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Chatelain P, Elias M, Fontaine C, Villemant C, Dajoz I, Perrard A. Müllerian mimicry among bees and wasps: a review of current knowledge and future avenues of research. Biol Rev Camb Philos Soc 2023; 98:1310-1328. [PMID: 36994698 DOI: 10.1111/brv.12955] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2022] [Revised: 03/15/2023] [Accepted: 03/20/2023] [Indexed: 03/31/2023]
Abstract
Many bees and stinging wasps, or aculeates, exhibit striking colour patterns or conspicuous coloration, such as black and yellow stripes. Such coloration is often interpreted as an aposematic signal advertising aculeate defences: the venomous sting. Aposematism can lead to Müllerian mimicry, the convergence of signals among different species unpalatable to predators. Müllerian mimicry has been extensively studied, notably on Neotropical butterflies and poison frogs. However, although a very high number of aculeate species harbour putative aposematic signals, aculeates are under-represented in mimicry studies. Here, we review the literature on mimicry rings that include bee and stinging wasp species. We report over a hundred described mimicry rings, involving a thousand species that belong to 19 aculeate families. These mimicry rings are found all throughout the world. Most importantly, we identify remaining knowledge gaps and unanswered questions related to the study of Müllerian mimicry in aculeates. Some of these questions are specific to aculeate models, such as the impact of sociality and of sexual dimorphism in defence levels on mimicry dynamics. Our review shows that aculeates may be one of the most diverse groups of organisms engaging in Müllerian mimicry and that the diversity of aculeate Müllerian mimetic interactions is currently under-explored. Thus, aculeates represent a new and major model system to study the evolution of Müllerian mimicry. Finally, aculeates are important pollinators and the global decline of pollinating insects raises considerable concern. In this context, a better understanding of the impact of Müllerian mimicry on aculeate communities may help design strategies for pollinator conservation, thereby providing future directions for evolutionary research.
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Affiliation(s)
- Paul Chatelain
- Institute of Ecology and Environmental Sciences-Paris (iEES-Paris), Sorbonne Université, CNRS, IRD, INRAE, Université Paris Cité, UPEC, 4 Place Jussieu, Paris, 75005, France
- Institut de Systématique, Évolution, Biodiversité (ISYEB), Muséum National d'Histoire Naturelle, CNRS, Sorbonne Université, EPHE, Université des Antilles, CP 50, 57 rue Cuvier, Paris, 75005, France
| | - Marianne Elias
- Institut de Systématique, Évolution, Biodiversité (ISYEB), Muséum National d'Histoire Naturelle, CNRS, Sorbonne Université, EPHE, Université des Antilles, CP 50, 57 rue Cuvier, Paris, 75005, France
- Smithsonian Tropical Research Institute, Gamboa, Panama
| | - Colin Fontaine
- Centre d'Ecologie et des Sciences de la conservation, CESCO UMR 7204, Muséum National d'Histoire Naturelle, CNRS, Sorbonne Université, 43 rue Cuvier, Paris, 75005, France
| | - Claire Villemant
- Institut de Systématique, Évolution, Biodiversité (ISYEB), Muséum National d'Histoire Naturelle, CNRS, Sorbonne Université, EPHE, Université des Antilles, CP 50, 57 rue Cuvier, Paris, 75005, France
| | - Isabelle Dajoz
- Institute of Ecology and Environmental Sciences-Paris (iEES-Paris), Sorbonne Université, CNRS, IRD, INRAE, Université Paris Cité, UPEC, 4 Place Jussieu, Paris, 75005, France
- Université Paris Cité, 45 Rue des Saints-Pères, Paris, F-75006, France
| | - Adrien Perrard
- Institute of Ecology and Environmental Sciences-Paris (iEES-Paris), Sorbonne Université, CNRS, IRD, INRAE, Université Paris Cité, UPEC, 4 Place Jussieu, Paris, 75005, France
- Université Paris Cité, 45 Rue des Saints-Pères, Paris, F-75006, France
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2
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Sugiura S, Hayashi M. Bombardiers and assassins: mimetic interactions between unequally defended insects. PeerJ 2023; 11:e15380. [PMID: 37304866 PMCID: PMC10252827 DOI: 10.7717/peerj.15380] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2022] [Accepted: 04/18/2023] [Indexed: 06/13/2023] Open
Abstract
In defensive mimicry, resemblance between unequally defended species can be parasitic; this phenomenon has been termed quasi-Batesian mimicry. Few studies have used real co-mimics and their predators to test whether the mimetic interactions were parasitic. Here, we investigated the mimetic interaction between two well-defended insect species, the bombardier beetle Pheropsophus occipitalis jessoensis (Coleoptera: Carabidae) and the assassin bug Sirthenea flavipes (Hemiptera: Reduviidae), using their potential predator, the pond frog Pelophylax nigromaculatus (Anura: Ranidae), which coexists with these insect species in the same habitat in Japan. We observed behavioural responses of this frog species (adults and juveniles) to adult Ph. occipitalis jessoensis and adult S. flavipes under laboratory conditions. Among the frogs, 100% and 75% rejected Ph. occipitalis jessoensis and S. flavipes, respectively, suggesting that, compared with the assassin bug S. flavipes, the bombardier beetle Ph. occipitalis jessoensis is more well-defended against frogs. An assassin bug or a bombardier beetle was provided to a frog that had encountered the other insect species. Frogs with a history of assassin bug encounter demonstrated a lower rate of attack toward bombardier beetles. Similarly, frogs with a history of bombardier beetle encounter demonstrated a lower rate of attack toward assassin bugs. Therefore, both the bombardier beetle Ph. occipitalis jessoensis and the assassin bug S. flavipes benefit from the mimetic interaction.
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Affiliation(s)
- Shinji Sugiura
- Graduate School of Agricultural Science, Kobe University, Kobe, Hyogo, Japan
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3
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Heerwig OT, Jain-Schlaepfer SMR, Sherratt TN, Kikuchi DW. Effects of predator associative learning and innate aversion on mimicry complexes. Evol Ecol 2023. [DOI: 10.1007/s10682-023-10238-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/29/2023]
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4
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Lev‐Yadun S. The phenomenon of red and yellow autumn leaves: Hypotheses, agreements and disagreements. J Evol Biol 2022; 35:1245-1282. [PMID: 35975328 PMCID: PMC9804425 DOI: 10.1111/jeb.14069] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2022] [Revised: 07/02/2022] [Accepted: 07/10/2022] [Indexed: 01/05/2023]
Abstract
Yellow and red autumn leaves are typical of many temperate/boreal woody plants. Since the 19th century, it has been either considered the non-functional outcome of chlorophyll degradation that unmasks the pre-existing yellow and red pigments or that the de novo synthesis of red anthocyanins in autumn leaves indicated that it should have a physiological function, although it was commonly ignored. Defending free amino acids and various other resources released especially following the breakdown of the photosynthetic system, and mobilizing them for storage in other organs before leaf fall, is the cornerstone of both the physiological and anti-herbivory hypotheses about the functions of yellow and red autumn leaf colouration. The complicated phenomenon of conspicuous autumn leaf colouration has received significant attention since the year 2000, especially because ecologists started paying attention to its anti-herbivory potential. The obvious imperfection of the hypotheses put forth in several papers stimulated many other scientists. Hot debates among physiologists, among ecologists, and between physiologists and ecologists have been common since the year 2000, first because the various functions of yellow and red autumn leaf colouration are non-exclusive, and second because many scientists were trained to focus on a single subject. Here, I will review the debates, especially between the photoprotective and the anti-herbivory hypotheses, and describe both the progress in their understanding and the required progress.
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Affiliation(s)
- Simcha Lev‐Yadun
- Department of Biology & Environment, Faculty of Natural SciencesUniversity of HaifaTivonIsrael
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5
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Maisonneuve L, Smadi C, Llaurens V. Evolutionary origins of sexual dimorphism: Lessons from female-limited mimicry in butterflies. Evolution 2022; 76:2404-2423. [PMID: 36005294 DOI: 10.1111/evo.14599] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2021] [Accepted: 07/18/2022] [Indexed: 01/22/2023]
Abstract
The striking female-limited mimicry observed in some butterfly species is a text-book example of sexually dimorphic trait submitted to intense natural selection. Two main evolutionary hypotheses, based on natural and sexual selection respectively, have been proposed. Predation pressure favoring mimicry toward defended species could be higher in females because of their slower flight, and thus overcome developmental constraints favoring the ancestral trait that limits the evolution of mimicry in males but not in females. Alternatively, the evolution of mimicry in males could be limited by female preference for non-mimetic males. However, the evolutionary origin of female preference for non-mimetic males remains unclear. Here, we hypothesize that costly sexual interactions between individuals from distinct sympatric species might intensify because of mimicry, therefore promoting female preference for non-mimetic trait. Using a mathematical model, we compare the evolution of female-limited mimicry when assuming either alternative selective hypotheses. We show that the patterns of divergence of male and female trait from the ancestral traits can differ between these selection regimes. We specifically highlight that divergence in female trait is not a signature of the effect of natural selection. Our results also evidence why female-limited mimicry is more frequently observed in Batesian mimics.
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Affiliation(s)
- Ludovic Maisonneuve
- Institut de Systématique, Evolution, Biodiversité (ISYEB), Muséum national d'Histoire naturelle, CNRS, Sorbonne Université, EPHE, Université des Antilles, CP 50, 57 rue Cuvier, Paris, 75005, France
| | - Charline Smadi
- Univ. Grenoble Alpes, INRAE, LESSEM, France, Saint-Martin-d'Hères, 38402.,Univ. Grenoble Alpes, CNRS, Institut Fourier, Gières, 38610, France
| | - Violaine Llaurens
- Institut de Systématique, Evolution, Biodiversité (ISYEB), Muséum national d'Histoire naturelle, CNRS, Sorbonne Université, EPHE, Université des Antilles, CP 50, 57 rue Cuvier, Paris, 75005, France
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6
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Abstract
Aposematism and mimicry are complex phenomena which have been studied extensively; however, much of our knowledge comes from just a few focal groups, especially butterflies. Aposematic species combine a warning signal with a secondary defense that reduces their profitability as prey. Aculeate hymenopterans are an extremely diverse lineage defined by the modification of the ovipositor into a stinger which represents a potent defense against predators. Aculeates are often brightly colored and broadly mimicked by members of other arthropod groups including Diptera, Lepidoptera, Coleoptera, and Araneae. However, aculeates are surprisingly understudied as aposematic and mimetic model organisms. Recent studies have described novel pigments contributing to warning coloration in insects and identified changes in cis-regulatory elements as potential drivers of color pattern evolution. Many biotic and abiotic factors contribute to the evolution and maintenance of conspicuous color patterns. Predator distribution and diversity seem to influence the phenotypic diversity of aposematic velvet ants while studies on bumble bees underscore the importance of intermediate mimetic phenotypes in transition zones between putative mimicry rings. Aculeate hymenopterans are attractive models for studying sex-based intraspecific mimicry as male aculeates lack the defense conferred by the females’ stinger. In some species, evolution of male and female color patterns appears to be decoupled. Future studies on aposematic aculeates and their associated mimics hold great promise for unraveling outstanding questions about the evolution of conspicuous color patterns and the factors which determine the composition and distribution of mimetic communities.
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7
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Boussens‐Dumon G, Llaurens V. Sex, competition and mimicry: an eco‐evolutionary model reveals unexpected impacts of ecological interactions on the evolution of phenotypes in sympatry. OIKOS 2021. [DOI: 10.1111/oik.08139] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Grégoire Boussens‐Dumon
- Inst. de Systématique, Evolution et Biodiversité (UMR 7205 CNRS/MNHN/SU/EPHE/UA), Muséum National d'Histoire Naturelle – CP50 Paris France
| | - Violaine Llaurens
- Inst. de Systématique, Evolution et Biodiversité (UMR 7205 CNRS/MNHN/SU/EPHE/UA), Muséum National d'Histoire Naturelle – CP50 Paris France
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8
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Dixit T, Caves EM, Spottiswoode CN, Horrocks NPC. Why and how to apply Weber's Law to coevolution and mimicry. Evolution 2021; 75:1906-1919. [PMID: 34165186 DOI: 10.1111/evo.14290] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2020] [Revised: 05/18/2021] [Accepted: 06/06/2021] [Indexed: 11/28/2022]
Abstract
In mimicry systems, receivers discriminate between the stimuli of models and mimics. Weber's Law of proportional processing states that receiver discrimination is based on proportional, not absolute, differences between stimuli. Weber's Law operates in a variety of taxa and modalities, yet it has largely been ignored in the context of mimicry, despite its potential relevance to whether receivers can discriminate models from mimics. Specifically, Weber's Law implies that for a given difference in stimulus magnitude between a model and mimic, as stimulus magnitudes increase, the mimic will be less discriminable from their model. This implies that mimics should benefit when stimulus magnitudes are high, and that high stimulus magnitudes will reduce selection for mimetic fidelity. Whether models benefit from high stimulus magnitudes depends on whether mimicry is honest or deceptive. We present four testable predictions about evolutionary trajectories of models and mimics based on this logic. We then provide a framework for testing whether receiver discrimination adheres to Weber's Law and illustrate it using coevolutionary examples and case studies from avian brood parasitism. We conclude that, when studying mimicry systems, researchers should consider whether receiver perception conforms to Weber's Law, because it could drive stimulus evolution in counterintuitive directions.
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Affiliation(s)
- Tanmay Dixit
- Department of Zoology, University of Cambridge, Cambridge, CB2 3EJ, United Kingdom
| | - Eleanor M Caves
- Centre for Ecology and Conservation, College of Life and Environmental Sciences, University of Exeter, Penryn, TR10 9FE, United Kingdom
| | - Claire N Spottiswoode
- Department of Zoology, University of Cambridge, Cambridge, CB2 3EJ, United Kingdom.,FitzPatrick Institute of African Ornithology, DST-NRF Centre of Excellence, Department of Biological Sciences, University of Cape Town, Cape Town, 7701, South Africa
| | - Nicholas P C Horrocks
- Department of Zoology, University of Cambridge, Cambridge, CB2 3EJ, United Kingdom.,Current Address: Cambridge Institute of Therapeutic Immunology & Infectious Disease (CITIID), Jeffrey Cheah Biomedical Centre, Cambridge Biomedical Campus, University of Cambridge, Cambridge, CB2 0AW, United Kingdom
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9
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Gordon SP, Burdfield-Steel E, Kirvesoja J, Mappes J. Safety in Numbers: How Color Morph Frequency Affects Predation Risk in an Aposematic Moth. Am Nat 2021; 198:128-141. [PMID: 34143722 DOI: 10.1086/714528] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
AbstractPolymorphic warning signals in aposematic systems are enigmatic because predator learning should favor the most common form, creating positive frequency-dependent survival. However, many populations exhibit variation in warning signals. There are various selective mechanisms that can counter positive frequency-dependent selection and lead to temporal or spatial warning signal diversification. Examining these mechanisms and their effects requires first confirming whether the most common morphs are favored at both local and regional scales. Empirical examples of this are uncommon and often include potentially confounding factors, such as a lack of knowledge of predator identity and behavior. We tested how bird behavior influences the survival of three coexisting morphs of the aposematic wood tiger moth Arctia plantaginis offered to a sympatric predator (great tit Parus major) at different frequencies. We found that although positive frequency-dependent selection is present, its strength is affected by predator characteristics and varying prey profitability. These results highlight the need to understand predator foraging in natural communities with variable prey defenses in order to better examine how behavioral interactions shape evolutionary outcomes.
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10
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Kikuchi DW, Herberstein ME, Barfield M, Holt RD, Mappes J. Why aren't warning signals everywhere? On the prevalence of aposematism and mimicry in communities. Biol Rev Camb Philos Soc 2021; 96:2446-2460. [PMID: 34128583 DOI: 10.1111/brv.12760] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2020] [Revised: 05/27/2021] [Accepted: 06/01/2021] [Indexed: 11/29/2022]
Abstract
Warning signals are a striking example of natural selection present in almost every ecological community - from Nordic meadows to tropical rainforests, defended prey species and their mimics ward off potential predators before they attack. Yet despite the wide distribution of warning signals, they are relatively scarce as a proportion of the total prey available, and more so in some biomes than others. Classically, warning signals are thought to be governed by positive density-dependent selection, i.e. they succeed better when they are more common. Therefore, after surmounting this initial barrier to their evolution, it is puzzling that they remain uncommon on the scale of the community. Here, we explore factors likely to determine the prevalence of warning signals in prey assemblages. These factors include the nature of prey defences and any constraints upon them, the behavioural interactions of predators with different prey defences, the numerical responses of predators governed by movement and reproduction, the diversity and abundance of undefended alternative prey and Batesian mimics in the community, and variability in other ecological circumstances. We also discuss the macroevolution of warning signals. Our review finds that we have a basic understanding of how many species in some taxonomic groups have warning signals, but very little information on the interrelationships among population abundances across prey communities, the diversity of signal phenotypes, and prey defences. We also have detailed knowledge of how a few generalist predator species forage in artificial laboratory environments, but we know much less about how predators forage in complex natural communities with variable prey defences. We describe how empirical work to address each of these knowledge gaps can test specific hypotheses for why warning signals exhibit their particular patterns of distribution. This will help us to understand how behavioural interactions shape ecological communities.
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Affiliation(s)
- David W Kikuchi
- Wissenschaftskolleg zu Berlin, Wallotstraße 19, Berlin, Germany.,Evolutionary Biology, Universität Bielefeld, Konsequez 45, Bielefeld, 33615, Germany
| | - Marie E Herberstein
- Wissenschaftskolleg zu Berlin, Wallotstraße 19, Berlin, Germany.,Department of Biological Sciences, Macquarie University, North Ryde, New South Wales, 2109, Australia
| | - Michael Barfield
- Department of Biology, University of Florida, Gainesville, FL, 32611-8525, U.S.A
| | - Robert D Holt
- Department of Biology, University of Florida, Gainesville, FL, 32611-8525, U.S.A
| | - Johanna Mappes
- Wissenschaftskolleg zu Berlin, Wallotstraße 19, Berlin, Germany.,Organismal and Evolutionary Biology Research Programme, Faculty of Biological and Environmental Sciences, Helsinki University, Helsinki, Finland.,Department of Biological and Environmental Science, University of Jyväskylä, Jyväskylä, FI-40014, Finland
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11
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Kaczmarek JM, Kaczmarski M, Mazurkiewicz J, Kloskowski J. Numbers, neighbors, and hungry predators: What makes chemically defended aposematic prey susceptible to predation? Ecol Evol 2020; 10:13705-13716. [PMID: 33391674 PMCID: PMC7771146 DOI: 10.1002/ece3.6956] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2019] [Revised: 09/17/2020] [Accepted: 09/21/2020] [Indexed: 11/23/2022] Open
Abstract
Many chemically defended aposematic species are characterized by relatively low toxin levels, which enables predators to include them in their diets under certain circumstances. Knowledge of the conditions governing the survival of such prey animals-especially in the context of the co-occurrence of similar but undefended prey, which may result in mimicry-like interactions-is crucial for understanding the initial evolution of aposematism. In a one-month outdoor experiment using fish (the common carp Cyprinus carpio) as predators, we examined the survival of moderately defended aposematic tadpole prey (the European common toad Bufo bufo) with varying absolute densities in single-species prey systems or varying relative densities in two-species prey systems containing morphologically similar but undefended prey (the European common frog Rana temporaria). The density effects were investigated in conjunction with the hunger levels of the predator, which were manipulated by means of the addition of alternative (nontadpole) food. The survival of the B. bufo tadpoles was promoted by increasing their absolute density in the single-species prey systems, increasing their relative density in the two-species prey systems, and providing ample alternative food for the predator. Hungry predators eliminated all R. temporaria individuals regardless of their proportion in the prey community; in treatments with ample alternative food, high relative B. bufo density supported R. temporaria survival. The results demonstrated that moderately defended prey did benefit from high population densities (both absolute and relative), even under long-term predation pressure. However, the physiological state of the predator was a crucial factor in the survival of moderately defended prey. While the availability of alternative prey in general should promote the spread and maintenance of aposematism, the results indicated that the resemblance between the co-occurring defended and undefended prey may impose mortality costs on the defended model species, even in the absence of actual mimicry.
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Affiliation(s)
- Jan M. Kaczmarek
- Department of ZoologyPoznań University of Life SciencesPoznańPoland
| | | | - Jan Mazurkiewicz
- Department of Inland Fisheries and AquaculturePoznań University of Life SciencesPoznańPoland
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12
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Aubier TG, Sherratt TN. State-Dependent Decision-Making by Predators and Its Consequences for Mimicry. Am Nat 2020; 196:E127-E144. [PMID: 33064589 DOI: 10.1086/710568] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
AbstractThe mimicry of one species by another provides one of the most celebrated examples of evolution by natural selection. Edible Batesian mimics deceive predators into believing they may be defended, whereas defended Müllerian mimics have evolved a shared warning signal, more rapidly educating predators to avoid them. However, it may benefit hungry predators to attack defended prey, while the benefits of learning about unfamiliar prey depends on the future value of this information. Previous energetic state-dependent models of predator foraging behavior have assumed complete knowledge, while informational state-dependent models have assumed fixed levels of hunger. Here, we identify the optimal decision rules of predators accounting for both energetic and informational states. We show that the nature of mimicry is qualitatively and quantitatively affected by both sources of state dependence. Associative learning weakens the extent of parasitic mimicry by edible prey because naive predators often attack defended models. More importantly, mimicry among equally highly defended prey may be parasitic or mutualistic depending on the ecological context (e.g., the source of mimics and the abundance of alternative prey). Finally, mimicry by prey with intermediate defenses corresponds to Batesian or Müllerian mimicry depending on whether the mimic is profitable to attack by hungry predators, but it is not a special case of mimicry.
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13
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Yamazaki Y, Pagani-Núñez E, Sota T, Barnett CRA. The truth is in the detail: predators attack aposematic prey with less aggression than other prey types. Biol J Linn Soc Lond 2020. [DOI: 10.1093/biolinnean/blaa119] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
Abstract
Aposematic organisms are often unprofitable to predators (e.g. because of defensive chemicals) which they advertise with a conspicuous signal (e.g. bright and conspicuous colour signals). Aposematism is thought to reduce predation of prey because the colour signal increases the ability of predators to learn, recognize and remember the prey’s defensive properties. The efficacy of aposematism has been extensively documented in laboratory studies, although its benefits seem to be harder to demonstrate in the field. In this study, we compared the levels of partial and overall predation among four prey types (undefended and cryptic, undefended and warning coloured, defended and cryptic, and aposematic prey). Overall, predation of warning coloured and defended (aposematic) prey was lower than the predation for cryptic and undefended prey; however, it was the same as predation of cryptic and defended prey. Moreover, aposematic prey had higher levels of partial predation (where prey was not wholly consumed by the predator) and lower attack intensities. This suggests that prey were being taste sampled, but also might be better able to survive attacks. Therefore, the benefits of aposematism may lie not only in reducing outright predation, but also in altering a predator’s post-attack behaviour, thus leading to greater escape opportunities and post-attack survival of prey. These results reinforce the importance of examining predation in more detail rather than simply examining attack rates.
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Affiliation(s)
- Yuki Yamazaki
- Department of Zoology, Graduate School of Science, Kyoto University, Kyoto, Japan
| | - Emilio Pagani-Núñez
- Department of Health and Environmental Sciences, Xi’an Jiaotong-Liverpool University, Suzhou, People’s Republic of China
| | - Teiji Sota
- Department of Zoology, Graduate School of Science, Kyoto University, Kyoto, Japan
| | - Craig R A Barnett
- Department of Zoology, Graduate School of Science, Kyoto University, Kyoto, Japan
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14
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McClure M, Clerc C, Desbois C, Meichanetzoglou A, Cau M, Bastin-Héline L, Bacigalupo J, Houssin C, Pinna C, Nay B, Llaurens V, Berthier S, Andraud C, Gomez D, Elias M. Why has transparency evolved in aposematic butterflies? Insights from the largest radiation of aposematic butterflies, the Ithomiini. Proc Biol Sci 2020; 286:20182769. [PMID: 30991931 DOI: 10.1098/rspb.2018.2769] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Defended species are often conspicuous and this is thought to be an honest signal of defences, i.e. more toxic prey are more conspicuous. Neotropical butterflies of the large Ithomiini tribe numerically dominate communities of chemically defended butterflies and may thus drive the evolution of mimetic warning patterns. Although many species are brightly coloured, most are transparent to some degree. The evolution of transparency from a warning-coloured ancestor is puzzling as it is generally assumed to be involved in concealment. Here, we show that transparent Ithomiini species are indeed less detectable by avian predators (i.e. concealment). Surprisingly, transparent species are not any less unpalatable, and may in fact be more unpalatable than opaque species, the latter spanning a larger range of unpalatability. We put forth various hypotheses to explain the evolution of weak aposematic signals in these butterflies and other cryptic defended prey. Our study is an important step in determining the selective pressures and constraints that regulate the interaction between conspicuousness and unpalatability.
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Affiliation(s)
- Melanie McClure
- 1 Institut Systématique Évolution Biodiversité (ISYEB), CNRS, MNHN, Sorbonne Université , EPHE, Université des Antilles, CP50 75005 Paris , France
| | - Corentin Clerc
- 1 Institut Systématique Évolution Biodiversité (ISYEB), CNRS, MNHN, Sorbonne Université , EPHE, Université des Antilles, CP50 75005 Paris , France
| | - Charlotte Desbois
- 1 Institut Systématique Évolution Biodiversité (ISYEB), CNRS, MNHN, Sorbonne Université , EPHE, Université des Antilles, CP50 75005 Paris , France
| | - Aimilia Meichanetzoglou
- 1 Institut Systématique Évolution Biodiversité (ISYEB), CNRS, MNHN, Sorbonne Université , EPHE, Université des Antilles, CP50 75005 Paris , France.,2 Unité Molécules de Communication et Adaptation des Micro-organismes (MCAM), CNRS, MNHN, Sorbonne Université , 75005 Paris , France
| | - Marion Cau
- 1 Institut Systématique Évolution Biodiversité (ISYEB), CNRS, MNHN, Sorbonne Université , EPHE, Université des Antilles, CP50 75005 Paris , France
| | - Lucie Bastin-Héline
- 1 Institut Systématique Évolution Biodiversité (ISYEB), CNRS, MNHN, Sorbonne Université , EPHE, Université des Antilles, CP50 75005 Paris , France.,4 Sorbonne Université, INRA, CNRS, IRD, UPEC, Université Paris Diderot, Institute of Ecology and Environmental Sciences of Paris , Paris and Versailles , France
| | - Javier Bacigalupo
- 1 Institut Systématique Évolution Biodiversité (ISYEB), CNRS, MNHN, Sorbonne Université , EPHE, Université des Antilles, CP50 75005 Paris , France
| | - Céline Houssin
- 1 Institut Systématique Évolution Biodiversité (ISYEB), CNRS, MNHN, Sorbonne Université , EPHE, Université des Antilles, CP50 75005 Paris , France
| | - Charline Pinna
- 1 Institut Systématique Évolution Biodiversité (ISYEB), CNRS, MNHN, Sorbonne Université , EPHE, Université des Antilles, CP50 75005 Paris , France
| | - Bastien Nay
- 2 Unité Molécules de Communication et Adaptation des Micro-organismes (MCAM), CNRS, MNHN, Sorbonne Université , 75005 Paris , France.,3 Laboratoire de Synthèse Organique, Ecole polytechnique, Institut Polytechnique de Paris , 91128 Palaiseau , France
| | - Violaine Llaurens
- 1 Institut Systématique Évolution Biodiversité (ISYEB), CNRS, MNHN, Sorbonne Université , EPHE, Université des Antilles, CP50 75005 Paris , France
| | - Serge Berthier
- 5 Institut des NanoSciences de Paris, UMR 7588, CNRS, Sorbonne Université , 75252 Paris , France
| | - Christine Andraud
- 6 Centre de recherche et Conservation des Collections (CRCC), MNHN , 75005 Paris , France
| | - Doris Gomez
- 7 CEFE, Université de Montpellier, CNRS, Université Paul Valéry Montpellier 3 , EPHE, IRD, Montpellier , France
| | - Marianne Elias
- 1 Institut Systématique Évolution Biodiversité (ISYEB), CNRS, MNHN, Sorbonne Université , EPHE, Université des Antilles, CP50 75005 Paris , France
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15
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Sculfort O, de Castro ECP, Kozak KM, Bak S, Elias M, Nay B, Llaurens V. Variation of chemical compounds in wild Heliconiini reveals ecological factors involved in the evolution of chemical defenses in mimetic butterflies. Ecol Evol 2020; 10:2677-2694. [PMID: 32185010 PMCID: PMC7069300 DOI: 10.1002/ece3.6044] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2019] [Revised: 01/06/2020] [Accepted: 01/07/2020] [Indexed: 01/08/2023] Open
Abstract
Evolutionary convergence of color pattern in mimetic species is tightly linked with the evolution of chemical defenses. Yet, the evolutionary forces involved in natural variations of chemical defenses in aposematic species are still understudied. Herein, we focus on the evolution of chemical defenses in the butterfly tribe Heliconiini. These neotropical butterflies contain large concentrations of cyanogenic glucosides, cyanide-releasing compounds acting as predator deterrent. These compounds are either de novo synthesized or sequestered from their Passiflora host plant, so that their concentrations may depend on host plant specialization and host plant availability. We sampled 375 wild Heliconiini butterflies across Central and South America, covering 43% species of this clade, and quantify individual variations in the different CGs using liquid chromatography coupled with tandem mass spectrometry. We detected new compounds and important variations in chemical defenses both within and among species. Based on the most recent and well-studied phylogeny of Heliconiini, we show that ecological factors such as mimetic interactions and host plant specialization have a significant association with chemical profiles, but these effects are largely explained by phylogenetic relationships. Our results therefore suggest that shared ancestries largely contribute to chemical defense variation, pointing out at the interaction between historical and ecological factors in the evolution of Müllerian mimicry.
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Affiliation(s)
- Ombeline Sculfort
- Institut de Systématique, Evolution, Biodiversité (ISYEB)Muséum National d'Histoire NaturelleCNRSSorbonne‐UniversitéEPHEUniversité des AntillesParisFrance
- Unité Molécules de Communication et Adaptations des Micro‐organismes (MCAM)Muséum National d'Histoire NaturelleCNRSParisFrance
| | | | | | - Søren Bak
- Department of Plant and Environmental SciencesUniversity of CopenhagenFrederiksbergDenmark
| | - Marianne Elias
- Institut de Systématique, Evolution, Biodiversité (ISYEB)Muséum National d'Histoire NaturelleCNRSSorbonne‐UniversitéEPHEUniversité des AntillesParisFrance
| | - Bastien Nay
- Unité Molécules de Communication et Adaptations des Micro‐organismes (MCAM)Muséum National d'Histoire NaturelleCNRSParisFrance
- Laboratoire de Synthèse OrganiqueEcole PolytechniqueCNRSENSTAInstitut Polytechnique de ParisPalaiseau CedexFrance
| | - Violaine Llaurens
- Institut de Systématique, Evolution, Biodiversité (ISYEB)Muséum National d'Histoire NaturelleCNRSSorbonne‐UniversitéEPHEUniversité des AntillesParisFrance
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16
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Raška J, Krajíček J, Bosáková Z, Štys P, Exnerová A. Larvae of pyrrhocorid true bugs are not to spiders’ taste: putative Müllerian mimicry. Biol J Linn Soc Lond 2019. [DOI: 10.1093/biolinnean/blz174] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
Abstract
Adults and larvae of a true bug, Scantius aegyptius (Heteroptera: Pyrrhocoridae), closely resemble sympatric firebugs, Pyrrhocoris apterus, and probably form a mimetic relationship with the latter species. Scantius aegyptius adults, although producing a secretion atypical of true bugs, are to some extent chemically protected against predators. In this study, we analysed the composition and function of the larval secretion in S. aegyptius, and investigated the mimetic relationship between larvae of S. aegyptius and P. apterus. The main component of the larval secretion in S. aegyptius is 2-heptanol, a chemical not known to function in anti-predatory defence, followed by (E)-2-octenal, a common defensive chemical of true bugs. When larvae of both species were presented to jumping spiders (Evarcha arcuata), S. aegyptius was slightly less well protected than P. apterus, but the spiders behaved towards the two species in a similar way: they quickly learned to avoid the bugs, but usually attacked them again on the second day. The spiders also generalized their learned avoidance from one true bug species to the other (with only slight asymmetry favouring S. aegyptius), suggesting that the bugs’ mimetic relationship is most probably Müllerian, being advantageous to both species.
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Affiliation(s)
- Jan Raška
- Department of Zoology, Faculty of Science, Charles University, Prague, Czech Republic
| | - Jan Krajíček
- Department of Analytical Chemistry, Faculty of Science, Charles University, Prague, Czech Republic
| | - Zuzana Bosáková
- Department of Analytical Chemistry, Faculty of Science, Charles University, Prague, Czech Republic
| | - Pavel Štys
- Department of Zoology, Faculty of Science, Charles University, Prague, Czech Republic
| | - Alice Exnerová
- Department of Zoology, Faculty of Science, Charles University, Prague, Czech Republic
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17
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Hämäläinen L, Mappes J, Rowland HM, Thorogood R. Social information use about novel aposematic prey is not influenced by a predator's previous experience with toxins. Funct Ecol 2019. [DOI: 10.1111/1365-2435.13395] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
| | - Johanna Mappes
- Department of Biological and Environmental Science University of Jyväskylä Jyväskylä Finland
| | - Hannah M. Rowland
- Department of Zoology University of Cambridge Cambridge UK
- Max Planck Institute for Chemical Ecology Jena Germany
- Institute of Zoology Zoological Society of London London UK
| | - Rose Thorogood
- Department of Zoology University of Cambridge Cambridge UK
- HiLIFE Helsinki Institute of Life Sciences, University of Helsinki Helsinki Finland
- Research Programme in Organismal & Evolutionary Biology, Faculty of Biological and Environmental Sciences University of Helsinki Helsinki Finland
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18
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Abstract
With our comprehensive set of field (model survival), laboratory (controlled learning, palatability, toxin analysis), and molecular data, we provide evidence that polymorphism can persist in an aposematic population, despite expectations of positive frequency-dependent selection. We show that this can happen if prey species carrying a strong signal can exploit predator learning to elicit broad avoidance of many signals, even if predators only have experience with a single signal. This could allow novel signals to be protected within a population of aposematic prey. Thus, under the expectations of broad generalization coupled with limited gene flow, weak aposematic signals can persist, contributing to the overall diversity of signals found within aposematic species. Aposematic organisms couple conspicuous warning signals with a secondary defense to deter predators from attacking. Novel signals of aposematic prey are expected to be selected against due to positive frequency-dependent selection. How, then, can novel phenotypes persist after they arise, and why do so many aposematic species exhibit intrapopulation signal variability? Using a polytypic poison frog (Dendrobates tinctorius), we explored the forces of selection on variable aposematic signals using 2 phenotypically distinct (white, yellow) populations. Contrary to expectations, local phenotype was not always better protected compared to novel phenotypes in either population; in the white population, the novel phenotype evoked greater avoidance in natural predators. Despite having a lower quantity of alkaloids, the skin extracts from yellow frogs provoked higher aversive reactions by birds than white frogs in the laboratory, although both populations differed from controls. Similarly, predators learned to avoid the yellow signal faster than the white signal, and generalized their learned avoidance of yellow but not white. We propose that signals that are easily learned and broadly generalized can protect rare, novel signals, and weak warning signals (i.e., signals with poor efficacy and/or poor defense) can persist when gene flow among populations, as in this case, is limited. This provides a mechanism for the persistence of intrapopulation aposematic variation, a likely precursor to polytypism and driver of speciation.
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19
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Is eliciting disgust responses from its predators beneficial for toxic prey? Anim Behav 2019. [DOI: 10.1016/j.anbehav.2019.07.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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20
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Chouteau M, Dezeure J, Sherratt TN, Llaurens V, Joron M. Similar predator aversion for natural prey with diverse toxicity levels. Anim Behav 2019. [DOI: 10.1016/j.anbehav.2019.04.017] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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21
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Abstract
Venomous teeth are rare in fishes, which typically utilise spines for defence. A new study reveals the evolutionary origins of fangs and venom in the Nemophini blennies and shows that, in contrast to snakes and lizards, the fangs pre-date the venom.
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Affiliation(s)
- Martin I Taylor
- School of Biological Sciences, University of East Anglia, Norwich, NR4 7TJ, UK.
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22
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Harris RJ, Jenner RA. Evolutionary Ecology of Fish Venom: Adaptations and Consequences of Evolving a Venom System. Toxins (Basel) 2019; 11:E60. [PMID: 30678265 PMCID: PMC6409815 DOI: 10.3390/toxins11020060] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2018] [Revised: 01/14/2019] [Accepted: 01/18/2019] [Indexed: 01/21/2023] Open
Abstract
Research on venomous animals has mainly focused on the molecular, biochemical, and pharmacological aspects of venom toxins. However, it is the relatively neglected broader study of evolutionary ecology that is crucial for understanding the biological relevance of venom systems. As fish have convergently evolved venom systems multiple times, it makes them ideal organisms to investigate the evolutionary ecology of venom on a broader scale. This review outlines what is known about how fish venom systems evolved as a result of natural enemy interactions and about the ecological consequences of evolving a venom system. This review will show how research on the evolutionary ecology of venom in fish can aid in understanding the evolutionary ecology of animal venoms more generally. Further, understanding these broad ecological questions can shed more light on the other areas of toxinology, with applications across multiple disciplinary fields.
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Affiliation(s)
- Richard J Harris
- Venom Evolution Lab, School of Biological Sciences, The University of Queensland, St Lucia, Brisbane, Queensland 4072, Australia.
| | - Ronald A Jenner
- Department of Life Sciences, the Natural History Museum, Cromwell Road, SW7 5BD London, UK.
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23
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Briolat ES, Burdfield-Steel ER, Paul SC, Rönkä KH, Seymoure BM, Stankowich T, Stuckert AMM. Diversity in warning coloration: selective paradox or the norm? Biol Rev Camb Philos Soc 2018; 94:388-414. [PMID: 30152037 PMCID: PMC6446817 DOI: 10.1111/brv.12460] [Citation(s) in RCA: 68] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2017] [Revised: 07/25/2018] [Accepted: 07/27/2018] [Indexed: 01/03/2023]
Abstract
Aposematic theory has historically predicted that predators should select for warning signals to converge on a single form, as a result of frequency‐dependent learning. However, widespread variation in warning signals is observed across closely related species, populations and, most problematically for evolutionary biologists, among individuals in the same population. Recent research has yielded an increased awareness of this diversity, challenging the paradigm of signal monomorphy in aposematic animals. Here we provide a comprehensive synthesis of these disparate lines of investigation, identifying within them three broad classes of explanation for variation in aposematic warning signals: genetic mechanisms, differences among predators and predator behaviour, and alternative selection pressures upon the signal. The mechanisms producing warning coloration are also important. Detailed studies of the genetic basis of warning signals in some species, most notably Heliconius butterflies, are beginning to shed light on the genetic architecture facilitating or limiting key processes such as the evolution and maintenance of polymorphisms, hybridisation, and speciation. Work on predator behaviour is changing our perception of the predator community as a single homogenous selective agent, emphasising the dynamic nature of predator–prey interactions. Predator variability in a range of factors (e.g. perceptual abilities, tolerance to chemical defences, and individual motivation), suggests that the role of predators is more complicated than previously appreciated. With complex selection regimes at work, polytypisms and polymorphisms may even occur in Müllerian mimicry systems. Meanwhile, phenotypes are often multifunctional, and thus subject to additional biotic and abiotic selection pressures. Some of these selective pressures, primarily sexual selection and thermoregulation, have received considerable attention, while others, such as disease risk and parental effects, offer promising avenues to explore. As well as reviewing the existing evidence from both empirical studies and theoretical modelling, we highlight hypotheses that could benefit from further investigation in aposematic species. Finally by collating known instances of variation in warning signals, we provide a valuable resource for understanding the taxonomic spread of diversity in aposematic signalling and with which to direct future research. A greater appreciation of the extent of variation in aposematic species, and of the selective pressures and constraints which contribute to this once‐paradoxical phenomenon, yields a new perspective for the field of aposematic signalling.
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Affiliation(s)
- Emmanuelle S Briolat
- Centre for Ecology & Conservation, College of Life & Environmental Sciences, University of Exeter, Penryn Campus, Penryn, Cornwall, TR10 9FE, U.K
| | - Emily R Burdfield-Steel
- Centre of Excellence in Biological Interactions, Department of Biological and Environmental Science, University of Jyväskylä, Jyväskylä, 40014, Finland
| | - Sarah C Paul
- Centre for Ecology & Conservation, College of Life & Environmental Sciences, University of Exeter, Penryn Campus, Penryn, Cornwall, TR10 9FE, U.K.,Department of Chemical Ecology, Bielefeld University, Universitätsstraße 25, 33615, Bielefeld, Germany
| | - Katja H Rönkä
- Centre of Excellence in Biological Interactions, Department of Biological and Environmental Science, University of Jyväskylä, Jyväskylä, 40014, Finland.,Organismal and Evolutionary Biology Research Programme, Faculty of Biological and Environmental Sciences, University of Helsinki, Helsinki, 00014, Finland
| | - Brett M Seymoure
- Department of Biology, Colorado State University, Fort Collins, CO 80525, U.S.A.,Department of Fish, Wildlife, and Conservation Biology, Colorado State University, Fort Collins, CO 80525, U.S.A
| | - Theodore Stankowich
- Department of Biological Sciences, California State University, Long Beach, CA 90840, U.S.A
| | - Adam M M Stuckert
- Department of Biology, East Carolina University, 1000 E Fifth St, Greenville, NC 27858, U.S.A
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24
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Lev-Yadun S. Müllerian and Batesian mimicry out, Darwinian and Wallacian mimicry in, for rewarding/rewardless flowers. PLANT SIGNALING & BEHAVIOR 2018; 13:e1480846. [PMID: 29888995 PMCID: PMC6110362 DOI: 10.1080/15592324.2018.1480846] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/12/2018] [Accepted: 05/17/2018] [Indexed: 06/08/2023]
Abstract
Müllerian and Batesian mimicry were originally defined in defensive (anti-predetory) animal systems. Later these terms were adopted by botanists studying pollination that defined rewarding flowers as Müllerian mimics and rewardless flowers as Batesian mimics. The use of these terms concerning pollination predated our recent understanding of how common plant aposematism is and the related defensive Müllerian and Batesian mimicry types. Being non-defensive, using the terms Müllerian and Batesian mimicry for rewarding/rewardless flowers is, however, confusing if not misleading, and is also logically inappropriate. I suggest to first stop using the terms Batesian and Müllerian mimicry concerning rewarding/rewardless flowers and pollination, and second, to define the guild of flowers that reward pollinatiors as Darwinian mimics and those that do not reward pollinators as Wallacian mimics.
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Affiliation(s)
- Simcha Lev-Yadun
- Department of Biology & Environment, Faculty of Natural Sciences, University of Haifa - Oranim, Tivon, Israel
- Iyar - The Israeli Institute for Advanced Studies, Lod, Israel
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25
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Akcali CK, Kikuchi DW, Pfennig DW. Coevolutionary arms races in Batesian mimicry? A test of the chase-away hypothesis. Biol J Linn Soc Lond 2018. [DOI: 10.1093/biolinnean/bly075] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- Christopher K Akcali
- Department of Biology, University of North Carolina, Chapel Hill, NC, USA
- North Carolina Museum of Natural Sciences, Raleigh, NC, USA
| | - David W Kikuchi
- Department of Ecology and Evolutionary Biology, University of Arizona, Tucson, USA
| | - David W Pfennig
- Department of Biology, University of North Carolina, Chapel Hill, NC, USA
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26
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Winters AE, Wilson NG, van den Berg CP, How MJ, Endler JA, Marshall NJ, White AM, Garson MJ, Cheney KL. Toxicity and taste: unequal chemical defences in a mimicry ring. Proc Biol Sci 2018; 285:20180457. [PMID: 29875302 PMCID: PMC6015865 DOI: 10.1098/rspb.2018.0457] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2018] [Accepted: 05/11/2018] [Indexed: 11/12/2022] Open
Abstract
Mimicry of warning signals is common, and can be mutualistic when mimetic species harbour equal levels of defence (Müllerian), or parasitic when mimics are undefended but still gain protection from their resemblance to the model (Batesian). However, whether chemically defended mimics should be similar in terms of toxicity (i.e. causing damage to the consumer) and/or unpalatability (i.e. distasteful to consumer) is unclear and in many studies remains undifferentiated. In this study, we investigated the evolution of visual signals and chemical defences in a putative mimicry ring of nudibranch molluscs. First, we demonstrated that the appearance of a group of red spotted nudibranchs molluscs was similar from the perspective of potential fish predators using visual modelling and pattern analysis. Second, using phylogenetic reconstruction, we demonstrated that this colour pattern has evolved multiple times in distantly related individuals. Third, we showed that these nudibranchs contained different chemical profiles used for defensive purposes. Finally, we demonstrated that although levels of distastefulness towards Palaemon shrimp remained relatively constant between species, toxicity levels towards brine shrimp varied significantly. We highlight the need to disentangle toxicity and taste when considering chemical defences in aposematic and mimetic species, and discuss the implications for aposematic and mimicry signal evolution.
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Affiliation(s)
- Anne E Winters
- School of Biological Sciences, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Nerida G Wilson
- Molecular Systematics Unit, Western Australian Museum, 49 Kew St, Welshpool, Western Australia 6106, Australia
- School of Biological Sciences, University of Western Australia, Crawley, Western Australia 6009, Australia
| | - Cedric P van den Berg
- School of Biological Sciences, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Martin J How
- School of Biological Sciences, University of Bristol, Bristol BS8 1TQ, UK
| | - John A Endler
- Centre for Integrative Ecology, School of Life and Environmental Science, Deakin University, Geelong, Victoria 3216, Australia
| | - N Justin Marshall
- Queensland Brain Institute, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Andrew M White
- School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Mary J Garson
- School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Karen L Cheney
- School of Biological Sciences, The University of Queensland, Brisbane, Queensland 4072, Australia
- Queensland Brain Institute, The University of Queensland, Brisbane, Queensland 4072, Australia
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27
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Rönkä K, Mappes J, Michalis C, Kiviö R, Salokannas J, Rojas B. Can multiple-model mimicry explain warning signal polymorphism in the wood tiger moth, Arctia plantaginis (Lepidoptera: Erebidae)? Biol J Linn Soc Lond 2018. [DOI: 10.1093/biolinnean/bly042] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Affiliation(s)
- K Rönkä
- Centre of Excellence in Biological Interactions, Department of Biological and Environmental Science, University of Jyväskylä, FI, Finland
| | - J Mappes
- Centre of Excellence in Biological Interactions, Department of Biological and Environmental Science, University of Jyväskylä, FI, Finland
| | - C Michalis
- School of Biological Sciences, University of Bristol, Bristol, UK
| | - R Kiviö
- Centre of Excellence in Biological Interactions, Department of Biological and Environmental Science, University of Jyväskylä, FI, Finland
| | - J Salokannas
- Centre of Excellence in Biological Interactions, Department of Biological and Environmental Science, University of Jyväskylä, FI, Finland
| | - B Rojas
- Centre of Excellence in Biological Interactions, Department of Biological and Environmental Science, University of Jyväskylä, FI, Finland
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28
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Aluthwattha ST, Harrison RD, Ranawana KB, Xu C, Lai R, Chen J. Does spatial variation in predation pressure modulate selection for aposematism? Ecol Evol 2017; 7:7560-7572. [PMID: 28944039 PMCID: PMC5606884 DOI: 10.1002/ece3.3221] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2017] [Revised: 05/25/2017] [Accepted: 05/30/2017] [Indexed: 11/16/2022] Open
Abstract
It is widely believed that aposematic signals should be conspicuous, but in nature, they vary from highly conspicuous to near cryptic. Current theory, including the honest signal or trade‐off hypotheses of the toxicity–conspicuousness relationship, cannot explain why adequately toxic species vary substantially in their conspicuousness. Through a study of similarly toxic Danainae (Nymphalidae) butterflies and their mimics that vary remarkably in their conspicuousness, we show that the benefits of conspicuousness vary along a gradient of predation pressure. Highly conspicuous butterflies experienced lower avian attack rates when background predation pressure was low, but attack rates increased rapidly as background predation pressure increased. Conversely, the least conspicuous butterflies experienced higher attack rates at low predation pressures, but at high predation pressures, they appeared to benefit from crypsis. Attack rates of intermediately conspicuous butterflies remained moderate and constant along the predation pressure gradient. Mimics had a similar pattern but higher attack rates than their models and mimics tended to imitate the signal of less attacked model species along the predation pressure gradient. Predation pressure modulated signal fitness provides a possible mechanism for the maintenance of variation in conspicuousness of aposematic signals, as well as the initial survival of conspicuous signals in cryptic populations in the process of aposematic signal evolution, and an alternative explanation for the evolutionary gain and loss of mimicry.
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Affiliation(s)
- S Tharanga Aluthwattha
- Key Laboratory of Tropical Forest Ecology Xishuangbanna Tropical Botanical Garden Chinese Academy of Sciences Mengla Yunnan China.,University of Chinese Academy of Sciences Beijing China
| | - Rhett D Harrison
- World Agroforestry Centre, East & Southern Africa Region Woodlands, Lusaka Zambia
| | | | - Cheng Xu
- Kunming Institute of Zoology Chinese Academy of Sciences Kunming Yunnan China
| | - Ren Lai
- Kunming Institute of Zoology Chinese Academy of Sciences Kunming Yunnan China
| | - Jin Chen
- Key Laboratory of Tropical Forest Ecology Xishuangbanna Tropical Botanical Garden Chinese Academy of Sciences Mengla Yunnan China
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29
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Aubier TG, Joron M, Sherratt TN. Mimicry among Unequally Defended Prey Should Be Mutualistic When Predators Sample Optimally. Am Nat 2017; 189:267-282. [DOI: 10.1086/690121] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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30
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Pekár S, Petráková L, Bulbert MW, Whiting MJ, Herberstein ME. The golden mimicry complex uses a wide spectrum of defence to deter a community of predators. eLife 2017; 6. [PMID: 28170317 PMCID: PMC5295815 DOI: 10.7554/elife.22089] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2016] [Accepted: 12/24/2016] [Indexed: 11/13/2022] Open
Abstract
Mimicry complexes typically consist of multiple species that deter predators using similar anti-predatory signals. Mimics in these complexes are assumed to vary in their level of defence from highly defended through to moderately defended, or not defended at all. Here, we report a new multi-order mimicry complex that includes at least 140 different putative mimics from four arthropod orders including ants, wasps, bugs, tree hoppers and spiders. All members of this mimicry complex are characterised by a conspicuous golden body and an ant Gestalt, but vary substantially in their defensive traits. However, they were similarly effective at deterring predators - even mildly defended mimics were rarely eaten by a community of invertebrate and vertebrate predators both in the wild and during staged trials. We propose that despite the predominance of less defended mimics the three predatory guilds avoid the mimics because of the additive influence of the various defensive traits. DOI:http://dx.doi.org/10.7554/eLife.22089.001 Many animals use bright colours to warn a potential predator that they can defend themselves. Wasps, for instance, are armed with a harmful sting and advertise this fact via their distinctive yellow and black stripes. Predators often learn to heed such warnings and avoid these unpalatable animals in future. As a result, animals that mimic another animal’s warning signals can reap the benefit of being left alone by predators even if they are otherwise undefended. Textbooks on evolution are typically full of different examples of mimicry. However, the specifics of these examples are often poorly understood. Ninety years ago a famous Australian entomologist, Alexander Nicholson, suggested the existence of large groups of mimics in the Australian wildlife. More of these so-called “mimetic complexes” have recently been recognized among several species of insect, but not previously in ants. Now, Pekár et al. have looked at all known ants and ant-like mimics in Australia and discovered over 140 species that use gold and black colours as a warning signal. Most of the species were ants, but the collection of mimics also includes wasps, spiders, true bugs and insects called treehoppers. Some of the mimics were less palatable than others, and they possessed a range of defences, including spines and foul-tasting chemicals. Pekár et al. then looked in the guts of 12 species of predators in the wild, and found that very few of them ate the mimics. When mimics were offered to three different predators (specifically a lizard and two species of spider), most avoided the mimics regardless of whether they were palatable or unpalatable. Instead, the predators preferred to eat a spider that was not a member of the group of mimics because it lacked the gold colouration. Further studies are now needed to continue to document the details of this and other mimetic complexes. For example, this includes revealing how the different defences protect the members of the complex from predators do not use vision to recognize their prey and so cannot see the warning colouration. All this is needed to understand evolutionary processes that have fascinated biologists for decades, and explain how such large mimetic complexes evolved and persisted in spite of the influence of the community of predators. DOI:http://dx.doi.org/10.7554/eLife.22089.002
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Affiliation(s)
- Stano Pekár
- Department of Botany and Zoology, Masaryk University, Brno, Czech Republic
| | - Lenka Petráková
- Department of Botany and Zoology, Masaryk University, Brno, Czech Republic
| | - Matthew W Bulbert
- Department of Biological Sciences, Macquarie University, North Ryde, Australia
| | - Martin J Whiting
- Department of Biological Sciences, Macquarie University, North Ryde, Australia
| | - Marie E Herberstein
- Department of Biological Sciences, Macquarie University, North Ryde, Australia
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Halpin CG, Skelhorn J, Rowe C, Ruxton GD, Higginson AD. The Impact of Detoxification Costs and Predation Risk on Foraging: Implications for Mimicry Dynamics. PLoS One 2017; 12:e0169043. [PMID: 28045959 PMCID: PMC5207405 DOI: 10.1371/journal.pone.0169043] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2016] [Accepted: 12/09/2016] [Indexed: 12/02/2022] Open
Abstract
Prey often evolve defences to deter predators, such as noxious chemicals including toxins. Toxic species often advertise their defence to potential predators by distinctive sensory signals. Predators learn to associate toxicity with the signals of these so-called aposematic prey, and may avoid them in future. In turn, this selects for mildly toxic prey to mimic the appearance of more toxic prey. Empirical evidence shows that mimicry could be either beneficial (‘Mullerian’) or detrimental (‘quasi-Batesian’) to the highly toxic prey, but the factors determining which are unknown. Here, we use state-dependent models to explore how tri-trophic interactions could influence the evolution of prey defences. We consider how predation risk affects predators’ optimal foraging strategies on aposematic prey, and explore the resultant impact this has on mimicry dynamics between unequally defended species. In addition, we also investigate how the potential energetic cost of metabolising a toxin can alter the benefits to eating toxic prey and thus impact on predators’ foraging decisions. Our model predicts that both how predators perceive their own predation risk, and the cost of detoxification, can have significant, sometimes counterintuitive, effects on the foraging decisions of predators. For example, in some conditions predators should: (i) avoid prey they know to be undefended, (ii) eat more mildly toxic prey as detoxification costs increase, (iii) increase their intake of highly toxic prey as the abundance of undefended prey increases. These effects mean that the relationship between a mimic and its model can qualitatively depend on the density of alternative prey and the cost of metabolising toxins. In addition, these effects are mediated by the predators’ own predation risk, which demonstrates that, higher trophic levels than previously considered can have fundamental impacts on interactions among aposematic prey species.
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Affiliation(s)
- Christina G. Halpin
- Centre for Behaviour and Evolution, Institute of Neuroscience, Newcastle University, Newcastle upon Tyne, United Kingdom
- * E-mail:
| | - John Skelhorn
- Centre for Behaviour and Evolution, Institute of Neuroscience, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - Candy Rowe
- Centre for Behaviour and Evolution, Institute of Neuroscience, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - Graeme D. Ruxton
- School of Biology, University of St. Andrews, St Andrews, United Kingdom
| | - Andrew D. Higginson
- Centre for Research in Animal Behaviour, College of Life and Environmental Sciences, University of Exeter, Exeter, United Kingdom
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Caro T. Wallace on Coloration: Contemporary Perspective and Unresolved Insights. Trends Ecol Evol 2017; 32:23-30. [DOI: 10.1016/j.tree.2016.10.003] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2016] [Revised: 09/30/2016] [Accepted: 10/03/2016] [Indexed: 10/20/2022]
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Barnett CA, Bateson M, Rowe C. Better the devil you know: avian predators find variation in prey toxicity aversive. Biol Lett 2015; 10:20140533. [PMID: 25392317 DOI: 10.1098/rsbl.2014.0533] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Toxic prey that signal their defences to predators using conspicuous warning signals are called 'aposematic'. Predators learn about the toxic content of aposematic prey and reduce their attacks on them. However, through regulating their toxin intake, predators will include aposematic prey in their diets when the benefits of gaining the nutrients they contain outweigh the costs of ingesting the prey's toxins. Predators face a problem when managing their toxin intake: prey sharing the same warning signal often vary in their toxicities. Given that predators should avoid uncertainty when managing their toxin intake, we tested whether European starlings (Sturnus vulgaris) preferred to eat fixed-defence prey (where all prey contained a 2% quinine solution) to mixed-defence prey (where half the prey contained a 4% quinine solution and the other half contained only water). Our results support the idea that predators should be more 'risk-averse' when foraging on variably defended prey and suggest that variation in toxicity levels could be a form of defence.
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Affiliation(s)
- Craig A Barnett
- Centre for Behaviour and Evolution, Institute of Neuroscience, Newcastle University, Newcastle upon Tyne NE2 4HH, UK
| | - Melissa Bateson
- Centre for Behaviour and Evolution, Institute of Neuroscience, Newcastle University, Newcastle upon Tyne NE2 4HH, UK
| | - Candy Rowe
- Centre for Behaviour and Evolution, Institute of Neuroscience, Newcastle University, Newcastle upon Tyne NE2 4HH, UK
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36
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Mokkonen M, Lindstedt C. The evolutionary ecology of deception. Biol Rev Camb Philos Soc 2015; 91:1020-1035. [PMID: 26118820 DOI: 10.1111/brv.12208] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2014] [Revised: 05/29/2015] [Accepted: 06/05/2015] [Indexed: 12/15/2022]
Abstract
Through dishonest signals or actions, individuals often misinform others to their own benefit. We review recent literature to explore the evolutionary and ecological conditions for deception to be more likely to evolve and be maintained. We identify four conditions: (1) high misinformation potential through perceptual constraints of perceiver; (2) costs and benefits of responding to deception; (3) asymmetric power relationships between individuals and (4) exploitation of common goods. We discuss behavioural and physiological mechanisms that form a deception continuum from secrecy to overt signals. Deceptive tactics usually succeed by being rare and are often evolving under co-evolutionary arms races, sometimes leading to the evolution of polymorphism. The degree of deception can also vary depending on the environmental conditions. Finally, we suggest a conceptual framework for studying deception and highlight important questions for future studies.
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Affiliation(s)
- Mikael Mokkonen
- Department of Biological and Environmental Science, University of Jyväskylä, PO Box 35, Jyväskylä 40014, Finland. .,Department of Biological Sciences, Simon Fraser University, 8888 University Drive, Burnaby, BC V5A 1S6, Canada.
| | - Carita Lindstedt
- Department of Biological and Environmental Science, Centre of Excellence in Biological Interactions, University of Jyväskylä, PO Box 35, Jyväskylä 40014, Finland
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Lehmann KDS, Goldman BW, Dworkin I, Bryson DM, Wagner AP. From cues to signals: evolution of interspecific communication via aposematism and mimicry in a predator-prey system. PLoS One 2014; 9:e91783. [PMID: 24614755 PMCID: PMC3948874 DOI: 10.1371/journal.pone.0091783] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2013] [Accepted: 02/14/2014] [Indexed: 11/19/2022] Open
Abstract
Current theory suggests that many signaling systems evolved from preexisting cues. In aposematic systems, prey warning signals benefit both predator and prey. When the signal is highly beneficial, a third species often evolves to mimic the toxic species, exploiting the signaling system for its own protection. We investigated the evolutionary dynamics of predator cue utilization and prey signaling in a digital predator-prey system in which prey could evolve to alter their appearance to mimic poison-free or poisonous prey. In predators, we observed rapid evolution of cue recognition (i.e. active behavioral responses) when presented with sufficiently poisonous prey. In addition, active signaling (i.e. mimicry) evolved in prey under all conditions that led to cue utilization. Thus we show that despite imperfect and dishonest signaling, given a high cost of consuming poisonous prey, complex systems of interspecific communication can evolve via predator cue recognition and prey signal manipulation. This provides evidence supporting hypotheses that cues may serve as stepping-stones in the evolution of more advanced communication and signaling systems that incorporate information about the environment.
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Affiliation(s)
- Kenna D. S. Lehmann
- Department of Zoology, Michigan State University, East Lansing, Michigan, United States of America
- BEACON Center for the Study of Evolution in Action, Michigan State University, East Lansing, Michigan, United States of America
- Program in Ecology, Evolutionary Biology, and Behavior, Michigan State University, East Lansing, Michigan, United States of America
| | - Brian W. Goldman
- Department of Computer Science and Engineering, Michigan State University, East Lansing, Michigan, United States of America
- BEACON Center for the Study of Evolution in Action, Michigan State University, East Lansing, Michigan, United States of America
| | - Ian Dworkin
- Department of Zoology, Michigan State University, East Lansing, Michigan, United States of America
- BEACON Center for the Study of Evolution in Action, Michigan State University, East Lansing, Michigan, United States of America
- Program in Ecology, Evolutionary Biology, and Behavior, Michigan State University, East Lansing, Michigan, United States of America
| | - David M. Bryson
- BEACON Center for the Study of Evolution in Action, Michigan State University, East Lansing, Michigan, United States of America
| | - Aaron P. Wagner
- BEACON Center for the Study of Evolution in Action, Michigan State University, East Lansing, Michigan, United States of America
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Abstract
Avian predators readily learn to associate the warning coloration of aposematic prey with the toxic effects of ingesting them, but they do not necessarily exclude aposematic prey from their diets. By eating aposematic prey ‘educated’ predators are thought to be trading-off the benefits of gaining nutrients with the costs of eating toxins. However, while we know that the toxin content of aposematic prey affects the foraging decisions made by avian predators, the extent to which the nutritional content of toxic prey affects predators' decisions to eat them remains to be tested. Here, we show that European starlings (Sturnus vulgaris) increase their intake of a toxic prey type when the nutritional content is artificially increased, and decrease their intake when nutritional enrichment is ceased. This clearly demonstrates that birds can detect the nutritional content of toxic prey by post-ingestive feedback, and use this information in their foraging decisions, raising new perspectives on the evolution of prey defences. Nutritional differences between individuals could result in equally toxic prey being unequally predated, and might explain why some species undergo ontogenetic shifts in defence strategies. Furthermore, the nutritional value of prey will likely have a significant impact on the evolutionary dynamics of mimicry systems.
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Affiliation(s)
- Christina G Halpin
- Centre for Behaviour and Evolution, Newcastle University, Newcastle upon Tyne, Tyne and Wear, UK
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Importance of conspicuous colours in warning signals: the great tit’s (Parus major) point of view. Evol Ecol 2014. [DOI: 10.1007/s10682-014-9690-2] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Hotová Svádová K, Exnerová A, Kopečková M, Štys P. How Do Predators Learn to Recognize a Mimetic Complex: Experiments with Naive Great Tits and Aposematic Heteroptera. Ethology 2013. [DOI: 10.1111/eth.12121] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Affiliation(s)
- Kateřina Hotová Svádová
- Department of Zoology; Faculty of Science; Charles University in Prague; Prague; Czech Republic
| | - Alice Exnerová
- Department of Zoology; Faculty of Science; Charles University in Prague; Prague; Czech Republic
| | - Michala Kopečková
- Department of Zoology; Faculty of Science; Charles University in Prague; Prague; Czech Republic
| | - Pavel Štys
- Department of Zoology; Faculty of Science; Charles University in Prague; Prague; Czech Republic
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Predators' decisions to eat defended prey depend on the size of undefended prey. Anim Behav 2013; 85:1315-1321. [PMID: 23814280 PMCID: PMC3693033 DOI: 10.1016/j.anbehav.2013.03.021] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2012] [Revised: 11/29/2012] [Accepted: 03/05/2013] [Indexed: 11/22/2022]
Abstract
Predators that have learned to associate warning coloration with toxicity often continue to include aposematic prey in their diet in order to gain the nutrients and energy that they contain. As body size is widely reported to correlate with energetic content, we predicted that prey size would affect predators' decisions to eat aposematic prey. We used a well-established system of wild-caught European starlings, Sturnus vulgaris, foraging on mealworms, Tenebrio molitor, to test how the size of undefended (water-injected) and defended (quinine-injected) prey, on different coloured backgrounds, affected birds' decisions to eat defended prey. We found that birds ate fewer defended prey, and less quinine, when undefended prey were large compared with when they were small, but that the size of the defended prey had no effect on the numbers eaten. Consequently, we found no evidence that the mass of the defended prey or the overall mass of prey ingested affected the amount of toxin that a predator was willing to ingest, and instead the mass of undefended prey eaten was more important. This is a surprising finding, challenging the assumptions of state-dependent models of aposematism and mimicry, and highlighting the need to understand better the mechanisms of predator decision making. In addition, the birds did not learn to discriminate visually between defended and undefended prey based on size, but only on the basis of colour. This suggests that colour signals may be more salient to predators than size differences, allowing Batesian mimics to benefit from aposematic models even when they differ in size.
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Abstract
Many predators quickly learn to avoid attacking aposematic prey. If the prey vary in toxicity, the predators may alternatively learn to capture and taste-sample prey carefully before ingesting or rejecting them (go-slow behaviour). An increase in prey toxicity is generally thought to decrease predation on prey populations. However, while prey with a higher toxin load are more harmful to ingest, they may also be easier to recognize and reject owing to greater distastefulness, which can facilitate a taste-sampling foraging strategy. Here, the classic diet model is used to study the separate effects of taste and toxicity on predator preferences. The taste-sampling process is modelled using signal detection theory. The model is applicable to automimicry and batesian mimicry. It shows that when the defensive toxin is sufficiently distasteful, a mimicry complex may be less profitable to the predator and better protected against predation if the models are moderately toxic than if they are highly toxic. Moreover, taste mimicry can reduce the profitability of the mimicry complex and increase protection against predation. The results are discussed in relation to the selection pressures acting on prey defences and the evolution of mimicry.
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Affiliation(s)
- Øistein Haugsten Holen
- Centre for Ecological and Evolutionary Synthesis (CEES), Department of Biology, University of Oslo, PO Box 1066 Blindern, 0316 Oslo, Norway.
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45
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Halpin CG, Skelhorn J, Rowe C. The relationship between sympatric defended species depends upon predators' discriminatory behaviour. PLoS One 2012; 7:e44895. [PMID: 22970323 PMCID: PMC3438165 DOI: 10.1371/journal.pone.0044895] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2012] [Accepted: 08/15/2012] [Indexed: 11/18/2022] Open
Abstract
Toxic prey species living in the same environment have long been thought to mutually benefit from having the same warning signal by sharing the education of naïve predators. In contrast, ‘saturation theory’ predicts that predators are physiologically limited by the amount of toxin that they can eat in a given time period. Therefore, sympatric species that contain the same toxin should mutually benefit from reduced predation even when they are visually distinct, reducing the benefits to visual mimicry. For the first time, we found that mutualism can occur between unequally defended prey that are visually distinct, although the benefits to each prey type depends on the predators' abilities and/or motivation to visually discriminate between them. Furthermore, we found that this variability in predatory behaviour had a significant impact on the benefits of mimicry for unequally defended prey. Our results demonstrate that variability in the foraging decisions of predators can have a significant effect on the benefits of shared toxicity and visual mimicry between sympatric species, and highlights the need to consider how predators exert selection pressures on models and mimics over their entire lifetimes.
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Affiliation(s)
- Christina G Halpin
- Centre for Behaviour and Evolution, Newcastle University, Newcastle upon Tyne, United Kingdom.
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46
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Abstract
Mimicry is an example of an adaptation that requires the integration of several components. Genetic characterisation of a mimicry polymorphism in a butterfly reveals the expected suppression of recombination among its components, preventing the production of unfit character combinations.
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Affiliation(s)
- Deborah Charlesworth
- Institute of Evolutionary Biology, School of Biological Sciences, The University of Edinburgh, Edinburgh EH9 3JT, UK.
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