1
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Whitcher C, Beaver L, Lemmon EM. The effect of biofluorescence on predation upon Cope's gray treefrog: A clay model experiment. Behav Processes 2024; 215:104996. [PMID: 38278426 DOI: 10.1016/j.beproc.2024.104996] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2023] [Revised: 01/14/2024] [Accepted: 01/22/2024] [Indexed: 01/28/2024]
Abstract
Biofluorescence, the ability to absorb light and reemit it at a longer wavelength, is present in many taxa but has been examined only recently in amphibians. Over half of the studies documenting biofluorescence in the last century suggest this fluorescent signal may affect predation; however, to date, only one other experimental study has tested this hypothesis. To address this question, we experimentally tested the effect of biofluorescence on predation through the study of the Cope's Gray Treefrog, Hyla chrysoscelis. First, we quantified the spectral characteristics of a novel biofluorescence pattern in H. chrysoscelis. In both sexes of this species, the fluorescent signal is concentrated in an area that contains a proposed aposematic pattern to warn predators of the frog's toxic secretions. We hypothesized that the biofluorescent trait may increase the conspicuousness of this pattern and enable the frogs to deter predators more effectively. Second, we tested this prediction by conducting a clay model field experiment to assess differences in predation attempts on fluorescent versus non-fluorescent H. chrysoscelis models by various predator types. We found no effect of biofluorescence on the overall presence, type, or location of predation, suggesting that biofluorescence alone does not act as an antipredator signal of H. chrysoscelis. This study represents one of the first attempts to experimentally test the effect of biofluorescence on predation in any organism and the first to do so in amphibians. Further work is needed to explore the role of this trait in predation in other systems and to investigate alternative functions for the biofluorescent signal in H. chrysoscelis.
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Affiliation(s)
- Courtney Whitcher
- Department of Biological Science, Florida State University, 319 Stadium Drive, Tallahassee, FL 32306, USA.
| | - Lilyanne Beaver
- Department of Neurobiology, Duke University, 3209 Duke Univserity School of Medicine, Durham, NC 27710, USA
| | - Emily Moriarty Lemmon
- Department of Biological Science, Florida State University, 319 Stadium Drive, Tallahassee, FL 32306, USA
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2
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Experimental evidence in a poison frog model suggests that tadpole transport on the dorsum may affects warning signal effectiveness in poison frogs. Evol Ecol 2022. [DOI: 10.1007/s10682-022-10219-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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3
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da Rocha SM, Magnusson WE, Rojas D, Lima AP. Colour, location and movement: what do models tell us about predation on colour morphs of a poison frog from eastern Amazonia? BEHAVIOUR 2022. [DOI: 10.1163/1568539x-bja10168] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Abstract
Many dendrobatid frogs are known to be aposematic: brightly coloured and unpalatable to predators. To deceive predators, frog models used to test for predatory colour bias must be similar in size, colour, shape, and movement to frogs. We carried out an experiment with moving models of the species Adelphobates galactonotus, in two localities. A. galactonotus is a polytypic frog and each population of the species has a distinct colour. Birds and mammals were the vertebrates responsible for the marks on the models, but there was no difference in frequency of attacks on local-, non-local- and cryptic-colour models. Only invertebrates avoided cryptic models. Different populations of the species seem to be under different predation pressure, but colour differentiation in this species is probably related to other mechanisms, such as sexual selection.
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Affiliation(s)
- Sulamita M.C. da Rocha
- Instituto Nacional de Pesquisas da Amazônia, Programa de Pós-Graduação em Ecologia, Av. André, Araújo 2936, 69011-970 Manaus, AM, Brazil
| | - William E. Magnusson
- Instituto Nacional de Pesquisas da Amazônia, Programa de Pós-Graduação em Ecologia, Av. André, Araújo 2936, 69011-970 Manaus, AM, Brazil
- Instituto Nacional de Pesquisas da Amazônia, Coordenação de Pesquisas em Biodiversidade, Av. André Araújo, 2936, 69011-970, Manaus, AM, Brazil
| | - Diana Rojas
- Ecopescado, P.O. Box 37, 69640-000 Tabatinga, AM, Brazil
| | - Albertina P. Lima
- Instituto Nacional de Pesquisas da Amazônia, Programa de Pós-Graduação em Ecologia, Av. André, Araújo 2936, 69011-970 Manaus, AM, Brazil
- Instituto Nacional de Pesquisas da Amazônia, Coordenação de Pesquisas em Biodiversidade, Av. André Araújo, 2936, 69011-970, Manaus, AM, Brazil
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4
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Yeager J, Barnett JB. Continuous Variation in an Aposematic Pattern Affects Background Contrast, but Is Not Associated With Differences in Microhabitat Use. Front Ecol Evol 2022. [DOI: 10.3389/fevo.2022.803996] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Variation in aposematic signals was once predicted to be rare, yet in recent years it has become increasingly well documented. Despite increases in the frequency with which polytypism and polymorphism have been suggested to occur, population-wide variance is rarely quantified. We comprehensively sampled a subpopulation of the poison frog Oophaga sylvatica, a species which is polytypic across its distribution and also shows considerable within-population polymorphism. On one hand, color pattern polymorphism could be the result of multifarious selection acting to balance different signaling functions and leading to the evolution of discrete sub-morphs which occupy different fitness peaks. Alternatively, variance could simply be due to relaxed selection, where variation would be predicted to be continuous. We used visual modeling of conspecific and heterospecific observers to quantify the extent of within population phenotypic variation and assess whether this variation produced distinct signals. We found that, despite considerable color pattern variation, variance could not be partitioned into distinct groups, but rather all viewers would be likely to perceive variation as continuous. Similarly, we found no evidence that frog color pattern contrast was either enhanced or diminished in the frogs’ chosen microhabitats compared to alternative patches in which conspecifics were observed. Within population phenotypic variance therefore does not seem to be indicative of strong selection toward multiple signaling strategies, but rather pattern divergence has likely arisen due to weak purifying selection, or neutral processes, on a signal that is highly salient to both conspecifics and predators.
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5
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Predation risk is a function of seasonality rather than habitat complexity in a tropical semiarid forest. Sci Rep 2021; 11:16670. [PMID: 34404872 PMCID: PMC8371019 DOI: 10.1038/s41598-021-96216-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2021] [Accepted: 08/06/2021] [Indexed: 11/08/2022] Open
Abstract
Predator-prey dynamics are some of the most important species' interactions in the natural structuring of communities, and are among the more complex ecological processes studied by ecologists. We measured predation risk using artificial lizard replicas to test two competing hypotheses regarding predation pressure in semi-arid environments: (1) predation risk is dependent on the habitat structural complexity; and (2) predation risk is dependent on seasonality. We placed 960 lizard replicas along three sites with different physical structures and in both dry and rainy seasons for seven consecutive days in a caatinga area in northeastern Brazil at Grota do Angico Natural Monument (GANM). Birds were responsible for the majority of attacks and more frequently on artificial lizards placed in trees. Attacks focused on the most vulnerable areas of the body (head and torso), proving that were perceived by predators as true prey items. We found that predation risk is not dependent on the habitat structural complexity, but rather dependent on the caatinga seasonality, with the overall attack rate being 19% higher in the dry season. Our study suggests that potential predation risk is highly context-dependent and that seasonality consistently drives of trophic interactions strength in the caatinga, an important ecological finding that could contribute to better understanding the complex evolution of predator-prey interactions within communities of animals living in different habitats.
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6
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Barnett JB, Varela BJ, Jennings BJ, Lesbarrères D, Pruitt JN, Green DM. Habitat disturbance alters color contrast and the detectability of cryptic and aposematic frogs. Behav Ecol 2021. [DOI: 10.1093/beheco/arab032] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Abstract
Animals use color both to conceal and signal their presence, with patterns that match the background, disrupt shape recognition, or highlight features important for communication. The forms that these color patterns take are responses to the visual systems that observe them and the environments within which they are viewed. Increasingly, however, these environments are being affected by human activity. We studied how pattern characteristics and habitat change may affect the detectability of three frog color patterns from the Bocas del Toro archipelago in Panama: Beige-Striped Brown Allobates talamancae and two spotted morphs of Oophaga pumilio, Black-Spotted Green and Black-Spotted Red. To assess detectability, we used visual modeling of conspecifics and potential predators, along with a computer-based detection experiment with human participants. Although we found no evidence for disruptive camouflage, we did find clear evidence that A. talamancae stripes are inherently more cryptic than O. pumilio spots regardless of color. We found no evidence that color pattern polytypism in O. pumilio is related to differences in the forest floor between natural sites. We did, however, find strong evidence that human disturbance affects the visual environment and modifies absolute and rank order frog detectability. Human-induced environmental change reduces the effectiveness of camouflage in A. talamancae, reduces detectability of Black-Spotted Green O. pumilio, and increases chromatic contrast, but not detectability, in Black-Spotted Red O. pumilio. Insofar as predators may learn about prey defenses and make foraging decisions based on relative prey availability and suitability, such changes may have wider implications for predator–prey dynamics.
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Affiliation(s)
- James B Barnett
- Department of Psychology, Neuroscience and Behaviour, McMaster University, Hamilton, ON, Canada
- Redpath Museum, McGill University, Montreal, QC, Canada
| | | | - Ben J Jennings
- The College of Health, Medicine and Life Sciences, Brunel University London, Kingston Lane, Uxbridge, UK
| | | | - Jonathan N Pruitt
- Department of Psychology, Neuroscience and Behaviour, McMaster University, Hamilton, ON, Canada
| | - David M Green
- Redpath Museum, McGill University, Montreal, QC, Canada
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7
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Rößler DC, Lötters S, Veith M, Fugmann M, Peters C, Künzel S, Krehenwinkel H. An amplicon sequencing protocol for attacker identification from DNA traces left on artificial prey. Methods Ecol Evol 2020. [DOI: 10.1111/2041-210x.13459] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Daniela C. Rößler
- FAS Center for Systems Biology Harvard University Cambridge MA USA
- Department of Biogeography Trier University Trier Germany
| | - Stefan Lötters
- Department of Biogeography Trier University Trier Germany
| | - Michael Veith
- Department of Biogeography Trier University Trier Germany
| | | | | | - Sven Künzel
- Max Planck Institute for Evolutionary Biology Plön Germany
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8
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Geographically separated orange and blue populations of the Amazonian poison frog Adelphobates galactonotus (Anura, Dendrobatidae) do not differ in alkaloid composition or palatability. CHEMOECOLOGY 2019. [DOI: 10.1007/s00049-019-00291-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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9
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Dallagnol Vargas N, Guimarães M, Caorsi V, Wolff Bordignon D, Borges‐Martins M. An experimental assessment of the antipredatory function of green dorsal coloration in poisonous Neotropical red‐bellied toads. J Zool (1987) 2019. [DOI: 10.1111/jzo.12740] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Affiliation(s)
- Natália Dallagnol Vargas
- Programa de Pós‐graduação em Biologia Animal Departamento de Zoologia Instituto de Biociências Universidade Federal do Rio Grande do Sul Porto Alegre Rio Grande do Sul Brazil
| | - Murilo Guimarães
- Programa de Pós‐graduação em Biologia Animal Departamento de Zoologia Instituto de Biociências Universidade Federal do Rio Grande do Sul Porto Alegre Rio Grande do Sul Brazil
| | - Valentina Caorsi
- Programa de Pós‐graduação em Biologia Animal Departamento de Zoologia Instituto de Biociências Universidade Federal do Rio Grande do Sul Porto Alegre Rio Grande do Sul Brazil
- The Istituto Agrario di San Michele all’Adige Research and Innovation Centre Fondazione Edmund Mach San Michele all’Adige TN Italy
| | - Debora Wolff Bordignon
- Programa de Pós‐graduação em Biologia Animal Departamento de Zoologia Instituto de Biociências Universidade Federal do Rio Grande do Sul Porto Alegre Rio Grande do Sul Brazil
| | - Márcio Borges‐Martins
- Programa de Pós‐graduação em Biologia Animal Departamento de Zoologia Instituto de Biociências Universidade Federal do Rio Grande do Sul Porto Alegre Rio Grande do Sul Brazil
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10
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Rojas B, Pašukonis A. From habitat use to social behavior: natural history of a voiceless poison frog, Dendrobates tinctorius. PeerJ 2019; 7:e7648. [PMID: 31576237 PMCID: PMC6753930 DOI: 10.7717/peerj.7648] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2019] [Accepted: 08/09/2019] [Indexed: 01/01/2023] Open
Abstract
Descriptive studies of natural history have always been a source of knowledge on which experimental work and scientific progress rely. Poison frogs are a well-studied group of small Neotropical frogs with diverse parental behaviors, distinct calls, and bright colors that warn predators about their toxicity; and a showcase of advances in fundamental biology through natural history observations. The dyeing poison frog, Dendrobates tinctorius, is emblematic of the Guianas region, widespread in the pet trade, and increasingly popular in research. This species shows several unusual behaviors, such as the lack of advertisement calls and the aggregation around tree-fall gaps, which remain poorly described and understood. Here, we summarize our observations from a natural population of D. tinctorius in French Guiana collected over various field trips between 2009 and 2017; our aim is to provide groundwork for future fundamental and applied research spanning parental care, animal dispersal, disease spread, habitat use in relation to color patterns, and intra-specific communication, to name a few. We report sex differences in habitat use and the striking invasion of tree-fall gaps; describe their courtship and aggressive behaviors; document egg development and tadpole transport; and discuss how the knowledge generated by this study could set the grounds for further research on the behavior, ecology, and conservation of this species.
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Affiliation(s)
- Bibiana Rojas
- Department of Biological and Environmental Science, University of Jyväskylä, Jyväskylä, Finland
| | - Andrius Pašukonis
- Department of Biology, Stanford University, Stanford, CA, USA
- Department of Cognitive Biology, University of Vienna, Vienna, Austria
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11
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Briolat ES, Zagrobelny M, Olsen CE, Blount JD, Stevens M. No evidence of quantitative signal honesty across species of aposematic burnet moths (Lepidoptera: Zygaenidae). J Evol Biol 2018; 32:31-48. [PMID: 30317689 PMCID: PMC6378400 DOI: 10.1111/jeb.13389] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2018] [Revised: 10/03/2018] [Accepted: 10/09/2018] [Indexed: 11/30/2022]
Abstract
Many defended species use conspicuous visual warning signals to deter potential predators from attacking. Traditional theory holds that these signals should converge on similar forms, yet variation in visual traits and the levels of defensive chemicals is common, both within and between species. It is currently unclear how the strength of signals and potency of defences might be related: conflicting theories suggest that aposematic signals should be quantitatively honest, or, in contrast, that investment in one component should be prioritized over the other, while empirical tests have yielded contrasting results. Here, we advance this debate by examining the relationship between defensive chemicals and signal properties in a family of aposematic Lepidoptera, accounting for phylogenetic relationships and quantifying coloration from the perspective of relevant predators. We test for correlations between toxin levels and measures of wing colour across 14 species of day‐flying burnet and forester moths (Lepidoptera: Zygaenidae), protected by highly aversive cyanogenic glucosides, and find no clear evidence of quantitative signal honesty. Significant relationships between toxin levels and coloration vary between sexes and sampling years, and several trends run contrary to expectations for signal honesty. Although toxin concentration is positively correlated with increasing luminance contrast in forewing pattern in 1 year, higher toxin levels are also associated with paler and less chromatically salient markings, at least in females, in another year. Our study also serves to highlight important factors, including sex‐specific trends and seasonal variation, that should be accounted for in future work on signal honesty in aposematic species.
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Affiliation(s)
- Emmanuelle S Briolat
- Centre for Ecology & Conservation, College of Life & Environmental Sciences, University of Exeter, Penryn, UK
| | - Mika Zagrobelny
- Plant Biochemistry Laboratory and Copenhagen Plant Science Centre, Department of Plant and Environmental Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Carl E Olsen
- Plant Biochemistry Laboratory and Copenhagen Plant Science Centre, Department of Plant and Environmental Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Jonathan D Blount
- Centre for Ecology & Conservation, College of Life & Environmental Sciences, University of Exeter, Penryn, UK
| | - Martin Stevens
- Centre for Ecology & Conservation, College of Life & Environmental Sciences, University of Exeter, Penryn, UK
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12
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Green NF, Urquhart HH, van den Berg CP, Marshall NJ, Cheney KL. Pattern edges improve predator learning of aposematic signals. Behav Ecol 2018. [DOI: 10.1093/beheco/ary089] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Naomi F Green
- School of Biological Sciences, The University of Queensland, Brisbane, Queensland, Australia
| | - Holly H Urquhart
- School of Biological Sciences, The University of Queensland, Brisbane, Queensland, Australia
| | - Cedric P van den Berg
- School of Biological Sciences, The University of Queensland, Brisbane, Queensland, Australia
| | - N Justin Marshall
- Queensland Brain Institute, The University of Queensland, Brisbane, Queensland, Australia
| | - Karen L Cheney
- School of Biological Sciences, The University of Queensland, Brisbane, Queensland, Australia
- Queensland Brain Institute, The University of Queensland, Brisbane, Queensland, Australia
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13
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Rojas B, Burdfield-Steel E, De Pasqual C, Gordon S, Hernández L, Mappes J, Nokelainen O, Rönkä K, Lindstedt C. Multimodal Aposematic Signals and Their Emerging Role in Mate Attraction. Front Ecol Evol 2018. [DOI: 10.3389/fevo.2018.00093] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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14
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An Empirical Test Indicates Only Qualitatively Honest Aposematic Signaling Within a Population of Vertebrates. J HERPETOL 2018. [DOI: 10.1670/17-047] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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15
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Differential responses of avian and mammalian predators to phenotypic variation in Australian Brood Frogs. PLoS One 2018; 13:e0195446. [PMID: 29621321 PMCID: PMC5886526 DOI: 10.1371/journal.pone.0195446] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2017] [Accepted: 03/22/2018] [Indexed: 11/29/2022] Open
Abstract
Anti-predator signaling is highly variable with numerous examples of species employing cryptic coloration to avoid detection or conspicuous coloration (often coupled with a secondary defense) to ensure detection and recollection. While the ends of this spectrum are clear in their function, how species use intermediate signals is less clear. Australian Brood Frogs (Pseudophryne) display conspicuous coloration on both their dorsum and venter. Coupled with the alkaloid toxins these frogs possess, this coloration may be aposematic, providing a protective warning signal to predators. We assessed predation rates of known and novel color patterns and found no difference for avian or mammalian predators. However, when Pseudophryne dorsal phenotypes were collectively compared to the high-contrast ventral phenotype of this genus, we found birds, but not mammals, attacked dorsal phenotypes significantly less frequently than the ventral phenotype. This study, importantly, shows a differential predator response to ventral coloration in this genus which has implications for the evolution of conspicuous signaling in Pseudophryne.
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16
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Bordignon DW, Caorsi VZ, Colombo P, Abadie M, Brack IV, Dasoler BT, Borges-Martins M. Are the unken reflex and the aposematic colouration of Red-Bellied Toads efficient against bird predation? PLoS One 2018; 13:e0193551. [PMID: 29596437 PMCID: PMC5875753 DOI: 10.1371/journal.pone.0193551] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2017] [Accepted: 02/13/2018] [Indexed: 11/19/2022] Open
Abstract
Aposematic signals as well as body behaviours may be important anti-predator defences. Species of the genus Melanophryniscus are characterised by having toxic lipophilic alkaloids in the skin and for presenting a red ventral colouration, which can be observed when they perform the behaviour called the unken reflex. Both the reflex behaviour and the colouration pattern are described as defence mechanisms. However, there are currently no studies testing their effectiveness against predators. This study aimed to test experimentally if both ventral conspicuous colouration and the unken reflex in Melanophryniscus cambaraensis function as aposematic signals against visually oriented predators (birds). We simulated the species studied using three different clay toad models as follows: (a) in a normal position with green coloured bodies, (b) in the unken reflex position with green coloured body and extremities and (c) in the unken reflex position with a green body and red extremities. Models were distributed on a known M. cambaraensis breeding site and in the adjacent forest. More than half of the attacks on the models were from birds; however, there was no preference for any model type. Thus, just the presence of the red colour associated with the motionless unken reflex position does not seem to prevent attacks from potential predators. It is possible that the effective aposematic signal in Melanophryniscus is achieved through the unken reflex movement together with the subsequent exhibition of the warning colouration and the secretion of toxins.
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Affiliation(s)
- Debora Wolff Bordignon
- Programa de Pós-Graduação em Biologia Animal, Departamento de Zoologia, Instituto de Biociências, Universidade Federal do Rio Grande do Sul, Porto Alegre, Rio Grande do Sul, Brasil
- * E-mail:
| | - Valentina Zaffaroni Caorsi
- Programa de Pós-Graduação em Biologia Animal, Departamento de Zoologia, Instituto de Biociências, Universidade Federal do Rio Grande do Sul, Porto Alegre, Rio Grande do Sul, Brasil
| | - Patrick Colombo
- Museu de Ciências Naturais, Fundação Zoobotânica do Rio Grande do Sul, Porto Alegre, Rio Grande do Sul, Brasil
| | - Michelle Abadie
- Programa de Pós-Graduação em Ecologia, Instituto de Biociências, Universidade Federal do Rio Grande do Sul, Porto Alegre, Rio Grande do Sul, Brasil
| | - Ismael Verrastro Brack
- Programa de Pós-Graduação em Ecologia, Instituto de Biociências, Universidade Federal do Rio Grande do Sul, Porto Alegre, Rio Grande do Sul, Brasil
| | - Bibiana Terra Dasoler
- Programa de Pós-Graduação em Ecologia, Instituto de Biociências, Universidade Federal do Rio Grande do Sul, Porto Alegre, Rio Grande do Sul, Brasil
| | - Márcio Borges-Martins
- Programa de Pós-Graduação em Biologia Animal, Departamento de Zoologia, Instituto de Biociências, Universidade Federal do Rio Grande do Sul, Porto Alegre, Rio Grande do Sul, Brasil
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17
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Casas-Cardona S, Márquez R, Vargas-Salinas F. Different colour morphs of the poison frogAndinobates bombetes(Dendrobatidae) are similarly effective visual predator deterrents. Ethology 2018. [DOI: 10.1111/eth.12729] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Affiliation(s)
- Santiago Casas-Cardona
- Grupo de Evolución, Ecología y Conservación (EECO); Programa de Biología; Facultad de Ciencias Básicas y Tecnologías; Universidad del Quindío; Armenia Colombia
| | - Roberto Márquez
- Department of Ecology and Evolution; University of Chicago; Chicago IL USA
| | - Fernando Vargas-Salinas
- Grupo de Evolución, Ecología y Conservación (EECO); Programa de Biología; Facultad de Ciencias Básicas y Tecnologías; Universidad del Quindío; Armenia Colombia
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18
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The effects of background coloration and dark spots on the risk of predation in poison frog models. Evol Ecol 2017. [DOI: 10.1007/s10682-017-9903-6] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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19
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Arenas LM, Stevens M. Diversity in warning coloration is easily recognized by avian predators. J Evol Biol 2017; 30:1288-1302. [PMID: 28338250 PMCID: PMC5518184 DOI: 10.1111/jeb.13074] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2016] [Revised: 01/14/2017] [Accepted: 03/10/2017] [Indexed: 11/29/2022]
Abstract
Warning coloration is a widespread strategy to alert predators about prey unprofitability. The success of this strategy partly depends on predators being able to learn and recognize certain signals as indicators of toxicity, and theory predicts that this is easier if signals converge on similar colours. However, the diversity in warning signal form is astonishing, contradicting predictions. Here, we quantified ladybird signal diversity with respect to avian vision, measuring how unique and discernible each signal is from one another. In addition, we measured signal conspicuousness against a series of backgrounds, namely an average green, average brown, and where we collected each species, to determine whether signals are more contrasting against the ladybirds' local substrates than compared to average ones. This allowed us to establish whether there are local adaptations in conspicuousness that promote signal diversity. We found that while ladybird signals are unique and recognizable, specialist species are more contrasting against the background they are most commonly found on. However, overall our study suggests that warning signals have evolved to be effective against a wide range of natural backgrounds, partly explaining the success of this strategy in nature.
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Affiliation(s)
- L M Arenas
- Department of Zoology, University of Cambridge, Cambridge, UK.,Centre for Ecology & Conservation, College of Life & Environmental Sciences, University of Exeter, Penryn, Cornwall, UK
| | - M Stevens
- Centre for Ecology & Conservation, College of Life & Environmental Sciences, University of Exeter, Penryn, Cornwall, UK
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20
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Kindermann C, Hero JM. Rapid dynamic colour change is an intrasexual signal in a lek breeding frog (Litoria wilcoxii). Behav Ecol Sociobiol 2016. [DOI: 10.1007/s00265-016-2220-1] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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21
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Barnett JB, Scott-Samuel NE, Cuthill IC. Aposematism: balancing salience and camouflage. Biol Lett 2016; 12:20160335. [PMID: 27484645 PMCID: PMC5014027 DOI: 10.1098/rsbl.2016.0335] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2016] [Accepted: 07/08/2016] [Indexed: 11/12/2022] Open
Abstract
Aposematic signals are often characterized by high conspicuousness. Larger and brighter signals reinforce avoidance learning, distinguish defended from palatable prey and are more easily memorized by predators. Conspicuous signalling, however, has costs: encounter rates with naive, specialized or nutritionally stressed predators are likely to increase. It has been suggested that intermediate levels of aposematic conspicuousness can evolve to balance deterrence and detectability, especially for moderately defended species. The effectiveness of such signals, however, has not yet been experimentally tested under field conditions. We used dough caterpillar-like baits to test whether reduced levels of aposematic conspicuousness can have survival benefits when predated by wild birds in natural conditions. Our results suggest that, when controlling for the number and intensity of internal contrast boundaries (stripes), a reduced-conspicuousness aposematic pattern can have a survival advantage over more conspicuous signals, as well as cryptic colours. Furthermore, we find a survival benefit from the addition of internal contrast for both high and low levels of conspicuousness. This adds ecological validity to evolutionary models of aposematic saliency and the evolution of honest signalling.
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Affiliation(s)
- James B Barnett
- School of Biological Sciences, University of Bristol, Bristol Life Sciences Building, 24 Tyndall Avenue, Bristol BS8 1TQ, UK
| | - Nicholas E Scott-Samuel
- School of Experimental Psychology, University of Bristol, 12a Priory Road, Bristol BS8 1TU, UK
| | - Innes C Cuthill
- School of Biological Sciences, University of Bristol, Bristol Life Sciences Building, 24 Tyndall Avenue, Bristol BS8 1TQ, UK
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22
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Warning signal properties covary with toxicity but not testosterone or aggregate carotenoids in a poison frog. Evol Ecol 2016. [DOI: 10.1007/s10682-016-9830-y] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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23
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Rojas B. Behavioural, ecological, and evolutionary aspects of diversity in frog colour patterns. Biol Rev Camb Philos Soc 2016; 92:1059-1080. [DOI: 10.1111/brv.12269] [Citation(s) in RCA: 68] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2015] [Revised: 02/26/2016] [Accepted: 02/29/2016] [Indexed: 02/03/2023]
Affiliation(s)
- Bibiana Rojas
- Centre of Excellence in Biological Interactions, Department of Biology and Environmental Sciences; University of Jyvaskyla; PO Box 35 Jyväskylä FI 40001 Finland
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24
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Flores EE, Stevens M, Moore AJ, Rowland HM, Blount JD. Body size but not warning signal luminance influences predation risk in recently metamorphosed poison frogs. Ecol Evol 2015; 5:4603-16. [PMID: 26668726 PMCID: PMC4670055 DOI: 10.1002/ece3.1731] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2015] [Revised: 08/19/2015] [Accepted: 08/22/2015] [Indexed: 01/05/2023] Open
Abstract
During early development, many aposematic species have bright and conspicuous warning appearance, but have yet to acquire chemical defenses, a phenotypic state which presumably makes them vulnerable to predation. Body size and signal luminance in particular are known to be sensitive to variation in early nutrition. However, the relative importance of these traits as determinants of predation risk in juveniles is not known. To address this question, we utilized computer‐assisted design (CAD) and information on putative predator visual sensitivities to produce artificial models of postmetamorphic froglets that varied in terms of body size and signal luminance. We then deployed the artificial models in the field and measured rates of attack by birds and unknown predators. Our results indicate that body size was a significant predictor of artificial prey survival. Rates of attack by bird predators were significantly higher on smaller models. However, predation by birds did not differ between artificial models of varying signal luminance. This suggests that at the completion of metamorphosis, smaller froglets may be at a selective disadvantage, potentially because predators can discern they have relatively low levels of chemical defense compared to larger froglets. There is likely to be a premium on efficient foraging, giving rise to rapid growth and the acquisition of toxins from dietary sources in juvenile poison frogs.
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Affiliation(s)
- Eric E Flores
- Centre for Ecology and Conservation College of Life & Environmental Sciences University of Exeter Penryn UK ; Sistema Nacional de Investigacion de Panama (SNI) Panama
| | - Martin Stevens
- Centre for Ecology and Conservation College of Life & Environmental Sciences University of Exeter Penryn UK
| | - Allen J Moore
- Centre for Ecology and Conservation College of Life & Environmental Sciences University of Exeter Penryn UK ; Department of Genetics University of Georgia 30602 Athens Georgia
| | | | - Jonathan D Blount
- Centre for Ecology and Conservation College of Life & Environmental Sciences University of Exeter Penryn UK
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25
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Summers K, Speed MP, Blount JD, Stuckert AMM. Are aposematic signals honest? A review. J Evol Biol 2015; 28:1583-99. [DOI: 10.1111/jeb.12676] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2014] [Revised: 06/08/2015] [Accepted: 06/11/2015] [Indexed: 01/22/2023]
Affiliation(s)
- K. Summers
- Department of Biology; East Carolina University; Greenville NC USA
| | - M. P. Speed
- Department of Evolution, Ecology, and Behaviour; University of Liverpool; Liverpool UK
| | - J. D. Blount
- Centre for Ecology and Conservation, Biosciences; University of Exeter; Penryn UK
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26
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Dreher CE, Cummings ME, Pröhl H. An Analysis of Predator Selection to Affect Aposematic Coloration in a Poison Frog Species. PLoS One 2015; 10:e0130571. [PMID: 26110826 PMCID: PMC4481408 DOI: 10.1371/journal.pone.0130571] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2015] [Accepted: 05/22/2015] [Indexed: 11/19/2022] Open
Abstract
Natural selection is widely noted to drive divergence of phenotypic traits. Predation pressure can facilitate morphological divergence, for example the evolution of both cryptic and conspicuous coloration in animals. In this context Dendrobatid frogs have been used to study evolutionary forces inducing diversity in protective coloration. The polytypic strawberry poison frog (Oophaga pumilio) shows strong divergence in aposematic coloration among populations. To investigate whether predation pressure is important for color divergence among populations of O. pumilio we selected four mainland populations and two island populations from Costa Rica and Panama. Spectrometric measurements of body coloration were used to calculate color and brightness contrasts of frogs as an indicator of conspicuousness for the visual systems of several potential predators (avian, crab and snake) and a conspecific observer. Additionally, we conducted experiments using clay model frogs of different coloration to investigate whether the local coloration of frogs is better protected than non-local color morphs, and if predator communities vary among populations. Overall predation risk differed strongly among populations and interestingly was higher on the two island populations. Imprints on clay models indicated that birds are the main predators while attacks of other predators were rare. Furthermore, clay models of local coloration were equally likely to be attacked as those of non-local coloration. Overall conspicuousness (and brightness contrast) of local frogs was positively correlated with attack rates by birds across populations. Together with results from earlier studies we conclude that conspicuousness honestly indicates toxicity to avian predators. The different coloration patterns among populations of strawberry poison frogs in combination with behavior and toxicity might integrate into equally efficient anti-predator strategies depending on local predation and other ecological factors.
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Affiliation(s)
- Corinna E Dreher
- Institute of Zoology, University of Veterinary Medicine Hannover, Foundation, Hannover, Germany.
| | - Molly E Cummings
- Department of Integrative Biology, University of Texas, Austin, TX, United States of America
| | - Heike Pröhl
- Institute of Zoology, University of Veterinary Medicine Hannover, Foundation, Hannover, Germany
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27
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María Arenas L, Walter D, Stevens M. Signal honesty and predation risk among a closely related group of aposematic species. Sci Rep 2015; 5:11021. [PMID: 26046332 PMCID: PMC4457162 DOI: 10.1038/srep11021] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2014] [Accepted: 05/12/2015] [Indexed: 11/13/2022] Open
Abstract
Many animals have bright colours to warn predators that they have defences and are not worth attacking. However, it remains unclear whether the strength of warning colours reliably indicate levels of defence. Few studies have unambiguously established if warning signals are honest, and have rarely considered predator vision or conspicuousness against the background. Importantly, little data exists either on how differences in signal strength translate into survival advantages. Ladybirds exhibit impressive variation in coloration both among and within species. Here we demonstrate that different levels of toxicity exist among and within ladybird species, and that signal contrast against the background is a good predictor of toxicity, showing that the colours are honest signals. Furthermore, field experiments with ladybird models created with regards to predator vision show that models with lower conspicuousness were attacked more frequently. This provides one of the most comprehensive studies on signal honesty in warning coloration to date.
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Affiliation(s)
- Lina María Arenas
- 1] Department of Zoology, University of Cambridge, Downing Street, CB2 3EJ, UK [2] Centre for Ecology &Conservation, College of Life &Environmental Sciences, University of Exeter, Penryn Campus, Penryn, Cornwall, TR10 9FE, UK
| | - Dominic Walter
- Centre for Ecology &Conservation, College of Life &Environmental Sciences, University of Exeter, Penryn Campus, Penryn, Cornwall, TR10 9FE, UK
| | - Martin Stevens
- Centre for Ecology &Conservation, College of Life &Environmental Sciences, University of Exeter, Penryn Campus, Penryn, Cornwall, TR10 9FE, UK
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28
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Dugas MB, Halbrook SR, Killius AM, del Sol JF, Richards-Zawacki CL. Colour and Escape Behaviour in Polymorphic Populations of an Aposematic Poison Frog. Ethology 2015. [DOI: 10.1111/eth.12396] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Matthew B. Dugas
- Department of Ecology and Evolutionary Biology; Tulane University; New Orleans LA USA
| | - Susannah R. Halbrook
- Department of Ecology and Evolutionary Biology; Tulane University; New Orleans LA USA
| | - Allison M. Killius
- Department of Ecology and Evolutionary Biology; Tulane University; New Orleans LA USA
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29
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Paluh DJ, Kenison EK, Saporito RA. Frog or Fruit? The Importance of Color and Shape to Bird Predators in Clay Model Experiments. COPEIA 2015. [DOI: 10.1643/ce-13-126] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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30
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Rojas DP, Stow A, Amézquita A, Simões PI, Lima AP. No predatory bias with respect to colour familiarity for the aposematic Adelphobates galactonotus (Anura: Dendrobatidae). BEHAVIOUR 2015. [DOI: 10.1163/1568539x-00003297] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Aposematic colouration deters visually oriented predators because conspicuous signals are easier to detect and associate with unpalatability. Consequently, brightly coloured prey that are novel are predicted to be preyed on more than those with bright but typical colours. Here we evaluated whether predatory bias is associated with the colour differences observed at two different localities for a large, conspicuously coloured and poisonous Amazonian frog, Adelphobates galactonotus. At each locality predation experiments were carried out using frog models of two naturally occurring colours of the study species (blue and orange) and a control (brown). We found no evidence that novel colours were more vulnerable to predation than local colours. These results do not therefore support our hypothesis that predatory bias explains the geographic variation of colour in A. galactonotus.
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Affiliation(s)
- Diana Patricia Rojas
- aCoordenação de Biodiversidade, Instituto Nacional de Pesquisas da Amazônia, P.O. Box 2223, 69011-970 Manaus, AM, Brazil
| | - Adam Stow
- bDepartment of Biological Sciences, Macquarie University, Sydney, NSW, Australia
| | - Adolfo Amézquita
- cDepartment of Biological Sciences, Universidad de los Andes, Bogotá, Colombia
| | - Pedro Ivo Simões
- aCoordenação de Biodiversidade, Instituto Nacional de Pesquisas da Amazônia, P.O. Box 2223, 69011-970 Manaus, AM, Brazil
- dLaboratório de Sistemática de Vertebrados, Pontificia Universidade Católica do Rio Grande do Sul, Porto Alegre, RS, Brazil
| | - Albertina Pimentel Lima
- aCoordenação de Biodiversidade, Instituto Nacional de Pesquisas da Amazônia, P.O. Box 2223, 69011-970 Manaus, AM, Brazil
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31
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Differential detectability of polymorphic warning signals under varying light environments. Behav Processes 2014; 109 Pt B:164-72. [DOI: 10.1016/j.beproc.2014.08.014] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2014] [Revised: 08/09/2014] [Accepted: 08/18/2014] [Indexed: 11/20/2022]
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32
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Willink B, García-Rodríguez A, Bolaños F, Pröhl H. The interplay between multiple predators and prey colour divergence. Biol J Linn Soc Lond 2014. [DOI: 10.1111/bij.12355] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Affiliation(s)
- Beatriz Willink
- Escuela de Biología; Universidad de Costa Rica; Ciudad Universitaria Rodrigo Facio 2060 San José Costa Rica
- Department of Biology; Lund University; SE-223 62 Lund Sweden
| | - Adrián García-Rodríguez
- Museo de Zoología; Universidad de Costa Rica; Ciudad Universitaria Rodrigo Facio 2060 San José Costa Rica
- Departamento de Botanica, Ecologia e Zoologia; Universidade Federal do Rio Grande do Norte; Natal Rio Grande do Norte Brazil
| | - Federico Bolaños
- Escuela de Biología; Universidad de Costa Rica; Ciudad Universitaria Rodrigo Facio 2060 San José Costa Rica
| | - Heike Pröhl
- Institute of Zoology; University of Veterinary Medicine of Hannover; Bünteweg 17 30559 Hannover Germany
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33
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A Test of Aposematism in the Dendrobatid Poison FrogOophaga pumilio: The Importance of Movement in Clay Model Experiments. J HERPETOL 2014. [DOI: 10.1670/13-027] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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34
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Fabricant SA, Exnerová A, Ježová D, Štys P. Scared by shiny? The value of iridescence in aposematic signalling of the hibiscus harlequin bug. Anim Behav 2014. [DOI: 10.1016/j.anbehav.2014.01.021] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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35
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Interacting selection diversifies warning signals in a polytypic frog: an examination with the strawberry poison frog. Evol Ecol 2013. [DOI: 10.1007/s10682-013-9648-9] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
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36
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Sexual dimorphism and intra-populational colour pattern variation in the aposematic frog Dendrobates tinctorius. Evol Ecol 2013. [DOI: 10.1007/s10682-013-9640-4] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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37
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No evidence for differential survival or predation between sympatric color morphs of an aposematic poison frog. Evol Ecol 2013. [DOI: 10.1007/s10682-013-9636-0] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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38
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Crothers LR, Cummings ME. Warning signal brightness variation: sexual selection may work under the radar of natural selection in populations of a polytypic poison frog. Am Nat 2013; 181:E116-24. [PMID: 23594556 DOI: 10.1086/670010] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Though theory predicts consistency of warning signals in aposematic species to facilitate predator learning, variation in these signals often occurs in nature. The strawberry poison frog Dendrobates pumilio is an exceptionally polytypic (populations are phenotypically distinct) aposematic frog exhibiting variation in warning color and brightness. In the Solarte population, males and females both respond differentially to male brightness variation. Here, we demonstrate through spectrophotometry and visual modeling that aposematic brightness variation within this population is likely visible to two putative predators (crabs, snakes) and conspecifics but not to the presumed major predator (birds). This study thus suggests that signal brightness within D. pumilio populations can be shaped by sexual selection, with limited opportunity for natural selection to influence this trait due to predator sensory constraints. Because signal brightness changes can ultimately lead to changes in hue, our findings at the within-population level can provide insights into understanding this polytypism at across-population scales.
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Affiliation(s)
- Laura R Crothers
- Section of Integrative Biology, University of Texas, Austin, Texas 78712, USA.
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39
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Hegna RH, Nokelainen O, Hegna JR, Mappes J. To quiver or to shiver: increased melanization benefits thermoregulation, but reduces warning signal efficacy in the wood tiger moth. Proc Biol Sci 2013; 280:20122812. [PMID: 23363631 DOI: 10.1098/rspb.2012.2812] [Citation(s) in RCA: 75] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Melanin production is often considered costly, yet beneficial for thermoregulation. Studies of variation in melanization and the opposing selective forces that underlie its variability contribute greatly to understanding natural selection. We investigated whether melanization benefits are traded off with predation risk to promote observed local and geographical variation in the warning signal of adult male wood tiger moths (Parasemia plantaginis). Warning signal variation is predicted to reduce survival in aposematic species. However, in P. plantaginis, male hindwings are either yellow or white in Europe, and show continuous variation in melanized markings that cover 20 to 90 per cent of the hindwing. We found that the amount of melanization increased from 40 to 59 per cent between Estonia (58° N) and north Finland (67° N), suggesting melanization carries thermoregulatory benefits. Our thermal measurements showed that more melanic individuals warmed up more quickly on average than less melanic individuals, which probably benefits flight in cold temperatures. With extensive field experiments in central Finland and the Alpine region, we found that more melanic individuals suffered increased predation. Together, our data suggest that warning signal efficiency is constrained by thermoregulatory benefits. Differences in relative costs and benefits of melanin probably help to maintain the geographical warning signal differences.
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Affiliation(s)
- Robert H Hegna
- Department of Biology and Environmental Science, Centre of Excellence in Biological Interactions, University of Jyväskylä, Survontie 9, Jyväskylä, Finland.
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40
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Not all colors are equal: predation and color polytypism in the aposematic poison frog Oophaga pumilio. Evol Ecol 2012. [DOI: 10.1007/s10682-012-9605-z] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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41
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Nokelainen O, Hegna RH, Reudler JH, Lindstedt C, Mappes J. Trade-off between warning signal efficacy and mating success in the wood tiger moth. Proc Biol Sci 2011; 279:257-65. [PMID: 21653589 DOI: 10.1098/rspb.2011.0880] [Citation(s) in RCA: 97] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
The coloration of species can have multiple functions, such as predator avoidance and sexual signalling, that directly affect fitness. As selection should favour traits that positively affect fitness, the genes underlying the trait should reach fixation, thereby preventing the evolution of polymorphisms. This is particularly true for aposematic species that rely on coloration as a warning signal to advertise their unprofitability to predators. Nonetheless, there are numerous examples of aposematic species showing remarkable colour polymorphisms. We examined whether colour polymorphism in the wood tiger moth is maintained by trade-offs between different functions of coloration. In Finland, males of this species have two distinct colour morphs: white and yellow. The efficacy of the warning signal of these morphs was tested by offering them to blue tits in the laboratory. Birds hesitated significantly longer to attack yellow than white males. In a field experiment, the survival of the yellow males was also higher than white males. However, mating experiments in the laboratory revealed that yellow males had lower mating success than white males. Our results offer an explanation for the maintenance of polymorphism via trade-off between survival selection and mating success.
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Affiliation(s)
- Ossi Nokelainen
- Department of Biological and Environmental Science, Centre of Excellence in Evolutionary Research, University of Jyväskylä, , PO Box 35, 40014 Jyväskylä, Finland.
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