Wolf Howling and Emergency Sirens: A Hypothesis of Natural and Technical Convergence of Aposematic Signals

Aposematism

10.1093/oso/9780199688678.003.0007 ◽

2018 ◽

Cited By ~ 2

Author(s):

Graeme D. Ruxton ◽

William L. Allen ◽

Thomas N. Sherratt ◽

Michael P. Speed

Keyword(s):

Secondary Effects ◽

Warning Coloration ◽

Common Features ◽

Initial Evolution ◽

The Common ◽

Aposematic Signals

Aposematism is the pairing of two kinds of defensive phenotype: an often repellent secondary defence that typically renders prey unprofitable to predators if they attack them and some evolved signal that indicates the presence of that defence. Aposematic signals often work to modify the behaviours of predators both before and during attacks. Warning coloration, for example, may increase wariness and hence improve the chances that a chemically defended prey is released unharmed after an attack. An aposematic signal may therefore first tend to reduce the probability that a predator commences attack (a primary defence) and then (as a component of secondary defence) reduce the probability that the prey is injured or killed during any subsequent attack. In this chapter we will consider both the primary and the secondary effects of aposematic signals on prey protection. We begin first by describing the common features of aposematic signals and attempting to show the wide use to which aposematic signalling is deployed across animals (and perhaps plants too). We then review the interesting evolutionary issues aposematic signals raise, including their initial evolution and their integration with sexual and other signals. We also discuss important ecological, co-evolutionary, and macroevolutionary consequences of aposematism.

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Stabilizing selection on individual pattern elements of aposematic signals

Proceedings of The Royal Society B Biological Sciences ◽

10.1098/rspb.2017.0926 ◽

2017 ◽

Vol 284 (1861) ◽

pp. 20170926 ◽

Cited By ~ 17

Author(s):

Anne E. Winters ◽

Naomi F. Green ◽

Nerida G. Wilson ◽

Martin J. How ◽

Mary J. Garson ◽

...

Keyword(s):

Pattern Analysis ◽

Marine Organism ◽

Warning Signal ◽

Colour Pattern ◽

Stabilizing Selection ◽

Warning Signals ◽

Fish Predator ◽

Selection For ◽

Aposematic Signals ◽

Behavioural Experiments

Warning signal variation is ubiquitous but paradoxical: low variability should aid recognition and learning by predators. However, spatial variability in the direction and strength of selection for individual elements of the warning signal may allow phenotypic variation for some components, but not others. Variation in selection may occur if predators only learn particular colour pattern components rather than the entire signal. Here, we used a nudibranch mollusc, Goniobranchus splendidus , which exhibits a conspicuous red spot/white body/yellow rim colour pattern, to test this hypothesis. We first demonstrated that secondary metabolites stored within the nudibranch were unpalatable to a marine organism. Using pattern analysis, we demonstrated that the yellow rim remained invariable within and between populations; however, red spots varied significantly in both colour and pattern. In behavioural experiments, a potential fish predator, Rhinecanthus aculeatus , used the presence of the yellow rims to recognize and avoid warning signals. Yellow rims remained stable in the presence of high genetic divergence among populations. We therefore suggest that how predators learn warning signals may cause stabilizing selection on individual colour pattern elements, and will thus have important implications on the evolution of warning signals.

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Advergence in Müllerian mimicry: the case of the poison dart frogs of Northern Peru revisited

Biology Letters ◽

10.1098/rsbl.2011.0039 ◽

2011 ◽

Vol 7 (5) ◽

pp. 796-800 ◽

Cited By ~ 15

Author(s):

Mathieu Chouteau ◽

Kyle Summers ◽

Victor Morales ◽

Bernard Angers

Keyword(s):

Nuclear Dna ◽

Phenotypic Variability ◽

Model Species ◽

Müllerian Mimicry ◽

Mitochondrial Haplotypes ◽

Ranitomeya Imitator ◽

Northern Peru ◽

Mullerian Mimicry ◽

Aposematic Signals ◽

Rule Out

Whether the evolution of similar aposematic signals in different unpalatable species (i.e. Müllerian mimicry) is because of phenotypic convergence or advergence continues to puzzle scientists. The poison dart frog Ranitomeya imitator provides a rare example in support of the hypothesis of advergence: this species was believed to mimic numerous distinct model species because of high phenotypic variability and low genetic divergence among populations. In this study, we test the evidence in support of advergence using a population genetic framework in two localities where R. imitator is sympatric with different model species, Ranitomeya ventrimaculata and Ranitomeya variabilis . Genetic analyses revealed incomplete sorting of mitochondrial haplotypes between the two model species. These two species are also less genetically differentiated than R. imitator populations on the basis of both mitochondrial and nuclear DNA comparisons. The genetic similarity between the model species suggests that they have either diverged more recently than R. imitator populations or that they are still connected by gene flow and were misidentified as different species. An analysis of phenotypic variability indicates that the model species are as variable as R. imitator . These results do not support the hypothesis of advergence by R. imitator . Although we cannot rule out phenotypic advergence in the evolution of Müllerian mimicry, this study reopens the discussion regarding the direction of the evolution of mimicry in the R. imitator system.

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Sexually dimorphic blue bands are intrasexual aposematic signals in nonterritorial damselflies

Animal Behaviour ◽

10.1016/j.anbehav.2019.07.011 ◽

2019 ◽

Vol 156 ◽

pp. 21-29 ◽

Cited By ~ 6

Author(s):

Md Kawsar Khan ◽

Marie E. Herberstein

Keyword(s):

Sexually Dimorphic ◽

Aposematic Signals

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Contrast versus colour in aposematic signals

Animal Behaviour ◽

10.1006/anbe.2003.2098 ◽

2003 ◽

Vol 65 (5) ◽

pp. 1021-1026 ◽

Cited By ~ 34

Author(s):

Gabriella Gamberale-Stille ◽

Tim Guilford

Keyword(s):

Versus Colour ◽

Aposematic Signals

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Aposematic signals in North American black widows are more conspicuous to predators than to prey

Behavioral Ecology ◽

10.1093/beheco/arw014 ◽

2016 ◽

Vol 27 (4) ◽

pp. 1104-1112 ◽

Cited By ~ 16

Author(s):

Nicholas Brandley ◽

Matthew Johnson ◽

Sönke Johnsen

Keyword(s):

North American ◽

Cost Benefit ◽

Wild Birds ◽

Ancestral Reconstruction ◽

Dorsal Region ◽

Black Widow ◽

American Black ◽

Aposematic Signals ◽

Black Widow Spiders ◽

Black Color

Abstract The iconic red hourglass of the black widow spiders (genus Latrodectus) is traditionally considered an aposematic signal, yet experimental evidence is lacking. Here, we present data that suggest that black widow coloration may have evolved to be an aposematic signal that is more conspicuous to their vertebrate predators than to their insect prey. In choice experiments with wild birds, we found that the red-and-black coloration deters potential predators: Wild birds were ~3 times less likely to attack a black widow model with an hourglass than one without. Using visual-system appropriate models, we also found that a black widow’s red-and-black color combo is more apparent to a typical bird than a typical insect. Additionally, an ancestral reconstruction reveals that red dorsal coloration is ancestral in black widows and that at some point some North American widows lost their red dorsal coloration. Behaviorally, differences in red dorsal coloration between 2 North American species are accompanied by differences in microhabitat that affects how often a bird will view a black widow’s dorsal region. All observations are consistent with a cost–benefit trade-off of being more conspicuous to predators than to prey. We suggest that limiting detection by prey may help explain why red and black aposematic signals occur frequently in nature.

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