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Tan M, Zhang S, Stevens M, Li D, Tan EJ. Antipredator defences in motion: animals reduce predation risks by concealing or misleading motion signals. Biol Rev Camb Philos Soc 2024; 99:778-796. [PMID: 38174819 DOI: 10.1111/brv.13044] [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: 12/06/2022] [Revised: 12/13/2023] [Accepted: 12/15/2023] [Indexed: 01/05/2024]
Abstract
Motion is a crucial part of the natural world, yet our understanding of how animals avoid predation whilst moving remains rather limited. Although several theories have been proposed for how antipredator defence may be facilitated during motion, there is often a lack of supporting empirical evidence, or conflicting findings. Furthermore, many studies have shown that motion often 'breaks' camouflage, as sudden movement can be detected even before an individual is recognised. Whilst some static camouflage strategies may conceal moving animals to a certain extent, more emphasis should be given to other modes of camouflage and related defences in the context of motion (e.g. flicker fusion camouflage, active motion camouflage, motion dazzle, and protean motion). Furthermore, when motion is involved, defence strategies are not necessarily limited to concealment. An animal can also rely on motion to mislead predators with regards to its trajectory, location, size, colour pattern, or even identity. In this review, we discuss the various underlying antipredator strategies and the mechanisms through which they may be linked to motion, conceptualising existing empirical and theoretical studies from two perspectives - concealing and misleading effects. We also highlight gaps in our understanding of these antipredator strategies, and suggest possible methodologies for experimental designs/test subjects (i.e. prey and/or predators) and future research directions.
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Affiliation(s)
- Min Tan
- Department of Biological Sciences, National University of Singapore, 14 Science Drive 4, Singapore, 117543, Singapore
| | - Shichang Zhang
- Centre for Behavioural Ecology & Evolution, State Key Laboratory of Biocatalysis and Enzyme Engineering, School of Life Sciences, Hubei University, Wuhan, 430062, Hubei, China
| | - Martin Stevens
- Centre for Ecology and Conservation, University of Exeter, Penryn Campus, Penryn, TR10 9FE, UK
| | - Daiqin Li
- Department of Biological Sciences, National University of Singapore, 14 Science Drive 4, Singapore, 117543, Singapore
- Centre for Behavioural Ecology & Evolution, State Key Laboratory of Biocatalysis and Enzyme Engineering, School of Life Sciences, Hubei University, Wuhan, 430062, Hubei, China
| | - Eunice J Tan
- Department of Biological Sciences, National University of Singapore, 14 Science Drive 4, Singapore, 117543, Singapore
- Division of Science, Yale-NUS College, 16 College Avenue West, Singapore, 138527, Singapore
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2
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Wan YC, Navarrete Méndez MJ, O'Connell LA, Uricchio LH, Roland AB, Maan ME, Ron SR, Betancourth-Cundar M, Pie MR, Howell KA, Richards-Zawacki CL, Cummings ME, Cannatella DC, Santos JC, Tarvin RD. Selection on Visual Opsin Genes in Diurnal Neotropical Frogs and Loss of the SWS2 Opsin in Poison Frogs. Mol Biol Evol 2023; 40:msad206. [PMID: 37791477 PMCID: PMC10548314 DOI: 10.1093/molbev/msad206] [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] [Indexed: 10/05/2023] Open
Abstract
Amphibians are ideal for studying visual system evolution because their biphasic (aquatic and terrestrial) life history and ecological diversity expose them to a broad range of visual conditions. Here, we evaluate signatures of selection on visual opsin genes across Neotropical anurans and focus on three diurnal clades that are well-known for the concurrence of conspicuous colors and chemical defense (i.e., aposematism): poison frogs (Dendrobatidae), Harlequin toads (Bufonidae: Atelopus), and pumpkin toadlets (Brachycephalidae: Brachycephalus). We found evidence of positive selection on 44 amino acid sites in LWS, SWS1, SWS2, and RH1 opsin genes, of which one in LWS and two in RH1 have been previously identified as spectral tuning sites in other vertebrates. Given that anurans have mostly nocturnal habits, the patterns of selection revealed new sites that might be important in spectral tuning for frogs, potentially for adaptation to diurnal habits and for color-based intraspecific communication. Furthermore, we provide evidence that SWS2, normally expressed in rod cells in frogs and some salamanders, has likely been lost in the ancestor of Dendrobatidae, suggesting that under low-light levels, dendrobatids have inferior wavelength discrimination compared to other frogs. This loss might follow the origin of diurnal activity in dendrobatids and could have implications for their behavior. Our analyses show that assessments of opsin diversification in across taxa could expand our understanding of the role of sensory system evolution in ecological adaptation.
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Affiliation(s)
- Yin Chen Wan
- Museum of Vertebrate Zoology and Department of Integrative Biology, University of California Berkeley, Berkeley, CA, USA
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada
- School of Biomolecular and Biomedical Science, University College Dublin, Belfield, Dublin, Ireland
| | - María José Navarrete Méndez
- Museum of Vertebrate Zoology and Department of Integrative Biology, University of California Berkeley, Berkeley, CA, USA
- Museo de Zoología, Facultad de Ciencias Exactas y Naturales, Pontificia Universidad Católica del Ecuador, Quito, Ecuador
| | | | - Lawrence H Uricchio
- Museum of Vertebrate Zoology and Department of Integrative Biology, University of California Berkeley, Berkeley, CA, USA
- Department of Biology, Tufts University, Medford, MA, USA
| | - Alexandre-Benoit Roland
- FAS Center for Systems Biology, Harvard University, Cambridge, MA, USA
- Research Centre on Animal Cognition (CRCA), Centre for Integrative Biology (CBI), UMR5169 CNRS, Toulouse University, Toulouse, France
| | - Martine E Maan
- Groningen Institute for Evolutionary Life Sciences, University of Groningen, Groningen, The Netherlands
| | - Santiago R Ron
- Museo de Zoología, Facultad de Ciencias Exactas y Naturales, Pontificia Universidad Católica del Ecuador, Quito, Ecuador
| | | | - Marcio R Pie
- Department of Zoology, Universidade Federal do Paraná, Curitiba, Brazil
- Biology Department, Edge Hill University, Ormskirk, United Kingdom
| | - Kimberly A Howell
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, PA, USA
| | | | - Molly E Cummings
- Department of Integrative Biology, University of Texas at Austin, Austin, TX, USA
| | - David C Cannatella
- Department of Integrative Biology, University of Texas at Austin, Austin, TX, USA
- Biodiversity Center, University of Texas at Austin, Austin, TX, USA
| | - Juan C Santos
- Department of Biological Sciences, St. John's University, New York City, NY, USA
| | - Rebecca D Tarvin
- Museum of Vertebrate Zoology and Department of Integrative Biology, University of California Berkeley, Berkeley, CA, USA
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3
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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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4
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Raynal RS, Schwanz LE, Riley JL, Umbers KDL. Genetic and environmental drivers of colour and pattern in the Australian jacky dragon (Amphibolurus muricatus). J Evol Biol 2022; 35:1229-1239. [PMID: 35861703 PMCID: PMC9544122 DOI: 10.1111/jeb.14066] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2022] [Revised: 06/06/2022] [Accepted: 06/29/2022] [Indexed: 11/26/2022]
Abstract
The underlying drivers of variation in the colouration (colour and pattern) of animals can be genetic, non‐genetic, or more likely, a combination of both. Understanding the role of heritable genetic elements, as well as non‐genetic factors such as age, habitat or temperature, in shaping colouration can provide insight into the evolution and function of these traits, as well as the speed of response to changing environments. This project examined the genetic and non‐genetic drivers of continuous variation in colouration in a lizard, the jacky dragon (Amphibolurus muricatus). We leveraged a large captive experiment that manipulated parental and offspring thermal environment to simultaneously estimate the genetic and non‐genetic drivers of variation in colouration. We found that the overall brightness, the elongation of the longitudinal stripes on the dorsum and the contrast between light and dark patches of the pattern were all heritable. Colouration varied according to the age of the hatchling; however, the thermal environment of neither the parents nor offspring contributed significantly to colouration. It appears that developmental plasticity and maternal effects associated with temperature are not important drivers of variation in our measures of colouration.
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Affiliation(s)
- Rebecca S Raynal
- Evolution & Ecology Research Centre, School of Biological, Earth, and Environmental Sciences, University of New South Wales, Sydney, New South Wales, Australia
| | - Lisa E Schwanz
- Evolution & Ecology Research Centre, School of Biological, Earth, and Environmental Sciences, University of New South Wales, Sydney, New South Wales, Australia
| | - Julia L Riley
- Evolution & Ecology Research Centre, School of Biological, Earth, and Environmental Sciences, University of New South Wales, Sydney, New South Wales, Australia.,Department of Biology, Mount Allison University, Sackville, New Brunswick, Canada
| | - Kate D L Umbers
- School of Science, Western Sydney University, Penrith, New South Wales, Australia.,Hawkesbury Institute for the Environment, Western Sydney University, Penrith, New South Wales, Australia
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5
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Yuan ML, Jung C, Bell RC, Nelson JL. Aposematic patterns shift continuously throughout the life of poison frogs. J Zool (1987) 2022. [DOI: 10.1111/jzo.12977] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Affiliation(s)
- M. L. Yuan
- Center for Population Biology University of California Davis CA USA
- Department of Evolution and Ecology University of California Davis CA USA
| | - C. Jung
- Department of Environmental Science, Policy, and Management University of California Berkeley CA USA
| | - R. C. Bell
- Department of Herpetology California Academy of Sciences San Francisco CA USA
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6
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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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7
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Clark MI, Bradburd GS, Akopyan M, Vega A, Rosenblum EB, Robertson JM. Genetic isolation by distance underlies colour pattern divergence in red-eyed treefrogs (Agalychnis callidryas). Mol Ecol 2022; 31:1666-1681. [PMID: 35034406 PMCID: PMC8923152 DOI: 10.1111/mec.16350] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2021] [Revised: 10/21/2021] [Accepted: 01/04/2022] [Indexed: 10/19/2022]
Abstract
Investigating the spatial distribution of genetic and phenotypic variation can provide insights into the evolutionary processes that shape diversity in natural systems. We characterized patterns of genetic and phenotypic diversity to learn about drivers of colour-pattern diversification in red-eyed treefrogs (Agalychnis callidryas) in Costa Rica. Along the Pacific coast, red-eyed treefrogs have conspicuous leg colour patterning that transitions from orange in the north to purple in the south. We measured phenotypic variation of frogs, with increased sampling at sites where the orange-to-purple transition occurs. At the transition zone, we discovered the co-occurrence of multiple colour-pattern morphs. To explore possible causes of this variation, we generated a single nucleotide polymorphism data set to analyse population genetic structure, measure genetic diversity and infer the processes that mediate genotype-phenotype dynamics. We investigated how patterns of genetic relatedness correspond to individual measures of colour pattern along the coast, including testing for the role of hybridization in geographic regions where orange and purple phenotypic groups co-occur. We found no evidence that colour-pattern polymorphism in the transition zone arose through recent hybridization. Instead, a strong pattern of genetic isolation by distance indicates that colour-pattern variation was either retained through other processes such as ancestral colour polymorphisms or ancient secondary contact, or else it was generated by novel mutations. We found that phenotype changes along the Pacific coast more than would be expected based on genetic divergence and geographic distance alone. Combined, our results suggest the possibility of selective pressures acting on colour pattern at a small geographic scale.
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Affiliation(s)
- Meaghan I. Clark
- Department of Biology, California State University Northridge, Northridge, California, USA,Department of integrative Biology, Ecology, Evolution and Behavior Program, Michigan State University, East Lansing, Michigan, USA,W.K. Kellogg Biological Station, Michigan State University, Hickory Corners, Michigan, USA
| | - Gideon S. Bradburd
- Department of integrative Biology, Ecology, Evolution and Behavior Program, Michigan State University, East Lansing, Michigan, USA
| | - Maria Akopyan
- Department of Biology, California State University Northridge, Northridge, California, USA,Department of Ecology and Evolutionary Biology, Cornell University, Ithaca, New York, USA
| | | | - Erica Bree Rosenblum
- Department of Environmental Science, Policy, and Management, University of California Berkeley, Berkeley, California, USA,Museum of Vertebrate Zoology, University of California Berkeley, Berkeley, California, USA
| | - Jeanne M. Robertson
- Department of Biology, California State University Northridge, Northridge, California, USA,Department of Herpetology, Natural History Museum of Los Angeles County, Los Angeles, California, USA
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8
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Urban S, Gerwin J, Hulsey CD, Meyer A, Kratochwil CF. The repeated evolution of stripe patterns is correlated with body morphology in the adaptive radiations of East African cichlid fishes. Ecol Evol 2022; 12:e8568. [PMID: 35154652 PMCID: PMC8820146 DOI: 10.1002/ece3.8568] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2021] [Revised: 12/20/2021] [Accepted: 12/30/2021] [Indexed: 01/01/2023] Open
Abstract
Color patterns are often linked to the behavioral and morphological characteristics of an animal, contributing to the effectiveness of such patterns as antipredatory strategies. Species-rich adaptive radiations, such as the freshwater fish family Cichlidae, provide an exciting opportunity to study trait correlations at a macroevolutionary scale. Cichlids are also well known for their diversity and repeated evolution of color patterns and body morphology. To study the evolutionary dynamics between color patterns and body morphology, we used an extensive dataset of 461 species. A phylogenetic supertree of these species shows that stripe patterns evolved ~70 times independently and were lost again ~30 times. Moreover, stripe patterns show strong signs of correlated evolution with body elongation, suggesting that the stripes' effectiveness as antipredatory strategy might differ depending on the body shape. Using pedigree-based analyses, we show that stripes and body elongation segregate independently, indicating that the two traits are not genetically linked. Their correlation in nature is therefore likely maintained by correlational selection. Lastly, by performing a mate preference assay using a striped CRISPR-Cas9 mutant of a nonstriped species, we show that females do not differentiate between striped CRISPR mutant males and nonstriped wild-type males, suggesting that these patterns might be less important for species recognition and mate choice. In summary, our study suggests that the massive rates of repeated evolution of stripe patterns are shaped by correlational selection with body elongation, but not by sexual selection.
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Affiliation(s)
- Sabine Urban
- Chair in Zoology and Evolutionary BiologyDepartment of BiologyUniversity of KonstanzKonstanzGermany
| | - Jan Gerwin
- Chair in Zoology and Evolutionary BiologyDepartment of BiologyUniversity of KonstanzKonstanzGermany
| | - C. Darrin Hulsey
- Chair in Zoology and Evolutionary BiologyDepartment of BiologyUniversity of KonstanzKonstanzGermany
- Present address:
School of Biology and Environmental ScienceUniversity College DublinBelfieldIreland
| | - Axel Meyer
- Chair in Zoology and Evolutionary BiologyDepartment of BiologyUniversity of KonstanzKonstanzGermany
| | - Claudius F. Kratochwil
- Chair in Zoology and Evolutionary BiologyDepartment of BiologyUniversity of KonstanzKonstanzGermany
- Present address:
Institute of Biotechnology, HiLIFEUniversity of HelsinkiHelsinkiFinland
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9
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White TE, Umbers KDL. Meta-analytic evidence for quantitative honesty in aposematic signals. Proc Biol Sci 2021; 288:20210679. [PMID: 33906408 PMCID: PMC8080005 DOI: 10.1098/rspb.2021.0679] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2021] [Accepted: 04/08/2021] [Indexed: 12/30/2022] Open
Abstract
The combined use of noxious chemical defences and conspicuous warning colours is a ubiquitous anti-predator strategy. That such signals advertise the presence of defences is inherent to their function, but their predicted potential for quantitative honesty-the positive scaling of signal salience with the strength of protection-is the subject of enduring debate. Here, we systematically synthesized the available evidence to test this prediction using meta-analysis. We found evidence for a positive correlation between warning colour expression and the extent of chemical defences across taxa. Notably, this relationship held at all scales; among individuals, populations and species, though substantial between-study heterogeneity remains unexplained. Consideration of the design of signals revealed that all visual features, from colour to contrast, were equally informative of the extent of prey defence. Our results affirm a central prediction of honesty-based models of signal function and narrow the scope of possible mechanisms shaping the evolution of aposematism. They suggest diverse pathways to the encoding and exchange of information, while highlighting the need for deeper knowledge of the ecology of chemical defences to enrich our understanding of this widespread anti-predator adaptation.
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Affiliation(s)
- Thomas E. White
- School of Life and Environmental Sciences, The University of Sydney, Sydney, New South Wales 2106, Australia
| | - Kate D. L. Umbers
- School of Science, Western Sydney University, Penrith, New South Wales 2751, Australia
- Hawkesbury Institute for the Environment, Western Sydney University, Penrith, New South Wales 2751, Australia
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10
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Fight or flight trade-offs and the defensive behaviour of the mountain katydid, Acripeza reticulata. Anim Behav 2020. [DOI: 10.1016/j.anbehav.2019.11.012] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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11
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van den Berg CP, Troscianko J, Endler JA, Marshall NJ, Cheney KL. Quantitative Colour Pattern Analysis (QCPA): A comprehensive framework for the analysis of colour patterns in nature. Methods Ecol Evol 2019. [DOI: 10.1111/2041-210x.13328] [Citation(s) in RCA: 63] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
| | | | - John A. Endler
- School of Life & Environmental Sciences Deakin University Geelong Australia
| | - N. Justin Marshall
- Queensland Brain Institute The University of Queensland St Lucia QLD Australia
| | - Karen L. Cheney
- The School of Biological Sciences The University of Queensland St Lucia QLD Australia
- Queensland Brain Institute The University of Queensland St Lucia QLD Australia
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12
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Preferences for and use of light microhabitats differ among and within populations of a polytypic poison frog. Biol J Linn Soc Lond 2019. [DOI: 10.1093/biolinnean/blz186] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Abstract
Anti-predator strategies can influence trade-offs governing other activities important to fitness. Crypsis, for example, might make conspicuous sexual display especially costly, whereas aposematism might reduce or remove such costs. We tested for correlates of anti-predator strategy in Oophaga pumilio, a polytypic poison frog with morphs spanning the crypsis–aposematism continuum. In the wild, males of visually conspicuous morphs display from conspicuous perches and behave as if they perceive predation risk to be low. We thus predicted that, given a choice of ambient light microhabitats, these males would use high ambient light conditions the most and be most likely to perch in high-light conditions. We found no evidence that differently colored male O. pumilio preferentially used bright microhabitats or that ambient light influenced perching in a morph-specific manner. Independent of light conditions, males from the most conspicuous population perched the least, but the most conspicuous individuals from a polymorphic population perched the most. These patterns suggest that preferences do not necessarily underlie among-morph differences observed in the wild. This could be explained, and remain consistent with theory, if risk aversion is shaped, in part, by experience.
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13
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Kodandaramaiah U, Palathingal S, Bindu Kurup G, Murali G. What makes motion dazzle markings effective against predation? Behav Ecol 2019. [DOI: 10.1093/beheco/arz154] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Abstract
Motion dazzle markings comprise patterns such as stripes and zig-zags that are postulated to protect moving prey by making predators misjudge the prey’s speed or trajectory. Recent experiments have provided conflicting results on their effect on speed perception and attack success. We focus on motion dazzle stripes and investigate the influence of four parameters—stripe orientation, stripe contrast, target size, and target speed—on perceived speed and attack success using a common experimental paradigm involving human “predators” attacking virtual moving targets on a computer touchscreen. We found that high-contrast stripes running parallel or perpendicular to the direction of motion reduce attack success compared to conspicuous uniform targets. Surprisingly, parallel stripes induced underestimation of speed, while perpendicular stripes induced overestimation of speed in relation to uniform black, suggesting that misjudgment of speed per se is sufficient to reduce attack accuracy. Across all the experiments, we found some support for parallel stripes inducing underestimation of target speed but these stripes reduced attack success only when targets were small, moved at an intermediate speed, and had high internal contrast. We suggest that prey features (e.g., size or speed) are an important determinant of capture success and that distortion of speed perception by a color pattern does not necessarily translate to reduced capture success of the prey. Overall, our results support the idea that striped patterns in prey animals can reduce capture in motion but are effective under a limited set of conditions.
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Affiliation(s)
- Ullasa Kodandaramaiah
- IISER-TVM Centre for Research and Education in Ecology and Evolution (ICREEE), School of Biology, Indian Institute of Science Education and Research Thiruvananthapuram, Thiruvananthapuram, India
| | - Shuaib Palathingal
- IISER-TVM Centre for Research and Education in Ecology and Evolution (ICREEE), School of Biology, Indian Institute of Science Education and Research Thiruvananthapuram, Thiruvananthapuram, India
- Centre for Ecological Sciences, Indian Institute of Science, Bengaluru, India
| | - Gayathri Bindu Kurup
- IISER-TVM Centre for Research and Education in Ecology and Evolution (ICREEE), School of Biology, Indian Institute of Science Education and Research Thiruvananthapuram, Thiruvananthapuram, India
| | - Gopal Murali
- IISER-TVM Centre for Research and Education in Ecology and Evolution (ICREEE), School of Biology, Indian Institute of Science Education and Research Thiruvananthapuram, Thiruvananthapuram, India
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14
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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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15
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Maia R, Gruson H, Endler JA, White TE. pavo
2: New tools for the spectral and spatial analysis of colour in
r. Methods Ecol Evol 2019. [DOI: 10.1111/2041-210x.13174] [Citation(s) in RCA: 193] [Impact Index Per Article: 38.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Affiliation(s)
- Rafael Maia
- Department of Ecology, Evolution and Environmental Biology Columbia University New York NY
| | - Hugo Gruson
- CEFE, University Montpellier CNRS University Paul Valery Montpellier 3 EPHE IRD Montpellier France
| | - John A. Endler
- School of Life and Environmental Sciences Deakin University Waurn Ponds Campus Vic. Australia
| | - Thomas E. White
- School of Life and Environmental Sciences University of Sydney Sydney NSW Australia
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16
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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 2019; 94:388-414. [PMID: 30152037 PMCID: PMC6446817 DOI: 10.1111/brv.12460] [Citation(s) in RCA: 68] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [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 SciencesUniversity of ExeterPenryn Campus, Penryn, Cornwall, TR10 9FEU.K.
| | - Emily R. Burdfield‐Steel
- Centre of Excellence in Biological Interactions, Department of Biological and Environmental ScienceUniversity of JyväskyläJyväskylä, 40014Finland
| | - Sarah C. Paul
- Centre for Ecology & Conservation, College of Life & Environmental SciencesUniversity of ExeterPenryn Campus, Penryn, Cornwall, TR10 9FEU.K.
- Department of Chemical EcologyBielefeld UniversityUniversitätsstraße 25, 33615, BielefeldGermany
| | - Katja H. Rönkä
- Centre of Excellence in Biological Interactions, Department of Biological and Environmental ScienceUniversity of JyväskyläJyväskylä, 40014Finland
- Organismal and Evolutionary Biology Research Programme, Faculty of Biological and Environmental SciencesUniversity of HelsinkiHelsinki, 00014Finland
| | - Brett M. Seymoure
- Department of BiologyColorado State UniversityFort CollinsCO 80525U.S.A.
- Department of Fish, Wildlife, and Conservation BiologyColorado State UniversityFort CollinsCO 80525U.S.A.
| | - Theodore Stankowich
- Department of Biological SciencesCalifornia State UniversityLong BeachCA 90840U.S.A.
| | - Adam M. M. Stuckert
- Department of BiologyEast Carolina University1000 E Fifth St, GreenvilleNC 27858U.S.A.
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17
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Klonoski K, Bi K, Rosenblum EB. Phenotypic and genetic diversity in aposematic Malagasy poison frogs (genus Mantella). Ecol Evol 2019; 9:2725-2742. [PMID: 30891212 PMCID: PMC6406014 DOI: 10.1002/ece3.4943] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2018] [Revised: 12/07/2018] [Accepted: 01/02/2019] [Indexed: 12/17/2022] Open
Abstract
Intraspecific color variation has long fascinated evolutionary biologists. In species with bright warning coloration, phenotypic diversity is particularly compelling because many factors, including natural and sexual selection, contribute to intraspecific variation. To better understand the causes of dramatic phenotypic variation in Malagasy poison frogs, we quantified genetic structure and color and pattern variation across three closely related species, Mantella aurantiaca, Mantella crocea, and Mantella milotympanum. Although our restriction site-associated DNA (RAD) sequencing approach identified clear genetic clusters, they do not align with current species designations, which has important conservation implications for these imperiled frogs. Moreover, our results suggest that levels of intraspecific color variation within this group have been overestimated, while species diversity has been underestimated. Within major genetic clusters, we observed distinct patterns of variation including: populations that are phenotypically similar yet genetically distinct, populations where phenotypic and genetic breaks coincide, and populations that are genetically similar but have high levels of within-population phenotypic variation. We also detected admixture between two of the major genetic clusters. Our study suggests that several mechanisms-including hybridization, selection, and drift-are contributing to phenotypic diversity. Ultimately, our work underscores the need for a reevaluation of how polymorphic and polytypic populations and species are classified, especially in aposematic organisms.
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Affiliation(s)
- Karina Klonoski
- Department of Environmental Science, Policy, and ManagementUniversity of California, BerkeleyBerkeleyCalifornia
- Museum of Vertebrate ZoologyUniversity of California, BerkeleyBerkeleyCalifornia
| | - Ke Bi
- Museum of Vertebrate ZoologyUniversity of California, BerkeleyBerkeleyCalifornia
- Computational Genomics Resource Laboratory (CGRL), California Institute for Quantitative Biosciences (QB3)University of California, BerkeleyBerkeleyCalifornia
| | - Erica Bree Rosenblum
- Department of Environmental Science, Policy, and ManagementUniversity of California, BerkeleyBerkeleyCalifornia
- Museum of Vertebrate ZoologyUniversity of California, BerkeleyBerkeleyCalifornia
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18
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Stoddard MC, Osorio D. Animal Coloration Patterns: Linking Spatial Vision to Quantitative Analysis. Am Nat 2019; 193:164-186. [DOI: 10.1086/701300] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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19
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Burdfield-Steel E, Brain M, Rojas B, Mappes J. The price of safety: food deprivation in early life influences the efficacy of chemical defence in an aposematic moth. OIKOS 2018. [DOI: 10.1111/oik.05420] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Affiliation(s)
- Emily Burdfield-Steel
- Centre of Excellence in Biological Interactions, Dept of Biological and Environmental Science; PO Box 35 FI-40014 Univ. of Jyväskylä Finland
| | - Morgan Brain
- Centre of Excellence in Biological Interactions, Dept of Biological and Environmental Science; PO Box 35 FI-40014 Univ. of Jyväskylä Finland
| | - Bibiana Rojas
- Centre of Excellence in Biological Interactions, Dept of Biological and Environmental Science; PO Box 35 FI-40014 Univ. of Jyväskylä Finland
| | - Johanna Mappes
- Centre of Excellence in Biological Interactions, Dept of Biological and Environmental Science; PO Box 35 FI-40014 Univ. of Jyväskylä Finland
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20
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Murali G. Now you see me, now you don't: dynamic flash coloration as an antipredator strategy in motion. Anim Behav 2018. [DOI: 10.1016/j.anbehav.2018.06.017] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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21
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Distance-dependent defensive coloration in the poison frog Dendrobates tinctorius, Dendrobatidae. Proc Natl Acad Sci U S A 2018; 115:6416-6421. [PMID: 29866847 DOI: 10.1073/pnas.1800826115] [Citation(s) in RCA: 47] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Poison dart frogs provide classic examples of warning signals: potent toxins signaled by distinctive, conspicuous coloration. We show that, counterintuitively, the bright yellow and blue-black color of Dendrobates tinctorius (Dendrobatidae) also provides camouflage. Through computational modeling of predator vision, and a screen-based detection experiment presenting frogs at different spatial resolutions, we demonstrate that at close range the frog is highly detectable, but from a distance the colors blend together, forming effective camouflage. This result was corroborated with an in situ experiment, which found survival to be background-dependent, a feature more associated with camouflage than aposematism. Our results suggest that in D. tinctorius the distribution of pattern elements, and the particular colors expressed, act as a highly salient close range aposematic signal, while simultaneously minimizing detectability to distant observers.
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22
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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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23
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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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Lawrence JP, Noonan BP. Avian learning favors colorful, not bright, signals. PLoS One 2018; 13:e0194279. [PMID: 29566013 PMCID: PMC5864004 DOI: 10.1371/journal.pone.0194279] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2017] [Accepted: 02/28/2018] [Indexed: 11/29/2022] Open
Abstract
A few colors, such as red and yellow, are commonly found in aposematic (warning) signaling across taxa, independent of evolutionary relationships. These colors have unique traits (i.e., hue, brightness) that aid in their differentiation, and perhaps, their effectiveness in promoting avoidance learning. This repeated use calls into question the influence of selection on specific warning colors adopted by aposematic prey-predator systems. To disentangle the influence of color characteristics on this process, we trained week-old chickens (Gallus gallus domesticus) to learn to avoid distasteful food that was associated with one of three color signals (yellow, white, red) that varied in both hue and in brightness in order to assess which of these traits most influenced their ability to learn avoidance. Our results show that while chicks learned to avoid all three colors, avoidance was based on the hue, not brightness of the different signals. We found that yellow was the most effective for avoidance learning, followed by red, and finally white. Our results suggest that while these three colors are commonly used in aposematic signaling, predators' ability to learn avoidance differs among them. These results may explain why yellow is among the most common signals across aposematic taxa.
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Affiliation(s)
- J. P. Lawrence
- University of Mississippi, Department of Biology, University, Mississippi United States of America
| | - Brice P. Noonan
- University of Mississippi, Department of Biology, University, Mississippi United States of America
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25
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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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26
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Pérez-Rodríguez L, Jovani R, Stevens M. Shape matters: animal colour patterns as signals of individual quality. Proc Biol Sci 2018; 284:rspb.2016.2446. [PMID: 28228513 DOI: 10.1098/rspb.2016.2446] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2016] [Accepted: 02/01/2017] [Indexed: 01/04/2023] Open
Abstract
Colour patterns (e.g. irregular, spotted or barred forms) are widespread in the animal kingdom, yet their potential role as signals of quality has been mostly neglected. However, a review of the published literature reveals that pattern itself (irrespective of its size or colour intensity) is a promising signal of individual quality across species of many different taxa. We propose at least four main pathways whereby patterns may reliably reflect individual quality: (i) as conventional signals of status, (ii) as indices of developmental homeostasis, (iii) by amplifying cues of somatic integrity and (iv) by amplifying individual investment in maintenance activities. Methodological constraints have traditionally hampered research on the signalling potential of colour patterns. To overcome this, we report a series of tools (e.g. colour adjacency and pattern regularity analyses, Fourier and granularity approaches, fractal geometry, geometric morphometrics) that allow objective quantification of pattern variability. We discuss how information provided by these methods should consider the visual system of the model species and behavioural responses to pattern metrics, in order to allow biologically meaningful conclusions. Finally, we propose future challenges in this research area that will require a multidisciplinary approach, bringing together inputs from genetics, physiology, behavioural ecology and evolutionary-developmental biology.
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Affiliation(s)
- Lorenzo Pérez-Rodríguez
- Departamento de Ecología Evolutiva, Estación Biológica de Doñana (EBD-CSIC), Avenida Américo Vespucio 26, Isla de la Cartuja, 41092 Sevilla, Spain
| | - Roger Jovani
- Departamento de Ecología Evolutiva, Estación Biológica de Doñana (EBD-CSIC), Avenida Américo Vespucio 26, Isla de la Cartuja, 41092 Sevilla, Spain
| | - Martin Stevens
- Centre for Ecology and Conservation, College of Life and Environmental Sciences, University of Exeter, Penryn Campus, Penryn TR10 9FE, UK
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27
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Bulbert MW, White TE, Saporito RA, Kraus F. Ontogenetic colour change in Oreophryne ezra (Anura: Microhylidae) reflects an unusual shift from conspicuousness to crypsis but not in toxicity. Biol J Linn Soc Lond 2017. [DOI: 10.1093/biolinnean/blx124] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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28
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Dreher CE, Rodríguez A, Cummings ME, Pröhl H. Mating status correlates with dorsal brightness in some but not all poison frog populations. Ecol Evol 2017; 7:10503-10512. [PMID: 29299233 PMCID: PMC5743646 DOI: 10.1002/ece3.3531] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2017] [Revised: 08/31/2017] [Accepted: 09/14/2017] [Indexed: 02/04/2023] Open
Abstract
Sexual signals are important for intraspecific communication and mate selection, but their evolution may be driven by both natural and sexual selection, and stochastic processes. Strawberry poison frogs (Oophaga pumilio) show strong color divergence among populations, but coloration also varies among individuals of the same population. The importance of coloration for female mate choice has been studied intensely, and sexual selection seems to affect color divergence in strawberry poison frogs. However, the effect of coloration on mating success under field conditions has received very little attention. Furthermore, few studies examined how phenotypic variation among individuals of the same color morph affects mate selection under natural conditions. We measured the spectral reflectance of courting and noncourting individuals and their background substrates in three geographically separated populations. In one population (Sarapiquí, Costa Rica), we found that naturally occurring courting pairs of males and females had significantly brighter dorsal coloration than individual males and females not engaged in courtship interactions. Our field observations suggest that, in the wild, females prefer brighter males while the reason for the higher courtship activity of brighter females remains unclear. Overall our results imply that brightness differences among individuals of the same color morph may actually affect reproductive success in some populations of strawberry poison frogs.
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Affiliation(s)
- Corinna E Dreher
- Institute of Zoology University of Veterinary Medicine Hannover, Foundation Hannover Germany
| | - Ariel Rodríguez
- Institute of Zoology University of Veterinary Medicine Hannover, Foundation Hannover Germany
| | - Molly E Cummings
- Section of Integrative Biology University of Texas Austin TX USA
| | - Heike Pröhl
- Institute of Zoology University of Veterinary Medicine Hannover, Foundation Hannover Germany
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29
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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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30
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Hughes AE, Jones C, Joshi K, Tolhurst DJ. Diverted by dazzle: perceived movement direction is biased by target pattern orientation. Proc Biol Sci 2017; 284:20170015. [PMID: 28275144 PMCID: PMC5360933 DOI: 10.1098/rspb.2017.0015] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2017] [Accepted: 02/09/2017] [Indexed: 11/12/2022] Open
Abstract
'Motion dazzle' is the hypothesis that predators may misjudge the speed or direction of moving prey which have high-contrast patterning, such as stripes. However, there is currently little experimental evidence that such patterns cause visual illusions. Here, observers binocularly tracked a Gabor target, moving with a linear trajectory randomly chosen within 18° of the horizontal. This target then became occluded, and observers were asked to judge where they thought it would later cross a vertical line to the side. We found that internal motion of the stripes within the Gabor biased judgements as expected: Gabors with upwards internal stripe motion relative to the overall direction of motion were perceived to be crossing above Gabors with downwards internal stripe movement. However, surprisingly, we found a much stronger effect of the rigid pattern orientation. Patches with oblique stripes pointing upwards relative to the direction of motion were perceived to cross above patches with downward-pointing stripes. This effect occurred only at high speeds, suggesting that it may reflect an orientation-dependent effect in which spatial signals are used in direction judgements. These findings have implications for our understanding of motion dazzle mechanisms and how human motion and form processing interact.
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Affiliation(s)
- Anna E Hughes
- Department of Psychology and Language Sciences, University College London, 26 Bedford Way, London WC1H 0AP, UK
- Department of Physiology, Development and Neuroscience, University of Cambridge, Downing Street, Cambridge CB2 3EG, UK
| | - Christian Jones
- Department of Physiology, Development and Neuroscience, University of Cambridge, Downing Street, Cambridge CB2 3EG, UK
| | - Kaustuv Joshi
- Department of Physiology, Development and Neuroscience, University of Cambridge, Downing Street, Cambridge CB2 3EG, UK
| | - David J Tolhurst
- Department of Physiology, Development and Neuroscience, University of Cambridge, Downing Street, Cambridge CB2 3EG, UK
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31
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Halperin T, Carmel L, Hawlena D. Movement correlates of lizards’ dorsal pigmentation patterns. Funct Ecol 2016. [DOI: 10.1111/1365-2435.12700] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Affiliation(s)
- Topaz Halperin
- Risk‐Management Ecology Lab Department of Ecology, Evolution & Behavior The Alexander Silberman Institute of Life Sciences The Hebrew University of Jerusalem Edmond J. Safra Campus Jerusalem 91904, Israel
- Herpetological Collection National Natural History Collections The Hebrew University of Jerusalem Edmond J. Safra Campus Jerusalem 91904, Israel
| | - Liran Carmel
- Department of Genetics Faculty of Science The Alexander Silberman Institute of Life Sciences The Hebrew University of Jerusalem Edmond J. Safra Campus Givat Ram Jerusalem 91904, Israel
| | - Dror Hawlena
- Risk‐Management Ecology Lab Department of Ecology, Evolution & Behavior The Alexander Silberman Institute of Life Sciences The Hebrew University of Jerusalem Edmond J. Safra Campus Jerusalem 91904, Israel
- Herpetological Collection National Natural History Collections The Hebrew University of Jerusalem Edmond J. Safra Campus Jerusalem 91904, Israel
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32
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Murali G, Kodandaramaiah U. Deceived by stripes: conspicuous patterning on vital anterior body parts can redirect predatory strikes to expendable posterior organs. ROYAL SOCIETY OPEN SCIENCE 2016; 3:160057. [PMID: 27429765 PMCID: PMC4929900 DOI: 10.1098/rsos.160057] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/26/2016] [Accepted: 05/10/2016] [Indexed: 06/06/2023]
Abstract
Conspicuous coloration, which presumably makes prey more visible to predators, has intrigued researchers for long. Contrastingly coloured, conspicuous striped patterns are common among lizards and other animals, but their function is not well known. We propose and test a novel hypothesis, the 'redirection hypothesis', wherein longitudinal striped patterns, such as those found on the anterior body parts of most lacertilians, redirect attacks away from themselves during motion towards less vulnerable posterior parts, for example, the autotomous tail. In experiments employing human 'predators' attacking virtual prey on a touchscreen, we show that longitudinal striped patterns on the anterior half of prey decreased attacks to the anterior and increased attacks to the posterior. The position of stripes mattered-they worked best when they were at the anterior. By employing an adaptive psychophysical procedure, we show that prey with striped patterning are perceived to move slower, offering a mechanistic explanation for the redirective effect. In summary, our results suggest that the presence of stripes on the body (i.e. head and trunk) of lizards in combination with caudal autotomy can work as an effective anti-predator strategy during motion.
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33
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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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34
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Coloration in the polymorphic frog Oophaga pumilio associates with level of aggressiveness in intraspecific and interspecific behavioral interactions. Behav Ecol Sociobiol 2015. [DOI: 10.1007/s00265-015-2027-5] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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35
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Visual illusions in predator–prey interactions: birds find moving patterned prey harder to catch. Anim Cogn 2015; 18:1059-68. [DOI: 10.1007/s10071-015-0874-0] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2014] [Revised: 04/29/2015] [Accepted: 04/29/2015] [Indexed: 11/25/2022]
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36
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Cole GL, Endler JA. Variable environmental effects on a multicomponent sexually selected trait. Am Nat 2015; 185:452-68. [PMID: 25811082 DOI: 10.1086/680022] [Citation(s) in RCA: 56] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
Multicomponent signals are made up of interacting elements that generate a functional signaling unit. The interactions between signal components and their effects on individual fitness are not well understood, and the effect of environment is even less so. It is usually assumed that color patterns appear the same in all light environments and that the effects of each color are additive. Using guppies, Poecilia reticulata, we investigated the effect of water color on the interactions between components of sexually selected male coloration. Through behavioral mate choice trials in four different water colors, we estimated the attractiveness of male color patterns, using multivariate fitness estimates and overall signal contrast. Our results show that females exhibit preferences that favor groups of colors rather than individual colors independently and that each environment favors different color combinations. We found that these effects are consistent with female guppies selecting entire color patterns on the basis of overall visual contrast. This suggests that both individuals and populations inhabiting different light environments will be subject to divergent, multivariate selection. Although the appearance of color patterns changes with light environment, achromatic components change little, suggesting that these could function in species recognition or other aspects of communication that must work across environments. Consequently, we predict different phylogenetic patterns between chromatic and achromatic signals within the same clades.
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Affiliation(s)
- Gemma L Cole
- Centre for Integrative Ecology, Deakin University, Waurn Ponds 3216, Victoria, Australia
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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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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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