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. Often, mimicry functions to protect a species from predators, making it an anti-predator adaptation. Mimicry evolves if a receiver perceives the similarity between a mimic and a model and as a result changes its behaviour in a way that provides a selective advantage to the mimic. The resemblances that evolve in mimicry can be visual, acoustic, chemical, tactile, or electric, or combinations of these sensory modalities. Mimicry may be to the advantage of both organisms that share a resemblance, in which case it is a form of mutualism; or mimicry can be to the detriment of one, making it parasitic or competitive. The evolutionary convergence between groups is driven by the selective action of a signal-receiver or dupe. Birds, for example, use sight to identify palatable insects and butterflies, whilst avoiding the noxious ones. Over time, palatable insects may evolve to resemble noxious ones, making them mimics and the noxious ones models. In the case of mutualism, sometimes both groups are referred to as "co-mimics". It is often thought that models must be more abundant than mimics, but this is not so. Mimicry may involve numerous species; many harmless species such as hoverflies are Batesian mimics of strongly defended species such as wasps, while many such well-defended species form Müllerian mimicry rings, all resembling each other. Mimicry between prey species and their predators often involves three or more species.
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, after his work 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 with its background. However, it is noteworthy for being able to impersonate a wide variety of other marine animals. Although 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 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.
Flower mantises are praying mantis species that use a special form of camouflage referred to as aggressive mimicry, which they not only use to attract prey, but avoid predators as well. These insects have specific colorations and behaviors that mimic flowers in their surrounding habitats. This strategy has been observed in other mantises including the stick mantis and dead-leaf mantis. The observed behavior of these mantises includes positioning themselves on a plant and either inserting themselves within the irradiance or on the foliage of the plants until a prey insect comes within range. Many species of flower mantises are popular as pets. The flower mantises are non-nocturnal group with a single ancestry, but the majority of the known species belong to family Hymenopodidea.
Erythrolamprus is a genus of colubrid snakes, commonly known as false coral snakes, native to Central America, the Caribbean, and the northern part of South America. They 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 coloration 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.
In evolutionary biology, mimicry in plants is where a plant organism evolves to resemble another organism physically or chemically, increasing the mimic's Darwinian fitness. Mimicry in plants has been studied far less than mimicry in animals, with fewer documented cases and peer-reviewed studies. However, it may provide protection against herbivory, or may deceptively encourage mutualists, like pollinators, to provide a service without offering a reward in return.
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.
