1
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van den Berg CP, Santon M, Endler JA, Cheney KL. Highly defended nudibranchs "escape" to visually distinct background habitats. Behav Ecol 2024; 35:arae053. [PMID: 39086666 PMCID: PMC11289952 DOI: 10.1093/beheco/arae053] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2023] [Revised: 06/06/2024] [Accepted: 07/03/2024] [Indexed: 08/02/2024] Open
Abstract
The "escape and radiate" hypothesis predicts that once species have evolved aposematism, defended species can utilize more visually diverse visual backgrounds as they "escape" the need to be well camouflaged. This enables species to explore new ecological niches, resulting in increased diversification rates. To test this hypothesis "escape" component, we examined whether the background habitats of 12 nudibranch mollusk species differed among species depending on the presence and strength of chemical defenses. We obtained a rich array of color pattern statistics using quantitative color pattern analysis to analyze backgrounds viewed through the eyes of a potential predator (triggerfish, Rhinecanthus aculeatus). Color pattern analysis was done at viewing distances simulating an escalating predation sequence. We identified 4 latent factors comprising 17 noncorrelated color pattern parameters, which captured the among-species variability associated with differences in chemical defenses. We found that chemically defended species, indeed, were found on visually distinct backgrounds with increased color and luminance contrast, independent of viewing distance. However, we found no evidence for increased among-species background diversity coinciding with the presence and strength of chemical defenses. Our results agree with the "escape and radiate" hypothesis, suggesting that potent chemical defenses in Dorid nudibranchs coincide with spatiochromatic differences of visual background habitats perceived by potential predators.
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Affiliation(s)
- Cedric P van den Berg
- School of the Environment, The University of Queensland, University Drive, St. Lucia, QLD 4072, Australia
- School of Biological Sciences, University of Bristol, 24 Tyndall Ave, Bristol, BS8 1TQ, United Kingdom
| | - Matteo Santon
- School of Biological Sciences, University of Bristol, 24 Tyndall Ave, Bristol, BS8 1TQ, United Kingdom
| | - John A Endler
- School of Life and Environmental Sciences, Deakin University, Waurn Ponds, VIC 3216, Australia
| | - Karen L Cheney
- School of the Environment, The University of Queensland, University Drive, St. Lucia, QLD 4072, Australia
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2
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Rubio AO, Dye AM, Ifill KE, Summers K. On the wings of dragons: Wing morphometric differences in the sexually dichromatic common whitetail skimmer dragonfly, Plathemis lydia (Odonata: Libellulidae). PLoS One 2024; 19:e0303690. [PMID: 38809838 PMCID: PMC11135787 DOI: 10.1371/journal.pone.0303690] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2024] [Accepted: 04/29/2024] [Indexed: 05/31/2024] Open
Abstract
Sexual dimorphism is common throughout the animal kingdom, leading to sex-specific phenotypic differences. The common whitetail skimmer dragonfly, Plathemis lydia (Drury, 1773), is sexually dichromatic, where males of this species display a conspicuous white abdomen and females display a dark brown abdomen. Differences in abdomen conspicuousness between male and female P. lydia are likely attributed to differences in selective pressure where males use their white conspicuous abdomen during male-male territorial chases. We hypothesized that male P. lydia would exhibit wing morphology adaptations to better offset the costs of predation and territoriality and that these adaptations would differ from females. We used field-collected images to quantify differences in body length, wing length, wing area, wing shape, and wing loading between male and female P. lydia. Our results show that male P. lydia have significantly shorter fore and hind wings relative to body size with a higher wing loading when compared to females. We also found that male P. lydia have narrower and pointier fore and hind wings compared to females. These results are consistent with the idea that males are adapted for faster flight, specifically higher acceleration capacity, and higher agility whereas females are adapted for higher maneuverability.
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Affiliation(s)
- Andrew O. Rubio
- Department of Biology, East Carolina University, Greenville, North Carolina, United States of America
- Department of Biology and Biochemistry, University of Houston, Houston, Texas, United States of America
| | - Ashley M. Dye
- Department of Biology, East Carolina University, Greenville, North Carolina, United States of America
- Department of Biology and Biochemistry, University of Houston, Houston, Texas, United States of America
| | - Kyle E. Ifill
- Department of Biology, East Carolina University, Greenville, North Carolina, United States of America
| | - Kyle Summers
- Department of Biology, East Carolina University, Greenville, North Carolina, United States of America
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3
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Friedman NR, Remeš V. Dorsal and Ventral Plumage Coloration Evolve as Distinct Modules with Different Environmental Correlations. Am Nat 2024; 203:528-534. [PMID: 38489773 DOI: 10.1086/728766] [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] [Indexed: 03/17/2024]
Abstract
AbstractMany animals exhibit contrast between their dorsal coloration and their ventral coloration. If selection acts differently on dorsal versus ventral coloration, ancestral covariance between these traits should break down, eventually leading to independent modules of trait evolution. Here, we compare the evolution of feather color across body regions for a clade of Australasian songbirds (Meliphagoidea). We find evidence for three modules of covarying color regions. Among these modules, ventral feathers evolve with high lability, evolving at three times the rate of dorsal plumage and 20 times the rate of flight feathers. While both dorsal plumage and ventral plumage are darker in areas with more precipitation and vegetation, we find that dorsal plumage is twice as similar to colors in satellite photos of background substrates. Overall, differential selection on ventral and dorsal colors likely maintains these as distinct modules over evolutionary timescales-a novel explanation for dorsoventral contrast in pigmentation.
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4
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Keren-Rotem T, Main DC, Barocas A, Donaire-Barroso D, Haddas-Sasson M, Vila C, Shaharabany T, Wolf L, Tolley KA, Geffen E. Genetic and behavioural factors affecting interpopulation colour pattern variation in two congeneric chameleon species. ROYAL SOCIETY OPEN SCIENCE 2024; 11:231554. [PMID: 38234439 PMCID: PMC10792394 DOI: 10.1098/rsos.231554] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/13/2023] [Accepted: 12/19/2023] [Indexed: 01/19/2024]
Abstract
We conducted a study on interpopulation variation of colour patterns in two congeneric chameleon species, which have an analogous life history. Both species are able to rapidly change colour pattern, and their context-dependent colour patterns often vary across a wide geographical range. Specifically, we tested four hypotheses that can explain the observed interpopulation variation of colour patterns by a series of behavioural field trials where the colour patterns of individuals were recorded and later analysed by a deep neural network algorithm. We used redundancy analysis to relate genetic, spectral and behavioural predictors to interpopulation colour pattern distance. Our results showed that both isolation by distance (IBD) and alternative mating tactics were significant predictors for interpopulation colour pattern variation in Chamaeleo chamaeleon males. By contrast, in Chamaeleo dilepis, the interpopulation colour pattern variation was largely explained by IBD, and evidence for alternative mating tactics was absent. In both chameleon species, the environmental colours showed no evidence of influencing chameleon interpopulation colour pattern variation, regardless of sex or behavioural context. This contrasting finding suggests that interpopulation context-dependent colour pattern variations in each species are maintained under a different set of selective pressures or circumstances.
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Affiliation(s)
- Tammy Keren-Rotem
- Ecology Department, Israel Nature and Parks Authority, Jerusalem, Israel
| | - Devon C. Main
- Centre for Ecological Genomics and Wildlife Conservation, University of Johannesburg, Auckland Park Campus, Johannesburg, South Africa
| | - Adi Barocas
- San Diego Zoo Wildlife Alliance, Escondido, CA, USA
- Wildlife Conservation Research Unit, University of Oxford, Oxford, UK
| | | | | | - Carles Vila
- Doñana Biological Station (EBD-CSIC), Seville, Spain
| | - Tal Shaharabany
- The Faculty of Engineering, Tel Aviv University, Tel Aviv, Israel
| | - Lior Wolf
- School of Computer Science, Tel Aviv University, Tel Aviv, Israel
| | - Krystal A. Tolley
- Centre for Ecological Genomics and Wildlife Conservation, University of Johannesburg, Auckland Park Campus, Johannesburg, South Africa
- Kirstenbosch Research Centre, South African National Biodiversity Institute, Cape Town, South Africa
| | - Eli Geffen
- School of Zoology, Tel Aviv University, Tel Aviv, Israel
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5
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Sexual dimorphism in dynamic body color in the green anole lizard. Behav Ecol Sociobiol 2023. [DOI: 10.1007/s00265-023-03308-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/13/2023]
Abstract
Abstract
Animals capable of rapid (i.e., physiological) body color change may use color to respond quickly to changing social or physical environments. Because males and females often differ in their environments, the sexes may use changes in body color differently, reflecting sexual dimorphism in ecological, behavioral, or morphological traits. Green anole lizards, Anolis carolinensis, frequently switch their dorsal body color between bright green and dark brown, a change that requires only seconds, but little is known regarding sexual dimorphism in their color change. We tested three hypotheses for the function of body color (thermoregulation, camouflage via background-matching, and social communication) to determine the ecological role(s) of physiological color change in anoles. First, we examined instantaneous body color to determine relationships between body color and body temperature, substrate color and type, and whether these varied between the sexes. Next, we examined the association between color change and behavioral displays. Altogether, we found that males were more likely to be green than females, and larger lizards were more often green than smaller ones, but there was no evidence that anole body color was associated with body temperature or background color during the summer breeding season. Instead, our results show that although the sexes change their color at approximately the same rates, males changed color more frequently during social displays, while females remained green when displaying. In sum, social communication appears to be the primary function of anole color change, although the functions of body color may differ in the nonbreeding season.
Significance statement
Many animals can change their body color in response to their environments, and in many species, males and females experience different environments. In this study, we examined whether the sexes of green anole lizards use the ability to rapidly change their body color between green and brown for different functions. We found that, when a lizard was first sighted, its body color did not appear to match its background color in either sex (suggesting that color change does not contribute to avoidance of detection by potential predators), and body color was not associated with temperature for either sex (i.e., color was unlikely to influence body temperature). Yet, males changed color more often when performing social displays to other lizards, while females remained green during social displays. Thus, rapid color change plays an important role in social communication in both sexes, highlighting how males and females may use the same behavior to convey different messages.
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6
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Bernal XE, Page RA. Tactics of evasion: strategies used by signallers to deter eavesdropping enemies from exploiting communication systems. Biol Rev Camb Philos Soc 2023; 98:222-242. [PMID: 36176190 DOI: 10.1111/brv.12904] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2022] [Revised: 09/03/2022] [Accepted: 09/06/2022] [Indexed: 01/12/2023]
Abstract
Eavesdropping predators, parasites and parasitoids exploit signals emitted by their prey and hosts for detection, assessment, localization and attack, and in the process impose strong selective pressures on the communication systems of the organisms they exploit. Signallers have evolved numerous anti-eavesdropper strategies to mitigate the trade-off between the costs imposed from signal exploitation and the need for conspecific communication. Eavesdropper strategies fall along a continuum from opportunistic to highly specialized, and the tightness of the eavesdropper-signaller relationship results in differential pressures on communication systems. A wide variety of anti-eavesdropper strategies mitigate the trade-off between eavesdropper exploitation and conspecific communication. Antagonistic selection from eavesdroppers can result in diverse outcomes including modulation of signalling displays, signal structure, and evolutionary loss or gain of a signal from a population. These strategies often result in reduced signal conspicuousness and in decreased signal ornamentation. Eavesdropping enemies, however, can also promote signal ornamentation. While less common, this alternative outcome offers a unique opportunity to dissect the factors that may lead to different evolutionary pathways. In addition, contrary to traditional assumptions, no sensory modality is completely 'safe' as eavesdroppers are ubiquitous and have a broad array of sensory filters that allow opportunity for signal exploitation. We discuss how anthropogenic change affects interactions between eavesdropping enemies and their victims as it rapidly modifies signalling environments and community composition. Drawing on diverse research from a range of taxa and sensory modalities, we synthesize current knowledge on anti-eavesdropper strategies, discuss challenges in this field and highlight fruitful new directions for future research. Ultimately, this review offers a conceptual framework to understand the diverse strategies used by signallers to communicate under the pressure imposed by their eavesdropping enemies.
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Affiliation(s)
- Ximena E Bernal
- Department of Biological Sciences, Purdue University, 915 W State Street, West Lafayette, IN, 47907, USA.,Smithsonian Tropical Research Institute, Apartado 0843-03092, Balboa, Ancón, Republic of Panama
| | - Rachel A Page
- Smithsonian Tropical Research Institute, Apartado 0843-03092, Balboa, Ancón, Republic of Panama
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7
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Stadler SR, Brock KM, Bednekoff PA, Foufopoulos J. More and bigger lizards reside on islands with more resources. J Zool (1987) 2022. [DOI: 10.1111/jzo.13036] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Affiliation(s)
- S. R. Stadler
- School for Environment and Sustainability University of Michigan, Ann Arbor Ann Arbor MI USA
| | - K. M. Brock
- Department of Environmental Science, Policy, and Management, College of Natural Resources University of California, Berkeley Berkeley CA USA
- Museum of Vertebrate Zoology University of California, Berkeley Berkeley CA USA
| | - P. A. Bednekoff
- Department of Biology Eastern Michigan University Ypsilanti MI USA
| | - J. Foufopoulos
- School for Environment and Sustainability University of Michigan, Ann Arbor Ann Arbor MI USA
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8
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Smolinský R, Hiadlovská Z, Maršala Š, Škrabánek P, Škrobánek M, Martínková N. High predation risk decimates survival during the reproduction season. Ecol Evol 2022; 12:e9407. [PMID: 36262266 PMCID: PMC9576000 DOI: 10.1002/ece3.9407] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2022] [Revised: 08/22/2022] [Accepted: 08/25/2022] [Indexed: 11/30/2022] Open
Abstract
Predators attack conspicuous prey phenotypes that are present in the environment. Male display behavior of conspicuous nuptial coloration becomes risky in the presence of a predator, and adult males face higher predation risk. High predation risk in one sex will lead to low survival and sex ratio bias in adult cohorts, unless the increased predation risk is compensated by higher escape rate.Here, we tested the hypothesis that sand lizards (Lacerta agilis) have sex-specific predation risk and escape rate. We expected the differences to manifest in changes in sex ratio with age, differences in frequency of tail autotomy, and in sex-specific survival rate.We developed a statistical model to estimate predation risk and escape rate, combining the observed sex ratio and frequency of tail autotomy with likelihood-based survival rate. Using Bayesian framework, we estimated the model parameters. We projected the date of the tail autotomy events from growth rates derived from capture-recapture data measurements.We found statistically stable sex ratio in age groups, equal frequency of tail regenerates between sexes, and similar survival rate. Predation risk is similar between sexes, and escape rate increases survival by about 5%. We found low survival rate and a low number of tail autotomy events in females during months when sand lizards mate and lay eggs, indicating high predator pressure throughout reproduction. Our data show that gravid females fail to escape predation.The risks of reproduction season in an ectotherm are a convolution of morphological changes (conspicuous coloration in males and body allometry changes in gravid females), behavior (nuptial displays), and environmental conditions which challenge lizard thermal performance. Performance of endotherm predators in cold spring months endangers gravid females more than displaying males in bright nuptial coloration.
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Affiliation(s)
- Radovan Smolinský
- Department of Biology, Faculty of EducationMasaryk UniversityBrnoCzech Republic
| | - Zuzana Hiadlovská
- Institute of Animal Physiology and GeneticsCzech Academy of SciencesBrnoCzech Republic
| | - Štěpán Maršala
- Institute of Automation and Computer ScienceBrno University of TechnologyBrnoCzech Republic
| | - Pavel Škrabánek
- Institute of Automation and Computer ScienceBrno University of TechnologyBrnoCzech Republic
| | - Michal Škrobánek
- Department of Biology, Faculty of EducationMasaryk UniversityBrnoCzech Republic
| | - Natália Martínková
- Institute of Vertebrate BiologyCzech Academy of SciencesBrnoCzech Republic
- RECETOX, Faculty of ScienceMasaryk UniversityBrnoCzech Republic
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9
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Colour morph predicts social behaviour and contest outcomes in a polymorphic lizard (Podarcis erhardii). Anim Behav 2022. [DOI: 10.1016/j.anbehav.2022.06.017] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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10
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Diversity and Sexual Dichromatism in Treefrog Throat Coloration: Potential Signal Function? J HERPETOL 2022. [DOI: 10.1670/21-047] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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11
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Murphy MJ, Westerman EL. Evolutionary history limits species' ability to match colour sensitivity to available habitat light. Proc Biol Sci 2022; 289:20220612. [PMID: 35582803 PMCID: PMC9115023 DOI: 10.1098/rspb.2022.0612] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
The spectrum of light that an animal sees-from ultraviolet to far red light-is governed by the number and wavelength sensitivity of a family of retinal proteins called opsins. It has been hypothesized that the spectrum of light available in an environment influences the range of colours that a species has evolved to see. However, invertebrates and vertebrates use phylogenetically distinct opsins in their retinae, and it remains unclear whether these distinct opsins influence what animals see, or how they adapt to their light environments. Systematically using published visual sensitivity data from across animal phyla, we found that terrestrial animals are more sensitive to shorter and longer wavelengths of light than aquatic animals and that invertebrates are more sensitive to shorter wavelengths of light than vertebrates. Using phylogenetically controlled analyses, we found that closed and open canopy habitat species have different spectral sensitivities when comparing across the Metazoa and excluding habitat generalists, while deepwater animals are no more sensitive to shorter wavelengths of light than shallow-water animals. Our results suggest that animals do adapt to their light environment; however, the invertebrate-vertebrate evolutionary divergence may limit the degree to which animals can perform visual tuning.
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Affiliation(s)
- Matthew J. Murphy
- Department of Biological Sciences, University of Arkansas, Fayetteville, AR 72701, USA
| | - Erica L. Westerman
- Department of Biological Sciences, University of Arkansas, Fayetteville, AR 72701, USA
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12
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Abalos J, Pérez i de Lanuza G, Bartolomé A, Aubret F, Uller T, Font E. Viability, behavior, and color expression in the offspring of matings between common wall lizard Podarcis muralis color morphs. Curr Zool 2022; 68:41-55. [PMID: 35169628 PMCID: PMC8836344 DOI: 10.1093/cz/zoab039] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2020] [Accepted: 05/07/2021] [Indexed: 01/21/2023] Open
Abstract
Color polymorphisms are widely studied to identify the mechanisms responsible for the origin and maintenance of phenotypic variability in nature. Two of the mechanisms of balancing selection currently thought to explain the long-term persistence of polymorphisms are the evolution of alternative phenotypic optima through correlational selection on suites of traits including color and heterosis. Both of these mechanisms can generate differences in offspring viability and fitness arising from different morph combinations. Here, we examined the effect of parental morph combination on fertilization success, embryonic viability, newborn quality, antipredator, and foraging behavior, as well as inter-annual survival by conducting controlled matings in a polymorphic lacertid Podarcis muralis, where color morphs are frequently assumed to reflect alternative phenotypic optima (e.g., alternative reproductive strategies). Juveniles were kept in outdoor tubs for a year in order to study inter-annual growth, survival, and morph inheritance. In agreement with a previous genome-wide association analysis, morph frequencies in the year-old juveniles matched the frequencies expected if orange and yellow expressions depended on recessive homozygosity at 2 separate loci. Our findings also agree with previous literature reporting higher reproductive output of heavy females and the higher overall viability of heavy newborn lizards, but we found no evidence for the existence of alternative breeding investment strategies in female morphs, or morph-combination effects on offspring viability and behavior. We conclude that inter-morph breeding remains entirely viable and genetic incompatibilities are of little significance for the maintenance of discrete color morphs in P. muralis from the Pyrenees.
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Affiliation(s)
- Javier Abalos
- Ethology Lab, Instituto Cavanilles de Biodiversidad y Biología Evolutiva, Universitat de València, Valencia, Spain
| | - Guillem Pérez i de Lanuza
- Ethology Lab, Instituto Cavanilles de Biodiversidad y Biología Evolutiva, Universitat de València, Valencia, Spain
- CIBIO/InBIO, Centro de Investigação em Biodiversidade e Recursos Genéticos da Universidade do Porto, Porto, Portugal
| | - Alicia Bartolomé
- Ethology Lab, Instituto Cavanilles de Biodiversidad y Biología Evolutiva, Universitat de València, Valencia, Spain
| | - Fabien Aubret
- SETE, Station d’Ecologie Théorique et Expérimentale, UPR2001, Centre National de la Recherche Scientifique, Paris, France
| | - Tobias Uller
- Department of Biology, Lund University, Lund, Sweden
| | - Enrique Font
- Ethology Lab, Instituto Cavanilles de Biodiversidad y Biología Evolutiva, Universitat de València, Valencia, Spain
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13
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14
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Storniolo F, Zuffi MAL, Coladonato AJ, Di Vozzo L, Giglio G, Gini AE, Leonetti FL, Luccini S, Mangiacotti M, Scali S, Abate F, Sperone E, Tatini I, Sacchi R. Patterns of variations in dorsal colouration of the Italian wall lizard Podarcis siculus. Biol Open 2021; 10:271968. [PMID: 34447997 PMCID: PMC8503538 DOI: 10.1242/bio.058793] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2021] [Accepted: 08/23/2021] [Indexed: 12/22/2022] Open
Abstract
Research on animal colouration has grown exponentially in the last decade thanks to multidisciplinary approaches. Most studies are focused on trade-offs between communication and mimicry, which represent the two main constraints and drivers of the evolution of body colourations. Reptiles are excellent model species for investigating this field of study and lizards in particular show great variability of body colourations and their functions. We studied the lizard Podarcis siculus, analysing the variations of dorsal colour of three populations and obtained clear patterns of seasonal and ontogenetical variation of dorsal colour. According to baseline colour, males were greener and brighter than females, although no difference in saturation was recorded. According to seasonal variations, analyses showed that both sexes significantly vary in colour over the year: males reached higher peaks of hue and saturation later than females during spring, while females showed higher peaks of brightness and reached earlier similarly to hue and saturation. Ontogenetic variations were recorded only in males, which become greener, less bright and saturated with growing size. Therefore, our results suggest the occurrence of two opposing strategies in colour expression between sexes: males’ dorsal colouration plays a major role in communication, while females are more crypsis-oriented. Summary: This research paper focuses on the dorsal chromatic variations in Mediterranean lizards, analysing the effect of seasonality and ontogeny.
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Affiliation(s)
- Federico Storniolo
- Museo di Storia Naturale, Università di Pisa, Via Roma 79, Calci (PI) 56011, Italy
| | - Marco A L Zuffi
- Museo di Storia Naturale, Università di Pisa, Via Roma 79, Calci (PI) 56011, Italy
| | - Alan J Coladonato
- Dipartimento di Scienze della Terra e dell'Ambiente, Università di Pavia, Viale Tamarelli 24, Pavia I-27100, Italy
| | - Loris Di Vozzo
- Museo di Storia Naturale, Università di Pisa, Via Roma 79, Calci (PI) 56011, Italy
| | - Gianni Giglio
- Dipartimento di Biologia, Ecologia e Scienze della Terra, Università della Calabria, Via Pietro Bucci, Arcavacata di Rende, Cosenza 87036, Italy
| | - Andrea E Gini
- Museo di Storia Naturale, Università di Pisa, Via Roma 79, Calci (PI) 56011, Italy.,Faculty of Sciences, Scuola Normale Superiore, Piazza dei Cavalieri 7, Pisa 5616, Italy
| | - Francesco L Leonetti
- Dipartimento di Biologia, Ecologia e Scienze della Terra, Università della Calabria, Via Pietro Bucci, Arcavacata di Rende, Cosenza 87036, Italy
| | - Simone Luccini
- Museo di Storia Naturale, Università di Pisa, Via Roma 79, Calci (PI) 56011, Italy
| | - Marco Mangiacotti
- Dipartimento di Scienze della Terra e dell'Ambiente, Università di Pavia, Viale Tamarelli 24, Pavia I-27100, Italy.,Museo di Storia Naturale, Corso Venezia 55, Milano 20121, Italy
| | - Stefano Scali
- Museo di Storia Naturale, Corso Venezia 55, Milano 20121, Italy
| | - Federico Abate
- Dipartimento di Scienze della Terra e dell'Ambiente, Università di Pavia, Viale Tamarelli 24, Pavia I-27100, Italy
| | - Emilio Sperone
- Dipartimento di Biologia, Ecologia e Scienze della Terra, Università della Calabria, Via Pietro Bucci, Arcavacata di Rende, Cosenza 87036, Italy
| | - Irene Tatini
- Museo di Storia Naturale, Università di Pisa, Via Roma 79, Calci (PI) 56011, Italy
| | - Roberto Sacchi
- Dipartimento di Scienze della Terra e dell'Ambiente, Università di Pavia, Viale Tamarelli 24, Pavia I-27100, Italy
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15
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Dynamic visual noise promotes social attraction, but does not affect group size preference, in a shoaling fish. Anim Behav 2021. [DOI: 10.1016/j.anbehav.2021.04.017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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16
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Information content of ultraviolet-reflecting colour patches and visual perception of body coloration in the Tyrrhenian wall lizard Podarcis tiliguerta. Behav Ecol Sociobiol 2021. [DOI: 10.1007/s00265-021-03023-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
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17
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Torres MDM, Viladrich LJ, Naretto S. Role of coloration in antipredator strategies of Pristidactylus achalensis (Squamata: Leiosauridae) related to sex and stages of predation. Biol J Linn Soc Lond 2021. [DOI: 10.1093/biolinnean/blab012] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
Abstract
The interaction between behavioural and phenotypic traits, such as coloration, plays a specific role at different stages of the predatory sequence. Cryptic coloration involves a match to the background that reduces the risk of detection, and it is usually optimized by immobility behaviour. In lizards, sexual dichromatism and within-individual changes of colour can influence the level of their crypsis and thus influence antipredator behaviour and the decision to flee. Here, we examined variation in coloration and antipredator behaviour between the sexes of the Achala copper lizard (Pristidactylus achalensis). We measured sexual dichromatism and crypsis in accordance with avian vision. We also exposed lizards to a raptor dummy to assess the colour change and behaviour at the detection and approach stages of the predatory event. Finally, we tested escape behaviour in the natural habitat. We found that males were more conspicuous than females. Additionally, individuals showed distinct behaviours at different stages of the predation simulation, but there were no differences between the sexes. However, in their natural habitat males initiated flight at greater distances than females, which might be related to their more conspicuous coloration. In summary, this study shows how differences in crypsis between the sexes affect escape behaviour during the approach stage of predation.
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Affiliation(s)
- María Del Milagro Torres
- Laboratorio de Biología del Comportamiento, Facultad de Ciencias Exactas, Físicas y Naturales, Universidad Nacional de Córdoba, Av. Vélez Sarsfield 299, 5000 Córdoba, Argentina
| | - Leonel Jeremías Viladrich
- Laboratorio de Biología del Comportamiento, Facultad de Ciencias Exactas, Físicas y Naturales, Universidad Nacional de Córdoba, Av. Vélez Sarsfield 299, 5000 Córdoba, Argentina
| | - Sergio Naretto
- Laboratorio de Biología del Comportamiento, Facultad de Ciencias Exactas, Físicas y Naturales, Universidad Nacional de Córdoba, Av. Vélez Sarsfield 299, 5000 Córdoba, Argentina
- Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Instituto de Diversidad y Ecología Animal (IDEA), Av. Vélez Sarsfield 299, 5000 Córdoba, Argentina
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18
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Swierk L, Boyer JFF, Chang J, Petelo M, Drobniak SM. Intrasexual variability of a conspicuous social signal influences attack rate of lizard models in an experimental test. Evol Ecol 2020. [DOI: 10.1007/s10682-020-10085-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
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19
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Abramjan A, Arakelyan M, Frynta D. Does reproductive mode affect sexually-selected coloration? Evaluating UV-blue spots in parthenogenetic and bisexual lizards of the genus Darevskia. Curr Zool 2020; 67:201-213. [PMID: 33854538 PMCID: PMC8026159 DOI: 10.1093/cz/zoaa039] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2020] [Accepted: 07/10/2020] [Indexed: 11/14/2022] Open
Abstract
Sexual selection often leads to evolution of conspicuous signals, raising the chances of attracting not only potential mates, but also predators. In lacertid lizards, ultraviolet (UV)–blue spots on flanks and shoulders represent such a trait. Some level of correlation between male and female ornamentation is also known to exist. Therefore, the phenotype of females may change in the absence of sexual selection. We tested this hypothesis on a complex of parthenogenetic and bisexual lizards of the genus Darevskia. We evaluated area, counts, and chromatic properties (UV opponency, saturation) of UV–blue spots and compared the values between the clones and their bisexual progenitor species. We found a fair heterogeneity between the parthenogenetic species, but no general tendency toward higher crypsis or conspicuousness. Values of the parthenogens were not significantly different from the values of sexual females. A possible explanation is that the changes in selective forces associated with parthenogenetic reproduction are too small to affect the resulting pattern of selective pressures on the studied traits, or that the phenotypes of the parthenogens result from the unique combination of parental genomes and are conserved by clonal reproduction.
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Affiliation(s)
- Andran Abramjan
- Department of Zoology, Faculty of Science, Charles University, Viničná 7, Prague, 12843, Czech Republic
| | - Marine Arakelyan
- Department of Zoology, Faculty of Biology, Yerevan State University, Alek Manoogian 1, Yerevan, 0025, Armenia
| | - Daniel Frynta
- Department of Zoology, Faculty of Science, Charles University, Viničná 7, Prague, 12843, Czech Republic
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Naretto S, Chiaraviglio M. Factors driving sexual dimorphism and colour variability in the Achala Copper Lizard (Pristidactylus achalensis), an endemic species to the highland mountains in central Argentina. CAN J ZOOL 2020. [DOI: 10.1139/cjz-2019-0293] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The intensity of mating competition varies according to the temporal and spatial distribution of individuals. Measuring sexual dimorphism over time and interpreting the association between individuals is therefore important if we aim to understand how sexual traits are influenced. We examined sex differences in the Achala Copper Lizard (Pristidactylus achalensis (Gallardo, 1964)), an endemic species from the highest part of mountains of central Argentina. Over 4 years, we explored sex-specific variation in body size, head size, interlimb length, and body colouration. Furthermore, we evaluated how these traits varied temporally, and we also explored whether the spatial distribution of individuals is explained by variation in these traits. We found that P. achalensis is a species with sexual dimorphism in multiple characters, including body size, head size, and colouration. Interestingly, some traits related to mating, such as head width, show a temporal variability in both sexes, whereas other traits, such as colouration, varies seasonally only in males. Our results underline the intriguing possibility of seasonal morphological changes related to mating, and more broadly that sex differences are influenced by sexual selection pressures mediated by temporal variation in mate competition.
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Affiliation(s)
- S. Naretto
- Laboratorio de Biología del Comportamiento, Facultad de Ciencias Exactas, Físicas y Naturales, Universidad Nacional de Córdoba, Vélez Sársfield 299, CP X5000JJC, Córdoba, Argentina; Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Instituto de Diversidad y Ecología Animal (IDEA), Córdoba, Argentina
- Laboratorio de Biología del Comportamiento, Facultad de Ciencias Exactas, Físicas y Naturales, Universidad Nacional de Córdoba, Vélez Sársfield 299, CP X5000JJC, Córdoba, Argentina; Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Instituto de Diversidad y Ecología Animal (IDEA), Córdoba, Argentina
| | - M. Chiaraviglio
- Laboratorio de Biología del Comportamiento, Facultad de Ciencias Exactas, Físicas y Naturales, Universidad Nacional de Córdoba, Vélez Sársfield 299, CP X5000JJC, Córdoba, Argentina; Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Instituto de Diversidad y Ecología Animal (IDEA), Córdoba, Argentina
- Laboratorio de Biología del Comportamiento, Facultad de Ciencias Exactas, Físicas y Naturales, Universidad Nacional de Córdoba, Vélez Sársfield 299, CP X5000JJC, Córdoba, Argentina; Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Instituto de Diversidad y Ecología Animal (IDEA), Córdoba, Argentina
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21
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Bliard L, Paquet M, Robert A, Dufour P, Renoult JP, Grégoire A, Crochet PA, Covas R, Doutrelant C. Examining the link between relaxed predation and bird coloration on islands. Biol Lett 2020; 16:20200002. [PMID: 32315593 DOI: 10.1098/rsbl.2020.0002] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Insular ecosystems share analogous ecological conditions, leading to patterns of convergent evolution that are collectively termed as the 'island syndrome'. In birds, part of this syndrome is a tendency for a duller plumage, possibly as a result of relaxed sexual selection. Despite this global pattern, some insular species display a more colourful plumage than their mainland relatives, but why this occurs has remained unexplained. Here, we examine the hypothesis that these cases of increased plumage coloration on islands could arise through a relaxation of predation pressure. We used comparative analyses to investigate whether average insular richness of raptors of suitable mass influences the plumage colourfulness and brightness across 110 pairs of insular endemic species and their closest mainland relatives. As predicted, we find a likely negative relationship between insular coloration and insular predation while controlling for mainland predation and coloration, suggesting that species were more likely to become more colourful as the number of insular predators decreased. By contrast, plumage brightness was not influenced by predation pressure. Relaxation from predation, together with drift, might thus be a key mechanism of species phenotypic responses to insularity.
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Affiliation(s)
- Louis Bliard
- CEFE UMR 5175, CNRS - Université de Montpellier - EPHE, 1919 route de Mende, 34293 Montpellier Cedex 05, France
| | - Matthieu Paquet
- Department of Ecology, Swedish University of Agricultural Sciences, Box 7044, SE-75007 Uppsala, Sweden
| | - Aloïs Robert
- CEFE UMR 5175, CNRS - Université de Montpellier - EPHE, 1919 route de Mende, 34293 Montpellier Cedex 05, France
| | - Paul Dufour
- Laboratoire d'Écologie Alpine, Université Grenoble Alpes, CNRS, Université Savoie Mont Blanc, LECA, F-38000 Grenoble, France
| | - Julien P Renoult
- CEFE UMR 5175, CNRS - Université de Montpellier - EPHE, 1919 route de Mende, 34293 Montpellier Cedex 05, France
| | - Arnaud Grégoire
- CEFE UMR 5175, CNRS - Université de Montpellier - EPHE, 1919 route de Mende, 34293 Montpellier Cedex 05, France
| | - Pierre-André Crochet
- CEFE UMR 5175, CNRS - Université de Montpellier - EPHE, 1919 route de Mende, 34293 Montpellier Cedex 05, France
| | - Rita Covas
- CIBIO-InBio, University of Porto, Rua Monte-Crasto, 4485-661 Vairão, Portugal.,Biology Department, Science Faculty, University of Porto, Porto, Portugal.,Percy FitzPatrick Institute, DST-NRF Centre of Excellence, University of Cape Town, Rondebosch 7701, South Africa
| | - Claire Doutrelant
- CEFE UMR 5175, CNRS - Université de Montpellier - EPHE, 1919 route de Mende, 34293 Montpellier Cedex 05, France.,Percy FitzPatrick Institute, DST-NRF Centre of Excellence, University of Cape Town, Rondebosch 7701, South Africa
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22
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Amdekar MS, Thaker M. Risk of social colours in an agamid lizard: implications for the evolution of dynamic signals. Biol Lett 2019; 15:20190207. [PMID: 31088284 DOI: 10.1098/rsbl.2019.0207] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
The forces of sexual and natural selection are typically invoked to explain variation in colour patterns of animals. Although the benefits of conspicuous colours for social signalling are well documented, evidence for their ecological cost, especially for dynamic colours, remains limited. We examined the riskiness of colour patterns of Psammophilus dorsalis, a species in which males express distinct colour combinations during social interactions. We first measured the conspicuousness of these colour patterns on different substrates based on the visual systems of conspecifics and predators (bird, snake, canid) and then quantified actual predation risk on these patterns using wax/polymer lizard models in the wild. The black and red male state exhibited during courtship was the most conspicuous to all visual systems, while the yellow and orange male aggression state and the brown female colour were least conspicuous. Models bearing the courtship colour pattern experienced the highest predator attacks, irrespective of the substrate they were placed on. Thus, social colours of males are not only conspicuous but also risky. Using physiological colours to shift in and out of conspicuous states may be an effective evolutionary solution to balance social signalling benefits with predation costs.
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Affiliation(s)
- Madhura S Amdekar
- Centre for Ecological Sciences, Indian Institute of Science , Bengaluru 560012 , India
| | - Maria Thaker
- Centre for Ecological Sciences, Indian Institute of Science , Bengaluru 560012 , India
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23
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Abstract
Predation usually selects for visual crypsis, the colour matching between an animal and its background. Geographic co-variation between animal and background colourations is well known, but how crypsis varies along elevational gradients remains unknown. We predict that dorsal colouration in the lizard Psammodromus algirus should covary with the colour of bare soil—where this lizard is mainly found—along a 2200 m elevational gradient in Sierra Nevada (SE Spain). Moreover, we predict that crypsis should decrease with elevation for two reasons: (1) Predation pressure typically decreases with elevation, and (2) at high elevation, dorsal colouration is under conflicting selection for both crypsis and thermoregulation. By means of standardised photographies of the substratum and colourimetric measurements of lizard dorsal skin, we tested the colour matching between lizard dorsum and background. We found that, along the gradient, lizard dorsal colouration covaried with the colouration of bare soil, but not with other background elements where the lizard is rarely detected. Moreover, supporting our prediction, the degree of crypsis against bare soil decreased with elevation. Hence, our findings suggest local adaptation for crypsis in this lizard along an elevational gradient, but this local adaptation would be hindered at high elevations.
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Rossi N, Benitez-Vieyra S, Cocucci A, Chiaraviglio M, Cardozo G. Sexual dichromatism and color diversity in the spiny lava lizard Tropidurus spinulosus using lizard visual modelling. Sci Rep 2019; 9:14270. [PMID: 31582783 PMCID: PMC6776660 DOI: 10.1038/s41598-019-50712-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2018] [Accepted: 09/17/2019] [Indexed: 12/04/2022] Open
Abstract
Colors are important vehicles for social signals in many taxa. In Squamata, previous studies have linked color characteristics and chromatic diversity to sexual selection and, particularly, species showing male-biased body size dimorphism also showed male-biased dichromatism and color diversity. Sexual dichromatism may occur in body regions used for conspecific communication and it may be expressed at wavelengths, such as ultraviolet, easily perceivable by conspecifics. We tested this prediction in a social lizard model, Tropidurus spinulosus, using spectrophotometry and visual modelling which enable colors to be interpreted as the individuals of the same taxon see them. Our results indicate that sexual dichromatism occurs in the ventral regions and the flanks, which are the body regions involved in sexual displays. Males show greater color diversity, having larger color volumes and more contrasting colors. These findings reinforce the idea that sexual selection towards males is coupled with the evolution of male-biased, diverse, coloration which could act as a signal in social reproductive contexts.
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Affiliation(s)
- N Rossi
- Universidad Nacional de Córdoba, Facultad de Ciencias Exactas Físicas y Naturales. Laboratorio de Biología del Comportamiento, Córdoba, Argentina. .,Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Instituto de Diversidad y Ecología Animal (IDEA), Córdoba, Argentina.
| | - S Benitez-Vieyra
- Laboratorio de Ecología Evolutiva y Biología Floral, IMBIV-CONICET, FCEFyN, Universidad Nacional de Córdoba, Córdoba, Argentina
| | - A Cocucci
- Laboratorio de Ecología Evolutiva y Biología Floral, IMBIV-CONICET, FCEFyN, Universidad Nacional de Córdoba, Córdoba, Argentina
| | - M Chiaraviglio
- Universidad Nacional de Córdoba, Facultad de Ciencias Exactas Físicas y Naturales. Laboratorio de Biología del Comportamiento, Córdoba, Argentina.,Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Instituto de Diversidad y Ecología Animal (IDEA), Córdoba, Argentina
| | - G Cardozo
- Universidad Nacional de Córdoba, Facultad de Ciencias Exactas Físicas y Naturales. Laboratorio de Biología del Comportamiento, Córdoba, Argentina.,Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Instituto de Diversidad y Ecología Animal (IDEA), Córdoba, Argentina
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25
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Cooption of the pteridine biosynthesis pathway underlies the diversification of embryonic colors in water striders. Proc Natl Acad Sci U S A 2019; 116:19046-19054. [PMID: 31484764 PMCID: PMC6754612 DOI: 10.1073/pnas.1908316116] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Understanding how existing genomic content can be reused to generate new phenotypes is important for understanding how species diversify. Here, we address this question by studying the origin of a phenotype consisting of bright coloration in the embryos of water striders. We found that the pteridine biosynthesis pathway, originally active in the eyes, has been coopted in the embryo to produce various colors in the antennae and legs. The coopted pathway remained stable for over 200 million years, yet resulted in a striking diversification of colors and color patterns during the evolution of water striders. This work demonstrates how the activation of a complete pathway in new developmental contexts can drive the evolution of novelty and fuel species diversification. Naturalists have been fascinated for centuries by animal colors and color patterns. While widely studied at the adult stage, we know little about color patterns in the embryo. Here, we study a trait consisting of coloration that is specific to the embryo and absent from postembryonic stages in water striders (Gerromorpha). By combining developmental genetics with chemical and phylogenetic analyses across a broad sample of species, we uncovered the mechanisms underlying the emergence and diversification of embryonic colors in this group of insects. We show that the pteridine biosynthesis pathway, which ancestrally produces red pigment in the eyes, has been recruited during embryogenesis in various extraocular tissues including antennae and legs. In addition, we discovered that this cooption is common to all water striders and initially resulted in the production of yellow extraocular color. Subsequently, 6 lineages evolved bright red color and 2 lineages lost the color independently. Despite the high diversity in colors and color patterns, we show that the underlying biosynthesis pathway remained stable throughout the 200 million years of Gerromorpha evolutionary time. Finally, we identified erythropterin and xanthopterin as the pigments responsible for these colors in the embryo of various species. These findings demonstrate how traits can emerge through the activation of a biosynthesis pathway in new developmental contexts.
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26
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The relative importance of body size and UV coloration in influencing male-male competition in a lacertid lizard. Behav Ecol Sociobiol 2019. [DOI: 10.1007/s00265-019-2710-z] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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27
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Pérez i de Lanuza G, Bellati A, Pellitteri‐Rosa D, Font E, Carretero MA. Colour variation between different lineages of a colour polymorphic lizard. J Zool (1987) 2019. [DOI: 10.1111/jzo.12658] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Affiliation(s)
- G. Pérez i de Lanuza
- CIBIO Research Centre in Biodiversity and Genetic Resources InBIO Universidade do Porto Vila do Conde Portugal
| | - A. Bellati
- Department of Earth and Environmental Sciences University of Pavia Pavia Italy
| | - D. Pellitteri‐Rosa
- Department of Earth and Environmental Sciences University of Pavia Pavia Italy
| | - E. Font
- Cavanilles Institute of Biodiversity and Evolutionary Biology University of Valencia València Spain
| | - M. A. Carretero
- CIBIO Research Centre in Biodiversity and Genetic Resources InBIO Universidade do Porto Vila do Conde Portugal
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28
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Bruinjé AC, Moura MO, Maggi BS, São-Pedro VA, Pessoa DM, Costa GC. Conspecifics of the Striped Lava Lizard are able to distinguish sex and male colour morphs in apparently homogeneous dull dorsal colouration. AMPHIBIA-REPTILIA 2019. [DOI: 10.1163/15685381-20181048] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Abstract
Animal colouration plays a key role in inter and intraspecific interactions, pre-eminently in mate signalling. When multiple types of colouration occur within sexes it is possible that they show alternative reproductive strategies. In lizards, most colouration studies do not incorporate how colour is perceived by conspecifics. Here, we used unbiased colour analysis methods (spectrophotometry and visual modelling) to test for sexual dimorphism and within male dichromatism in the Striped Lava Lizard. We found that males express two distinct colourations that are different from females in several dorsal and ventral body regions. Our results showed UV reflection at the throat, an important body region for signalling. Ventral patches, the coloured badge seen in adult males of Tropidurus spp., have two distinct colour classes within males (Y and B males). Morphs are best discriminated by blue and yellow chroma, and brightness. Body size had little influence on colouration, suggesting that colour may be linked to inheritance rather than growth. Our study clearly shows sexual dichromatism and the existence of colour morphs in this species. Moreover, morph differences in colouration are perceptible by conspecifics. These differences are not only between ventral patches, but also in other body parts such as the dorsum, previously considered as cryptic by human observers. We suggest that colouration at the ventral patches and throat might play a role in intraspecific interactions. Patches increase colour intensity during breeding season and are likely to be costly by pigment-based expression, whereas throat’s UV reflection might have a cost infringed by conspicuousness.
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Affiliation(s)
- Andre C. Bruinjé
- 1Graduate Program in Ecology and Conservation Biology, Department of Zoology, Universidade Federal do Paraná, Curitiba, Paraná, Brazil
- 2Laboratory of Biogeography, Macroecology and Evolutionary Biology, Universidade Federal do Rio Grande do Norte, Natal, Rio Grande do Norte, Brazil
| | - Mauricio O. Moura
- 1Graduate Program in Ecology and Conservation Biology, Department of Zoology, Universidade Federal do Paraná, Curitiba, Paraná, Brazil
| | - Bruno S. Maggi
- 2Laboratory of Biogeography, Macroecology and Evolutionary Biology, Universidade Federal do Rio Grande do Norte, Natal, Rio Grande do Norte, Brazil
| | - Vinicius A. São-Pedro
- 3Laboratory of Sensory Ecology, Department of Physiology, Universidade Federal do Rio Grande do Norte, Natal, Rio Grande do Norte, Brazil
- 4Centro de Ciências da Natureza, Universidade Federal de São Carlos, Campus Lagoa do Sino, Buri, São Paulo, Brazil
| | - Daniel M.A. Pessoa
- 3Laboratory of Sensory Ecology, Department of Physiology, Universidade Federal do Rio Grande do Norte, Natal, Rio Grande do Norte, Brazil
| | - Gabriel C. Costa
- 5Department of Biology, Auburn University at Montgomery, Montgomery, AL 36124, USA
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29
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Resolving tradeoffs among crypsis, escape behavior, and microhabitat use in sexually dichromatic species. Oecologia 2018; 189:91-104. [PMID: 30430233 DOI: 10.1007/s00442-018-4301-5] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2018] [Accepted: 11/08/2018] [Indexed: 10/27/2022]
Abstract
Variation in color pattern between populations of cryptic animals is common and typically attributed to selection pressures from visual predators combined with variation in substrate composition. However, little is known about how cryptic color pattern relates to varied rates of predation, and few studies simultaneously analyze patterns of escape behavior and microhabitat use along with variation in color pattern, even though these traits evolve in tandem. Here, we use a combination of calibrated photographs and spectrometry to examine the influence of spatial heterogeneity in rates of predation on dorsal brightness in the Florida scrub lizard (Sceloporus woodi), a cryptic and sexually dimorphic species. Simultaneously, we analyze patterns of escape behavior and microhabitat use measured in the field. The results of this study indicate that populations inhabiting environments of increased predation have less color variation and more closely match the color of local substrate than populations sampled in environments of relaxed predation. Populations exposed to increased predation also show more pronounced escape behavior and are more selective in their use of microhabitat. Interestingly, geographic variation of dorsal brightness, escape behavior, and microhabitat use were greater for females than for males. Our results not only provide empirical evidence for theories of adaptive coloration, but suggest that sexual dichromatism can be maintained by selection pressures related to predation.
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30
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Caro T, Newell C, Stankowich T. Ecocorrelates of pelage coloration in pigs and peccaries. J Mammal 2018. [DOI: 10.1093/jmammal/gyy107] [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)
- Tim Caro
- Department of Wildlife, Fish and Conservation Biology, University of California, Davis, Shields Avenue, Davis, CA, USA
| | - Caroline Newell
- Department of Wildlife, Fish and Conservation Biology, University of California, Davis, Shields Avenue, Davis, CA, USA
| | - Theodore Stankowich
- Department of Biological Sciences, California State University, Long Beach, Bellflower Boulevard, Long Beach, CA, USA
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31
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Bohórquez-Alonso ML, Mesa-Avila G, Suárez-Rancel M, Font E, Molina-Borja M. Predictors of contest outcome in males of two subspecies of Gallotia galloti (Squamata: Lacertidae). Behav Ecol Sociobiol 2018. [DOI: 10.1007/s00265-018-2480-z] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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32
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Pérez i de Lanuza G, Ábalos J, Bartolomé A, Font E. Through the eye of a lizard: hue discrimination in a lizard with ventral polymorphic coloration. J Exp Biol 2018; 221:jeb.169565. [DOI: 10.1242/jeb.169565] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2017] [Accepted: 01/18/2018] [Indexed: 12/19/2022]
Abstract
Colour polymorphisms are thought to be maintained by complex evolutionary processes some of which require that the colours of the alternative morphs function as chromatic signals to conspecifics. Unfortunately, a key aspect of this hypothesis has rarely been studied: whether the study species perceives its own colour variation as discrete rather than continuous. The European common wall lizard (Podarcis muralis) presents a striking colour polymorphism: the ventral surface of adults of both sexes may be coloured orange, white, yellow, or with a mosaic of scales combining two colours (orange-white, orange-yellow). Here we use a discrimination learning paradigm to test if P. muralis is capable of discriminating colour stimuli designed to match the ventral colours of conspecifics. We trained 20 lizards to eat from colour-coded wells bored in wooden blocks. Blocks had four colour-coded wells (orange, white, yellow, and an achromatic control), but only one contained food (mealworm larvae). After six trials, the lizards performed significantly better than expected by chance, showing a decrease in both the number of wells explored and the latency to finding the food. Using visual modelling techniques we found that, based on their spectral properties and the lizards’ cone sensitivities, the ventral colours of P. muralis correspond to discrete rather than continuous colour categories, and that colour discriminability (i.e. distance in perceptual space) varies depending on the morphs compared, which may have implications for signal detection and discrimination. These results suggest that P. muralis can discriminate hue differences matching their own ventral colour variation.
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Affiliation(s)
- Guillem Pérez i de Lanuza
- CIBIO/InBIO, Centro de Investigação em Biodiversidade e Recursos Genéticos da Universidade do Porto, Portugal
| | - Javier Ábalos
- CIBIO/InBIO, Centro de Investigação em Biodiversidade e Recursos Genéticos da Universidade do Porto, Portugal
- Ethology Lab, Instituto Cavanilles de Biodiversidad y Biología Evolutiva, Universitat de València, Spain
| | - Alicia Bartolomé
- CIBIO/InBIO, Centro de Investigação em Biodiversidade e Recursos Genéticos da Universidade do Porto, Portugal
- Ethology Lab, Instituto Cavanilles de Biodiversidad y Biología Evolutiva, Universitat de València, Spain
| | - Enrique Font
- Ethology Lab, Instituto Cavanilles de Biodiversidad y Biología Evolutiva, Universitat de València, Spain
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Stevens M, Troscianko J, Wilson-Aggarwal JK, Spottiswoode CN. Improvement of individual camouflage through background choice in ground-nesting birds. Nat Ecol Evol 2017; 1:1325-1333. [PMID: 28890937 PMCID: PMC5584661 DOI: 10.1038/s41559-017-0256-x] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2016] [Accepted: 06/26/2017] [Indexed: 12/29/2022]
Abstract
Animal camouflage is a longstanding example of adaptation. Much research has tested how camouflage prevents detection and recognition, largely focusing on changes to an animal's own appearance over evolution. However, animals could also substantially alter their camouflage by behaviourally choosing appropriate substrates. Recent studies suggest that individuals from several animal taxa could select backgrounds or positions to improve concealment. Here, we test whether individual wild animals choose backgrounds in complex environments, and whether this improves camouflage against predator vision. We studied nest site selection by nine species of ground-nesting birds (nightjars, plovers and coursers) in Zambia, and used image analysis and vision modeling to quantify egg and plumage camouflage to predator vision. Individual birds chose backgrounds that enhanced their camouflage, being better matched to their chosen backgrounds than to other potential backgrounds with respect to multiple aspects of camouflage. This occurred at all three spatial scales tested (a few cm and five meters from the nest, and compared to other sites chosen by conspecifics), and was the case for the eggs of all bird groups studied, and for adult nightjar plumage. Thus, individual wild animals improve their camouflage through active background choice, with choices highly refined across multiple spatial scales.
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Affiliation(s)
- Martin Stevens
- Centre for Ecology & Conservation, College of Life & Environmental Sciences, University of Exeter, Penryn Campus, Penryn, Cornwall, TR10 9FE, UK.
| | - Jolyon Troscianko
- Centre for Ecology & Conservation, College of Life & Environmental Sciences, University of Exeter, Penryn Campus, Penryn, Cornwall, TR10 9FE, UK
| | - Jared K Wilson-Aggarwal
- Centre for Ecology & Conservation, College of Life & Environmental Sciences, University of Exeter, Penryn Campus, Penryn, Cornwall, TR10 9FE, UK
| | - Claire N Spottiswoode
- Department of Zoology, University of Cambridge, Downing Street, Cambridge, CB2 3EJ, UK
- DST-NRF Centre of Excellence at the FitzPatrick Institute of African Ornithology, University of Cape Town, Rondebosch, 7701, South Africa
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Cuthill IC, Allen WL, Arbuckle K, Caspers B, Chaplin G, Hauber ME, Hill GE, Jablonski NG, Jiggins CD, Kelber A, Mappes J, Marshall J, Merrill R, Osorio D, Prum R, Roberts NW, Roulin A, Rowland HM, Sherratt TN, Skelhorn J, Speed MP, Stevens M, Stoddard MC, Stuart-Fox D, Talas L, Tibbetts E, Caro T. The biology of color. Science 2017; 357:357/6350/eaan0221. [DOI: 10.1126/science.aan0221] [Citation(s) in RCA: 353] [Impact Index Per Article: 50.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
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35
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Megía-Palma R, Martínez J, Merino S. Manipulation of parasite load induces significant changes in the structural-based throat color of male iberian green lizards. Curr Zool 2017; 64:293-302. [PMID: 30402070 PMCID: PMC6007217 DOI: 10.1093/cz/zox036] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2016] [Accepted: 05/12/2017] [Indexed: 11/16/2022] Open
Abstract
The honesty of structural-based ornaments is controversial. Sexual selection theory predicts that the honesty of a sexual signal relies on its cost of production or maintenance. Therefore, environmental factors with negative impact on individuals could generate high costs and affect the expression of these sexual signals. In this sense, parasites are a main cost for their hosts. To probe the effect of parasites on the structural-based coloration of a lacertid species Lacerta schreiberi, we have experimentally removed ticks from a group of male Iberian green lizards using an acaricide treatment (i.e., the broad-use insecticide fipronil). All individuals were radio-tracked and recaptured after 15 days to study changes in coloration in both the ultraviolet (UV)-blue (structural-based) and UV-yellow (structural and pigment-based) ornamentations after manipulation, as well as changes in endo- and ectoparasitic load and body condition. Additionally, after the experiment, we measured the skin inflammatory response to a mitogen. The fipronil treatment was effective in reducing ticks and it was associated with a significant reduction of hemoparasite load. Throughout the season, individuals treated with fipronil tended to maintain the brightness of the UV-blue throat coloration while control lizards tended to increase it. However, individuals treated with fipronil that were not infected with hemoparasites significantly reduced the brightness of the UV-blue throat coloration. Individuals with a higher initial tick load exhibited a lower UV saturation increment (UV-blue) and a higher brightness increment (UV-yellow) during the experiment. Overall these results experimentally support the idea that parasites adversely influence the expression of the structural-based coloration of male Iberian green lizards. This adds evidence to the hypothesis that sexual ornaments in lizards function as honest signals.
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Affiliation(s)
- Rodrigo Megía-Palma
- Dept Ecología Evolutiva, Museo Nacional de Ciencias Naturales-CSIC, J. Gutiérrez Abascal 2, E-28006, Madrid, Spain
| | - Javier Martínez
- Área Parasitología, Dept Biomedicina y Biotecnología, Área de Parasitología. Facultad de Farmacia, Universidad de Alcalá de Henares, Alcalá de Henares, E-28871, Madrid, Spain
| | - Santiago Merino
- Dept Ecología Evolutiva, Museo Nacional de Ciencias Naturales-CSIC, J. Gutiérrez Abascal 2, E-28006, Madrid, Spain
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36
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Klomp DA, Stuart-Fox D, Cassidy EJ, Ahmad N, Ord TJ. Color pattern facilitates species recognition but not signal detection: a field test using robots. Behav Ecol 2017. [DOI: 10.1093/beheco/arw186] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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37
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Caro T. Wallace on Coloration: Contemporary Perspective and Unresolved Insights. Trends Ecol Evol 2017; 32:23-30. [DOI: 10.1016/j.tree.2016.10.003] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2016] [Revised: 09/30/2016] [Accepted: 10/03/2016] [Indexed: 10/20/2022]
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38
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39
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Microhabitat choice in island lizards enhances camouflage against avian predators. Sci Rep 2016; 6:19815. [PMID: 26804463 PMCID: PMC4726299 DOI: 10.1038/srep19815] [Citation(s) in RCA: 44] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2015] [Accepted: 12/07/2015] [Indexed: 11/21/2022] Open
Abstract
Camouflage can often be enhanced by genetic adaptation to different local environments. However, it is less clear how individual behaviour improves camouflage effectiveness. We investigated whether individual Aegean wall lizards (Podarcis erhardii) inhabiting different islands rest on backgrounds that improve camouflage against avian predators. In free-ranging lizards, we found that dorsal regions were better matched against chosen backgrounds than against other backgrounds on the same island. This suggests that P. erhardii make background choices that heighten individual-specific concealment. In achromatic camouflage, this effect was more evident in females and was less distinct in an island population with lower predation risk. This suggests that behavioural enhancement of camouflage may be more important in females than in sexually competing males and related to predation risk. However, in an arena experiment, lizards did not choose the background that improved camouflage, most likely due to the artificial conditions. Overall, our results provide evidence that behavioural preferences for substrates can enhance individual camouflage of lizards in natural microhabitats, and that such adaptations may be sexually dimorphic and dependent on local environments. This research emphasizes the importance of considering links between ecology, behaviour, and appearance in studies of intraspecific colour variation and local adaptation.
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40
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Pérez I de Lanuza G, Font E. The evolution of colour pattern complexity: selection for conspicuousness favours contrasting within-body colour combinations in lizards. J Evol Biol 2016; 29:942-51. [PMID: 26801820 DOI: 10.1111/jeb.12835] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2015] [Revised: 01/11/2016] [Accepted: 01/15/2016] [Indexed: 02/04/2023]
Abstract
Many animals display complex colour patterns that comprise several adjacent, often contrasting colour patches. Combining patches of complementary colours increases the overall conspicuousness of the complex pattern, enhancing signal detection. Therefore, selection for conspicuousness may act not only on the design of single colour patches, but also on their combination. Contrasting long- and short-wavelength colour patches are located on the ventral and lateral surfaces of many lacertid lizards. As the combination of long- and short-wavelength-based colours generates local chromatic contrast, we hypothesized that selection may favour the co-occurrence of lateral and ventral contrasting patches, resulting in complex colour patterns that maximize the overall conspicuousness of the signal. To test this hypothesis, we performed a comparative phylogenetic study using a categorical colour classification based on spectral data and descriptive information on lacertid coloration collected from the literature. Our results demonstrate that conspicuous ventral (long-wavelength-based) and lateral (short-wavelength-based) colour patches co-occur throughout the lacertid phylogeny more often than expected by chance, especially in the subfamily Lacertini. These results suggest that selection promotes the evolution of the complex pattern rather than the acquisition of a single conspicuous colour patch, possibly due to the increased conspicuousness caused by the combination of colours with contrasting spectral properties.
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Affiliation(s)
- G Pérez I de Lanuza
- CIBIO Research Centre in Biodiversity and Genetic Resources, InBIO, Universidade do Porto, Campus Agrário de Vairão, Vairão, Vila do Conde, Portugal
| | - E Font
- Ethology Lab, Cavanilles Institute of Biodiversity and Evolutionary Biology, University of Valencia, Paterna, Spain
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41
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Abalos J, Pérez i de Lanuza G, Carazo P, Font E. The role of male coloration in the outcome of staged contests in the European common wall lizard (Podarcis muralis). BEHAVIOUR 2016. [DOI: 10.1163/1568539x-00003366] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Colour signals play a key role in regulating the intensity and outcome of animal contests. Males of the common wall lizard (Podarcis muralis) show conspicuous ventrolateral ultraviolet (UV)-blue and black patches. In addition, some populations express a striking ventral colour polymorphism (i.e., discrete orange, white and yellow morphs). In this study, we set out to evaluate the potential signalling function of these colour patches by staging pairwise combats between 60 size-matched adult lizards (20 per morph). Combats were held in a neutral arena, with each lizard facing rivals from the three morphs in a tournament with a balanced design. We then calculated a fighting ability ranking using the Bradley–Terry model, and used it to explore whether ventral colour morph, the size of UV-blue and black patches or the spectral characteristics of UV-blue patches (i.e., brightness, hue, chroma) are good predictors of fighting ability. We did not find an effect of the UV-blue patches on contest outcome, but the size of black patches emerged as a good predictor of fighting ability. We also found that winners were more aggressive when facing rivals with black patches of similar size, suggesting that black patches play a role in rival assessment and fighting rules. Finally, we found that orange males lost fights against heteromorphic males more often than yellow or white males. In light of these results, we discuss the potential signalling function of ventrolateral and ventral colour patches in mediating agonistic encounters in this species.
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Affiliation(s)
- J. Abalos
- Ethology Lab, Cavanilles Institute of Biodiversity and Evolutionary Biology, University of Valencia, calle Catedrático José Beltrán 2, 46980 Paterna, Valencia
- Centro de Investigacão em Biodiversidade e Recursos Genéticos, Universidade do Porto, Rua Padre Armando Quintas 7, 4485-661 Vairão, Vila do Conde, Portugal
| | - G. Pérez i de Lanuza
- Centro de Investigacão em Biodiversidade e Recursos Genéticos, Universidade do Porto, Rua Padre Armando Quintas 7, 4485-661 Vairão, Vila do Conde, Portugal
| | - P. Carazo
- Ethology Lab, Cavanilles Institute of Biodiversity and Evolutionary Biology, University of Valencia, calle Catedrático José Beltrán 2, 46980 Paterna, Valencia
- Edward Grey Institute, Department of Zoology, Tinbergen Building, University of Oxford, South Parks Road, Oxford, OX1 3PS, UK
| | - E. Font
- Ethology Lab, Cavanilles Institute of Biodiversity and Evolutionary Biology, University of Valencia, calle Catedrático José Beltrán 2, 46980 Paterna, Valencia
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42
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Marshall KLA, Philpot KE, Damas-Moreira I, Stevens M. Intraspecific Colour Variation among Lizards in Distinct Island Environments Enhances Local Camouflage. PLoS One 2015; 10:e0135241. [PMID: 26372454 PMCID: PMC4570707 DOI: 10.1371/journal.pone.0135241] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2015] [Accepted: 07/20/2015] [Indexed: 11/19/2022] Open
Abstract
Within-species colour variation is widespread among animals. Understanding how this arises can elucidate evolutionary mechanisms, such as those underlying reproductive isolation and speciation. Here, we investigated whether five island populations of Aegean wall lizards (Podarcis erhardii) have more effective camouflage against their own (local) island substrates than against other (non-local) island substrates to avian predators, and whether this was linked to island differences in substrate appearance. We also investigated whether degree of local substrate matching varied among island populations and between sexes. In most populations, both sexes were better matched against local backgrounds than against non-local backgrounds, particularly in terms of luminance (perceived lightness), which usually occurred when local and non-local backgrounds were different in appearance. This was found even between island populations that historically had a land connection and in populations that have been isolated relatively recently, suggesting that isolation in these distinct island environments has been sufficient to cause enhanced local background matching, sometimes on a rapid evolutionary time-scale. However, heightened local matching was poorer in populations inhabiting more variable and unstable environments with a prolonged history of volcanic activity. Overall, these results show that lizard coloration is tuned to provide camouflage in local environments, either due to genetic adaptation or changes during development. Yet, the occurrence and extent of selection for local matching may depend on specific conditions associated with local ecology and biogeographic history. These results emphasize how anti-predator adaptations to different environments can drive divergence within a species, which may contribute to reproductive isolation among populations and lead to ecological speciation.
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Affiliation(s)
- Kate L. A. Marshall
- Behavioural Ecology Group, Department of Zoology, University of Cambridge, Cambridge, United Kingdom
| | - Kate E. Philpot
- Centre for Ecology and Conservation, College of Life and Environmental Sciences, University of Exeter, Penryn Campus, Penryn, Cornwall, United Kingdom
| | - Isabel Damas-Moreira
- CIBIO Research Centre in Biodiversity and Genetic Resources, InBIO, Universidade do Porto, Campus Agrário de Vairão, Rua Padre Armando Quintas, Vairão, Vila do Conde, Portugal
| | - Martin Stevens
- Centre for Ecology and Conservation, College of Life and Environmental Sciences, University of Exeter, Penryn Campus, Penryn, Cornwall, United Kingdom
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43
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Marshall KLA, Philpot KE, Stevens M. Conspicuous male coloration impairs survival against avian predators in Aegean wall lizards, Podarcis erhardii. Ecol Evol 2015; 5:4115-31. [PMID: 26442582 PMCID: PMC4588654 DOI: 10.1002/ece3.1650] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2015] [Revised: 06/03/2015] [Accepted: 07/09/2015] [Indexed: 11/09/2022] Open
Abstract
Animal coloration is strikingly diverse in nature. Within-species color variation can arise through local adaptation for camouflage, sexual dimorphism and conspicuous sexual signals, which often have conflicting effects on survival. Here, we tested whether color variation between two island populations of Aegean wall lizards (Podarcis erhardii) is due to sexual dimorphism and differential survival of individuals varying in appearance. On both islands, we measured attack rates by wild avian predators on clay models matching the coloration of real male and female P. erhardii from each island population, modeled to avian predator vision. Avian predator attack rates differed among model treatments, although only on one island. Male-colored models, which were more conspicuous against their experimental backgrounds to avian predators, were accordingly detected and attacked more frequently by birds than less conspicuous female-colored models. This suggests that female coloration has evolved primarily under selection for camouflage, whereas sexually competing males exhibit costly conspicuous coloration. Unexpectedly, there was no difference in avian attack frequency between local and non-local model types. This may have arisen if the models did not resemble lizard coloration with sufficient precision, or if real lizards behaviorally choose backgrounds that improve camouflage. Overall, these results show that sexually dimorphic coloration can affect the risk of predator attacks, indicating that color variation within a species can be caused by interactions between natural and sexual selection. However, more work is needed to determine how these findings depend on the island environment that each population inhabits.
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Affiliation(s)
| | | | - Martin Stevens
- Centre for Ecology and Conservation University of Exeter Penryn Campus Penryn Cornwall TR10 9FE UK
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44
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Abramjan A, Bauerová A, Somerová B, Frynta D. Why is the tongue of blue-tongued skinks blue? Reflectance of lingual surface and its consequences for visual perception by conspecifics and predators. Naturwissenschaften 2015; 102:42. [DOI: 10.1007/s00114-015-1293-4] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2015] [Revised: 06/30/2015] [Accepted: 07/03/2015] [Indexed: 12/28/2022]
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45
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Pérez i de Lanuza G, Font E. Differences in conspicuousness between alternative color morphs in a polychromatic lizard. Behav Ecol 2015. [DOI: 10.1093/beheco/arv075] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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46
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Stevens M, Lown AE, Wood LE. Camouflage and individual variation in shore crabs (Carcinus maenas) from different habitats. PLoS One 2014; 9:e115586. [PMID: 25551233 PMCID: PMC4281232 DOI: 10.1371/journal.pone.0115586] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2014] [Accepted: 11/29/2014] [Indexed: 12/01/2022] Open
Abstract
Camouflage is widespread throughout the natural world and conceals animals from predators in a vast range of habitats. Because successful camouflage usually involves matching aspects of the background environment, species and populations should evolve appearances tuned to their local habitat, termed phenotype-environment associations. However, although this has been studied in various species, little work has objectively quantified the appearances of camouflaged animals from different habitats, or related this to factors such as ontogeny and individual variation. Here, we tested for phenotype-environment associations in the common shore crab (Carcinus maenas), a species highly variable in appearance and found in a wide range of habitats. We used field surveys and digital image analysis of the colors and patterns of crabs found in four locations around Cornwall in the UK to quantify how individuals vary with habitat (predominantly rockpool, mussel bed, and mudflat). We find that individuals from sites comprising different backgrounds show substantial differences in several aspects of color and pattern, and that this is also dependent on life stage (adult or juvenile). Furthermore, the level of individual variation is dependent on site and life stage, with juvenile crabs often more variable than adults, and individuals from more homogenous habitats less diverse. Ours is the most comprehensive study to date exploring phenotype-environment associations for camouflage and individual variation in a species, and we discuss the implications of our results in terms of the mechanisms and selection pressures that may drive this.
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Affiliation(s)
- Martin Stevens
- Centre for Ecology and Conservation, College of Life and Environmental Sciences, University of Exeter, Penryn Campus, Penryn, Cornwall, United Kingdom
| | - Alice E Lown
- Centre for Ecology and Conservation, College of Life and Environmental Sciences, University of Exeter, Penryn Campus, Penryn, Cornwall, United Kingdom
| | - Louisa E Wood
- Centre for Ecology and Conservation, College of Life and Environmental Sciences, University of Exeter, Penryn Campus, Penryn, Cornwall, United Kingdom
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