Müller, who first proposed the concept in 1878, supporting his theory with the first mathematical model of frequency-dependent selection, one of the first such models anywhere in biology.
Aposematism is the advertising by an animal, whether terrestrial or marine, to potential predators that it is not worth attacking or eating. This unprofitability may consist of any defenses which make the prey difficult to kill and eat, such as toxicity, venom, foul taste or smell, sharp spines, or aggressive nature. These advertising signals may take the form of conspicuous coloration, sounds, odours, or other perceivable characteristics. Aposematic signals are beneficial for both predator and prey, since both avoid potential harm.
In zoology, automimicry, Browerian mimicry, or intraspecific mimicry, is a form of mimicry in which the same species of animal is imitated. There are two different forms.
Erythrolamprus is a genus of colubrid snakes native to Central America, the Caribbean, and South America. They include the false coral snakes, which appear to be coral snake mimics.
Aggressive mimicry is a form of mimicry in which predators, parasites, or parasitoids share similar signals, using a harmless model, allowing them to avoid being correctly identified by their prey or host. Zoologists have repeatedly compared this strategy to a wolf in sheep's clothing. In its broadest sense, aggressive mimicry could include various types of exploitation, as when an orchid exploits a male insect by mimicking a sexually receptive female, but will here be restricted to forms of exploitation involving feeding. For example, indigenous Australians who dress up as and imitate kangaroos when hunting would not be considered aggressive mimics, nor would a human angler, though they are undoubtedly practising self-decoration camouflage. Treated separately is molecular mimicry, which shares some similarity; for instance a virus may mimic the molecular properties of its host, allowing it access to its cells. An alternative term, Peckhamian mimicry, has been suggested, but it is seldom used.
Animal colouration is the general appearance of an animal resulting from the reflection or emission of light from its surfaces. Some animals are brightly coloured, while others are hard to see. In some species, such as the peafowl, the male has strong patterns, conspicuous colours and is iridescent, while the female is far less visible.
Caudal luring is a form of aggressive mimicry characterized by the waving or wriggling of the predator's tail to attract prey. This movement attracts small animals who mistake the tail for a small worm or other small animal. When the animal approaches to prey on the worm-like tail, the predator will strike. This behavior has been recorded in snakes, sharks, and eels.
Deimatic behaviour or startle display means any pattern of bluffing behaviour in an animal that lacks strong defences, such as suddenly displaying conspicuous eyespots, to scare off or momentarily distract a predator, thus giving the prey animal an opportunity to escape. The term deimatic or dymantic originates from the Greek δειματόω (deimatóo), meaning "to frighten".
The novel world method is a technique used in animal behaviour experiments that address questions on the evolution of warning signals that chemically defended prey use to deter predators, and also on warning signal mimicry.
Deception in animals is the transmission of misinformation by one animal to another, of the same or different species, in a way that propagates beliefs that are not true.
Oxyrhopus guibei is a species of snake in the family Colubridae. The species is endemic to South America. It is often called the false coral snake, but this common name can refer to any of a long list of other species, genera, and even entire families of snakes. Many nonvenomous snakes have evolved coloration that mimics that of venomous true coral snakes, a trait which helps them avoid predation.
Locomotor mimicry is a subtype of Batesian mimicry in which animals avoid predation by mimicking the movements of another species phylogenetically separated. This can be in the form of mimicking a less desirable species or by mimicking the predator itself. Animals can show similarity in swimming, walking, or flying of their model animals.
In evolutionary biology, mimicry in vertebrates is mimicry by a vertebrate of some model, deceiving some other animal, the dupe. Mimicry differs from camouflage as it is meant to be seen, while animals use camouflage to remain hidden. Visual, olfactory, auditory, biochemical, and behavioral modalities of mimicry have been documented in vertebrates.
Fish coloration, a subset of animal coloration, is extremely diverse. Fish across all taxa vary greatly in their coloration through special mechanisms, mainly pigment cells called chromatophores. Fish can have any colors of the visual spectrum on their skin, evolutionarily derived for many reasons. There are three factors to coloration, brightness, hue, and saturation. Fish coloration has three proposed functions: thermoregulation, intraspecific communication, and interspecific communication. Fishes' diverse coloration is possibly derivative of the fact that "fish most likely see colors very differently than humans".
