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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Nicolaï MPJ, Van Hecke B, Rogalla S, Debruyn G, Bowie RCK, Matzke NJ, Hackett SJ, D'Alba L, Shawkey MD. The Evolution of Multiple Color Mechanisms Is Correlated with Diversification in Sunbirds (Nectariniidae). Syst Biol 2024; 73:343-354. [PMID: 38289860 DOI: 10.1093/sysbio/syae006] [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: 08/31/2022] [Revised: 01/08/2024] [Accepted: 01/29/2024] [Indexed: 02/01/2024] Open
Abstract
How and why certain groups become speciose is a key question in evolutionary biology. Novel traits that enable diversification by opening new ecological niches are likely important mechanisms. However, ornamental traits can also promote diversification by opening up novel sensory niches and thereby creating novel inter-specific interactions. More specifically, ornamental colors may enable more precise and/or easier species recognition and may act as key innovations by increasing the number of species-specific patterns and promoting diversification. While the influence of coloration on diversification is well-studied, the influence of the mechanisms that produce those colors (e.g., pigmentary, nanostructural) is less so, even though the ontogeny and evolution of these mechanisms differ. We estimated a new phylogenetic tree for 121 sunbird species and combined color data of 106 species with a range of phylogenetic tools to test the hypothesis that the evolution of novel color mechanisms increases diversification in sunbirds, one of the most colorful bird clades. Results suggest that: (1) the evolution of novel color mechanisms expands the visual sensory niche, increasing the number of achievable colors, (2) structural coloration diverges more readily across the body than pigment-based coloration, enabling an increase in color complexity, (3) novel color mechanisms might minimize trade-offs between natural and sexual selection such that color can function both as camouflage and conspicuous signal, and (4) despite structural colors being more colorful and mobile, only melanin-based coloration is positively correlated with net diversification. Together, these findings explain why color distances increase with an increasing number of sympatric species, even though packing of color space predicts otherwise.
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Affiliation(s)
- Michaël P J Nicolaï
- Biology Department, Evolution and Optics of Nanostructures Group, Ghent University, Ledeganckstraat 35, 9000, Ghent, Belgium
| | - Bert Van Hecke
- Biology Department, Evolution and Optics of Nanostructures Group, Ghent University, Ledeganckstraat 35, 9000, Ghent, Belgium
| | - Svana Rogalla
- Biology Department, Evolution and Optics of Nanostructures Group, Ghent University, Ledeganckstraat 35, 9000, Ghent, Belgium
- Instituto Biofisika (UPV/EHU, CSIC), Barrio Sarriena, 48940 Leioa, Spain
| | - Gerben Debruyn
- Biology Department, Evolution and Optics of Nanostructures Group, Ghent University, Ledeganckstraat 35, 9000, Ghent, Belgium
| | - Rauri C K Bowie
- Museum of Vertebrate Zoology and Department of Integrative Biology, University of California, Berkeley, CA 94720, USA
| | - Nicholas J Matzke
- School of Biological Sciences, University of Auckland, Private Bag 92019, Auckland, New Zealand
| | - Shannon J Hackett
- Negaunee Integrative Research Center, Field Museum of Natural History, Chicago, IL, USA
| | - Liliana D'Alba
- Biology Department, Evolution and Optics of Nanostructures Group, Ghent University, Ledeganckstraat 35, 9000, Ghent, Belgium
- Evolutionary Ecology, Naturalis Biodiversity Center, Leiden, The Netherlands
| | - Matthew D Shawkey
- Biology Department, Evolution and Optics of Nanostructures Group, Ghent University, Ledeganckstraat 35, 9000, Ghent, Belgium
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3
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Monteiro JPC, Pröhl H, Lyra ML, Brunetti AE, de Nardin EC, Condez TH, Haddad CFB, Rodríguez A. Expression patterns of melanin-related genes are linked to crypsis and conspicuousness in a pumpkin toadlet. Mol Ecol 2024:e17458. [PMID: 38970414 DOI: 10.1111/mec.17458] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2023] [Revised: 06/14/2024] [Accepted: 06/24/2024] [Indexed: 07/08/2024]
Abstract
Colour signals play pivotal roles in different communication systems, and the evolution of these characters has been associated with behavioural ecology, integumentary production processes and perceptual mechanisms of the species involved. Here, we present the first insight into the molecular and histological basis of skin colour polymorphism within a miniaturized species of pumpkin toadlet, potentially representing the lowest size threshold for colour polytypism in tetrapods. Brachycephalus actaeus exhibits a coloration ranging from cryptic green to conspicuous orange skin, and our findings suggest that colour morphs differ in their capability to be detected by potential predators. We also found that the distribution and abundance of chromatophores are variable in the different colour morphs. The expression pattern of coloration related genes was predominantly associated with melanin synthesis (including dct, edn1, mlana, oca2, pmel, slc24a5, tyrp1 and wnt9a). Up-regulation of melanin genes in grey, green and brown skin was associated with higher melanophore abundance than in orange skin, where xanthophores predominate. Our findings provide a significant foundation for comparing and understanding the diverse pathways that contribute to the evolution of pigment production in the skin of amphibians.
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Affiliation(s)
- Juliane P C Monteiro
- Post-Graduate Program in Biodiversity, Institute of Biosciences, São Paulo State University (UNESP), Rio Claro, São Paulo, Brazil
- Department of Biodiversity and Aquaculture Center (CAUNESP), Institute of Biosciences, São Paulo State University (UNESP), Rio Claro, São Paulo, Brazil
- Center for Research on Biodiversity Dynamics and Climate Change, Institute of Biosciences, São Paulo State University (UNESP), Rio Claro, São Paulo, Brazil
- Institute of Zoology, University of Veterinary Medicine of Hannover, Hannover, Lower Saxony, Germany
| | - Heike Pröhl
- Institute of Zoology, University of Veterinary Medicine of Hannover, Hannover, Lower Saxony, Germany
| | - Mariana L Lyra
- Center for Research on Biodiversity Dynamics and Climate Change, Institute of Biosciences, São Paulo State University (UNESP), Rio Claro, São Paulo, Brazil
- New York University Abu Dhabi, Abu Dhabi, United Arab Emirates
| | - Andrés E Brunetti
- Center for Research on Biodiversity Dynamics and Climate Change, Institute of Biosciences, São Paulo State University (UNESP), Rio Claro, São Paulo, Brazil
- Institute of Subtropical Biology (IBS, UNaM-CONICET), Posadas, Misiones, Argentina
- Department of Insect Symbiosis, Max Planck Institute of Chemical Ecology, Jena, Thuringia, Germany
| | - Eli C de Nardin
- Department of Biodiversity and Aquaculture Center (CAUNESP), Institute of Biosciences, São Paulo State University (UNESP), Rio Claro, São Paulo, Brazil
| | - Thais H Condez
- Center for Research on Biodiversity Dynamics and Climate Change, Institute of Biosciences, São Paulo State University (UNESP), Rio Claro, São Paulo, Brazil
- Department of Earth Sciences, Carleton University, Ottawa, Ontario, Canada
| | - Célio F B Haddad
- Department of Biodiversity and Aquaculture Center (CAUNESP), Institute of Biosciences, São Paulo State University (UNESP), Rio Claro, São Paulo, Brazil
- Center for Research on Biodiversity Dynamics and Climate Change, Institute of Biosciences, São Paulo State University (UNESP), Rio Claro, São Paulo, Brazil
| | - Ariel Rodríguez
- Institute of Zoology, University of Veterinary Medicine of Hannover, Hannover, Lower Saxony, Germany
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4
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Lunau K, Dyer AG. The modelling of flower colour: spectral purity or colour contrast as biologically relevant descriptors of flower colour signals for bees depending upon the perceptual task. PLANT BIOLOGY (STUTTGART, GERMANY) 2024. [PMID: 38958933 DOI: 10.1111/plb.13682] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/04/2023] [Accepted: 05/07/2024] [Indexed: 07/04/2024]
Abstract
Flower colour is an important mediator of plant-pollinator interactions. While the reflectance of light from the flower surface and background are governed by physical properties, the perceptual interpretation of such information is generated by complex multilayered visual processing. Should quantitative modelling of flower signals strive for repeatable consistency enabled by parameter simplification, or should modelling reflect the dynamic way in which bees are known to process signals? We discuss why colour is an interpretation of spectral information by the brain of an animal. Different species, or individuals within a species, may respond differently to colour signals depending on sensory apparatus and/or individual experience. Humans and bees have different spectral ranges, but colour theory is strongly rooted in human colour perception and many principles of colour vision appear to be common. We discuss bee colour perception based on physiological, neuroanatomical and behavioural evidence to provide a pathway for modelling flower colours. We examine whether flower petals and floral guides as viewed against spectrally different backgrounds should be considered as a simple colour contrast problem or require a more dynamic consideration of how bees make perceptual decisions. We discuss that plants such as deceptive orchids may present signals to exploit bee perception, whilst many plants do provide honest signalling where perceived saturation indicates the probability of collecting nutritional rewards towards the centre of a flower that then facilitates effective pollination.
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Affiliation(s)
- K Lunau
- Faculty of Mathematics and Natural Sciences, Institute of Sensory Ecology, Heinrich-Heine University, Düsseldorf, Germany
| | - A G Dyer
- Department of Physiology, Monash University, Clayton, Australia
- Institut für Entwicklungsbiologie, und Neurobiologie, Johannes Gutenberg Universität, Mainz, Germany
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5
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Su Y, Shi Z, Wachtler T. A Bayesian observer model reveals a prior for natural daylights in hue perception. Vision Res 2024; 220:108406. [PMID: 38626536 DOI: 10.1016/j.visres.2024.108406] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2023] [Revised: 03/20/2024] [Accepted: 03/25/2024] [Indexed: 04/18/2024]
Abstract
Incorporating statistical characteristics of stimuli in perceptual processing can be highly beneficial for reliable estimation from noisy sensory measurements but may generate perceptual bias. According to Bayesian inference, perceptual biases arise from the integration of internal priors with noisy sensory inputs. In this study, we used a Bayesian observer model to derive biases and priors in hue perception based on discrimination data for hue ensembles with varying levels of chromatic noise. Our results showed that discrimination thresholds for isoluminant stimuli with hue defined by azimuth angle in cone-opponent color space exhibited a bimodal pattern, with lowest thresholds near a non-cardinal blue-yellow axis that aligns closely with the variation of natural daylights. Perceptual biases showed zero crossings around this axis, indicating repulsion away from yellow and attraction towards blue. These biases could be explained by the Bayesian observer model through a non-uniform prior with a preference for blue. Our findings suggest that visual processing takes advantage of knowledge of the distribution of colors in natural environments for hue perception.
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Affiliation(s)
- Yannan Su
- Faculty of Biology, Ludwig-Maximilians-Universität München, Planegg-Martinsried, Germany; Graduate School of Systemic Neurosciences, Ludwig-Maximilians-Universität München, Planegg-Martinsried, Germany.
| | - Zhuanghua Shi
- General and Experimental Psychology, Ludwig-Maximilians-Universität München, Munich, Germany.
| | - Thomas Wachtler
- Faculty of Biology, Ludwig-Maximilians-Universität München, Planegg-Martinsried, Germany; Bernstein Center for Computational Neuroscience Munich, Planegg-Martinsried, Germany.
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6
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Briolat ES, Hancock GRA, Troscianko J. Adapting genetic algorithms for artificial evolution of visual patterns under selection from wild predators. PLoS One 2024; 19:e0295106. [PMID: 38753609 PMCID: PMC11098352 DOI: 10.1371/journal.pone.0295106] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2023] [Accepted: 04/26/2024] [Indexed: 05/18/2024] Open
Abstract
Camouflage is a widespread and well-studied anti-predator strategy, yet identifying which patterns provide optimal protection in any given scenario remains challenging. Besides the virtually limitless combinations of colours and patterns available to prey, selection for camouflage strategies will depend on complex interactions between prey appearance, background properties and predator traits, across repeated encounters between co-evolving predators and prey. Experiments in artificial evolution, pairing psychophysics detection tasks with genetic algorithms, offer a promising way to tackle this complexity, but sophisticated genetic algorithms have so far been restricted to screen-based experiments. Here, we present methods to test the evolution of colour patterns on physical prey items, under selection from wild predators in the field. Our techniques expand on a recently-developed open-access pattern generation and genetic algorithm framework, modified to operate alongside artificial predation experiments. In this system, predators freely interact with prey, and the order of attack determines the survival and reproduction of prey patterns into future generations. We demonstrate the feasibility of these methods with a case study, in which free-flying birds feed on artificial prey deployed in semi-natural conditions, against backgrounds differing in three-dimensional complexity. Wild predators reliably participated in this experiment, foraging for 11 to 16 generations of artificial prey and encountering a total of 1,296 evolved prey items. Changes in prey pattern across generations indicated improvements in several metrics of similarity to the background, and greater edge disruption, although effect sizes were relatively small. Computer-based replicates of these trials, with human volunteers, highlighted the importance of starting population parameters for subsequent evolution, a key consideration when applying these methods. Ultimately, these methods provide pathways for integrating complex genetic algorithms into more naturalistic predation trials. Customisable open-access tools should facilitate application of these tools to investigate a wide range of visual pattern types in more ecologically-relevant contexts.
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Affiliation(s)
- Emmanuelle S. Briolat
- Faculty of Environment, Centre for Ecology and Conservation, Science and Economy, University of Exeter, Penryn, Cornwall, United Kingdom
| | - George R. A. Hancock
- Faculty of Environment, Centre for Ecology and Conservation, Science and Economy, University of Exeter, Penryn, Cornwall, United Kingdom
- Faculty of Biological and Environmental Sciences, University of Helsinki, Helsinki, Finland
| | - Jolyon Troscianko
- Faculty of Environment, Centre for Ecology and Conservation, Science and Economy, University of Exeter, Penryn, Cornwall, United Kingdom
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7
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Peng F, Sun X, van Vloten C, Correll J, Langdon M, Ngochanthra W, Johnson K, Amador Kane S. Hybrid Mimulus flowers attract a new pollinator. THE NEW PHYTOLOGIST 2024; 242:1324-1332. [PMID: 38482697 DOI: 10.1111/nph.19668] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/03/2023] [Accepted: 02/23/2024] [Indexed: 04/12/2024]
Abstract
Hybridization is common in flowering plants and is believed to be an important force driving adaptation and speciation. The flowers of hybrids often exhibit new trait combinations, which, theoretically, could attract new species of pollinators. In this study, we found that the hybrids between a hummingbird-pollinated species Mimulus cardinalis and a self-pollinated species Mimulus parishii attract bumblebees (Bombus impatiens), a pollinator not attracted to either of the progenitor species. This novel attraction is explained by new combinations of floral traits in hybrids, including, most importantly, petal color, in addition to nectar concentration and corolla size. To understand how petal color variation is perceived by bumblebees, we performed reflectance spectroscopy and multispectral imaging to model the flower appearance in bee vision. This analysis showed that color variation would impact the ease of detection. We also found that YUP, the genetic locus responsible for a large portion of floral color variation and previously shown to be important in bee interactions with other Mimulus species, also played an important role in this novel attraction. These results together suggest that the attraction of new pollinators to hybrid plants could be an underexplored avenue for pollinator shift and speciation.
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Affiliation(s)
- Foen Peng
- Department of Biology, Haverford College, Haverford, PA, 19041, USA
| | - Xiaohe Sun
- Department of Biology, Haverford College, Haverford, PA, 19041, USA
| | | | - Jude Correll
- Department of Biology, Haverford College, Haverford, PA, 19041, USA
| | - Marlena Langdon
- Department of Biology, Haverford College, Haverford, PA, 19041, USA
| | | | - Karl Johnson
- Department of Biology, Haverford College, Haverford, PA, 19041, USA
| | - Suzanne Amador Kane
- Department of Physics and Astronomy, Haverford College, Haverford, PA, 19041, USA
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8
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Mizuno T, Mori S, Sugahara K, Yukawa T, Koi S, Iwashina T. Floral pigments and their perception by avian pollinators in three Chilean Puya species. JOURNAL OF PLANT RESEARCH 2024; 137:395-409. [PMID: 38436743 DOI: 10.1007/s10265-024-01531-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/08/2023] [Accepted: 02/01/2024] [Indexed: 03/05/2024]
Abstract
The Chilean Puya species, Puya coerulea var. violacea and P. chilensis bear blue and pale-yellow flowers, respectively, while P. alpestris considered to be their hybrid-derived species has unique turquoise flowers. In this study, the chemical basis underlying the different coloration of the three Puya species was explored. We first isolated and identified three anthocyanins: delphinidin 3,3',5'-tri-O-glucoside, delphinidin 3,3'-di-O-glucoside and delphinidin 3-O-glucoside; seven flavonols: quercetin 3-O-rutinoside-3'-O-glucoside, quercetin 3,3'-di-O-glucoside, quercetin 3-O-rutinoside, isorhamnetin 3-O-rutinoside, myricetin 3,3',5'-tri-O-glucoside, myricetin 3,3'-di-O-glucoside and laricitrin 3,5'-di-O-glucoside; and six flavones: luteolin 4'-O-glucoside, apigenin 4'-O-glucoside, tricetin 4'-O-glucoside, tricetin 3',5'-di-O-glucoside, tricetin 3'-O-glucoside and selagin 5'-O-glucoside, which is a previously undescribed flavone, from their petals. We also compared compositions of floral flavonoid and their aglycone among these species, which suggested that the turquoise species P. alpestris has an essentially intermediate composition between the blue and pale-yellow species. The vacuolar pH was relatively higher in the turquoise (pH 6.2) and pale-yellow (pH 6.2) flower species, while that of blue flower species was usual (pH 5.2). The flower color was reconstructed in vitro using isolated anthocyanin, flavonol and flavone at neutral and acidic pH, and its color was analyzed by reflectance spectra and the visual modeling of their avian pollinators. The modeling demonstrated that the higher pH of the turquoise and pale-yellow species enhances the chromatic contrast and spectral purity. The precise regulation of flower color by flavonoid composition and vacuolar pH may be adapted to the visual perception of their avian pollinator vision.
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Affiliation(s)
- Takayuki Mizuno
- Department of Botany, National Museum of Nature and Science, Ibaraki, 305-0005, Japan.
| | - Shinnosuke Mori
- Faculty of Science and Technology, Keio University, Kanagawa, 223-8522, Japan
| | - Kohtaro Sugahara
- Bioorganic Research Institute, Suntory Foundation for Life Sciences, Kyoto, 619-0284, Japan
| | - Tomohisa Yukawa
- Department of Botany, National Museum of Nature and Science, Ibaraki, 305-0005, Japan
| | - Satoshi Koi
- Graduate School of Science, Osaka Metropolitan University, Osaka, 576-0004, Japan
| | - Tsukasa Iwashina
- Department of Botany, National Museum of Nature and Science, Ibaraki, 305-0005, Japan
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9
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Mitchell LJ, Phelan A, Cortesi F, Marshall NJ, Chung WS, Osorio DC, Cheney KL. Ultraviolet vision in anemonefish improves colour discrimination. J Exp Biol 2024; 227:jeb247425. [PMID: 38586934 PMCID: PMC11057877 DOI: 10.1242/jeb.247425] [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: 01/29/2024] [Accepted: 02/19/2024] [Indexed: 04/09/2024]
Abstract
In many animals, ultraviolet (UV) vision guides navigation, foraging, and communication, but few studies have addressed the contribution of UV signals to colour vision, or measured UV discrimination thresholds using behavioural experiments. Here, we tested UV colour vision in an anemonefish (Amphiprion ocellaris) using a five-channel (RGB-V-UV) LED display. We first determined that the maximal sensitivity of the A. ocellaris UV cone was ∼386 nm using microspectrophotometry. Three additional cone spectral sensitivities had maxima at ∼497, 515 and ∼535 nm. We then behaviourally measured colour discrimination thresholds by training anemonefish to distinguish a coloured target pixel from grey distractor pixels of varying intensity. Thresholds were calculated for nine sets of colours with and without UV signals. Using a tetrachromatic vision model, we found that anemonefish were better (i.e. discrimination thresholds were lower) at discriminating colours when target pixels had higher UV chromatic contrast. These colours caused a greater stimulation of the UV cone relative to other cone types. These findings imply that a UV component of colour signals and cues improves their detectability, which likely increases the prominence of anemonefish body patterns for communication and the silhouette of zooplankton prey.
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Affiliation(s)
- Laurie J. Mitchell
- School of the Environment, The University of Queensland, Brisbane, QLD 4072, Australia
- Queensland Brain Institute, The University of Queensland, Brisbane, QLD 4072, Australia
- Marine Eco-Evo-Devo Unit, Okinawa Institute of Science and Technology, Onna son, Okinawa 904-0495, Japan
| | - Amelia Phelan
- School of the Environment, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Fabio Cortesi
- School of the Environment, The University of Queensland, Brisbane, QLD 4072, Australia
- Queensland Brain Institute, The University of Queensland, Brisbane, QLD 4072, Australia
| | - N. Justin Marshall
- Queensland Brain Institute, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Wen-sung Chung
- Queensland Brain Institute, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Daniel C. Osorio
- School of Life Sciences, University of Sussex, Brighton BN1 9QG, UK
| | - Karen L. Cheney
- School of the Environment, The University of Queensland, Brisbane, QLD 4072, Australia
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10
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Rossi M, Hausmann AE, Alcami P, Moest M, Roussou R, Van Belleghem SM, Wright DS, Kuo CY, Lozano-Urrego D, Maulana A, Melo-Flórez L, Rueda-Muñoz G, McMahon S, Linares M, Osman C, McMillan WO, Pardo-Diaz C, Salazar C, Merrill RM. Adaptive introgression of a visual preference gene. Science 2024; 383:1368-1373. [PMID: 38513020 PMCID: PMC7616200 DOI: 10.1126/science.adj9201] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2023] [Accepted: 01/30/2024] [Indexed: 03/23/2024]
Abstract
Visual preferences are important drivers of mate choice and sexual selection, but little is known of how they evolve at the genetic level. In this study, we took advantage of the diversity of bright warning patterns displayed by Heliconius butterflies, which are also used during mate choice. Combining behavioral, population genomic, and expression analyses, we show that two Heliconius species have evolved the same preferences for red patterns by exchanging genetic material through hybridization. Neural expression of regucalcin1 correlates with visual preference across populations, and disruption of regucalcin1 with CRISPR-Cas9 impairs courtship toward conspecific females, providing a direct link between gene and behavior. Our results support a role for hybridization during behavioral evolution and show how visually guided behaviors contributing to adaptation and speciation are encoded within the genome.
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Affiliation(s)
- Matteo Rossi
- Faculty of Biology, Ludwig Maximilian University; Munich, Germany
| | | | - Pepe Alcami
- Faculty of Biology, Ludwig Maximilian University; Munich, Germany
| | - Markus Moest
- Department of Ecology and Research Department for Limnology, Mondsee; University of Innsbruck, Innsbruck, Austria
| | - Rodaria Roussou
- Faculty of Biology, Ludwig Maximilian University; Munich, Germany
| | | | | | - Chi-Yun Kuo
- Faculty of Biology, Ludwig Maximilian University; Munich, Germany
- Smithsonian Tropical Research Institute; Gamboa, Panama
| | - Daniela Lozano-Urrego
- Faculty of Biology, Ludwig Maximilian University; Munich, Germany
- Faculty of Natural Sciences, Universidad del Rosario; Bogotá, Colombia
| | - Arif Maulana
- Faculty of Biology, Ludwig Maximilian University; Munich, Germany
| | - Lina Melo-Flórez
- Faculty of Biology, Ludwig Maximilian University; Munich, Germany
- Faculty of Natural Sciences, Universidad del Rosario; Bogotá, Colombia
| | - Geraldine Rueda-Muñoz
- Faculty of Biology, Ludwig Maximilian University; Munich, Germany
- Faculty of Natural Sciences, Universidad del Rosario; Bogotá, Colombia
| | - Saoirse McMahon
- Faculty of Biology, Ludwig Maximilian University; Munich, Germany
| | - Mauricio Linares
- Faculty of Natural Sciences, Universidad del Rosario; Bogotá, Colombia
| | - Christof Osman
- Faculty of Biology, Ludwig Maximilian University; Munich, Germany
| | | | | | - Camilo Salazar
- Faculty of Natural Sciences, Universidad del Rosario; Bogotá, Colombia
| | - Richard M. Merrill
- Faculty of Biology, Ludwig Maximilian University; Munich, Germany
- Smithsonian Tropical Research Institute; Gamboa, Panama
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11
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Terrones-Ramírez AK, Robles-Bello SM, Vázquez-López M, Ramírez-Barrera SM, Zamudio-Beltrán LE, López López A, Arizmendi MDC, Durán-Suárez del Real AP, Eguiarte LE, Hernández-Baños BE. Recent genetic, phenetic and ecological divergence across the Mesoamerican highlands: a study case with Diglossa baritula (Aves: Thraupidae). PeerJ 2024; 12:e16797. [PMID: 38529306 PMCID: PMC10962342 DOI: 10.7717/peerj.16797] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2022] [Accepted: 12/24/2023] [Indexed: 03/27/2024] Open
Abstract
The topographical, geological, climatic and biodiversity complexity of Mesoamerica has made it a primary research focus. The Mesoamerican highlands is a region with particularly high species richness and within-species variation. The Cinnamon-bellied Flowerpiercer, Diglossa baritula (Wagler, 1832), is a species endemic to the Mesoamerican highlands, with three allopatric subspecies currently recognized. To characterize divergence within this species, we integrated genomics, morphology, coloration and ecological niche modeling approaches, obtained from sampling individuals across the entire geographic distribution of the species. Our results revealed a clear genomic divergence between the populations to the east versus the west of the Isthmus of Tehuantepec. In contrast to the genomic results, morphology and coloration analyses showed intermediate levels of differentiation, indicating that population groups within D. baritula have probably been under similar selective pressures. Our morphology results indicated that the only sexually dimorphic morphological variable is the wing chord, with males having a longer wing chord than females. Finally, ecological data indicated that there are differences in ecological niche within D. baritula. Our data suggest that D. baritula could contain two or more incipient species at the intermediate phase of the speciation continuum. These results highlight the importance of the geographical barrier of the Isthmus of Tehuantepec and Pleistocene climatic events in driving isolation and population divergence in D. baritula. The present investigation illustrates the speciation potential of the D. baritula complex and the capacity of Mesoamerican highlands to create cryptic biodiversity and endemism.
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Affiliation(s)
- Alondra K. Terrones-Ramírez
- Departamento de Biología Evolutiva, Facultad de Ciencias, Universidad Nacional Autónoma de México, Ciudad de México, CdMx, Mexico
- Posgrado en Ciencias Biológicas, Universidad Nacional Autónoma de México, Ciudad de México, CDMX, México
| | - Sahid M. Robles-Bello
- Departamento de Biología Evolutiva, Facultad de Ciencias, Universidad Nacional Autónoma de México, Ciudad de México, CdMx, Mexico
| | - Melisa Vázquez-López
- Departamento de Biología Evolutiva, Facultad de Ciencias, Universidad Nacional Autónoma de México, Ciudad de México, CdMx, Mexico
| | - Sandra M. Ramírez-Barrera
- Departamento de Biología Evolutiva, Facultad de Ciencias, Universidad Nacional Autónoma de México, Ciudad de México, CdMx, Mexico
| | - Luz E. Zamudio-Beltrán
- Departamento de Biología Evolutiva, Facultad de Ciencias, Universidad Nacional Autónoma de México, Ciudad de México, CdMx, Mexico
| | - Anuar López López
- Departamento de Biología Evolutiva, Facultad de Ciencias, Universidad Nacional Autónoma de México, Ciudad de México, CdMx, Mexico
| | - Maria del Coro Arizmendi
- Laboratorio de Ecología, UBIPRO Facultad de Estudios Superiores Iztacala, Universidad Nacional Autónoma de México, Tlalnepantla, Estado de México, Mexico
| | - Ana Paula Durán-Suárez del Real
- Departamento de Ecología Evolutiva, Instituto de Ecología, Universidad Nacional Autónoma de México, Ciudad de México, CdMx, Mexico
| | - Luis E. Eguiarte
- Departamento de Ecología Evolutiva, Instituto de Ecología, Universidad Nacional Autónoma de México, Ciudad de México, CdMx, Mexico
| | - Blanca E. Hernández-Baños
- Departamento de Biología Evolutiva, Facultad de Ciencias, Universidad Nacional Autónoma de México, Ciudad de México, CdMx, Mexico
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12
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van den Berg CP, Condon ND, Conradsen C, White TE, Cheney KL. Automated workflows using Quantitative Colour Pattern Analysis (QCPA): a guide to batch processing and downstream data analysis. Evol Ecol 2024; 38:387-397. [PMID: 38946730 PMCID: PMC11208187 DOI: 10.1007/s10682-024-10291-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2023] [Accepted: 02/05/2024] [Indexed: 07/02/2024]
Abstract
Animal and plant colouration presents a striking dimension of phenotypic variation, the study of which has driven general advances in ecology, evolution, and animal behaviour. Quantitative Colour Pattern Analysis (QCPA) is a dynamic framework for analysing colour patterns through the eyes of non-human observers. However, its extensive array of user-defined image processing and analysis tools means image analysis is often time-consuming. This hinders the full use of analytical power provided by QCPA and its application to large datasets. Here, we offer a robust and comprehensive batch script, allowing users to automate many QCPA workflows. We also provide a complimentary set of useful R scripts for downstream data extraction and analysis. The presented batch processing extension will empower users to further utilise the analytical power of QCPA and facilitate the development of customised semi-automated workflows. Such quantitatively scaled workflows are crucial for exploring colour pattern spaces and developing ever-richer frameworks for analysing organismal colouration accounting for visual perception in animals other than humans. These advances will, in turn, facilitate testing hypotheses on the function and evolution of vision and signals at quantitative and qualitative scales, which are otherwise computationally unfeasible. Supplementary Information The online version contains supplementary material available at 10.1007/s10682-024-10291-7.
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Affiliation(s)
- Cedric P. van den Berg
- School of the Environment, The University of Queensland, Brisbane, QLD 4072 Australia
- School of Life and Environmental Sciences, The University of Sydney, Sydney, NSW 2050 Australia
- School of Biological Sciences, University of Bristol, Bristol, BS8 1TQ UK
| | - Nicholas D. Condon
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD 4072 Australia
| | - Cara Conradsen
- School of the Environment, The University of Queensland, Brisbane, QLD 4072 Australia
| | - Thomas E. White
- School of Life and Environmental Sciences, The University of Sydney, Sydney, NSW 2050 Australia
| | - Karen L. Cheney
- School of the Environment, The University of Queensland, Brisbane, QLD 4072 Australia
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13
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Lu B, Qiu X, Yang W, Yao Z, Ma X, Deng S, Zhang Q, Fu J, Qi Y. Genetic Basis and Evolutionary Forces of Sexually Dimorphic Color Variation in a Toad-Headed Agamid Lizard. Mol Biol Evol 2024; 41:msae054. [PMID: 38466135 PMCID: PMC10963123 DOI: 10.1093/molbev/msae054] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2023] [Revised: 02/17/2024] [Accepted: 03/04/2024] [Indexed: 03/12/2024] Open
Abstract
In the animal kingdom, sexually dimorphic color variation is a widespread phenomenon that significantly influences survival and reproductive success. However, the genetic underpinnings of this variation remain inadequately understood. Our investigation into sexually dimorphic color variation in the desert-dwelling Guinan population of the toad-headed agamid lizard (Phrynocephalus putjatai) utilized a multidisciplinary approach, encompassing phenotypic, ultrastructural, biochemical, genomic analyses, and behavioral experiments. Our findings unveil the association between distinct skin colorations and varying levels of carotenoid and pteridine pigments. The red coloration in males is determined by a genomic region on chromosome 14, housing four pigmentation genes: BCO2 and three 6-pyruvoyltetrahydropterin synthases. A Guinan population-specific nonsynonymous single nucleotide polymorphism in BCO2 is predicted to alter the electrostatic potential within the binding domain of the BCO2-β-carotene complex, influencing their interaction. Additionally, the gene MAP7 on chromosome 2 emerges as a potential contributor to the blue coloration in subadults and adult females. Sex-specific expression patterns point to steroid hormone-associated genes (SULT2B1 and SRD5A2) as potential upstream regulators influencing sexually dimorphic coloration. Visual modeling and field experiments support the potential selective advantages of vibrant coloration in desert environments. This implies that natural selection, potentially coupled with assortative mating, might have played a role in fixing color alleles, contributing to prevalence in the local desert habitat. This study provides novel insights into the genetic basis of carotenoid and pteridine-based color variation, shedding light on the evolution of sexually dimorphic coloration in animals. Moreover, it advances our understanding of the driving forces behind such intricate coloration patterns.
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Affiliation(s)
- Bin Lu
- Chengdu Institute of Biology, Chinese Academy of Sciences, 610041 Chengdu, Sichuan, China
| | - Xia Qiu
- Chengdu Institute of Biology, Chinese Academy of Sciences, 610041 Chengdu, Sichuan, China
- College of Life Sciences, China Jiliang University, Hangzhou, China
| | - Weizhao Yang
- Chengdu Institute of Biology, Chinese Academy of Sciences, 610041 Chengdu, Sichuan, China
| | - Zhongyi Yao
- Chengdu Institute of Biology, Chinese Academy of Sciences, 610041 Chengdu, Sichuan, China
| | - Xiaofeng Ma
- Chengdu Institute of Biology, Chinese Academy of Sciences, 610041 Chengdu, Sichuan, China
| | - Shunyan Deng
- Chengdu Institute of Biology, Chinese Academy of Sciences, 610041 Chengdu, Sichuan, China
| | - Qi Zhang
- Chengdu Institute of Biology, Chinese Academy of Sciences, 610041 Chengdu, Sichuan, China
| | - Jinzhong Fu
- Chengdu Institute of Biology, Chinese Academy of Sciences, 610041 Chengdu, Sichuan, China
- Department of Integrative Biology, University of Guelph, Guelph, ON N1G2W1, Canada
| | - Yin Qi
- Chengdu Institute of Biology, Chinese Academy of Sciences, 610041 Chengdu, Sichuan, China
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14
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Hemingson CR, Cowman PF, Bellwood DR. Analysing biological colour patterns from digital images: An introduction to the current toolbox. Ecol Evol 2024; 14:e11045. [PMID: 38500859 PMCID: PMC10945235 DOI: 10.1002/ece3.11045] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2023] [Revised: 02/02/2024] [Accepted: 02/03/2024] [Indexed: 03/20/2024] Open
Abstract
Understanding the numerous roles that colouration serves in the natural world has remained a central focus in many evolutionary and ecological studies. However, to accurately characterise and then compare colours or patterns among individuals or species has been historically challenging. In recent years, there have been a myriad of new resources developed that allow researchers to characterise biological colours and patterns, specifically from digital imagery. However, each resource has its own strengths and weaknesses, answers a specific question and requires a detailed understanding of how it functions to be used properly. These nuances can make navigating this emerging field rather difficult. Herein, we evaluate several new techniques for analysing biological colouration, with a specific focus on digital images. First, we introduce fundamental background knowledge about light and perception to be considered when designing and implementing a study of colouration. We then show how numerous modifications can be made to images to ensure consistent formatting prior to analysis. After, we describe many of the new image analysis approaches and their respective functions, highlighting the type of research questions that they can address. We demonstrate how these various techniques can be brought together to examine novel research questions and test specific hypotheses. Finally, we outline potential future directions in colour pattern studies. Our goal is to provide a starting point and pathway for researchers wanting to study biological colour patterns from digital imagery.
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Affiliation(s)
- Christopher R. Hemingson
- The Research Hub for Coral Reef Ecosystem FunctionsJames Cook UniversityTownsvilleQueenslandAustralia
- College of Science and EngineeringJames Cook UniversityTownsvilleQueenslandAustralia
| | - Peter F. Cowman
- Biodiversity and Geosciences Program, Queensland Museum TropicsTownsvilleQueenslandAustralia
| | - David R. Bellwood
- The Research Hub for Coral Reef Ecosystem FunctionsJames Cook UniversityTownsvilleQueenslandAustralia
- College of Science and EngineeringJames Cook UniversityTownsvilleQueenslandAustralia
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15
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Santer RD, Allen WL. Optimising the colour of traps requires an insect's eye view. PEST MANAGEMENT SCIENCE 2024; 80:931-934. [PMID: 37755337 DOI: 10.1002/ps.7790] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/20/2023] [Revised: 09/19/2023] [Accepted: 09/27/2023] [Indexed: 09/28/2023]
Abstract
Colour is a critical property of many traps used to control or monitor insect pests, and applied entomologists continue to devote time and effort to improving colour for greater trapping efficiency. This work has often been guided by human colour perceptions, which differ greatly from those of the pests being studied. As a result, trap development can be a laborious process that is heavily reliant on trial and error. However, the responses of an insect's photoreceptors to a given trap colour can be calculated using well-established procedures. Photoreceptor responses represent sensory inputs that drive insect behaviour, and if their relationship to insect attraction can be determined or hypothesised, they provide metrics that can guide the rational optimisation of trap colour. This approach has recently been used successfully in separate studies of tsetse flies and thrips, but could be applied to a wide diversity of pest insects. Here we describe this approach to facilitate its use by applied entomologists. © 2023 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.
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Affiliation(s)
- Roger D Santer
- Department of Life Sciences, Aberystwyth University, Aberystwyth, UK
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16
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Middleton R, Tunstad SA, Knapp A, Winters S, McCallum S, Whitney H. Self-assembled, disordered structural color from fruit wax bloom. SCIENCE ADVANCES 2024; 10:eadk4219. [PMID: 38324684 PMCID: PMC10849586 DOI: 10.1126/sciadv.adk4219] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/22/2023] [Accepted: 01/05/2024] [Indexed: 02/09/2024]
Abstract
Many visually guided frugivores have eyes highly adapted for blue sensitivity, which makes it perhaps surprising that blue pigmented fruits are not more common. However, some fruits are blue even though they do not contain blue pigments. We investigate dark pigmented fruits with wax blooms, like blueberries, plums, and juniper cones, and find that a structural color mechanism is responsible for their appearance. The chromatic blue-ultraviolet reflectance arises from the interaction of the randomly arranged nonspherical scatterers with light. We reproduce the structural color in the laboratory by recrystallizing wax bloom, allowing it to self-assemble to produce the blue appearance. We demonstrate that blue fruits and structurally colored fruits are not constrained to those with blue subcuticular structure or pigment. Further, convergent optical properties appear across a wide phylogenetic range despite diverse morphologies. Epicuticular waxes are elements of the future bioengineering toolbox as sustainable and biocompatible, self-assembling, self-cleaning, and self-repairing optical biomaterials.
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Affiliation(s)
- Rox Middleton
- University of Bristol, Bristol, UK
- Technische Universität Dresden, Dresden, Germany
| | | | | | - Sandra Winters
- University of Bristol, Bristol, UK
- University of Helsinki, Helsinki, Finland
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17
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Caves EM, Davis AL, Nowicki S, Johnsen S. Backgrounds and the evolution of visual signals. Trends Ecol Evol 2024; 39:188-198. [PMID: 37802667 DOI: 10.1016/j.tree.2023.09.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2023] [Revised: 09/04/2023] [Accepted: 09/08/2023] [Indexed: 10/08/2023]
Abstract
Color signals which mediate behavioral interactions across taxa and contexts are often thought of as color 'patches' - parts of an animal that appear colorful compared to other parts of that animal. Color patches, however, cannot be considered in isolation because how a color is perceived depends on its visual background. This is of special relevance to the function and evolution of signals because backgrounds give rise to a fundamental tradeoff between color signal detectability and discriminability: as its contrast with the background increases, a color patch becomes more detectable, but discriminating variation in that color becomes more difficult. Thus, the signal function of color patches can only be fully understood by considering patch and background together as an integrated whole.
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Affiliation(s)
- Eleanor M Caves
- Department of Ecology, Evolution, and Marine Biology, University of California Santa Barbara, Santa Barbara, CA 93106, USA.
| | | | - Stephen Nowicki
- Department of Biology, Duke University, Durham, NC, 27708, USA
| | - Sönke Johnsen
- Department of Biology, Duke University, Durham, NC, 27708, USA
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18
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Weller HI, Hiller AE, Lord NP, Van Belleghem SM. recolorize: An R package for flexible colour segmentation of biological images. Ecol Lett 2024; 27:e14378. [PMID: 38361466 DOI: 10.1111/ele.14378] [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: 03/09/2023] [Revised: 12/18/2023] [Accepted: 01/04/2024] [Indexed: 02/17/2024]
Abstract
Colour pattern variation provides biological information in fields ranging from disease ecology to speciation dynamics. Comparing colour pattern geometries across images requires colour segmentation, where pixels in an image are assigned to one of a set of colour classes shared by all images. Manual methods for colour segmentation are slow and subjective, while automated methods can struggle with high technical variation in aggregate image sets. We present recolorize, an R package toolbox for human-subjective colour segmentation with functions for batch-processing low-variation image sets and additional tools for handling images from diverse (high-variation) sources. The package also includes export options for a variety of formats and colour analysis packages. This paper illustrates recolorize for three example datasets, including high variation, batch processing and combining with reflectance spectra, and demonstrates the downstream use of methods that rely on this output.
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Affiliation(s)
- Hannah I Weller
- Department of Ecology, Evolution, and Organismal Biology, Brown University, Providence, Rhode Island, USA
- Helsinki Institute of Life Sciences, University of Helsinki, Helsinki, Finland
| | - Anna E Hiller
- Museum of Natural Science and Department of Biological Sciences, Louisiana State University, Baton Rouge, Louisiana, USA
| | - Nathan P Lord
- Department of Entomology, Louisiana State University Agricultural Center, Baton Rouge, Louisiana, USA
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19
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Vasas V, Lowell MC, Villa J, Jamison QD, Siegle AG, Katta PKR, Bhagavathula P, Kevan PG, Fulton D, Losin N, Kepplinger D, Yetzbacher MK, Salehian S, Forkner RE, Hanley D. Recording animal-view videos of the natural world using a novel camera system and software package. PLoS Biol 2024; 22:e3002444. [PMID: 38261631 PMCID: PMC10805291 DOI: 10.1371/journal.pbio.3002444] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2022] [Accepted: 11/21/2023] [Indexed: 01/25/2024] Open
Abstract
Plants, animals, and fungi display a rich tapestry of colors. Animals, in particular, use colors in dynamic displays performed in spatially complex environments. Although current approaches for studying colors are objective and repeatable, they miss the temporal variation of color signals entirely. Here, we introduce hardware and software that provide ecologists and filmmakers the ability to accurately record animal-perceived colors in motion. Specifically, our Python codes transform photos or videos into perceivable units (quantum catches) for animals of known photoreceptor sensitivity. The plans and codes necessary for end-users to capture animal-view videos are all open source and publicly available to encourage continual community development. The camera system and the associated software package will allow ecologists to investigate how animals use colors in dynamic behavioral displays, the ways natural illumination alters perceived colors, and other questions that remained unaddressed until now due to a lack of suitable tools. Finally, it provides scientists and filmmakers with a new, empirically grounded approach for depicting the perceptual worlds of nonhuman animals.
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Affiliation(s)
- Vera Vasas
- School of Biological and Behavioural Sciences, Queen Mary University of London, London, United Kingdom
| | - Mark C. Lowell
- Theorem Engine, Alexandria, Virginia, United States of America
- Department of Biology, George Mason University, Fairfax, Virginia, United States of America
| | - Juliana Villa
- Department of Biology, George Mason University, Fairfax, Virginia, United States of America
| | - Quentin D. Jamison
- Department of Biology, George Mason University, Fairfax, Virginia, United States of America
| | - Anna G. Siegle
- Department of Biology, George Mason University, Fairfax, Virginia, United States of America
| | - Pavan Kumar Reddy Katta
- Department of Computer Science, George Mason University, Fairfax, Virginia, United States of America
| | - Pushyami Bhagavathula
- Department of Computer Science, George Mason University, Fairfax, Virginia, United States of America
| | - Peter G. Kevan
- School of Environmental Sciences, University of Guelph, Guelph, Canada
| | - Drew Fulton
- Drew Fulton Photography, Gainesville, Florida, United States of America
| | - Neil Losin
- Day’s Edge Productions, San Diego, California, United States of America
| | - David Kepplinger
- Department of Statistics, George Mason University, Fairfax, Virginia, United States of America
| | | | - Shakiba Salehian
- Department of Biology, George Mason University, Fairfax, Virginia, United States of America
| | - Rebecca E. Forkner
- Department of Biology, George Mason University, Fairfax, Virginia, United States of America
| | - Daniel Hanley
- Department of Biology, George Mason University, Fairfax, Virginia, United States of America
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20
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Boycott TJ, Sherrard MG, Gall MD, Ronald KL. Deer management influences perception of avian plumage in temperate deciduous forests. Vision Res 2023; 213:108312. [PMID: 37703599 DOI: 10.1016/j.visres.2023.108312] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2023] [Revised: 08/07/2023] [Accepted: 08/17/2023] [Indexed: 09/15/2023]
Abstract
Many animals use visual signals to communicate; birds use colorful plumage to attract mates and repel intruders. Visual signal conspicuousness is influenced by the lighting environment, which can be altered by human-induced changes. For example, deer-management efforts can affect vegetation structure and light availability. Whether these changes alter animal communication is still unknown. We investigated the effect of deer management on forest light and the contrast of understory birds against the forest background. We modeled visual perception using: (1) an ultraviolet-sensitive (UVS) avian model and plumage parameters representative of red, yellow, and blue birds (2) species-specific turkey visual and plumage parameters, and (3) individual-specific brown-headed cowbird visual and plumage parameters. Deer management led to greater light irradiance and lowered forest background reflectance. Management increased chromatic contrasts in the UVS model, primarily in deciduous forests and low understory, and across all habitat types in turkey and cowbird models. Deer management did not affect achromatic contrasts in the UVS model, but was associated with lower contrast in mixed forests for turkeys and across habitats for cowbirds. Together, this suggests that management of deer browsing is likely to impact visual signaling for a wide range of avian species. However, we also suspect that species- and individual-specific parameters increased the resolution of models, warranting consideration in future studies. Further work should determine if differences in visual perception translate to biologically relevant consequences. Our results suggest that, at least for some species, deer browsing and anthropogenic change may impose an evolutionary driver on visual communication.
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Affiliation(s)
- Timothy J Boycott
- Department of Biology, Vassar College, 124 Raymond Ave., Poughkeepsie, NY 12604, USA; New York Cooperative Fish and Wildlife Research Unit, Department of Natural Resources and the Environment, Cornell University, 226 Mann Drive, Ithaca, NY 14853, USA
| | - Morgan G Sherrard
- Department of Biology, Hope College, 35 East 12th Street, Holland, MI 49423, USA; University of Detroit Mercy School of Dentistry, 2700 Martin Luther King Jr. Blvd. Detroit, MI 48208-2576, USA
| | - Megan D Gall
- Department of Biology, Vassar College, 124 Raymond Ave., Poughkeepsie, NY 12604, USA; Neuroscience and Behavior Program, Vassar College, 124 Raymond Ave., Poughkeepsie, NY 12604, USA
| | - Kelly L Ronald
- Department of Biology, Hope College, 35 East 12th Street, Holland, MI 49423, USA.
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21
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Porter CK, Romero FG, Adams DC, Bowie RCK, Riddell EA. Adaptive and non-adaptive convergent evolution in feather reflectance of California Channel Islands songbirds. Proc Biol Sci 2023; 290:20231914. [PMID: 37964520 PMCID: PMC10646447 DOI: 10.1098/rspb.2023.1914] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2023] [Accepted: 10/23/2023] [Indexed: 11/16/2023] Open
Abstract
Convergent evolution is widely regarded as a signature of adaptation. However, testing the adaptive consequences of convergent phenotypes is challenging, making it difficult to exclude non-adaptive explanations for convergence. Here, we combined feather reflectance spectra and phenotypic trajectory analyses with visual and thermoregulatory modelling to test the adaptive significance of dark plumage in songbirds of the California Channel Islands. By evolving dark dorsal plumage, island birds are generally less conspicuous to visual-hunting raptors in the island environment than mainland birds. Dark dorsal plumage also reduces the energetic demands associated with maintaining homeothermy in the cool island climate. We also found an unexpected pattern of convergence, wherein the most divergent island populations evolved greater reflectance of near-infrared radiation. However, our heat flux models indicate that elevated near-infrared reflectance is not adaptive. Analysis of feather microstructure suggests that mainland-island differences are related to coloration of feather barbs and barbules rather than their structure. Our results indicate that adaptive and non-adaptive mechanisms interact to drive plumage evolution in this system. This study sheds light on the mechanisms driving the association between dark colour and wet, cold environments across the tree of life, especially in island birds.
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Affiliation(s)
- Cody K. Porter
- Department of Ecology, Evolution, and Organismal Biology, Iowa State University, Ames, IA 50011, USA
| | - Faye G. Romero
- Department of Biology, University of Rochester, Rochester, NY 14620, USA
| | - Dean C. Adams
- Department of Ecology, Evolution, and Organismal Biology, Iowa State University, Ames, IA 50011, USA
| | - Rauri C. K. Bowie
- Museum of Vertebrate Zoology and Department of Integrative Biology, University of California Berkeley, Berkeley, CA 94720, USA
| | - Eric A. Riddell
- Department of Ecology, Evolution, and Organismal Biology, Iowa State University, Ames, IA 50011, USA
- Department of Biology, University of North Carolina – Chapel Hill, Chapel Hill, NC 27599, USA
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22
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Williams HJ, Sridhar VH, Hurme E, Gall GE, Borrego N, Finerty GE, Couzin ID, Galizia CG, Dominy NJ, Rowland HM, Hauber ME, Higham JP, Strandburg-Peshkin A, Melin AD. Sensory collectives in natural systems. eLife 2023; 12:e88028. [PMID: 38019274 PMCID: PMC10686622 DOI: 10.7554/elife.88028] [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: 04/03/2023] [Accepted: 11/10/2023] [Indexed: 11/30/2023] Open
Abstract
Groups of animals inhabit vastly different sensory worlds, or umwelten, which shape fundamental aspects of their behaviour. Yet the sensory ecology of species is rarely incorporated into the emerging field of collective behaviour, which studies the movements, population-level behaviours, and emergent properties of animal groups. Here, we review the contributions of sensory ecology and collective behaviour to understanding how animals move and interact within the context of their social and physical environments. Our goal is to advance and bridge these two areas of inquiry and highlight the potential for their creative integration. To achieve this goal, we organise our review around the following themes: (1) identifying the promise of integrating collective behaviour and sensory ecology; (2) defining and exploring the concept of a 'sensory collective'; (3) considering the potential for sensory collectives to shape the evolution of sensory systems; (4) exploring examples from diverse taxa to illustrate neural circuits involved in sensing and collective behaviour; and (5) suggesting the need for creative conceptual and methodological advances to quantify 'sensescapes'. In the final section, (6) applications to biological conservation, we argue that these topics are timely, given the ongoing anthropogenic changes to sensory stimuli (e.g. via light, sound, and chemical pollution) which are anticipated to impact animal collectives and group-level behaviour and, in turn, ecosystem composition and function. Our synthesis seeks to provide a forward-looking perspective on how sensory ecologists and collective behaviourists can both learn from and inspire one another to advance our understanding of animal behaviour, ecology, adaptation, and evolution.
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Affiliation(s)
- Hannah J Williams
- Max Planck Institute of Animal BehaviorKonstanzGermany
- Centre for the Advanced Study of Collective Behaviour, University of KonstanzKonstanzGermany
- Biology Department, University of KonstanzKonstanzGermany
| | - Vivek H Sridhar
- Max Planck Institute of Animal BehaviorKonstanzGermany
- Centre for the Advanced Study of Collective Behaviour, University of KonstanzKonstanzGermany
- Biology Department, University of KonstanzKonstanzGermany
| | - Edward Hurme
- Max Planck Institute of Animal BehaviorKonstanzGermany
- Centre for the Advanced Study of Collective Behaviour, University of KonstanzKonstanzGermany
- Biology Department, University of KonstanzKonstanzGermany
| | - Gabriella E Gall
- Max Planck Institute of Animal BehaviorKonstanzGermany
- Centre for the Advanced Study of Collective Behaviour, University of KonstanzKonstanzGermany
- Biology Department, University of KonstanzKonstanzGermany
- Zukunftskolleg, University of KonstanzKonstanzGermany
| | | | | | - Iain D Couzin
- Max Planck Institute of Animal BehaviorKonstanzGermany
- Centre for the Advanced Study of Collective Behaviour, University of KonstanzKonstanzGermany
- Biology Department, University of KonstanzKonstanzGermany
| | - C Giovanni Galizia
- Biology Department, University of KonstanzKonstanzGermany
- Zukunftskolleg, University of KonstanzKonstanzGermany
| | - Nathaniel J Dominy
- Zukunftskolleg, University of KonstanzKonstanzGermany
- Department of Anthropology, Dartmouth CollegeHanoverUnited States
| | - Hannah M Rowland
- Max Planck Research Group Predators and Toxic Prey, Max Planck Institute for Chemical EcologyJenaGermany
| | - Mark E Hauber
- Department of Evolution, Ecology, and Behavior, School of Integrative Biology, University of Illinois at Urbana-ChampaignUrbana-ChampaignUnited States
| | - James P Higham
- Zukunftskolleg, University of KonstanzKonstanzGermany
- Department of Anthropology, New York UniversityNew YorkUnited States
| | - Ariana Strandburg-Peshkin
- Max Planck Institute of Animal BehaviorKonstanzGermany
- Centre for the Advanced Study of Collective Behaviour, University of KonstanzKonstanzGermany
- Biology Department, University of KonstanzKonstanzGermany
| | - Amanda D Melin
- Zukunftskolleg, University of KonstanzKonstanzGermany
- Department of Anthropology and Archaeology, University of CalgaryCalgaryCanada
- Alberta Children’s Hospital Research Institute, University of CalgaryCalgaryCanada
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23
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Lunn R, Baumhardt PE, Blackwell BF, Freyssinier JP, Fernández-Juricic E. Light wavelength and pulsing frequency affect avoidance responses of Canada geese. PeerJ 2023; 11:e16379. [PMID: 38025716 PMCID: PMC10668863 DOI: 10.7717/peerj.16379] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2023] [Accepted: 10/09/2023] [Indexed: 12/01/2023] Open
Abstract
Collisions between birds and aircraft cause bird mortality, economic damage, and aviation safety hazards. One proposed solution to increasing the distance at which birds detect and move away from an approaching aircraft, ultimately mitigating the probability of collision, is through onboard lighting systems. Lights in vehicles have been shown to lead to earlier reactions in some bird species but they could also generate attraction, potentially increasing the probability of collision. Using information on the visual system of the Canada goose (Branta canadensis), we developed light stimuli of high chromatic contrast to their eyes. We then conducted a controlled behavioral experiment (i.e., single-choice test) to assess the avoidance or attraction responses of Canada geese to LED lights of different wavelengths (blue, 483 nm; red, 631 nm) and pulsing frequencies (steady, pulsing at 2 Hz). Overall, Canada geese tended to avoid the blue light and move towards the red light; however, these responses depended heavily on light exposure order. At the beginning of the experiment, geese tended to avoid the red light. After further exposure the birds developed an attraction to the red light, consistent with the mere exposure effect. The response to the blue light generally followed a U-shape relationship (avoidance, attraction, avoidance) with increasing number of exposures, again consistent with the mere exposure effect, but followed by the satiation effect. Lights pulsing at 2 Hz enhanced avoidance responses under high ambient light conditions; whereas steady lights enhanced avoidance responses under dim ambient light conditions. Our results have implications for the design of lighting systems aimed at mitigating collisions between birds and human objects. LED lights in the blue portion of the spectrum are good candidates for deterrents and lights in the red portion of the spectrum may be counterproductive given the attraction effects with increasing exposure. Additionally, consideration should be given to systems that automatically modify pulsing of the light depending on ambient light intensity to enhance avoidance.
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Affiliation(s)
- Ryan Lunn
- Department of Biological Sciences, Purdue University, West Lafayette, IN, United States of America
| | - Patrice E. Baumhardt
- Department of Biological Sciences, Purdue University, West Lafayette, IN, United States of America
| | - Bradley F. Blackwell
- United States Department of Agriculture, Animal and Plant Health and Inspection Services, National Wildlife Research Center, Sandusky, OH, United States of America
| | - Jean Paul Freyssinier
- Lighting Research Center, Rensselaer Polytechnic Institute, Troy, NY, United States of America
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24
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de Alcantara Viana JV, Campos Duarte R, Vieira C, Augusto Poleto Antiqueira P, Bach A, de Mello G, Silva L, Rabelo Oliveira Leal C, Quevedo Romero G. Crypsis by background matching and disruptive coloration as drivers of substrate occupation in sympatric Amazonian bark praying mantises. Sci Rep 2023; 13:19985. [PMID: 37968331 PMCID: PMC10652001 DOI: 10.1038/s41598-023-46204-x] [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: 08/02/2023] [Accepted: 10/29/2023] [Indexed: 11/17/2023] Open
Abstract
Background matching and disruptive coloration are common camouflage strategies in nature, but few studies have accurately measured their protective value in living organisms. Amazon's Bark praying mantises exhibit colour patterns matching whitish and greenish-brown tree trunks. We tested the functional significance of background matching and disruptive coloration of different praying mantis morphospecies (white, grey and green) detected by DNA barcoding. Through image analysis, avian visual models and field experiments using humans as potential predators, we explored whether the background occupation of mantises provides camouflage against predation. Data were obtained for individuals against their occupied tree trunks (whitish or greenish-brown) and microhabitats (lichen or bryophyte patches), compared to non-occupied trunks. White and grey mantises showed lower colour contrasts against occupied trunks at the scale of tree trunk, with no differences in luminance contrasts. Conversely, green mantises showed lower colour and luminance contrasts against microhabitats and also exhibited high edge disruption against greenish-brown trunks. The camouflage of white and green mantis models against colour-matching trunks increased search time and reduced encounter distance of human predators. We highlight the importance of camouflage strategies at different spatial scales to enhance individual survival against predators. Specifically, we present a stunning study system to investigate the relationship of phylogenetically related species that use camouflage in sympatry.
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Affiliation(s)
- João Vitor de Alcantara Viana
- Programa de Pós-Graduação em Ecologia, Instituto de Biologia, Universidade Estadual de Campinas, Campinas, São Paulo, Brazil.
- Laboratório de Interações Multitróficas e Biodiversidade, Departamento de Biologia Animal, Instituto de Biologia, Universidade Estadual de Campinas (UNICAMP), CP 6109, Campinas, São Paulo, CEP 13083-970, Brazil.
| | - Rafael Campos Duarte
- Universidade Federal Do ABC, São Bernardo Do Campo, São Paulo, CEP 09606-045, Brazil
- Centre for Ecology and Conservation, College of Life and Environmental Sciences, University of Exeter, Penryn Campus, Penryn, TR10 9FE, UK
| | - Camila Vieira
- Departamento de Ciências Básicas, Universidade de São Paulo (USP), Campus de Pirassununga, Pirassununga, São Paulo, CEP 13635-900, Brazil
| | - Pablo Augusto Poleto Antiqueira
- Laboratório de Interações Multitróficas e Biodiversidade, Departamento de Biologia Animal, Instituto de Biologia, Universidade Estadual de Campinas (UNICAMP), CP 6109, Campinas, São Paulo, CEP 13083-970, Brazil
| | - Andressa Bach
- Programa de Pós-Graduação Em Ecologia E Conservação da Biodiversidade, Instituto de Biociências, Universidade Federal de Mato Grosso, Avenida Fernando Corrêa da Costa, N° 2367, Boa Esperança, Cuiabá, 78060900, Brazil
| | - Gabriel de Mello
- Programa de Pós-Graduação Em Ecologia E Conservação da Biodiversidade, Instituto de Biociências, Universidade Federal de Mato Grosso, Avenida Fernando Corrêa da Costa, N° 2367, Boa Esperança, Cuiabá, 78060900, Brazil
| | - Lorhaine Silva
- Programa de Pós-Graduação Em Ecologia E Conservação da Biodiversidade, Instituto de Biociências, Universidade Federal de Mato Grosso, Avenida Fernando Corrêa da Costa, N° 2367, Boa Esperança, Cuiabá, 78060900, Brazil
| | - Camila Rabelo Oliveira Leal
- Laboratório de Interações Multitróficas e Biodiversidade, Departamento de Biologia Animal, Instituto de Biologia, Universidade Estadual de Campinas (UNICAMP), CP 6109, Campinas, São Paulo, CEP 13083-970, Brazil
| | - Gustavo Quevedo Romero
- Laboratório de Interações Multitróficas e Biodiversidade, Departamento de Biologia Animal, Instituto de Biologia, Universidade Estadual de Campinas (UNICAMP), CP 6109, Campinas, São Paulo, CEP 13083-970, Brazil
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25
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Protti-Sánchez F, Mayer U, Rowland HM. In paired preference tests, domestic chicks innately choose the colour green over red, and the shape of a frog over a sphere when both stimuli are green. Anim Cogn 2023; 26:1973-1983. [PMID: 37610527 PMCID: PMC10769926 DOI: 10.1007/s10071-023-01821-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2023] [Revised: 07/21/2023] [Accepted: 08/15/2023] [Indexed: 08/24/2023]
Abstract
Many animals express unlearned colour preferences that depend on the context in which signals are encountered. These colour biases may have evolved in response to the signalling system to which they relate. For example, many aposematic animals advertise their unprofitability with red warning signals. Predators' innate biases against these warning colours have been suggested as one of the potential explanations for the initial evolution of aposematism. It is unclear, however, whether unlearned colour preferences reported in a number of species is truly an innate behaviour or whether it is based on prior experience. We tested the spontaneous colour and shape preferences of dark-hatched, unfed, and visually naive domestic chicks (Gallus gallus). In four experiments, we presented chicks with a choice between either red (a colour typically associated with warning patterns) or green (a colour associated with palatable cryptic prey), volume-matched spheres (representing a generalised fruit shape) or frogs (representing an aposematic animal's shape). Chicks innately preferred green stimuli and avoided red. Chicks also preferred the shape of a frog over a sphere when both stimuli were green. However, no preference for frogs over spheres was present when stimuli were red. Male chicks that experienced a bitter taste of quinine immediately before the preference test showed a higher preference for green frog-shaped stimuli. Our results suggest that newly hatched chicks innately integrate colour and shape cues during decision making, and that this can be augmented by other sensory experiences. Innate and experience-based behaviour could confer a fitness advantage to novel aposematic prey, and favour the initial evolution of conspicuous colouration.
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Affiliation(s)
- Francesca Protti-Sánchez
- Max Planck Research Group Predators and Toxic Prey, Max Planck Institute for Chemical Ecology, Hans Knöll Straße 8, 07745, Jena, Germany.
| | - Uwe Mayer
- Center for Mind/Brain Sciences (CIMeC), University of Trento, Piazza Manifattura 1, 38068, Rovereto, TN, Italy
| | - Hannah M Rowland
- Max Planck Research Group Predators and Toxic Prey, Max Planck Institute for Chemical Ecology, Hans Knöll Straße 8, 07745, Jena, Germany
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26
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Hancock GRA, Grayshon L, Burrell R, Cuthill I, Hoodless A, Troscianko J. Habitat geometry rather than visual acuity limits the visibility of a ground-nesting bird's clutch to terrestrial predators. Ecol Evol 2023; 13:e10471. [PMID: 37720061 PMCID: PMC10501817 DOI: 10.1002/ece3.10471] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2023] [Revised: 08/10/2023] [Accepted: 08/18/2023] [Indexed: 09/19/2023] Open
Abstract
The nests of ground-nesting birds rely heavily on camouflage for their survival, and predation risk, often linked to ecological changes from human activity, is a major source of mortality. Numerous ground-nesting bird populations are in decline, so understanding the effects of camouflage on their nesting behavior is relevant to their conservation concerns. Habitat three-dimensional (3D) geometry, together with predator visual abilities, viewing distance, and viewing angle, determine whether a nest is either visible, occluded, or too far away to detect. While this link is intuitive, few studies have investigated how fine-scale geometry is likely to help defend nests from different predator guilds. We quantified nest visibility based on 3D occlusion, camouflage, and predator visual modeling in northern lapwings, Vanellus vanellus, on different land management regimes. Lapwings selected local backgrounds that had a higher 3D complexity at a spatial scale greater than their entire clutches compared to local control sites. Importantly, our findings show that habitat geometry-rather than predator visual acuity-restricts nest visibility for terrestrial predators and that their field habitats, perceived by humans as open, are functionally closed with respect to a terrestrial predator searching for nests on the ground. Taken together with lapwings' careful nest site selection, our findings highlight the importance of considering habitat geometry for understanding the evolutionary ecology and management of conservation sites for ground-nesting birds.
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Affiliation(s)
| | | | - Ryan Burrell
- Faculty of Science and TechnologyBournemouth UniversityDorsetUK
| | - Innes Cuthill
- School of Biological SciencesUniversity of BristolBristolUK
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27
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McCoy DE, Shultz AJ, Dall JE, Dionne JA, Johnsen S. The carotenoid redshift: Physical basis and implications for visual signaling. Ecol Evol 2023; 13:e10408. [PMID: 37693937 PMCID: PMC10485323 DOI: 10.1002/ece3.10408] [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: 07/17/2023] [Accepted: 07/21/2023] [Indexed: 09/12/2023] Open
Abstract
Carotenoid pigments are the basis for much red, orange, and yellow coloration in nature and central to visual signaling. However, as pigment concentration increases, carotenoid signals not only darken and become more saturated but they also redshift; for example, orange pigments can look red at higher concentration. This occurs because light experiences exponential attenuation, and carotenoid-based signals have spectrally asymmetric reflectance in the visible range. Adding pigment disproportionately affects the high-absorbance regions of the reflectance spectra, which redshifts the perceived hue. This carotenoid redshift is substantial and perceivable by animal observers. In addition, beyond pigment concentration, anything that increases the path length of light through pigment causes this redshift (including optical nano- and microstructures). For example, male Ramphocelus tanagers appear redder than females, despite the same population and concentration of carotenoids, due to microstructures that enhance light-pigment interaction. This mechanism of carotenoid redshift has sensory and evolutionary consequences for honest signaling in that structures that redshift carotenoid ornaments may decrease signal honesty. More generally, nearly all colorful signals vary in hue, saturation, and brightness as light-pigment interactions change, due to spectrally asymmetrical reflectance within the visible range of the relevant species. Therefore, the three attributes of color need to be considered together in studies of honest visual signaling.
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Affiliation(s)
- Dakota E. McCoy
- Department of Materials Science and EngineeringStanford UniversityStanfordCaliforniaUSA
- Hopkins Marine StationStanford UniversityPacific GroveCaliforniaUSA
- Department of BiologyDuke UniversityDurhamNorth CarolinaUSA
| | - Allison J. Shultz
- Ornithology DepartmentNatural History Museum of Los Angeles CountyLos AngelesCaliforniaUSA
| | - Jacqueline E. Dall
- Ornithology DepartmentNatural History Museum of Los Angeles CountyLos AngelesCaliforniaUSA
| | - Jennifer A. Dionne
- Department of Materials Science and EngineeringStanford UniversityStanfordCaliforniaUSA
- Department of RadiologyStanford UniversityStanfordCaliforniaUSA
| | - Sönke Johnsen
- Department of BiologyDuke UniversityDurhamNorth CarolinaUSA
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28
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Vijayan S, Balamurali GS, Johnson J, Kelber A, Warrant EJ, Somanathan H. Dim-light colour vision in the facultatively nocturnal Asian giant honeybee, Apis dorsata. Proc Biol Sci 2023; 290:20231267. [PMID: 37554033 PMCID: PMC10410228 DOI: 10.1098/rspb.2023.1267] [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: 06/07/2023] [Accepted: 07/21/2023] [Indexed: 08/10/2023] Open
Abstract
We discovered nocturnal colour vision in the Asian giant honeybee Apis dorsata-a facultatively nocturnal species-at mesopic light intensities, down to half-moon light levels (approx. 10-2 cd m-2). The visual threshold of nocturnality aligns with their reported nocturnal activity down to the same light levels. Nocturnal colour vision in A. dorsata is interesting because, despite being primarily diurnal, its colour vision capabilities extend into dim light, while the 'model' European honeybee Apis mellifera is reported to be colour-blind at twilight. By employing behavioural experiments with naturally nesting A. dorsata colonies, we show discrimination of the trained colour from other stimuli during the day, and significantly, even at night. Nocturnal colour vision in bees has so far only been reported in the obligately nocturnal carpenter bee Xylocopa tranquebarica. The discovery of colour vision in these two bee species, despite differences in the extent of their nocturnality and the limitations of their apposition compound eye optics, opens avenues for future studies on visual adaptations for dim-light colour vision, their role in pollination of flowers at night, and the effect of light pollution on nocturnal activity in A. dorsata, a ubiquitous pollinator in natural, agricultural and urban habitats in the Asian tropics and sub-tropics.
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Affiliation(s)
- Sajesh Vijayan
- School of Biology, IISER-TVM Centre for Research and Education in Ecology and Evolution (ICREEE), Indian Institute of Science Education and Research Thiruvananthapuram, Thiruvananthapuram, Kerala, India
| | - G. S. Balamurali
- School of Biology, IISER-TVM Centre for Research and Education in Ecology and Evolution (ICREEE), Indian Institute of Science Education and Research Thiruvananthapuram, Thiruvananthapuram, Kerala, India
- Lund Vision Group, Department of Biology, University of Lund, Sölvegatan 35, Lund 22362, Sweden
| | - Jewel Johnson
- School of Biology, IISER-TVM Centre for Research and Education in Ecology and Evolution (ICREEE), Indian Institute of Science Education and Research Thiruvananthapuram, Thiruvananthapuram, Kerala, India
| | - Almut Kelber
- Lund Vision Group, Department of Biology, University of Lund, Sölvegatan 35, Lund 22362, Sweden
| | - Eric J. Warrant
- Lund Vision Group, Department of Biology, University of Lund, Sölvegatan 35, Lund 22362, Sweden
| | - Hema Somanathan
- School of Biology, IISER-TVM Centre for Research and Education in Ecology and Evolution (ICREEE), Indian Institute of Science Education and Research Thiruvananthapuram, Thiruvananthapuram, Kerala, India
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29
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Reichert MS, Bolek MG, McCullagh EA. Parasite effects on receivers in animal communication: Hidden impacts on behavior, ecology, and evolution. Proc Natl Acad Sci U S A 2023; 120:e2300186120. [PMID: 37459523 PMCID: PMC10372545 DOI: 10.1073/pnas.2300186120] [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: 07/20/2023] Open
Abstract
Parasites exert a profound effect on biological processes. In animal communication, parasite effects on signalers are well-known drivers of the evolution of communication systems. Receiver behavior is also likely to be altered when they are parasitized or at risk of parasitism, but these effects have received much less attention. Here, we present a broad framework for understanding the consequences of parasitism on receivers for behavioral, ecological, and evolutionary processes. First, we outline the different kinds of effects parasites can have on receivers, including effects on signal processing from the many parasites that inhabit, occlude, or damage the sensory periphery and the central nervous system or that affect physiological processes that support these organs, and effects on receiver response strategies. We then demonstrate how understanding parasite effects on receivers could answer important questions about the mechanistic causes and functional consequences of variation in animal communication systems. Variation in parasitism levels is a likely source of among-individual differences in response to signals, which can affect receiver fitness and, through effects on signaler fitness, impact population levels of signal variability. The prevalence of parasitic effects on specific sensory organs may be an important selective force for the evolution of elaborate and multimodal signals. Finally, host-parasite coevolution across heterogeneous landscapes will generate geographic variation in communication systems, which could ultimately lead to evolutionary divergence. We discuss applications of experimental techniques to manipulate parasitism levels and point the way forward by calling for integrative research collaborations between parasitologists, neurobiologists, and behavioral and evolutionary ecologists.
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Affiliation(s)
- Michael S. Reichert
- Department of Integrative Biology, Oklahoma State University, Stillwater, OK74078
| | - Matthew G. Bolek
- Department of Integrative Biology, Oklahoma State University, Stillwater, OK74078
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30
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Di Giovanni AJ, Villa J, Stanback MT, Thompson CF, Sakaluk SK, Hauber ME, Hanley D. Decision rules for egg-color-based rejection by two cavity-nesting hosts of the brown-headed cowbird. J Exp Biol 2023; 226:jeb245188. [PMID: 37357579 PMCID: PMC10399979 DOI: 10.1242/jeb.245188] [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: 10/13/2022] [Accepted: 06/21/2023] [Indexed: 06/27/2023]
Abstract
Hosts of obligate avian brood parasites often evolve defense mechanisms to avoid rearing unrelated young. One common defense is egg rejection, for which hosts often rely on eggshell color. Most research has assumed that hosts respond to perceived color differences between their own eggs and parasite eggs regardless of the particular color; however, recent experiments have found that many hosts respond more strongly to brown foreign eggs than to equally dissimilar blue eggs. Yet, none of these prior studies tested a brown-egg-laying species and, with only one exception, all were conducted in open nests where light levels are considered sufficient for effective color-based egg discrimination. Here, we explored how two cavity-nesting hosts of the parasitic brown-headed cowbird (Molothrus ater) - the blue-egg-laying eastern bluebird (Sialia sialis) and the brown-egg-laying house wren (Troglodytes aedon) - respond to experimental eggs painted six distinct colors ranging from blue to brown. Rejection responses of both hosts were best predicted by perceived differences in color between the model egg and their own eggs. Specifically, we found that house wrens preferentially rejected eggs bluer than their own eggs. However, although we found that bluebirds relied on perceived differences in color for their egg rejection decisions, further tests are needed to determine whether they preferentially rejected brown eggs or simply responded to absolute perceived differences in color. These findings demonstrate that these cavity-nesting birds treat perceived color differences in distinct ways, which has important implications on the coevolutionary arms races and the interpretation of avian-perceived color differences.
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Affiliation(s)
| | - Juliana Villa
- Department of Biology, George Mason University, Fairfax, VA 22030, USA
| | - Mark T. Stanback
- Department of Biology, Davidson College, Davidson, NC 28035, USA
| | - Charles F. Thompson
- Behavior, Ecology, Evolution, and Conservation Section, School of Biological Sciences, Illinois State University, Normal, IL 61790, USA
| | - Scott K. Sakaluk
- Behavior, Ecology, Evolution, and Conservation Section, School of Biological Sciences, Illinois State University, Normal, IL 61790, USA
| | - Mark E. Hauber
- Department of Evolution, Ecology, and Behavior, School of Integrative Biology, University of Illinois Urbana-Champaign, Urbana, IL 61801, USA
| | - Daniel Hanley
- Department of Biology, George Mason University, Fairfax, VA 22030, USA
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31
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Batabyal A, Zambre A, Mclaren T, Rankin KJ, Somaweera R, Stuart‐Fox D, Thaker M. The extent of rapid colour change in male agamid lizards is unrelated to overall sexual dichromatism. Ecol Evol 2023; 13:e10293. [PMID: 37435020 PMCID: PMC10329938 DOI: 10.1002/ece3.10293] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2023] [Revised: 06/12/2023] [Accepted: 06/21/2023] [Indexed: 07/13/2023] Open
Abstract
Dynamic colour change is widespread in ectothermic animals, but has primarily been studied in the context of background matching. For most species, we lack quantitative data on the extent of colour change across different contexts. It is also unclear whether and how colour change varies across body regions, and how overall sexual dichromatism relates to the extent of individual colour change. In this study, we obtained reflectance measures in response to different stimuli for males and females of six species of agamid lizards (Agamidae, sister family to Chameleonidae) comprising three closely related species pairs. We computed the colour volume in a lizard-vision colour space occupied by males and females of each species and estimated overall sexual dichromatism based on the area of non-overlapping male and female colour volumes. As expected, males had larger colour volumes than females, but the extent of colour change in males differed between species and between body regions. Notably, species that were most sexually dichromatic were not necessarily those in which males showed the greatest individual colour change. Our results indicate that the extent of colour change is independent of the degree of sexual dichromatism and demonstrate that colour change on different body regions can vary substantially even between pairs of closely related species.
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Affiliation(s)
- Anuradha Batabyal
- Department of Physical and Natural SciencesFLAME UniversityPuneIndia
- Centre for Ecological SciencesIndian Institute of ScienceBengaluruIndia
| | - Amod Zambre
- Centre for Ecological SciencesIndian Institute of ScienceBengaluruIndia
- Department of Ecology, Evolution and BehaviorUniversity of MinnesotaMinneapolisMinnesotaUSA
| | - Tess Mclaren
- School of BioSciencesThe University of MelbourneParkvilleVictoriaAustralia
| | - Katrina J. Rankin
- School of BioSciencesThe University of MelbourneParkvilleVictoriaAustralia
| | - Ruchira Somaweera
- Stantec AustraliaPerthWestern AustraliaAustralia
- School of Biological SciencesUniversity of Western AustraliaPerthWestern AustraliaAustralia
| | - Devi Stuart‐Fox
- School of BioSciencesThe University of MelbourneParkvilleVictoriaAustralia
| | - Maria Thaker
- Centre for Ecological SciencesIndian Institute of ScienceBengaluruIndia
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32
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Zeng H, Zhao D, Zhang Z, Gao H, Zhang W. Imperfect ant mimicry contributes to local adaptation in a jumping spider. iScience 2023; 26:106747. [PMID: 37378345 PMCID: PMC10291251 DOI: 10.1016/j.isci.2023.106747] [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: 07/28/2022] [Revised: 08/29/2022] [Accepted: 04/21/2023] [Indexed: 06/29/2023] Open
Abstract
Putative ant mimicry is a remarkable example of an evolutionary strategy that can be well integrated into the framework of natural selection and adaptation. However, challenges remain in understanding imperfect ant mimicry. Here, we combine trait quantification and behavioral assays to investigate imperfect ant mimicry in the jumping spider Siler collingwoodi. We performed trajectory analysis and gait analysis to show that the locomotor characters of S. collingwoodi generally resemble those of the putative ant models, supporting the multiple models hypothesis. We then performed background-matching analysis, revealing that body coloration may be involved in background camouflage. We further carried out antipredation assays and found that S. collingwoodi had a significantly lower risk of predation than nonmimetic salticids, suggesting an overall protective effect of Batesian mimicry. Our findings quantitatively demonstrate a combination of mimicry and camouflage in S. collingwoodi and thus highlight the significance of a complex phenomenon driven by natural selection.
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Affiliation(s)
- Hua Zeng
- State Key Laboratory of Protein and Plant Gene Research, School of Life Sciences, Peking University, Beijing 100871, China
- Peking-Tsinghua Center for Life Sciences, Academy for Advanced Interdisciplinary Studies, Peking University, Beijing 100871, China
- Chineses Institute for Brain Research, Beijing 102206, China
| | - Dong Zhao
- State Key Laboratory of Protein and Plant Gene Research, School of Life Sciences, Peking University, Beijing 100871, China
| | - Zixuan Zhang
- State Key Laboratory of Protein and Plant Gene Research, School of Life Sciences, Peking University, Beijing 100871, China
- College of Urban and Environmental Sciences, Peking University, Beijing 100871, China
| | - Huize Gao
- State Key Laboratory of Protein and Plant Gene Research, School of Life Sciences, Peking University, Beijing 100871, China
| | - Wei Zhang
- State Key Laboratory of Protein and Plant Gene Research, School of Life Sciences, Peking University, Beijing 100871, China
- Peking-Tsinghua Center for Life Sciences, Academy for Advanced Interdisciplinary Studies, Peking University, Beijing 100871, China
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Yang C, Ye P, Wu N, Yao X, Liang W. Revealing the roles of egg darkness and nest similarity for a cryptic parasite egg versus host's cognition: an alternate coevolutionary trajectory. Proc Biol Sci 2023; 290:20230103. [PMID: 37132235 PMCID: PMC10154918 DOI: 10.1098/rspb.2023.0103] [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: 01/14/2023] [Accepted: 03/27/2023] [Indexed: 05/04/2023] Open
Abstract
As a text-book example of coevolution, the escalating interactions between egg mimicry by parasitic cuckoos and egg recognition by their hosts constitute a key battlefield for parasitism and anti-parasitism strategies. However, some parasite-host systems have deviated from this coevolutionary trajectory because some cuckoos do not lay mimetic eggs, while the hosts do not recognize them, even under the high costs of parasitism. The cryptic egg hypothesis was proposed to explain this puzzle, but the evidence to date is mixed and the relationship between the two components of egg crypticity, egg darkness (dim egg coloration) and nest similarity (similarity to host nest appearance), remains unknown. Here, we developed a 'field psychophysics' experimental design to dissect these components while controlling for undesired confounding factors. Our results clearly show that both egg darkness and nest similarity of cryptic eggs affect recognition by hosts, and egg darkness plays a more influential role than nest similarity. This study provides unambiguous evidence to resolve the puzzle of absent mimicry and recognition in cuckoo-host systems and explains why some cuckoo eggs were more likely to evolve dim coloration rather than similarity to host eggs or host nests.
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Affiliation(s)
- Canchao Yang
- Ministry of Education Key Laboratory for Ecology of Tropical Islands, College of Life Sciences, Hainan Normal University, Haikou 571158, People's Republic of China
| | - Ping Ye
- Ministry of Education Key Laboratory for Ecology of Tropical Islands, College of Life Sciences, Hainan Normal University, Haikou 571158, People's Republic of China
| | - Neng Wu
- Ministry of Education Key Laboratory for Ecology of Tropical Islands, College of Life Sciences, Hainan Normal University, Haikou 571158, People's Republic of China
| | - Xiaogang Yao
- Ministry of Education Key Laboratory for Ecology of Tropical Islands, College of Life Sciences, Hainan Normal University, Haikou 571158, People's Republic of China
- Kuankuoshui National Nature Reserve, Suiyang 563300, People's Republic of China
| | - Wei Liang
- Ministry of Education Key Laboratory for Ecology of Tropical Islands, College of Life Sciences, Hainan Normal University, Haikou 571158, People's Republic of China
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Stieb SM, Cortesi F, de Queiroz LJ, Carleton KL, Seehausen O, Marshall NJ. Long-wavelength-sensitive (lws) opsin gene expression, foraging and visual communication in coral reef fishes. Mol Ecol 2023; 32:1656-1672. [PMID: 36560895 PMCID: PMC10065935 DOI: 10.1111/mec.16831] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2022] [Revised: 11/25/2022] [Accepted: 12/15/2022] [Indexed: 12/24/2022]
Abstract
Coral reef fishes are diverse in ecology and behaviour and show remarkable colour variability. Investigating the visual pigment gene (opsin) expression in these fishes makes it possible to associate their visual genotype and phenotype (spectral sensitivities) to visual tasks, such as feeding strategy or conspecific detection. By studying all major damselfish clades (Pomacentridae) and representatives from five other coral reef fish families, we show that the long-wavelength-sensitive (lws) opsin is highly expressed in algivorous and less or not expressed in zooplanktivorous species. Lws is also upregulated in species with orange/red colours (reflectance >520 nm) and expression is highest in orange/red-coloured algivores. Visual models from the perspective of a typical damselfish indicate that sensitivity to longer wavelengths does enhance the ability to detect the red to far-red component of algae and orange/red-coloured conspecifics, possibly enabling social signalling. Character state reconstructions indicate that in the early evolutionary history of damselfishes, there was no lws expression and no orange/red coloration. Omnivory was most often the dominant state. Although herbivory was sometimes dominant, zooplanktivory was never dominant. Sensitivity to long wavelength (increased lws expression) only emerged in association with algivory but never with zooplanktivory. Higher lws expression is also exploited by social signalling in orange/red, which emerged after the transition to algivory. Although the relative timing of traits may deviate by different reconstructions and alternative explanations are possible, our results are consistent with sensory bias whereby social signals evolve as a correlated response to natural selection on sensory system properties in other contexts.
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Affiliation(s)
- Sara M. Stieb
- Centre for Ecology, Evolution and Biogeochemistry (CEEB), EAWAG Swiss Federal Institute of Aquatic Science and Technology, Kastanienbaum, Switzerland
- Institute of Ecology and Evolution, University of Bern, Switzerland
- Queensland Brain Institute, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Fabio Cortesi
- Queensland Brain Institute, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Luiz Jardim de Queiroz
- Centre for Ecology, Evolution and Biogeochemistry (CEEB), EAWAG Swiss Federal Institute of Aquatic Science and Technology, Kastanienbaum, Switzerland
- Institute of Ecology and Evolution, University of Bern, Switzerland
| | - Karen L. Carleton
- Department of Biology, University of Maryland, College Park, MD 20742, USA
| | - Ole Seehausen
- Centre for Ecology, Evolution and Biogeochemistry (CEEB), EAWAG Swiss Federal Institute of Aquatic Science and Technology, Kastanienbaum, Switzerland
- Institute of Ecology and Evolution, University of Bern, Switzerland
| | - N. Justin Marshall
- Queensland Brain Institute, The University of Queensland, Brisbane, QLD 4072, Australia
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Ontogenetic change in the effectiveness of camouflage: growth versus pattern matching in Fowler's toad. Anim Behav 2023. [DOI: 10.1016/j.anbehav.2023.01.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/19/2023]
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36
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Costa A, Moré M, Sérsic AN, Cocucci AA, Drewniak ME, Izquierdo JV, Coetzee A, Pauw A, Traveset A, Paiaro V. Floral colour variation of Nicotiana glauca in native and non-native ranges: Testing the role of pollinators' perception and abiotic factors. PLANT BIOLOGY (STUTTGART, GERMANY) 2023; 25:403-410. [PMID: 36744723 DOI: 10.1111/plb.13509] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/01/2022] [Accepted: 01/31/2023] [Indexed: 06/18/2023]
Abstract
Invasive plants displaying disparate pollination environments and abiotic conditions in native and non-native ranges provide ideal systems to test the role of different ecological factors driving flower colour variation. We quantified corolla reflectance of the ornithophilous South American Nicotiana glauca in native populations, where plants are pollinated by hummingbirds, and in populations from two invaded regions: South Africa, where plants are pollinated by sunbirds, and the Balearic island of Mallorca, where plants reproduce by selfing. Using visual modelling we examined how corolla reflectance could be perceived by floral visitors present in each region. Through Mantel tests we assessed a possible association between flower colour and different abiotic factors. Corolla reflectance variation (mainly along medium to long wavelengths, i.e. human green-yellow to red colours) was greater among studied regions than within them. Flower colour was more similar between South America and South Africa, which share birds as pollinators. Within invaded regions, corolla reflectance variation was lower in South Africa, where populations could not be distinguished from each other by sunbirds, than in Spain, where populations could be distinguished from each other by their occasional visitors. Differences in corolla colour among populations were partially associated with differences in temperature. Our findings suggest that shifts in flower colour of N. glauca across native and invaded ranges could be shaped by changes in both pollination environment and climatic factors. This is the first study on plant invasions considering visual perception of different pollinators and abiotic drivers of flower colour variation.
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Affiliation(s)
- A Costa
- Instituto Multidisciplinario de Biología Vegetal (CONICET-UNC), Córdoba, Argentina
| | - M Moré
- Instituto Multidisciplinario de Biología Vegetal (CONICET-UNC), Córdoba, Argentina
| | - A N Sérsic
- Instituto Multidisciplinario de Biología Vegetal (CONICET-UNC), Córdoba, Argentina
| | - A A Cocucci
- Instituto Multidisciplinario de Biología Vegetal (CONICET-UNC), Córdoba, Argentina
| | - M E Drewniak
- Instituto Multidisciplinario de Biología Vegetal (CONICET-UNC), Córdoba, Argentina
| | - J V Izquierdo
- Instituto Multidisciplinario de Biología Vegetal (CONICET-UNC), Córdoba, Argentina
| | - A Coetzee
- Fitz Patrick Institute of African Ornithology, DSI-NRF Centre of Excellence, University of Cape Town, Rondebosch, South Africa
| | - A Pauw
- Department of Botany and Zoology, Stellenbosch University, Matieland, South Africa
| | - A Traveset
- Instituto Mediterráneo de Estudios Avanzados (CSIC, UIB), Mallorca, Balearic Islands, Spain
| | - V Paiaro
- Instituto Multidisciplinario de Biología Vegetal (CONICET-UNC), Córdoba, Argentina
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de La Cruz F, Pérez i de Lanuza G, Font E. Signalling on islands: the case of Lilford’s wall lizard ( Podarcis lilfordi gigliolii) from Dragonera. Biol J Linn Soc Lond 2023. [DOI: 10.1093/biolinnean/blac152] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/19/2023]
Abstract
AbstractStudies of the effects of insularity on animal signals are scarce, particularly in lizards. Here, we use Lilford’s wall lizard from Dragonera (Podarcis lilfordi gigliolii) to ask how island conditions have affected its repertoire of social signals, focusing on two visual signals shared by many Podarcis species: ultraviolet (UV)–blue-reflecting ventrolateral colour patches and visual displays. We examined whether the number or spectral characteristics of the UV–blue patches are associated with traits related to individual quality. We also used visual models to assess visual conspicuousness and to measure sexual dichromatism. We did not observe foot shakes or any other visual displays usually found in continental Podarcis. We found that none of the UV–blue patch variables covaried with morphometric variables indicative of fighting ability or body condition in males, suggesting that this coloration does not signal individual quality. We also found very little sexual dichromatism. In particular, the UV–blue patches of females seem over-expressed and more similar to those of males than those of continental Podarcis. Ancestral state reconstruction reveals that the lack of sexual dimorphism in the UV–blue patches is a derived condition for P. lilfordi gigliolii and other Podarcis living on small islands. Our results thus show a pattern of reduced social signalling in P. lilfordi gigliolii relative to mainland Podarcis, with some signals being lost or under-expressed (visual displays) and others losing their signalling function (UV–blue patches). We hypothesize that these changes are attributable to the high population density of P. lilfordi gigliolii, which discourages territorial behaviour and promotes extreme social tolerance, making most social signals unnecessary. More work will be needed to determine whether this is a common pattern in lizards inhabiting small and densely populated islands.
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Affiliation(s)
- Ferran de La Cruz
- Ethology Lab, Cavanilles Institute of Biodiversity and Evolutionary Biology, University of Valencia , APDO 22085, 46071 , Spain
- CIBIO Research Centre in Biodiversity and Genetic Resources, InBIO, Campus de Vairão, Universidade do Porto , 4485-661 , Portugal
| | - Guillem Pérez i de Lanuza
- Ethology Lab, Cavanilles Institute of Biodiversity and Evolutionary Biology, University of Valencia , APDO 22085, 46071 , Spain
| | - Enrique Font
- Ethology Lab, Cavanilles Institute of Biodiversity and Evolutionary Biology, University of Valencia , APDO 22085, 46071 , Spain
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John L, Santon M, Michiels NK. Scorpionfish rapidly change colour in response to their background. Front Zool 2023; 20:10. [PMID: 36864453 PMCID: PMC9983180 DOI: 10.1186/s12983-023-00488-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2023] [Accepted: 02/20/2023] [Indexed: 03/04/2023] Open
Abstract
BACKGROUND To facilitate background matching in heterogenous environments, some animals rapidly change body colouration. Marine predatory fishes might use this ability to hide from predators and prey. Here, we focus on scorpionfishes (Scorpaenidae), well-camouflaged, bottom-dwelling sit-and-wait predators. We tested whether Scorpaena maderensis and Scorpaena porcus adjust body luminance and hue in response to three artificial backgrounds and thereby achieve background matching. Both scorpionfish species are also red fluorescent, which could contribute to background matching at depth. Therefore, we tested whether red fluorescence is also regulated in response to different backgrounds. The darkest and the lightest backgrounds were grey, while the third background was orange of intermediate luminance. Scorpionfish were placed on all three backgrounds in a randomised repeated measures design. We documented changes in scorpionfish luminance and hue with image analysis and calculated contrast to the backgrounds. Changes were quantified from the visual perspective of two potential prey fishes, the triplefin Tripterygion delaisi and the goby Pomatoschistus flavescens. Additionally, we measured changes in the area of scorpionfish red fluorescence. Because scorpionfish changed quicker than initially expected, we measured luminance change at a higher temporal resolution in a second experiment. RESULTS Both scorpionfish species rapidly adjusted luminance and hue in response to a change of background. From prey visual perspective, scorpionfishes' body achromatic and chromatic contrasts against the background were high, indicating imperfect background matching. Chromatic contrasts differed considerably between the two observer species, highlighting the importance of choosing natural observers with care when studying camouflage. Scorpionfish displayed larger areas of red fluorescence with increasing luminance of the background. With the second experiment, we showed that about 50% of the total luminance change observed after one minute is achieved very rapidly, in five to ten seconds. CONCLUSION Both scorpionfish species change body luminance and hue in response to different backgrounds within seconds. While the achieved background matching was suboptimal for the artificial backgrounds, we propose that the observed changes were intended to reduce detectability, and are an essential strategy to camouflage in the natural environment.
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Affiliation(s)
- Leonie John
- Animal Evolutionary Ecology, Institute of Evolution and Ecology, University of Tübingen, Auf Der Morgenstelle 28, 72076, Tübingen, Germany.
| | - Matteo Santon
- grid.10392.390000 0001 2190 1447Animal Evolutionary Ecology, Institute of Evolution and Ecology, University of Tübingen, Auf Der Morgenstelle 28, 72076 Tübingen, Germany ,grid.5337.20000 0004 1936 7603Ecology of Vision Group, School of Biological Sciences, University of Bristol, 24 Tyndall Avenue, Bristol, BS8 1TQ UK
| | - Nico K. Michiels
- grid.10392.390000 0001 2190 1447Animal Evolutionary Ecology, Institute of Evolution and Ecology, University of Tübingen, Auf Der Morgenstelle 28, 72076 Tübingen, Germany
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39
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Mori S, Hasegawa Y, Moriguchi Y. Color strategies of camellias recruiting different pollinators. PHYTOCHEMISTRY 2023; 207:113559. [PMID: 36528119 DOI: 10.1016/j.phytochem.2022.113559] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/01/2022] [Revised: 12/09/2022] [Accepted: 12/10/2022] [Indexed: 06/17/2023]
Abstract
Most ornithophilous plants have red flowers; this has been associated with 'the bee avoidance hypothesis', in which ornithophilous flowers may bear colors that are less conspicuous to bees than melittophilous flowers. In the genus Camellia, C. rusticana and C. japonica bear red flowers and yet recruit different pollinators; the former is entomophilous, while the latter is ornithophilous. C. japonica is considered to have been speciated from a common ancestor later than C. rusticana, accompanying a pollinator shift from insects to birds. Nevertheless, factors explaining the pollinator difference in camellias remain rudimentary. In this study, the color traits of the two camellias were investigated, to determine their color strategy to allure different pollinators. The behavior of bees towards the two camellias was examined by a two-choice assay. Flower color characteristics of the two camellias were analyzed with diffuse reflectance and fluorescence spectra. Based on the visual sensory system of bees and birds, the achromatic contrast, chromatic contrast, intensity, and spectral purity of the two species were evaluated, testing the bee avoidance hypothesis. Furthermore, the compounds responsible for the fluorescence, likely serving as a visual attractant, were identified by NMR and MS. Bees visited C. rusticana flowers almost exclusively and C. japonica hardly at all. Reflectance spectral data showed that C. rusticana petals are more conspicuous to bees than birds due to a UV-reflection secondary peak; and that C. japonica petals exhibited crucially low chromatic contrast against a leaf background to bees, suggesting them to be almost indistinguishable. On the other hand, C. japonica flowers appeared conspicuous to birds. The anthers of C. rusticana exhibited blue fluorescence derived from two anthranilates, while those of C. japonica did not. The two camellias offer different color strategies to be conspicuous to their respective pollinators, and C. japonica seemed to have evolved to avoid bees. Alterations in these color traits may have played a role in pollinator shift.
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Affiliation(s)
- Shinnosuke Mori
- Science and Technology, Keio University, 3-14-1 Hiyoshi, Kohoku-ku, Yokohama, 223-8522, Japan.
| | - Yoichi Hasegawa
- Forestry and Forest Products Research Institute, Forest Research and Management Organization, 1 Matsunosato, Tsukuba, Ibaraki, 305-8687, Japan
| | - Yoshinari Moriguchi
- Graduate School of Science and Technology, Niigata University, 8050, Ikarashi 2-Nocho, Nishi-ku, Niigata, 950-2181, Japan
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40
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Valdez DJ, Benitez-Vieyra SM. Annual molt period and seasonal color variation in the Eared Dove´s crown. PLoS One 2023; 18:e0280819. [PMID: 36827341 PMCID: PMC9955656 DOI: 10.1371/journal.pone.0280819] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2022] [Accepted: 01/09/2023] [Indexed: 02/25/2023] Open
Abstract
Molting is an important process in which old and worn feathers are exchanged for new ones. Plumage color is determined by pigments such as carotenes, melanin and by the ultrastructure of the feather. The importance of plumage coloration has been widely studied in different groups of birds, generally at a particular time of the year. However, plumage coloration is not static and few studies have addressed the change in plumage color over time and its relationship to reproductive tasks. The Eared Dove (Zenaida auriculata, Des Murs, 1847) has a melanistic coloration with sexual dichromatism in different body regions. The Eared Dove´s crown is the most exposed body region during the bowing display. Our objective was therefore to accurately determine the molting period of the crown feathers and study the seasonal variation in their coloration in females and males. Our findings indicate a molting period of 6 months (January to June). The new feathers are undergoing changes in their coloration from July to December. During that period we apply an avian vision model then enabled us to reveal a seasonal variation in the coloration of the crown feathers in both sexes, as given by a change in the chromatic distances. The highest values in the chromatic distances towards the reproductive period are given by a change in the UV-violet component of the spectrum, indicating changes in the microstructure of the feather. This change in crown coloration towards the breeding season could be linked to reproductive behaviors.
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Affiliation(s)
- Diego J. Valdez
- Facultad de Ciencias Exactas, Físicas y Naturales, Centro de Zoología Aplicada, Universidad Nacional de Córdoba, Córdoba, Argentina
- Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Instituto de Diversidad y Ecología Animal (IDEA), Córdoba, Argentina
- * E-mail:
| | - Santiago M. Benitez-Vieyra
- Instituto Multidisciplinario de Biología Vegetal (IMBIV), Universidad Nacional de Córdoba–Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Córdoba, Argentina
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41
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Zhang J, Santema P, Lin Z, Yang L, Liu M, Li J, Deng W, Kempenaers B. Experimental evidence that cuckoos choose host nests following an egg matching strategy. Proc Biol Sci 2023; 290:20222094. [PMID: 36809803 PMCID: PMC9943643 DOI: 10.1098/rspb.2022.2094] [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] [Indexed: 02/23/2023] Open
Abstract
The arms race between brood parasites and their hosts provides a classic model to study coevolution. Hosts often reject the parasitic egg, and brood parasites should therefore select host nests in which the colour of the eggs best matches that of their own. Although this hypothesis has received some support, direct experimental evidence is still lacking. Here, we report on a study of Daurian redstarts, which show a distinct egg-colour dimorphism, with females laying either blue or pink eggs. Redstarts are often parasitized by common cuckoos, which lay light blue eggs. First, we showed that cuckoo eggs were more similar in spectral reflectance to the blue than to the pink redstart egg morph. Second, we report that the natural parasitism rate was higher in blue than in pink host clutches. Third, we performed a field experiment in which we presented a dummy clutch of each colour morph adjacent to active redstart nests. In this set-up, cuckoos almost always chose to parasitize a blue clutch. Our results demonstrate that cuckoos actively choose redstart nests in which the egg colour matches the colour of their own eggs. Our study thus provides direct experimental evidence in support of the egg matching hypothesis.
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Affiliation(s)
- Jinggang Zhang
- Ministry of Education Key Laboratory for Biodiversity Sciences and Ecological Engineering, College of Life Sciences, Beijing Normal University, Beijing 100875, People's Republic of China.,Department of Behavioural Ecology and Evolutionary Genetics, Max Planck Institute for Ornithology, Seewiesen 82319, Germany
| | - Peter Santema
- Department of Behavioural Ecology and Evolutionary Genetics, Max Planck Institute for Ornithology, Seewiesen 82319, Germany.,Edward Grey Institute, Department of Zoology, University of Oxford, Oxford OX1 3PS, UK
| | - Zixuan Lin
- Ministry of Education Key Laboratory for Biodiversity Sciences and Ecological Engineering, College of Life Sciences, Beijing Normal University, Beijing 100875, People's Republic of China
| | - Lixing Yang
- Ministry of Education Key Laboratory for Biodiversity Sciences and Ecological Engineering, College of Life Sciences, Beijing Normal University, Beijing 100875, People's Republic of China.,Academy of Forestry Inventory and Planning, National Forestry and Grassland Administration, Beijing 100714, People's Republic of China
| | - Meijun Liu
- Ministry of Education Key Laboratory for Biodiversity Sciences and Ecological Engineering, College of Life Sciences, Beijing Normal University, Beijing 100875, People's Republic of China
| | - Jianqiang Li
- School of Ecology and Nature Conservation, Beijing Forestry University, Beijing 100083, People's Republic of China
| | - Wenhong Deng
- Ministry of Education Key Laboratory for Biodiversity Sciences and Ecological Engineering, College of Life Sciences, Beijing Normal University, Beijing 100875, People's Republic of China
| | - Bart Kempenaers
- Department of Behavioural Ecology and Evolutionary Genetics, Max Planck Institute for Ornithology, Seewiesen 82319, Germany
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42
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McDiarmid CS, Finch F, Peso M, van Rooij E, Hooper DM, Rowe M, Griffith SC. Experimentally testing mate preference in an avian system with unidirectional bill color introgression. Ecol Evol 2023; 13:e9812. [PMID: 36825134 PMCID: PMC9942114 DOI: 10.1002/ece3.9812] [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: 01/05/2023] [Accepted: 01/16/2023] [Indexed: 02/23/2023] Open
Abstract
Mating behavior can play a key role in speciation by inhibiting or facilitating gene flow between closely related taxa. Hybrid zones facilitate a direct examination of mating behavior and the traits involved in establishing species barriers. The long-tailed finch (Poephila acuticauda) has two hybridizing subspecies that differ in bill color (red and yellow), and the yellow bill phenotype appears to have introgressed ~350 km eastward following secondary contact. To examine the role of mate choice on bill color introgression, we performed behavioral assays using natural and manipulated bill colors. We found an assortative female mating preference for males of their own subspecies when bill color was not manipulated. However, we did not find this assortative preference in trials based on artificially manipulated bill color. This could suggest that assortative preference is not fixed entirely on bill color and instead may be based on a different trait (e.g., song) or a combination of traits, or alternatively may be due to lower statistical power alongside the bill manipulations being unconvincing to the female choosers. Intriguingly, we find a bias in the inheritance of bill color in captive bred F1 hybrid females. Previous modeling suggests that assortative mate preference and this kind of partial dominance in the underlying genes may together contribute to introgression, making the genetic architecture of bill color in this system a priority for future research.
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Affiliation(s)
- Callum S. McDiarmid
- School of Natural SciencesMacquarie UniversitySydneyNew South WalesAustralia
| | - Fiona Finch
- School of Natural SciencesMacquarie UniversitySydneyNew South WalesAustralia
| | - Marianne Peso
- School of Natural SciencesMacquarie UniversitySydneyNew South WalesAustralia
| | - Erica van Rooij
- School of Natural SciencesMacquarie UniversitySydneyNew South WalesAustralia
| | - Daniel M. Hooper
- Department of Biological SciencesColumbia UniversityNew YorkNew YorkUSA,Institute for Comparative GenomicsAmerican Museum of Natural HistoryNew YorkNew YorkUSA
| | - Melissah Rowe
- Department of Animal EcologyNetherlands Institute of Ecology (NIOO‐KNAW)WageningenThe Netherlands
| | - Simon C. Griffith
- School of Natural SciencesMacquarie UniversitySydneyNew South WalesAustralia
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43
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Moreira LAA, Watsa M, Erkenswick G, Higham JP, Melin AD. Evaluating genital skin color as a putative sexual signal in wild saddleback (Leontocebus weddelli) and emperor (Saguinus imperator) tamarins. Am J Primatol 2023; 85:e23456. [PMID: 36437549 DOI: 10.1002/ajp.23456] [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: 05/17/2022] [Revised: 11/14/2022] [Accepted: 11/17/2022] [Indexed: 11/29/2022]
Abstract
Coevolution between signalers and receivers has played a significant role in the diversity of animal signals and sensory systems. Platyrrhines (monkeys in the Americas) exhibit a remarkable color vision polymorphism that may have been selected by both natural and sexual selection, but sociosexual color signaling among platyrrhines has received almost no attention. Here, we study the color of reproductive skin among different reproductive classes in free-ranging female saddleback (Leontocebus weddelli) and emperor (Saguinus imperator) tamarins, modeling color spaces, and contrasts for the different visual systems. We find that the chromatic saturation and luminance of genital color vary between reproductive classes in saddleback tamarins. Chromatic contrast between the vulva and belly is lower in the parous females (PFs) relative to adult but not currently breeding females, while achromatic contrast is higher in PFs in saddleback tamarins relative to nonparous females. However, in emperor tamarins, genital color (saturation, hue, and luminance) does not vary between reproductive classes. Overall, genital skin color variation is present in tamarins and may play a role in sexual signaling. Nevertheless, the patterns are inconsistent between species, suggesting interspecific variation. Future studies should integrate the perceiver's behavioral responses and the physical and social signaling environments into comprehensive studies of communication as well as consider the role and interaction between multiple sensory modalities.
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Affiliation(s)
- Lais A A Moreira
- Department of Anthropology and Archaeology, University of Calgary, Calgary, Canada
| | - Mrinalini Watsa
- Beckman Center for Conservation Research, San Diego Zoo Global, Escondido, California, USA.,Field Projects International, Saint Louis, Missouri, USA
| | - Gideon Erkenswick
- Field Projects International, Saint Louis, Missouri, USA.,Department of Biology, University of Missouri St. Louis, Saint Louis, Missouri, USA.,Department of Molecular Microbiology, Washington University School of Medicine, Saint Louis, Missouri, USA
| | - James P Higham
- Department of Anthropology, New York University, New York City, New York, USA
| | - Amanda D Melin
- Department of Anthropology and Archaeology, University of Calgary, Calgary, Canada.,Department of Medical Genetics, Alberta Children's Hospital Research Institute, University of Calgary, Calgary, Canada
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Blount JD, Rowland HM, Mitchell C, Speed MP, Ruxton GD, Endler JA, Brower LP. The price of defence: toxins, visual signals and oxidative state in an aposematic butterfly. Proc Biol Sci 2023; 290:20222068. [PMID: 36651049 PMCID: PMC9845971 DOI: 10.1098/rspb.2022.2068] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
In a variety of aposematic species, the conspicuousness of an individual's warning signal and the quantity of its chemical defence are positively correlated. This apparent honest signalling is predicted by resource competition models which assume that the production and maintenance of aposematic defences compete for access to antioxidant molecules that have dual functions as pigments and in protecting against oxidative damage. To test for such trade-offs, we raised monarch butterflies (Danaus plexippus) on different species of their milkweed host plants (Apocynaceae) that vary in quantities of cardenolides to test whether (i) the sequestration of cardenolides as a secondary defence is associated with costs in the form of oxidative lipid damage and reduced antioxidant defences; and (ii) lower oxidative state is associated with a reduced capacity to produce aposematic displays. In male monarchs conspicuousness was explained by an interaction between oxidative damage and sequestration: males with high levels of oxidative damage became less conspicuous with increased sequestration of cardenolides, whereas those with low oxidative damage became more conspicuous with increased levels of cardenolides. There was no significant effect of oxidative damage or concentration of sequestered cardenolides on female conspicuousness. Our results demonstrate a physiological linkage between the production of coloration and oxidative state, and differential costs of sequestration and signalling in monarch butterflies.
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Affiliation(s)
- Jonathan D. Blount
- Centre for Ecology and Conservation, College of Life and Environmental Sciences, University of Exeter, Penryn Campus, Cornwall TR10 9FE, UK
| | - Hannah M. Rowland
- Research Group Predators and Toxic Prey, Max Planck Institute for Chemical Ecology, Hans-Knöll-Straße 8, Jena, 07745, Germany
| | - Christopher Mitchell
- Centre for Ecology and Conservation, College of Life and Environmental Sciences, University of Exeter, Penryn Campus, Cornwall TR10 9FE, UK
| | - Michael P. Speed
- Institute of Systems, Molecular and Integrative Biology, University of Liverpool, Liverpool L69 7BE, UK
| | - Graeme D. Ruxton
- School of Biology, Sir Harold Mitchell Building, Greenside Place, St Andrews, UK
| | - John A. Endler
- Centre for Integrative Ecology, School of Life and Environmental Sciences, Deakin University, Waurn Ponds, Victoria 3216, Australia
| | - Lincoln P. Brower
- Department of Biology, Sweet Briar College, Sweet Briar, VA 24595, USA
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45
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Maintenance of a fruit colour polymorphism along an elevational gradient in the Southern Alps of New Zealand. Oecologia 2023; 201:83-90. [PMID: 36416931 DOI: 10.1007/s00442-022-05287-5] [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: 06/06/2022] [Accepted: 11/07/2022] [Indexed: 11/24/2022]
Abstract
Many plants produce colour-polymorphic fruits. However, the processes responsible for the evolution and maintenance of fruit colour polymorphisms are poorly understood. We investigated the fruit colour polymorphism in Gaultheria depressa var. novae-zealandiae (Ericaceae), a predominantly bird-dispersed, alpine shrub from New Zealand, by testing whether colour morph frequencies vary geographically to maximise fruit-foliage colour contrasts. We also conducted a seed germination experiment to test whether fruit colour morphs vary in their susceptibility to UV damage. Results showed that 'red' fruits were more abundant at lower elevations, while 'white' fruits were predominant at higher elevations. Leaf colours shifted from 'green' in appearance at lower elevations to 'red' at higher elevations. Analyses of fruit-foliage colour contrasts showed that 'red' fruits were more conspicuous at lower elevations, and 'white' fruits were more conspicuous at higher elevations, which was consistent with the hypothesis that colour morph frequencies vary geographically to maximise their conspicuousness to dispersers. However, 'red' fruits were generally more conspicuous than 'white' fruits, regardless of elevation, indicating that the maintenance of the polymorphism could not be attributed to fruit-foliage colour contrasts alone. The seed germination experiment showed that 'white' fruits were more resistant to UV damage, suggesting the preponderance of 'white' fruited individuals in the landscape results from a greater degree of protection from UV damage. The fruit colour polymorphism in Gaultheria depressa var. novae-zealandiae therefore appears to be maintained by trade-offs between conspicuousness to dispersers and tolerance to UV damage, advocating a pluralistic approach to the problem in the future.
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46
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Costa FPD, Arruda MDF, Ribeiro K, Pessoa DMDA. Influence of color and brightness on ontogenetic shelter preference by the prawn Macrobrachium rosenbergii (Decapoda: Palaemonidae). ZOOLOGIA 2023. [DOI: 10.1590/s1984-4689.v40.e22023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/17/2023]
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47
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Beltrán DF, Araya-Salas M, Parra JL, Stiles FG, Rico-Guevara A. The evolution of sexually dimorphic traits in ecological gradients: an interplay between natural and sexual selection in hummingbirds. Proc Biol Sci 2022; 289:20221783. [PMID: 36515116 PMCID: PMC9748779 DOI: 10.1098/rspb.2022.1783] [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: 09/08/2022] [Accepted: 11/22/2022] [Indexed: 12/15/2022] Open
Abstract
Traits that exhibit differences between the sexes have been of special interest in the study of phenotypic evolution. Classic hypotheses explain sexually dimorphic traits via intra-sexual competition and mate selection, yet natural selection may also act differentially on the sexes to produce dimorphism. Natural selection can act either through physiological and ecological constraints on one of the sexes, or by modulating the strength of sexual/social selection. This predicts an association between the degree of dimorphism and variation in ecological environments. Here, we characterize the variation in hummingbird dimorphism across ecological gradients using rich databases of morphology, colouration and song. We show that morphological dimorphism decreases with elevation in the understorey and increases with elevation in mixed habitats, that dichromatism increases at high altitudes in open and mixed habitats, and that song is less complex in mixed habitats. Our results are consistent with flight constraints, lower predation pressure at high elevations and with habitat effects on song transmission. We also show that dichromatism and song complexity are positively associated, while tail dimorphism and song complexity are negatively associated. Our results suggest that key ecological factors shape sexually dimorphic traits, and that different communication modalities do not always evolve in tandem.
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Affiliation(s)
- Diego F. Beltrán
- Department of Biology, University of Washington, Seattle, WA 98195, USA
| | - Marcelo Araya-Salas
- Centro de Investigación en Neurociencias, Universidad de Costa Rica, San José, Costa Rica
- Escuela de Biología, Universidad de Costa Rica, San José, Costa Rica
| | - Juan L. Parra
- Grupo de Ecología y Evolución de Vertebrados, Instituto de Biología, Universidad de Antioquia, Medellín, Colombia
| | - F. Gary Stiles
- Instituto de Ciencias Naturales, Universidad Nacional de Colombia, Bogotá D.C., Colombia
| | - Alejandro Rico-Guevara
- Department of Biology, University of Washington, Seattle, WA 98195, USA
- Burke Museum of Natural History and Culture, University of Washington, Seattle, WA 98105, USA
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48
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Rao D, Long SM, Tapia-McClung H, Salgado-Espinosa K, Narendra A, Aguilar-Arguello S, Robledo-Ospina L, Rodriguez-Morales D, Jakob EM. Visual signals in the wing display of a tephritid fly deter jumping spider attacks. J Exp Biol 2022; 225:286139. [PMID: 36478243 DOI: 10.1242/jeb.244223] [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] [Received: 03/02/2022] [Accepted: 11/28/2022] [Indexed: 12/14/2022]
Abstract
Visual animal communication, whether to the same or to other species, is largely conducted through dynamic and colourful signals. For a signal to be effective, the signaller must capture and retain the attention of the receiver. Signal efficacy is also dependent on the sensory limitations of the receiver. However, most signalling studies consider movement and colour separately, resulting in a partial understanding of the signal in question. We explored the structure and function of predator-prey signalling in the jumping spider-tephritid fly system, where the prey performs a wing waving display that deters an attack from the predator. Using a custom-built spider retinal tracker combined with visual modelling, as well as behavioural assays, we studied the effect of fly wing movement and colour on the jumping spider's visual system. We show that jumping spiders track their prey less effectively during wing display and this can be attributed to a series of fluctuations in chromatic and achromatic contrasts arising from the wing movements. These results suggest that displaying flies deter spider attacks by manipulating the movement biases of the spider's visual system. Our results emphasise the importance of receiver attention on the evolution of interspecific communication.
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Affiliation(s)
- Dinesh Rao
- Instituto de Biotecnologia y Ecologia Aplicada, Universidad Veracruzana, 91090 Xalapa, Veracruz, Mexico
| | - Skye M Long
- Department of Biology, University of Massachusetts, Amherst, MA 01003, USA
| | - Horacio Tapia-McClung
- Instituto de Investigacion en Inteligencia Artificial, Universidad Veracruzana, 91097 Xalapa, Veracruz, Mexico
| | - Kevin Salgado-Espinosa
- Instituto de Biotecnologia y Ecologia Aplicada, Universidad Veracruzana, 91090 Xalapa, Veracruz, Mexico
| | - Ajay Narendra
- School of Natural Sciences, Macquarie University, Sydney, NSW 2109, Australia
| | | | - Luis Robledo-Ospina
- Instituto de Biotecnologia y Ecologia Aplicada, Universidad Veracruzana, 91090 Xalapa, Veracruz, Mexico
| | - Dulce Rodriguez-Morales
- Instituto de Biotecnologia y Ecologia Aplicada, Universidad Veracruzana, 91090 Xalapa, Veracruz, Mexico.,Instituo de Neuroetologia, Universidad Veracruzana, 91190 Xalapa, Veracruz, Mexico
| | - Elizabeth M Jakob
- Department of Biology, University of Massachusetts, Amherst, MA 01003, USA
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49
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van den Berg CP, Endler JA, Papinczak DEJ, Cheney KL. Using colour pattern edge contrast statistics to predict detection speed and success in triggerfish (Rhinecanthus aculeatus). J Exp Biol 2022; 225:285905. [PMID: 36354306 PMCID: PMC9789405 DOI: 10.1242/jeb.244677] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2022] [Accepted: 10/26/2022] [Indexed: 11/12/2022]
Abstract
Edge detection is important for object detection and recognition. However, we do not know whether edge statistics accurately predict the detection of prey by potential predators. This is crucial given the growing availability of image analysis software and their application across non-human visual systems. Here, we investigated whether Boundary Strength Analysis (BSA), Local Edge Intensity Analysis (LEIA) and the Gabor edge disruption ratio (GabRat) could predict the speed and success with which triggerfish (Rhinecanthus aculeatus) detected patterned circular stimuli against a noisy visual background, in both chromatic and achromatic presentations. We found various statistically significant correlations between edge statistics and detection speed depending on treatment and viewing distance; however, individual pattern statistics only explained up to 2% of the variation in detection time, and up to 6% when considering edge statistics simultaneously. We also found changes in fish response over time. While highlighting the importance of spatial acuity and relevant viewing distances in the study of visual signals, our results demonstrate the importance of considering explained variation when interpreting colour pattern statistics in behavioural experiments. We emphasize the need for statistical approaches suitable for investigating task-specific predictive relationships and ecological effects when considering animal behaviour. This is particularly important given the ever-increasing dimensionality and size of datasets in the field of visual ecology.
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Affiliation(s)
- Cedric P. van den Berg
- Visual Ecology Lab, School of Biological Sciences, The University of Queensland, St Lucia, QLD 4072, Australia,Author for correspondence ()
| | - John A. Endler
- Centre for Integrative Ecology, School of Life and Environmental Sciences, Deakin University, Geelong, VIC 3216, Australia
| | - Daniel E. J. Papinczak
- Visual Ecology Lab, School of Biological Sciences, The University of Queensland, St Lucia, QLD 4072, Australia
| | - Karen L. Cheney
- Visual Ecology Lab, School of Biological Sciences, The University of Queensland, St Lucia, QLD 4072, Australia
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50
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Steck MK, Zambre AM, Snell-Rood EC. Plasticity in resource choice: a time-limited butterfly prioritizes apparency over quality. Anim Behav 2022. [DOI: 10.1016/j.anbehav.2022.11.012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
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