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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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2
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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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3
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John L, Santon M, Michiels NK. Scorpionfish adjust skin pattern contrast on different backgrounds. Ecol Evol 2024; 14:e11124. [PMID: 38476704 PMCID: PMC10928359 DOI: 10.1002/ece3.11124] [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: 11/15/2023] [Revised: 02/06/2024] [Accepted: 02/23/2024] [Indexed: 03/14/2024] Open
Abstract
The two scorpionfish species Scorpaena maderensis and S. porcus are well camouflaged ambush predators that rapidly change body colouration to adjust to background colour in less than 1 min. We tested whether individuals of both species also adjust body pattern to that of the background. We placed fish on backgrounds of different pattern granularity and quantified the change in fish body pattern over 1 min. We used calibrated image analysis to analyse the patterns from the visual perspective of a prey fish species using a granularity (pattern energy) analysis and an image clustering approach. In our experiment, fish did not change their most contrasting pattern components as defined by the dominant marking size, but changed their average marking size. Moreover, fish responded with a change in pattern in contrast to the different experimental backgrounds, especially when compared to the acclimation phase. These results indicate that scorpionfish have one main pattern that can be adjusted by modulating its internal contrast. A reduction in pattern contrast could thereby improve background matching, while an increase could promote camouflage via disruptive colouration.
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Affiliation(s)
- Leonie John
- Animal Evolutionary EcologyInstitute of Evolution and Ecology, University of TübingenTübingenGermany
| | - Matteo Santon
- Ecology of Vision Group, School of Biological SciencesUniversity of BristolBristolUK
| | - Nico K. Michiels
- Animal Evolutionary EcologyInstitute of Evolution and Ecology, University of TübingenTübingenGermany
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4
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Kidyoo A, Kidyoo M, Ekkaphan P, Blatrix R, McKey D, Proffit M. Specialized pollination by cecidomyiid flies and associated floral traits in Vincetoxicum sangyojarniae (Apocynaceae, Asclepiadoideae). PLANT BIOLOGY (STUTTGART, GERMANY) 2024; 26:166-180. [PMID: 38196297 DOI: 10.1111/plb.13607] [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: 06/08/2023] [Accepted: 11/27/2023] [Indexed: 01/11/2024]
Abstract
Specialized pollination systems frequently match a particular set of floral characteristics. Vincetoxicum spp. (Apocynaceae, Asclepiadoideae) have disk-shaped flowers with open access to rewards and reproductive organs. Flowers with these traits are usually associated with generalized pollination. However, the highly modified androecium and gynoecium that characterize asclepiads are thought to be associated with specialized pollinators. In V. sangyojarniae, we investigated floral biology, pollination, and the degree of pollinator specialization in two localities in Thailand. We examined floral traits that target legitimate pollinators. Flowers of V. sangyojarniae opened only at night, emitted floral scents containing mainly (E)-β-ocimene, 1-octen-3-ol, (E)-4,8-dimethyl-1,3,7-nonatriene (E-DMNT) and N-(3-methylbutyl)acetamide, and provided sucrose-dominated nectar openly to insect visitors. Assessment of pollinator effectiveness indicated that V. sangyojarniae is functionally specialized for pollination by cecidomyiid flies. Although various insects, particularly cockroaches, frequently visited flowers, they did not carry pollinaria. Our results suggest that V. sangyojarniae attracts its fly pollinators by emitting floral volatiles bearing olfactory notes associated with the presence of fungi or, less likely, of prey captured by predatory arthropods (food sources of its pollinators) but offers a nectar reward upon insect arrival. Hence, there is a mismatch between the advertisement and the actual reward. Our results also suggest that the size of floral parts constitutes a mechanical filter where reciprocal fit between flower and insect structures ensures that only suitable pollinators can extract the pollinaria, a prerequisite for successful pollination.
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Affiliation(s)
- A Kidyoo
- Plants of Thailand Research Unit, Department of Botany, Faculty of Science, Chulalongkorn University, Bangkok, Thailand
| | - M Kidyoo
- Plants of Thailand Research Unit, Department of Botany, Faculty of Science, Chulalongkorn University, Bangkok, Thailand
| | - P Ekkaphan
- Scientific and Technological Research Equipment Centre, Chulalongkorn University, Bangkok, Thailand
| | - R Blatrix
- CEFE, University of Montpellier, CNRS, EPHE, IRD, Montpellier, France
| | - D McKey
- CEFE, University of Montpellier, CNRS, EPHE, IRD, Montpellier, France
| | - M Proffit
- CEFE, University of Montpellier, CNRS, EPHE, IRD, Montpellier, France
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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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6
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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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7
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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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8
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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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9
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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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10
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Eliason CM, McCullough JM, Hackett SJ, Andersen MJ. Complex plumages spur rapid color diversification in kingfishers (Aves: Alcedinidae). eLife 2023; 12:83426. [PMID: 37083474 PMCID: PMC10121218 DOI: 10.7554/elife.83426] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2022] [Accepted: 03/22/2023] [Indexed: 04/22/2023] Open
Abstract
Colorful signals in nature provide some of the most stunning examples of rapid phenotypic evolution. Yet, studying color pattern evolution has been historically difficult owing to differences in perceptual ability of humans and analytical challenges with studying how complex color patterns evolve. Island systems provide a natural laboratory for testing hypotheses about the direction and magnitude of phenotypic change. A recent study found that plumage colors of island species are darker and less complex than continental species. Whether such shifts in plumage complexity are associated with increased rates of color evolution remains unknown. Here, we use geometric morphometric techniques to test the hypothesis that plumage complexity and insularity interact to influence color diversity in a species-rich clade of colorful birds-kingfishers (Aves: Alcedinidae). In particular, we test three predictions: (1) plumage complexity enhances interspecific rates of color evolution, (2) plumage complexity is lower on islands, and (3) rates of plumage color evolution are higher on islands. Our results show that more complex plumages result in more diverse colors among species and that island species have higher rates of color evolution. Importantly, we found that island species did not have more complex plumages than their continental relatives. Thus, complexity may be a key innovation that facilitates evolutionary response of individual color patches to distinct selection pressures on islands, rather than being a direct target of selection itself. This study demonstrates how a truly multivariate treatment of color data can reveal evolutionary patterns that might otherwise go unnoticed.
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Affiliation(s)
- Chad M Eliason
- Grainger Bioinformatics Center, Field Museum of Natural History, Chicago, United States
- Negaunee Integrative Research Center, Field Museum of Natural History, Chicago, United States
| | - Jenna M McCullough
- Department of Biology and Museum of Southwestern Biology, University of New Mexico, Albuquerque, United States
| | - Shannon J Hackett
- Negaunee Integrative Research Center, Field Museum of Natural History, Chicago, United States
| | - Michael J Andersen
- Department of Biology and Museum of Southwestern Biology, University of New Mexico, Albuquerque, United States
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11
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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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12
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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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13
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Lo YC, Blamires SJ, Liao CP, Tso IM. Nocturnal and diurnal predator and prey interactions with crab spider color polymorphs. Behav Ecol Sociobiol 2023. [DOI: 10.1007/s00265-023-03291-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
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14
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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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15
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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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16
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Mark CJ, O'Hanlon JC, Holwell GI. Camouflage in lichen moths: Field predation experiments and avian vision modelling demonstrate the importance of wing pattern elements and background for survival. J Anim Ecol 2022; 91:2358-2369. [PMID: 36169598 PMCID: PMC10092008 DOI: 10.1111/1365-2656.13817] [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: 02/02/2022] [Accepted: 09/15/2022] [Indexed: 12/15/2022]
Abstract
Background matching is perhaps the most ubiquitous form of defensive camouflage in the animal kingdom, an adaptive strategy that relies on the visual resemblance between a prey organism and its background to promote concealment from predators. The importance of background matching has been acknowledged for over a century, yet despite its renown and apparent pervasiveness, few studies exist that have objectively quantified its occurrence and tested the functional significance of background matching in a specific animal study system. The North Island lichen moth Declana atronivea presents a fascinating system to investigate such anti-predator coloration. This species possesses high contrast black and white forewings that appear to resemble lichen. Here we assessed the contribution of background matching to the antipredator defence of D. atronivea using field predation experiments with realistic models. We found that D. atronivea coloration confers a significant survival advantage against native avian predators when on lichen backgrounds compared to bark backgrounds, with an intermediate level of predation occurring when models were near, but not on lichen. This suggests that D. atronivea wing patterns are an adaptation for background matching. We subsequently used calibrated digital photography, avian vision modelling and image analysis techniques to objectively quantify the degree of background matching exhibited by D. atronivea and assessed the contribution of different visual elements (colour, luminance and pattern) to camouflage in this species. Only the pattern elements of D. atronivea presented a close match to that of the lichen backgrounds, with both chromatic and achromatic cues found to be poor predictors of background matching in this species. This study is one of the first to integrate vision modelling, quantitative image analysis and field predation experiments using realistic models to objectively quantify the level and functional significance of background matching in a real species, and presents an ideal system for further investigating the interrelation between multiple mechanisms of camouflage.
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Affiliation(s)
- Cassandra J Mark
- School of Biological Sciences, The University of Auckland, Auckland, New Zealand
| | - James C O'Hanlon
- School of Science and Technology, University of New England, Armidale, New South Wales, Australia
| | - Gregory I Holwell
- School of Biological Sciences, The University of Auckland, Auckland, New Zealand
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17
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Nolazco S, Delhey K, Fan M, Hall ML, Kingma SA, Roast MJ, Teunissen N, Peters A. Which plumage patches provide information about condition and success in a female fairy-wren? Behav Ecol 2022. [DOI: 10.1093/beheco/arac096] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Abstract
Recent evidence suggests that female ornaments can commonly act as signals. However, how signaling functions might be affected by the tendency for reduced ornament elaboration in relation to males is less well-understood. We address this in mutually ornamented purple-crowned fairy-wrens. We investigated putatively ornamental (tail, ear coverts, crown) and non-ornamental (throat, back) plumage patches in females and compared our findings to previous studies in males. Both sexes have brown backs, buff-white throats, and turquoise-blue tails (bluer in males), while ear coverts are rufous in females and black in males. Both sexes also have a seasonal crown (slate-gray in females, black-and-purple in males). Dominant (breeder) females expressed more complete and grayer (more ornamented) crowns, although variation in coloration should not be discriminable by individuals. Unexpectedly, subordinates showed more colorful (saturated) rufous ear coverts, which should be discriminable. Condition-dependence was only evident for crown completeness (% slate-gray cover). Females with more reddish-brown backs were more reproductively successful. Variation in plumage characteristics did not explain differential allocation by mates or chances of gaining dominance. Our outcomes were not entirely consistent with findings in males. The most notable disparity was for the crown, a signal used in male-male competition that in females seems to be expressed as an incomplete version of the male crown that is not associated with fitness benefits. Our study shows that in a species, multiple traits can vary in their information content and that female ornaments can sometimes be less informative than in males, even those that are produced seasonally.
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Affiliation(s)
- Sergio Nolazco
- School of Biological Sciences, Monash University , 25 Rainforest Walk, Clayton, Victoria 3800 , Australia
| | - Kaspar Delhey
- School of Biological Sciences, Monash University , 25 Rainforest Walk, Clayton, Victoria 3800 , Australia
- Max Planck Institute for Ornithology , Seewiesen , Germany
| | - Marie Fan
- School of Biological Sciences, Monash University , 25 Rainforest Walk, Clayton, Victoria 3800 , Australia
| | - Michelle L Hall
- Max Planck Institute for Ornithology , Seewiesen , Germany
- School of Biological Sciences, University of Western Australia , 35 Stirling Highway, Perth, Western Australia 6009 , Australia
| | - Sjouke A Kingma
- Max Planck Institute for Ornithology , Seewiesen , Germany
- Behavioural Ecology Group, Department of Animal Sciences, Wageningen University and Research , De Elst 1, 6708 WD Wageningen , The Netherlands
| | - Michael J Roast
- School of Biological Sciences, Monash University , 25 Rainforest Walk, Clayton, Victoria 3800 , Australia
| | - Niki Teunissen
- School of Biological Sciences, Monash University , 25 Rainforest Walk, Clayton, Victoria 3800 , Australia
| | - Anne Peters
- School of Biological Sciences, Monash University , 25 Rainforest Walk, Clayton, Victoria 3800 , Australia
- Max Planck Institute for Ornithology , Seewiesen , Germany
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18
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Yorzinski JL, Troscianko J, Briolat E, Schapiro SJ, Whitham W. A songbird can detect the eyes of conspecifics under daylight and artificial nighttime lighting. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2022; 313:120000. [PMID: 35995296 DOI: 10.1016/j.envpol.2022.120000] [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: 04/21/2022] [Revised: 07/25/2022] [Accepted: 08/16/2022] [Indexed: 06/15/2023]
Abstract
Eyes convey important information about the external and internal worlds of animals. Individuals can follow the gaze of others to learn about the location of salient objects as well as assess eye qualities to evaluate the health, age or other internal states of conspecifics. Because of the increasing prevalence of artificial lighting at night (ALAN), urbanized individuals can potentially garner information from conspecific eyes under both daylight and ALAN. We tested this possibility using a visual modeling approach in which we estimated the maximum distance at which individuals could detect conspecific eyes under daylight and high levels of ALAN. We also estimated the minimum light level at which individuals could detect conspecific eyes. Great-tailed grackles (Quiscalus mexicanus) were used as our study species because they are highly social and are unusual among birds in that they regularly gather at nocturnal roosts in areas with high levels of ALAN. This visual modelling approach revealed that grackles can detect conspecific eyes under both daylight and ALAN, regardless of iris coloration. The grackles could detect conspecific eyes at farther distances in daylight compared to ALAN. Our results highlight the potential importance of lighting conditions in shaping social interactions.
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Affiliation(s)
- Jessica L Yorzinski
- Department of Ecology and Conservation Biology, Texas A&M University, College Station, TX, USA.
| | - Jolyon Troscianko
- Centre for Ecology & Conservation, University of Exeter, Penryn, United Kingdom
| | - Emmanuelle Briolat
- Centre for Ecology & Conservation, University of Exeter, Penryn, United Kingdom
| | - Steven J Schapiro
- Department of Comparative Medicine, The University of Texas MD Anderson Cancer Center, Bastrop, TX, USA
| | - Will Whitham
- Department of Ecology and Conservation Biology, Texas A&M University, College Station, TX, USA; Department of Comparative Medicine, The University of Texas MD Anderson Cancer Center, Bastrop, TX, USA
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19
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Miller AE, Hogan BG, Stoddard MC. Color in motion: Generating 3-dimensional multispectral models to study dynamic visual signals in animals. Front Ecol Evol 2022. [DOI: 10.3389/fevo.2022.983369] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Analyzing color and pattern in the context of motion is a central and ongoing challenge in the quantification of animal coloration. Many animal signals are spatially and temporally variable, but traditional methods fail to capture this dynamism because they use stationary animals in fixed positions. To investigate dynamic visual displays and to understand the evolutionary forces that shape dynamic colorful signals, we require cross-disciplinary methods that combine measurements of color, pattern, 3-dimensional (3D) shape, and motion. Here, we outline a workflow for producing digital 3D models with objective color information from museum specimens with diffuse colors. The workflow combines multispectral imaging with photogrammetry to produce digital 3D models that contain calibrated ultraviolet (UV) and human-visible (VIS) color information and incorporate pattern and 3D shape. These “3D multispectral models” can subsequently be animated to incorporate both signaler and receiver movement and analyzed in silico using a variety of receiver-specific visual models. This approach—which can be flexibly integrated with other tools and methods—represents a key first step toward analyzing visual signals in motion. We describe several timely applications of this workflow and next steps for multispectral 3D photogrammetry and animation techniques.
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20
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The Colours of Octopus: Using Spectral Data to Measure Octopus Camouflage. Vision (Basel) 2022; 6:vision6040059. [PMID: 36278671 PMCID: PMC9590006 DOI: 10.3390/vision6040059] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2022] [Revised: 09/16/2022] [Accepted: 09/16/2022] [Indexed: 11/17/2022] Open
Abstract
No animal can so effectively camouflage in such a wide range of environments as the octopus. Thanks to their highly malleable skin, they are capable of adapting their body patterns to the brightness and texture of their immediate environment, and they often seemingly match the colour of background objects. However, octopuses are colour-blind as their eyes have only one type of visual pigment. Therefore, chromatophores in their skin are likely to respond to changes in brightness, not chromaticity. To determine whether octopuses actually match background colours, we used a SpectraScan® PR-655 spectroradiometer to measure the reflectance spectra of Octopus tetricus skin in captivity. The spectra were compared with those of green algae, brown algae, and sponges—all of these being colourful objects commonly found in the octopus’s natural environment. Even though we show that octopuses change both lightness and chromaticity, allowing them to potentially camouflage in a wide range of backgrounds in an effective manner, the overall octopus colours did not reach the same level of saturation compared to some background objects. Spectra were then modelled under the visual systems of four potential octopus predators: one dichromatic fish (Heller’s barracuda), two trichromatic fish (blue-spotted stingray and two-spotted red snapper), and one tetrachromatic bird (wedge-tailed shearwater). We show that octopuses are able to match certain background colours for some visual systems. How a colour-blind animal is capable of colour-matching is still unknown.
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21
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de Alcantara Viana JV, Lourenço Garcia de Brito V, de Melo C. Colour matching by arthropods in burned and unburned backgrounds in a Neotropical savanna. AUSTRAL ECOL 2022. [DOI: 10.1111/aec.13225] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- João Vitor de Alcantara Viana
- Programa de Pós‐Graduação em Ecologia e Conservação de Recursos Naturais, Laboratório de Ornitologia e Bioacústica Universidade Federal de Uberlândia (UFU) Uberlândia Brazil
- Programa de Pós‐Graduação em Ecologia, Laboratório de Interações Multitróficas e Biodiversidade, Instituto de Biologia Universidade Estadual de Campinas (UNICAMP) Campinas
- Laboratório de Interações Multitróficas e Biodiversidade Departamento de Biologia Animal, Instituto de Biologia Universidade Estadual de Campinas CP 6109, CEP 13083-970 Campinas São Paulo Brazil
| | | | - Celine de Melo
- Instituto de Biologia Universidade Federal de Uberlândia Uberlândia Brazil
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22
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Massote C, Pessoa DMA, Peixoto PEC. The conspicuousness contradiction: brighter males have lower mating chances in the damselfly Argia hasemani but not in Argia croceipennis. Biol J Linn Soc Lond 2022. [DOI: 10.1093/biolinnean/blac076] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Abstract
In odonates, male coloration is often more conspicuous than female coloration. This difference is frequently attributed to the role of male colour in male–male competition to access females. However, there are sexually dimorphic odonate species, such as the damselflies Argia hasemani and Argia croceipennis, in which male–male interactions are much less intense. In these species, it might be that male coloration affects male success directly when interacting with females. Therefore, we hypothesized that males with more intense coloration present higher copulation success. To investigate this hypothesis, we registered which males copulated in the field during 4 days and estimated the coloration of all observed males in the female visual spectrum. Surprisingly, we found that dull males had higher chances of copulation in A. hasemani, whereas in A. croceipennis male coloration did not influence the chances of copulation. Our data also indicated that brighter males of A. hasemani were also more conspicuous to potential avian predators, whereas this was not the case in A. croceipennis. We suggest that females of A. hasemani might avoid brighter males owing to increased risk of predation during copulation.
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Affiliation(s)
- Clara Massote
- Laboratory of Agonistic Interactions and Sexual Selection, Federal University of Minas Gerais , Avenida Antônio Carlos, Belo Horizonte, MG , Brazil
| | - Daniel Marques Almeida Pessoa
- Laboratory of Sensory Ecology, Department of Physiology and Behavior, Biosciences Center, Federal University of Rio Grande do Norte , Natal, RN , Brazil
| | - Paulo Enrique Cardoso Peixoto
- Laboratory of Agonistic Interactions and Sexual Selection, Department of Genetics, Ecology and Evolution, Federal University of Minas Gerais , Avenida Antônio Carlos, Belo Horizonte, MG , Brazil
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23
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Tedore C, Tedore K, Westcott D, Suttner C, Nilsson DE. The role of detectability in the evolution of avian-dispersed fruit color. Vision Res 2022; 196:108046. [DOI: 10.1016/j.visres.2022.108046] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2021] [Revised: 03/18/2022] [Accepted: 03/21/2022] [Indexed: 11/26/2022]
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Davis A, Zipple MN, Diaz D, Peters S, Nowicki S, Johnsen S. Influence of visual background on discrimination of signal-relevant colours in zebra finches ( Taeniopygia guttata). Proc Biol Sci 2022; 289:20220756. [PMID: 35673868 PMCID: PMC9174715 DOI: 10.1098/rspb.2022.0756] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Colour signals of many animals are surrounded by a high-contrast achromatic background, but little is known about the possible function of this arrangement. For both humans and non-human animals, the background colour surrounding a colour stimulus affects the perception of that stimulus, an effect that can influence detection and discrimination of colour signals. Specifically, high colour contrast between the background and two given colour stimuli makes discrimination more difficult. However, it remains unclear how achromatic background contrast affects signal discrimination in non-human animals. Here, we test whether achromatic contrast between signal-relevant colours and an achromatic background affects the ability of zebra finches to discriminate between those colours. Using an odd-one-out paradigm and generalized linear mixed models, we found that higher achromatic contrast with the background, whether positive or negative, decreases the ability of zebra finches to discriminate between target and non-target stimuli. This effect is particularly strong when colour distances are small (less than 4 ΔS) and Michelson achromatic contrast with the background is high (greater than 0.5). We suggest that researchers should consider focal colour patches and their backgrounds as collectively comprising a signal, rather than focusing on solely the focal colour patch itself.
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Affiliation(s)
- Alexander Davis
- Department of Biology, Duke University, Durham, NC 27708, USA
| | - Matthew N. Zipple
- Department of Biology, Duke University, Durham, NC 27708, USA,Department of Neurobiology and Behavior, Cornell University, Ithaca, NY 14853, USA
| | - Danae Diaz
- Department of Biology, Duke University, Durham, NC 27708, USA
| | - Susan Peters
- Department of Biology, Duke University, Durham, NC 27708, 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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25
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Silva DJA, Erickson MF, dos Santos Guidi R, Pessoa DMA. Thin-fingered fiddler crabs display a natural preference for UV light cues but show no sensory bias to other hypertrophied claw coloration. Behav Processes 2022; 200:104667. [DOI: 10.1016/j.beproc.2022.104667] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2021] [Revised: 05/06/2022] [Accepted: 05/30/2022] [Indexed: 12/27/2022]
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Whiting MJ, Holland BS, Keogh JS, Noble DWA, Rankin KJ, Stuart-Fox D. Invasive chameleons released from predation display more conspicuous colors. SCIENCE ADVANCES 2022; 8:eabn2415. [PMID: 35544573 PMCID: PMC9094656 DOI: 10.1126/sciadv.abn2415] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/12/2021] [Accepted: 03/25/2022] [Indexed: 06/15/2023]
Abstract
Conspicuous social and sexual signals are predicted to experience pronounced character release when natural selection via predation is relaxed. However, we have few good examples of this phenomenon in the wild and none in species with dynamic color change. Here, we show that Jackson's chameleons inadvertently introduced from Kenya to Hawaii (Oahu), where there are no coevolved, native lizard predators, experienced pronounced character release of color signals. Hawaiian chameleons displayed more conspicuous social color signals than Kenyan chameleons during male contests and courtship, were less cryptic in response to bird and snake predators, and showed greater change between display and antipredator color states. Hawaiian chameleon display colors were also more conspicuous in their local than ancestral habitats, consistent with local adaptation of social signals. These results demonstrate that relaxed predation pressure can result in character release of dynamic social signals in introduced species experiencing strong sexual selection.
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Affiliation(s)
- Martin J. Whiting
- School of Natural Sciences, Macquarie University, Sydney, NSW 2109, Australia
- School of Animal, Plant and Environmental Sciences, University of the Witwatersrand, Wits 2050, South Africa
| | - Brenden S. Holland
- Department of Natural Science, Hawaii Pacific University, Honolulu, HI, USA
| | - J. Scott Keogh
- Division of Ecology and Evolution, Research School of Biology, The Australian National University, Canberra, ACT 2602, Australia
| | - Daniel W. A. Noble
- Division of Ecology and Evolution, Research School of Biology, The Australian National University, Canberra, ACT 2602, Australia
| | - Katrina J. Rankin
- School of BioSciences, The University of Melbourne, Parkville, Victoria 3010, Australia
| | - Devi Stuart-Fox
- School of BioSciences, The University of Melbourne, Parkville, Victoria 3010, Australia
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28
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Fleishman LJ, Perez-Martinez CA, Leal M. Can sensory drive explain the evolution of visual signal diversity in terrestrial species? A test with Anolis lizards. Am Nat 2022; 200:236-249. [DOI: 10.1086/720267] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
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29
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Robertson JM, Bell RC, Loew ER. Vision in dim light and the evolution of color pattern in a crepuscular/nocturnal frog. Evol Ecol 2022. [DOI: 10.1007/s10682-022-10173-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
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30
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McMahon O, Smyth T, Davies TW. Broad spectrum artificial light at night increases the conspicuousness of camouflaged prey. J Appl Ecol 2022. [DOI: 10.1111/1365-2664.14146] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Affiliation(s)
- Oak McMahon
- School of Biological and Marine Sciences University of Plymouth Plymouth UK
| | - Tim Smyth
- Plymouth Marine Laboratory Plymouth UK
| | - Thomas W. Davies
- School of Biological and Marine Sciences University of Plymouth Plymouth UK
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31
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Cezário RR, Gorb SN, Guillermo‐Ferreira R. Camouflage by counter‐brightness: the blue wings of Morpho dragonflies
Zenithoptera lanei
(Anisoptera: Libellulidae) match the water background. J Zool (1987) 2022. [DOI: 10.1111/jzo.12955] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- R. R. Cezário
- Department of Biological Sciences Universidade Federal do Triângulo Mineiro Uberaba Brazil
- Graduate Program in Entomology University of São Paulo (USP) Ribeirão Preto Brazil
| | - S. N. Gorb
- Department of Functional Morphology and Biomechanics Zoological Institute Kiel University Kiel Germany
| | - R. Guillermo‐Ferreira
- Department of Biological Sciences Universidade Federal do Triângulo Mineiro Uberaba Brazil
- Graduate Program in Entomology University of São Paulo (USP) Ribeirão Preto Brazil
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32
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Green P, George E, Rosvall K, Johnsen S, Nowicki S. Testosterone, signal coloration, and signal color perception in male zebra finch contests. Ethology 2022; 128:131-142. [PMID: 35185233 PMCID: PMC8849566 DOI: 10.1111/eth.13247] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Many animals use assessment signals to resolve contests over limited resources while minimizing the costs of those contests. The carotenoid-based orange to red bills of male zebra finches (Taeniopygia guttata) are thought to function as assessment signals in male-male contests, but behavioral analyses relating contest behaviors and outcomes to bill coloration have yielded mixed results. We examined the relationship between bill color and contests while incorporating measurements of color perception and testosterone (T) production, for an integrative view of aggressive signal behavior, production, and perception. We assayed the T production capabilities of 12 males in response to a gonadotropin-releasing hormone (GnRH) challenge. We then quantified the initiation, escalation, and outcome of over 400 contests in the group, and measured bill color using calibrated photography. Finally, because signal perception can influence signal function, we tested how males perceive variation in bill coloration, asking if males exhibit categorical perception of bill color, as has been shown recently in female zebra finches. The data suggest that males with greater T production capabilities than their rivals were more likely to initiate contests against those rivals, while males with redder bills than their rivals were more likely to win contests. Males exhibited categorical color perception, but individual variation in the effect of categorical perception on color discrimination abilities did not predict any aspects of contest behavior or outcomes. Our results are consistent with the hypotheses that T plays a role in zebra finch contests and that bill coloration functions as an aggressive signal. We suggest future approaches, based on animal contest theory, for how links among signals, perception, and assessment can be tested.
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Affiliation(s)
- P.A. Green
- Department of Biology, Duke University, Durham, NC 27708, USA,Centre for Ecology and Conservation, College of Life and Environmental Sciences, University of Exeter, Penryn, TR10 9FE, UK
| | - E.M. George
- Department of Biology, Indiana University Bloomington, Bloomington, IN 47405, USA,Center for the Integrative Study of Animal Behavior, Indiana University Bloomington, Bloomington, IN 47405, USA
| | - K.A. Rosvall
- Department of Biology, Indiana University Bloomington, Bloomington, IN 47405, USA,Center for the Integrative Study of Animal Behavior, Indiana University Bloomington, Bloomington, IN 47405, USA
| | - S. Johnsen
- Department of Biology, Duke University, Durham, NC 27708, USA
| | - S. Nowicki
- Department of Biology, Duke University, Durham, NC 27708, USA,Department of Neurobiology, Duke University, Durham, NC 27708, USA
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33
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Yu L, Xu X, Li F, Zhou W, Zeng H, Tan EJ, Zhang S, Li D. From crypsis to masquerade: Ontogeny changes the colour defences of a crab spider hiding as bird droppings. Funct Ecol 2022. [DOI: 10.1111/1365-2435.13998] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Long Yu
- State Key Laboratory of Biocatalysis and Enzyme Engineering & Centre for Behavioural Ecology & Evolution School of Life Sciences Hubei University Wuhan China
| | - Xin Xu
- State Key Laboratory of Biocatalysis and Enzyme Engineering & Centre for Behavioural Ecology & Evolution School of Life Sciences Hubei University Wuhan China
- School of Life Sciences Hunan Normal University Changsha China
| | - Fan Li
- State Key Laboratory of Biocatalysis and Enzyme Engineering & Centre for Behavioural Ecology & Evolution School of Life Sciences Hubei University Wuhan China
- Department of Biological Sciences National University of Singapore Singapore
- College of Life Sciences University of Chinese Academy of Sciences Beijing China
| | - Wei Zhou
- Department of Biological Sciences National University of Singapore Singapore
| | - Hua Zeng
- State Key Laboratory of Protein and Plant Gene Research Peking‐Tsinghua Center for Life Sciences Academy for Advanced Interdisciplinary Studies Peking University Beijing China
| | | | - Shichang Zhang
- State Key Laboratory of Biocatalysis and Enzyme Engineering & Centre for Behavioural Ecology & Evolution School of Life Sciences Hubei University Wuhan China
| | - Daiqin Li
- Department of Biological Sciences National University of Singapore Singapore
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34
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Ontogenetic colour change of a sexual ornament in males of a damselfly: female mimicry, crypsis or both? Naturwissenschaften 2021; 109:2. [PMID: 34874492 DOI: 10.1007/s00114-021-01775-5] [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: 10/18/2021] [Revised: 11/25/2021] [Accepted: 11/29/2021] [Indexed: 10/19/2022]
Abstract
Female mimicry by males is a widespread phenomenon in several taxa and may be involved in aggression avoidance or facilitated access to resources. In early developmental stages, female mimicry may be a mechanism involved in signalling sexual immaturity or, when coupled with strategies related to visual camouflage, may be involved in the avoidance of male-male agonistic interactions. Here, we addressed whether the delayed colour maturation of a sexual ornament in males of Mnesarete pudica damselflies might be a case of crypsis, female mimicry or both. We analysed how conspecifics and predators perceive the pigmented wings of juvenile males by contrasting the wing spectra against a savannah background and the wings of both juvenile and sexually mature males and females. Our results based on the modelled visual system of conspecifics and predators suggest that the colour maturation of juvenile males may function as both crypsis and female mimicry. We discuss whether these results related to age- and sexual-dichromatism might be a mechanism to avoid unwanted intraspecific interactions or to avoid territorial and aggressive males. We conclude that the female mimicry and crypsis in juvenile males of M. pudica are mechanisms involved in avoidance of predators and unwanted intraspecific interactions, and the signalling of sexual maturity.
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35
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Wale N, Fuller RC, Johnsen S, Turrill ML, Duffy MA. The visual ecology of selective predation: Are unhealthy hosts less stealthy hosts? Ecol Evol 2021; 11:18591-18603. [PMID: 35003695 PMCID: PMC8717294 DOI: 10.1002/ece3.8464] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2021] [Revised: 11/22/2021] [Accepted: 11/25/2021] [Indexed: 12/04/2022] Open
Abstract
Predators can strongly influence disease transmission and evolution, particularly when they prey selectively on infected hosts. Although selective predation has been observed in numerous systems, why predators select infected prey remains poorly understood. Here, we use a mathematical model of predator vision to test a long-standing hypothesis about the mechanistic basis of selective predation in a Daphnia-microparasite system, which serves as a model for the ecology and evolution of infectious diseases. Bluegill sunfish feed selectively on Daphnia infected by a variety of parasites, particularly in water uncolored by dissolved organic carbon. The leading hypothesis for selective predation in this system is that infection-induced changes in the transparency of Daphnia render them more visible to bluegill. Rigorously evaluating this hypothesis requires that we quantify the effect of infection on the visibility of prey from the predator's perspective, rather than our own. Using a model of the bluegill visual system, we show that three common parasites, Metschnikowia bicuspidata, Pasteuria ramosa, and Spirobacillus cienkowskii, decrease the transparency of Daphnia, rendering infected Daphnia darker against a background of bright downwelling light. As a result of this increased brightness contrast, bluegill can see infected Daphnia at greater distances than uninfected Daphnia-between 19% and 33% further, depending on the parasite. Pasteuria and Spirobacillus also increase the chromatic contrast of Daphnia. These findings lend support to the hypothesis that selective predation by fish on infected Daphnia could result from the effects of infection on Daphnia's visibility. However, contrary to expectations, the visibility of Daphnia was not strongly impacted by water color in our model. Our work demonstrates that models of animal visual systems can be useful in understanding ecological interactions that impact disease transmission.
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Affiliation(s)
- Nina Wale
- Program in Ecology, Evolution and BehaviorDepartments of Microbiology & Molecular Genetics and Integrative BiologyMichigan State UniversityMichiganUSA
| | - Rebecca C. Fuller
- Program in Ecology, Evolution and BehaviorDepartments of Microbiology & Molecular Genetics and Integrative BiologyMichigan State UniversityMichiganUSA
| | - Sönke Johnsen
- Program in Ecology, Evolution and BehaviorDepartments of Microbiology & Molecular Genetics and Integrative BiologyMichigan State UniversityMichiganUSA
| | - McKenna L. Turrill
- Program in Ecology, Evolution and BehaviorDepartments of Microbiology & Molecular Genetics and Integrative BiologyMichigan State UniversityMichiganUSA
| | - Meghan. A. Duffy
- Program in Ecology, Evolution and BehaviorDepartments of Microbiology & Molecular Genetics and Integrative BiologyMichigan State UniversityMichiganUSA
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36
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Preißler K, Rodríguez A, Pröhl H. Evidence for coloration plasticity in the yellow-bellied toad, Bombina variegata. Ecol Evol 2021; 11:17557-17567. [PMID: 34938529 PMCID: PMC8668782 DOI: 10.1002/ece3.8391] [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: 03/09/2021] [Revised: 10/29/2021] [Accepted: 11/02/2021] [Indexed: 11/09/2022] Open
Abstract
Phenotypic adaptation in terms of background color matching to the local habitat is an important mechanism for survival in prey species. Thus, intraspecific variation in cryptic coloration is expected among localities with dissimilar habitat features (e.g., soil, vegetation). Yellow-bellied toads (Bombina variegata) display a dark dorsal coloration that varies between populations, assumed to convey crypsis. In this study, we explored I) geographic variation in dorsal coloration and II) coloration plasticity in B. variegata from three localities differing in substrate coloration. Using avian visual modeling, we found that the brightness contrasts of the cryptic dorsa were significantly lower on the local substrates than substrates of other localities. In experiments, individuals from one population were able to quickly change the dorsal coloration to match a lighter substrate. We conclude that the environment mediates an adaptation in cryptic dorsal coloration. We suggest further studies to test the mechanisms by which the color change occurs and explore the adaptive potential of coloration plasticity on substrates of varying brightness in B. variegata and other species.
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Affiliation(s)
- Kathleen Preißler
- Molecular Evolution and Systematics of AnimalsInstitute of BiologyUniversity LeipzigLeipzigGermany
| | - Ariel Rodríguez
- Institute of ZoologyUniversity of Veterinary Medicine of HannoverHannoverGermany
| | - Heike Pröhl
- Institute of ZoologyUniversity of Veterinary Medicine of HannoverHannoverGermany
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37
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Hanley D, Moghaddame-Jafari B, Rutledge SL. Could diffuse coevolution explain the generic eggshell color of the brown-headed cowbird? Curr Zool 2021; 67:645-652. [PMID: 34805542 PMCID: PMC8599007 DOI: 10.1093/cz/zoab078] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2021] [Accepted: 09/13/2021] [Indexed: 11/14/2022] Open
Abstract
The brown-headed cowbird (hereafter cowbird) is an avian brood parasite that produces an egg dissimilar to those produced by the majority of its diverse host community. The cowbird’s generic egg may result from a Jack-of-all-trades strategy; however, the evolutionary mechanisms that select for their generic eggs are unclear. Here we propose that the cowbird’s eggshell phenotypes have evolved via diffuse coevolution, which results from community-level selective pressures, rather than via pairwise coevolution that occurs between a particular host species and its brood parasite. Under diffuse coevolution the cowbird’s host community, with varying eggshell phenotypes and recognition abilities, would select for a cowbird eggshell phenotype intermediate to those of its host community. This selection is exerted by hosts that reject cowbird eggs, rather than those that accept them; therefore, we expect cowbird eggshell colors can be approximated by both the phenotypes and rejection abilities of their host community. Here we use eggshell reflectance data from 43 host species to demonstrate that the cowbird eggshell phenotypes are reasonably predicted (within 2 just noticeable differences) by the eggshell phenotypes and rejection rates of their hosts. These findings suggest that cowbird eggshell phenotypes, and potentially those of other some generalist parasites, may evolve via diffuse coevolution. Importantly, this research provides insight into the underlying evolutionary processes that explain observed phenotypic variation and provides a framework for studying selection on both specialist and generalist parasites’ traits.
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Affiliation(s)
- Daniel Hanley
- Department of Biology, George Mason University, Fairfax, VA 22030, USA
| | | | - Samantha L Rutledge
- Department of Biology, Mansfield University of Pennsylvania, Mansfield, PA 16933, USA.,Museum of Natural Science and Department of Biological Sciences, Louisiana State University, Baton Rouge, LA 70803, USA
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38
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Hanley D, Rutledge SL, Villa J. The Perceptual and Cognitive Processes That Govern Egg Rejection in Hosts of Avian Brood Parasites. Front Ecol Evol 2021. [DOI: 10.3389/fevo.2021.702934] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Hosts of avian brood parasites are under intense selective pressure to prevent or reduce the cost of parasitism. Many have evolved refined egg discrimination abilities, which can select for eggshell mimicry in their parasite. A classic assumption underlying these coevolutionary dynamics is that host egg recognition depends on the perceivable difference between their own eggs and those of their parasite. Over the past two decades, the receptor noise-limited (RNL) model has contributed to our understanding of these coevolutionary interactions by providing researchers a method to predict a host’s ability to discriminate a parasite’s egg from its own. Recent research has shown that some hosts are more likely to reject brown eggs than blue eggs, regardless of the perceived differences to their own. Such responses suggest that host egg recognition may be due to perceptual or cognitive processes not currently predictable by the RNL model. In this perspective, we discuss the potential value of using the RNL model as a null model to explore alternative perceptual processes and higher-order cognitive processes that could explain how and why some hosts make seemingly counter-intuitive decisions. Further, we outline experiments that should be fruitful for determining the perceptual and cognitive processing used by hosts for egg recognition tasks.
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39
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González Bardeci N, Lagorio MG. A mathematical approach to assess the ability of light filters to improve color discriminability of color vision deficient persons. Heliyon 2021; 7:e08058. [PMID: 34622063 PMCID: PMC8482439 DOI: 10.1016/j.heliyon.2021.e08058] [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: 05/10/2021] [Revised: 06/26/2021] [Accepted: 09/20/2021] [Indexed: 11/25/2022] Open
Abstract
Color vision deficiency (CVD) is a frequent condition that alters color perception to such an extent that many people encounter serious difficulties on their everyday lives. In this work, we present a strategy to analyze the effectiveness of light filters aimed to improve color discriminability of persons with CVD. The calculations are based on a simple model of color discrimination which has been successfully applied to several animal species. We first tested the calculations on three well-known commercial lenses designed for persons with CVD. In agreement with results of clinical studies, the calculations show that the highly colored lenses (VINO® and X-Chrom®) enhance chromaticity contrasts between problematic colors, whereas the more neutral Enchroma® do not provide any benefit. Also, we predict that two light filters proposed in recent works for novel lenses would not improve the performance of the commercial ones. Since the mathematical approach presented in this work enables predictive filter assessment, it opens the door to future research on the design of more effective lenses to improve color discriminability of persons with CVD. The calculations allow for large-scale screening of numerous light filters and different colored stimuli, CVD conditions, light sources, etc.
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Affiliation(s)
- Nicolás González Bardeci
- CONICET, Universidad de Buenos Aires, INQUIMAE, Facultad de Ciencias Exactas y Naturales, Buenos Aires, Argentina.,Universidad de Buenos Aires, Facultad de Ciencias Exactas y Naturales, Departamento de Química Inorgánica, Analítica y Química Física, Ciudad Universitaria. Pabellón II, 1er piso, C1428EHA, Buenos Aires, Argentina
| | - María Gabriela Lagorio
- CONICET, Universidad de Buenos Aires, INQUIMAE, Facultad de Ciencias Exactas y Naturales, Buenos Aires, Argentina.,Universidad de Buenos Aires, Facultad de Ciencias Exactas y Naturales, Departamento de Química Inorgánica, Analítica y Química Física, Ciudad Universitaria. Pabellón II, 1er piso, C1428EHA, Buenos Aires, Argentina
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40
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Chen CW, Whiting MJ, Yang EC, Lin SM. Do I stay or do I go? Shifts in perch use by lizards during morning twilight suggest anticipatory behaviour. Biol Lett 2021; 17:20210388. [PMID: 34610252 PMCID: PMC8492168 DOI: 10.1098/rsbl.2021.0388] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2021] [Accepted: 09/13/2021] [Indexed: 11/12/2022] Open
Abstract
Anticipatory behaviour is the expectation of a near-future event based on information processed in the past and influences an animal's tactical decisions, particularly when there are significant fitness consequences. The grass lizard (Takydromus viridipunctatus) perches on blades of grass at night which likely reduces the probability of predation by terrestrial predators such as snakes, rodents and shrews. During twilight (starting 30 min before sunrise), they move from above the grass to within grass clumps and this is thought to afford the lizard protection while reducing detection by avian predators. Here, we examined how lizards shift their behaviour as a function of visual detectability to their primary predator, the cattle egret (Bubulcus ibis). We show that the lizards shift from their perch site during twilight at the earliest time at which egrets depart communal roosts. At the same time, visual modelling shows a dramatic increase in the detectability of the lizards to the visual system of egrets. Therefore, anticipatory behaviour in response to environmental cues acts to reduce predation risk as lizards become more conspicuous and predators become more active. Grass lizard anticipatory behaviour appears to be finely tuned by natural selection to adjust to temporal changes in predation risk.
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Affiliation(s)
- Chih-Wei Chen
- School of Life Science, National Taiwan Normal University, Taipei, Taiwan
| | - Martin J. Whiting
- Department of Biological Sciences, Macquarie University, Sydney, New South Wales, Australia
| | - En-Cheng Yang
- Department of Entomology, National Taiwan University, Taipei, Taiwan
| | - Si-Min Lin
- School of Life Science, National Taiwan Normal University, Taipei, Taiwan
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41
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Guidi RDS, São-Pedro VDA, da Silva HR, Costa GC, Pessoa DMA. The trade-off between color and size in lizards' conspicuous tails. Behav Processes 2021; 192:104496. [PMID: 34492324 DOI: 10.1016/j.beproc.2021.104496] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2021] [Revised: 08/25/2021] [Accepted: 09/01/2021] [Indexed: 12/29/2022]
Abstract
A tail of conspicuous coloration is hypothesized to be an advantageous trait for many species of lizards. Predator attacks would be directed to a non-vital, and autotomizable, body part, increasing the chance of survival. However, as body size increases it also increases the signaling area that could attract predators from greater distances, increasing the overall chance of predation. Here, we test the hypothesis that there is a trade-off between tail color and size, affecting predation probabilities. We used plasticine replicas of lizards to study the predation patterns of small and large lizards with red and blue tails. In a natural environment, we exposed six hundred replicas to the attacks of free-ranging predators. Large red-tailed replicas were more attacked by birds. Mammals and unidentified predators showed no preference for any size or colors. The attacks were not primarily directed to conspicuous tails when compared to the bodies/heads of our replicas. Our study suggests that red color signals in large lizards could enhance their detection by visually oriented predators (i.e., birds). The efficacy of conspicuous tails as a decoy may rely on associated behavioral displays, which are hard to test with static replicas.
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Affiliation(s)
- Raiane Dos Santos Guidi
- Laboratory of Sensory Ecology, Department of Physiology & Behavior, Federal University of Rio Grande do Norte, Natal, RN, Brazil
| | - Vinicius de Avelar São-Pedro
- Laboratory of Sensory Ecology, Department of Physiology & Behavior, Federal University of Rio Grande do Norte, Natal, RN, Brazil; Center of Natural Sciences, Federal University of São Carlos -Campus Lagoa do Sino, Buri, SP, Brazil
| | - Holda Ramos da Silva
- Laboratory of Sensory Ecology, Department of Physiology & Behavior, Federal University of Rio Grande do Norte, Natal, RN, Brazil
| | - Gabriel Correa Costa
- Department of Biology and Environmental Sciences, Auburn University at Montgomery, Montgomery, AL, USA
| | - Daniel Marques Almeida Pessoa
- Laboratory of Sensory Ecology, Department of Physiology & Behavior, Federal University of Rio Grande do Norte, Natal, RN, Brazil.
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42
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Fan M, Hall ML, Roast M, Peters A, Delhey K. Variability, heritability and condition-dependence of the multidimensional male colour phenotype in a passerine bird. Heredity (Edinb) 2021; 127:300-311. [PMID: 34188194 PMCID: PMC8405751 DOI: 10.1038/s41437-021-00453-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2020] [Revised: 06/18/2021] [Accepted: 06/18/2021] [Indexed: 02/06/2023] Open
Abstract
Elaborate ornamental traits are commonly assumed to be honest signals of individual quality, owing to the presumed costs involved in their production and/or maintenance. Such traits are often highly variable, possibly because of condition-dependence and/or high underlying genetic variation, and it has been suggested that their expression should be more sensitive to condition and/or more heritable than non-ornamental traits. Many bird species display colourful plumage with multiple distinct patches of different developmental origins, forming complex colour phenotypes. Despite this complexity, colourful ornaments are often studied in isolation, without comparison to suitable non-ornamental controls. Based on plumage reflectance data collected over 8 years, we assessed the signalling potential of the multidimensional male colour phenotype in a tropical bird: the purple-crowned fairy-wren Malurus coronatus. Specifically, we tested the predictions that the expression of putative ornamental colours (purple and black - the breeding colours - and blue) is (1) more variable, (2) more heritable and (3) more condition-dependent compared to year-round non-ornamental colours (buff-white and brown). Our results show that ornamental colours exhibit greater levels of variability, and some chromatic components of purple and blue colouration appear slightly heritable (h² = 0.19-0.30). However, contrary to predictions of heightened condition-dependence in ornaments, only brightness of the buff-white and brown colouration increased with male body condition, although brightness of the purple colouration was related to male age as expected. Despite partial support for predictions, the lack of consistent patterns illustrates the complexity of visual signals and highlights the need to study colour phenotypes in their entirety.
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Affiliation(s)
- Marie Fan
- School of Biological Sciences, Monash University, Clayton, VIC, Australia.
| | - Michelle L Hall
- School of BioSciences, University of Melbourne, Melbourne, Parkville, VIC, Australia.,Max Planck Institute for Ornithology, Radolfzell, Germany
| | - Michael Roast
- School of Biological Sciences, Monash University, Clayton, VIC, Australia
| | - Anne Peters
- School of Biological Sciences, Monash University, Clayton, VIC, Australia.,Max Planck Institute for Ornithology, Radolfzell, Germany
| | - Kaspar Delhey
- School of Biological Sciences, Monash University, Clayton, VIC, Australia.,Max Planck Institute for Ornithology, Radolfzell, Germany.,Max Planck Institute for Ornithology, Seewiesen, Germany
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43
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Cezário RR, Lopez VM, Gorb S, Guillermo-Ferreira R. Dynamic iridescent signals of male copperwing damselflies coupled with wing-clapping displays: the perspective of different receivers. Biol J Linn Soc Lond 2021. [DOI: 10.1093/biolinnean/blab068] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Abstract
Dynamic signals are a widespread phenomenon in several taxa, usually associated with intraspecific communication. In contrast, dynamic iridescent signals are detectable only at specific angles of illumination; hence, the animal can hide the signal to avoid detection when necessary. This structural coloration is mostly dependent on the illumination, the contrast against the background and the vision of the receiver. Complex behavioural displays can be coupled with structural coloration to create dynamic visual signals that enhance these functions. Here, we address whether iridescence of the males of a damselfly that inhabits dark rainforests, Chalcopteryx scintillans, can be considered a dynamic visual signal. We analyse whether coloration is perceived by conspecifics, while reducing detectability to eavesdroppers against three types of backgrounds. Our results suggest that the visual background affects the detectability of male hindwings by different receivers, mostly predators and prey. We discuss whether these results and the angle dependence of colour could indicate a mechanism to avoid unwanted intraspecific interactions or even to lure both predators and prey. We conclude that the main functions of the dynamic iridescent signal are to communicate with conspecifics while hindering the signal for prey, adding evidence of the multifunctionality of structural coloration coupled with behavioural displays in animals.
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Affiliation(s)
- Rodrigo Roucourt Cezário
- Laboratory of Ecological Studies on Ethology and Evolution (LESTES Lab), Federal University of São Carlos, São Carlos, SP, Brazil
- Graduate program in Entomology, University of São Paulo, Ribeirão Preto, SP, Brazil
| | - Vinicius Marques Lopez
- Laboratory of Ecological Studies on Ethology and Evolution (LESTES Lab), Federal University of São Carlos, São Carlos, SP, Brazil
- Graduate program in Entomology, University of São Paulo, Ribeirão Preto, SP, Brazil
| | - Stanislav Gorb
- Department of Functional Morphology and Biomechanics, Zoological Institute, Kiel University, Am Botanischen Garten 1–9, D-24098 Kiel, Germany
| | - Rhainer Guillermo-Ferreira
- Laboratory of Ecological Studies on Ethology and Evolution (LESTES Lab), Federal University of São Carlos, São Carlos, SP, Brazil
- Graduate program in Entomology, University of São Paulo, Ribeirão Preto, SP, Brazil
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44
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Assis BA, Avery JD, Tylan C, Engler HI, Earley RL, Langkilde T. Honest signals and sexual conflict: Female lizards carry undesirable indicators of quality. Ecol Evol 2021; 11:7647-7659. [PMID: 34188841 PMCID: PMC8216924 DOI: 10.1002/ece3.7598] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2021] [Revised: 03/31/2021] [Accepted: 04/06/2021] [Indexed: 12/22/2022] Open
Abstract
Sex differences in animal coloration often result from sex-dependent regulatory mechanisms. Still, some species exhibit incomplete sexual dimorphism as females carry a rudimentary version of a costly male trait, leading to intralocus sexual conflict. The underlying physiology and condition dependence of these traits can inform why such conflicts remain unresolved. In eastern fence lizards (Sceloporus undulatus), blue iridophore badges are found in males and females, but melanin pigmentation underneath and surrounding badges is male-exclusive. We track color saturation and area of badges across sexual maturity, and their relationship to individual quality (body condition and immunocompetence) and relevant hormones (testosterone and corticosterone). Saturation and testosterone were positively correlated in both sexes, but hormone and trait had little overlap between males and females. Saturation was correlated with body condition and immunocompetence in males but not in females. Co-regulation by androgens may have released females from resource allocation costs of color saturation, even when in high condition. Badge area was independent of testosterone, but associated with low corticosterone in females, indicating that a nonsex hormone underlies incomplete sexual dimorphism. Given the evidence in this species for female reproductive costs associated with ornamentation, this sex-nonspecific regulation of an honest signal may underlie intralocus sexual conflict.
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Affiliation(s)
- Braulio A. Assis
- Department of BiologyThe Pennsylvania State UniversityUniversity ParkPAUSA
- Intercollege Graduate Degree Program in EcologyThe Pennsylvania State UniversityUniversity ParkPAUSA
| | - Julian D. Avery
- Intercollege Graduate Degree Program in EcologyThe Pennsylvania State UniversityUniversity ParkPAUSA
- The Department of Ecosystem Science and ManagementThe Pennsylvania State UniversityUniversity ParkPAUSA
| | - Catherine Tylan
- Department of BiologyThe Pennsylvania State UniversityUniversity ParkPAUSA
| | - Heather I. Engler
- Department of BiologyThe Pennsylvania State UniversityUniversity ParkPAUSA
| | - Ryan L. Earley
- Department of Biological SciencesUniversity of AlabamaTuscaloosaALUSA
| | - Tracy Langkilde
- Department of BiologyThe Pennsylvania State UniversityUniversity ParkPAUSA
- Intercollege Graduate Degree Program in EcologyThe Pennsylvania State UniversityUniversity ParkPAUSA
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45
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Garcia JE, Rohr DH, Dyer AG. Colour Discrimination From Perceived Differences by Birds. Front Ecol Evol 2021. [DOI: 10.3389/fevo.2021.639513] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
The ability of visual generalists to see and perceive displayed colour signals is essential to understanding decision making in natural environments. Whilst modelling approaches have typically considered relatively simple physiological explanations of how colour may be processed, data on key bee species reveals that colour is a complex multistage perception largely generated by opponent neural representations in a brain. Thus, a biologically meaningful unit of colour information must consider the psychophysics responses of an animal engaged in colour decision making. We extracted previously collected psychophysics data for a Violet-Sensitive (VS) bird, the pigeon (Columba livia), and used a non-linear function that reliably represents the behavioural choices of hymenopteran and dipteran pollinators to produce the first behaviourally validated and biologically meaningful representation of how VS birds use colour information in a probabilistic way. The function describes how similar or dis-similar spectral information can lead to different choice behaviours in birds, even though all such spectral information is above discrimination threshold. This new representation of bird vision will enable enhanced modelling representations of how bird vision can sense and use colour information in complex environments.
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46
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Risau-Gusman S. Color discrimination properties arising from optimal decoding in the early stages of visual systems. J Theor Biol 2021; 526:110773. [PMID: 34033813 DOI: 10.1016/j.jtbi.2021.110773] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2020] [Revised: 05/13/2021] [Accepted: 05/18/2021] [Indexed: 11/28/2022]
Abstract
In order to interpret animal behavior we need to understand how they see the world. As directly testing color discrimination in animals is difficult and time consuming, it is important to develop theoretical models based in the properties of visual systems. One of the most successful for the prediction of color discrimination behavior is the receptor noise-limited (RNL) model, which depends only on the level of noise in photoreceptors and opponent mechanisms. Here a complementary approach to model construction is used, and optimal color discrimination properties are obtained using information theoretical tools, for the early stages of visual systems. It is shown here that, for most biologically relevant conditions the optimal discrimination function of an ideal observer coincides with the one obtained with the RNL model. Furthermore, within this framework the influence of opponency can be studied by considering models with and without that mechanism but with exactly the same parameters at the level of photoreceptors. As an example, it is shown here that opponency is necessary to explain the discrimination of monochromatic stimuli in honeybees, but not in budgerigars. Since this is a consequence of the narrowing of absorption spectra of photoreceptors, produced by the presence of oil droplets, this could also be true for most other species of birds. This suggests that in order to study opponency in birds, stimuli should have a relatively wide spectrum.
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Affiliation(s)
- Sebastián Risau-Gusman
- Consejo Nacional de Investigaciones Científicas y Técnicas and Department of Medical Physics, Centro Atómico Bariloche, San Carlos de Bariloche, 8400 Río Negro, Argentina.
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47
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Tedore C, Nilsson DE. Ultraviolet vision aids the detection of nutrient-dense non-signaling plant foods. Vision Res 2021; 183:16-29. [PMID: 33639304 DOI: 10.1016/j.visres.2021.01.009] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2020] [Revised: 01/10/2021] [Accepted: 01/24/2021] [Indexed: 11/29/2022]
Abstract
To expand our understanding of what tasks are particularly helped by UV vision and may justify the costs of focusing high-energy light onto the retina, we used an avian-vision multispectral camera to image diverse vegetated habitats in search of UV contrasts that differ markedly from visible-light contrasts. One UV contrast that stood out as very different from visible-light contrasts was that of nutrient-dense non-signaling plant foods (such as young leaves and immature fruits) against their natural backgrounds. From our images, we calculated color contrasts between 62+ species of such foods and mature foliage for the two predominant color vision systems of birds, UVS and VS. We also computationally generated images of what a generalized tetrachromat, unfiltered by oil droplets, would see, by developing a new methodology that uses constrained linear least squares to solve for optimal weighted combinations of avian camera filters to mimic new spectral sensitivities. In all visual systems, we found that nutrient-dense non-signaling plant foods presented a lower, often negative figure-ground contrast in the UV channels, and a higher, often positive figure-ground contrast in the visible channels. Although a zero contrast may sound unhelpful, it can actually enhance color contrast when compared in a color opponent system to other channels with nonzero contrasts. Here, low or negative UV contrasts markedly enhanced color contrasts. We propose that plants may struggle to evolve better UV crypsis since UV reflectance from vegetation is largely specular and thus highly dependent on object orientation, shape, and texture.
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Affiliation(s)
- Cynthia Tedore
- Lund Vision Group, Lund University, Sölvegatan 35, 223 62 Lund, Sweden.
| | - Dan-Eric Nilsson
- Lund Vision Group, Lund University, Sölvegatan 35, 223 62 Lund, Sweden
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48
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Silvasti SA, Valkonen JK, Nokelainen O. Behavioural thresholds of blue tit colour vision and the effect of background chromatic complexity. Vision Res 2021; 182:46-57. [PMID: 33596523 DOI: 10.1016/j.visres.2020.11.013] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2020] [Revised: 10/23/2020] [Accepted: 11/04/2020] [Indexed: 01/09/2023]
Abstract
Vision is a vital attribute to foraging, navigation, mate selection and social signalling in animals, which often have a very different colour perception in comparison to humans. For understanding how animal colour perception works, vision models provide the smallest colour difference that animals of a given species are assumed to detect. To determine the just-noticeable-difference, or JND, vision models use Weber fractions that set discrimination thresholds of a stimulus compared to its background. However, although vision models are widely used, they rely on assumptions of Weber fractions since the exact fractions are unknown for most species. Here, we test; i) which Weber fractions in long-, middle- and shortwave (i.e. L, M, S) colour channels best describe the blue tit (Cyanistes caeruleus) colour discrimination, ii) how changes in hue of saturated colours and iii) chromatic background noise impair search behaviour in blue tits. We show that the behaviourally verified Weber fractions on achromatic backgrounds were L: 0.05, M: 0.03 and S: 0.03, indicating a high colour sensitivity. In contrast, on saturated chromatic backgrounds, the correct Weber fractions were considerably higher for L: 0.20, M: 0.17 and S: 0.15, indicating a less detailed colour perception. Chromatic complexity of backgrounds affected the longwave channel, while middle- and shortwave channels were mostly unaffected. We caution that using a vision model whereby colour discrimination is determined in achromatic viewing conditions, as they often are, can lead to misleading interpretations of biological interactions in natural - colourful - environments.
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Affiliation(s)
- Sanni A Silvasti
- Department of Biological and Environmental Science, University of Jyväskylä, P.O. Box 35, FI-40014 University of Jyväskylä, Finland.
| | - Janne K Valkonen
- Department of Biological and Environmental Science, University of Jyväskylä, P.O. Box 35, FI-40014 University of Jyväskylä, Finland
| | - Ossi Nokelainen
- Department of Biological and Environmental Science, University of Jyväskylä, P.O. Box 35, FI-40014 University of Jyväskylä, Finland
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49
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de Moraes PZ, Diniz P, Spyrides MHC, Pessoa DMA. The effect of pelage, background, and distance on predator detection and the evolution of primate color vision. Am J Primatol 2021; 83:e23230. [PMID: 33475188 DOI: 10.1002/ajp.23230] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2020] [Revised: 10/23/2020] [Accepted: 11/17/2020] [Indexed: 11/10/2022]
Abstract
Primates' predators, such as carnivore mammals, usually rely on camouflage to increase proximity to prey and start a predatory attempt. Camouflage depends not only on the color pattern presented by a predator's pelage but also on the background scene in which the hunting takes place. Another factor that influences camouflage effectiveness is prey's color vision since a given camouflage strategy might not work for all visual phenotypes. Still, little research has been made on the effect of primate visual phenotype on predator detection. Here, we investigate the effects of natural pelages, background scenarios, visual phenotypes, and detection distances on predator detection. We used photographs of taxidermized carnivores (ocelots, cougars, and lesser grisons) as detection stimuli, taken in three different natural scenarios (forest, savanna, and grassland), and at two viewing distances (near and far). On a touchscreen monitor, sets of four images (only one containing a hidden animal) were randomly presented to 39 human males (19 dichromats and 20 trichromats). We found that trichromats, when compared to dichromats, present a lower latency and a higher accuracy of carnivore detection for some conditions tested. We also found that pelage color, background scenario, and detection distance interact to influence the effectiveness of camouflage. Our results suggest that trichromacy might be even more advantageous for carnivore detection than thought before, since it facilitates detection of mammals with diverse pelage colorations, in environments with different phytophysiognomies, and at longer distances. We also propose that the higher rates of dichromacy found in modern human societies could have resulted from a relaxation in predation.
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Affiliation(s)
- Pedro Z de Moraes
- Laboratory of Sensory Ecology, Department of Physiology and Behavior, Federal University of Rio Grande do Norte, Natal, 59078-970, Brazil
| | - Pedro Diniz
- Ecology Graduation Program, University of Brasilia, Brasilia, 70910-900, Brazil.,Laboratory of Animal Behavior, Department of Zoology, University of Brasilia, Brasilia, 70910-900, Brazil
| | - Maria Helena C Spyrides
- Department of Statistics, Federal University of Rio Grande do Norte, Natal, 59078-970, Brazil
| | - Daniel M A Pessoa
- Laboratory of Sensory Ecology, Department of Physiology and Behavior, Federal University of Rio Grande do Norte, Natal, 59078-970, Brazil.,Primate Center, Department of Physiology and Behavior, Federal University of Rio Grande do Norte, Natal, 59078-970, Brazil
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50
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McQueen A, Delhey K, Barzan FR, Naimo AC, Peters A. Male fairy-wrens produce and maintain vibrant breeding colors irrespective of individual quality. Behav Ecol 2020. [DOI: 10.1093/beheco/araa128] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Abstract
Conspicuous colors may signal individual quality if high-quality individuals produce more elaborate colors or have a greater capacity to invest in color maintenance. We investigate these hypotheses using repeated within-individual observations and experimentally induced color production in a wild bird, the superb fairy-wren (Malurus cyaneus). Male superb fairy-wrens undergo an annual molt from brown, nonbreeding plumage to an ultraviolet-blue and black breeding plumage. Color maintenance is especially relevant for this species because structural, ultraviolet-blue plumage colors are particularly susceptible to fading. Further, only the most sexually attractive males molt to breeding plumage early (before spring) and thereby keep their colors for an extended time before the breeding season. Our results show that (i) sexually attractive, early-molting males do not have higher quality breeding colors and (ii) breeding colors are not impacted by experimentally inducing males to molt early and while in low body condition. We found that (iii) breeding colors do not fade but remain consistent or become more saturated within individuals over time. Despite this, (iv) males do not spend more time preening while in breeding plumage. Instead, males keep their colors in pristine condition by re-molting parts of their breeding plumage throughout the breeding season, suggesting an alternative, potential cost of maintaining ornamental colors. We conclude that variation in structural breeding colors is unlikely to indicate individual quality in superb fairy-wrens.
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Affiliation(s)
- Alexandra McQueen
- School of Biological Sciences, Monash University, Wellington Road, Clayton, Victoria, Australia
- Centre for Integrative Ecology, School of Life and Environmental Sciences, Deakin University, Burwood Highway, Burwood, Victoria, Australia
| | - Kaspar Delhey
- School of Biological Sciences, Monash University, Wellington Road, Clayton, Victoria, Australia
- Max Planck Institute for Ornithology, Eberhard-Gwinner-Straße, Seewiesen, Germany
| | - Flavia R Barzan
- School of Biological Sciences, Monash University, Wellington Road, Clayton, Victoria, Australia
- Departamento de Recursos Naturales y Gestión Ambiental, Estación Experimental Agropecuaria Paraná, Instituto Nacional de Tecnología Agropecuaria (INTA) and CONICET, Oro Verde, Entre Ríos, Argentina
| | - Annalise C Naimo
- School of Biological Sciences, Monash University, Wellington Road, Clayton, Victoria, Australia
| | - Anne Peters
- School of Biological Sciences, Monash University, Wellington Road, Clayton, Victoria, Australia
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