1
|
Graham ZA, Padilla Perez DJ. Correlated evolution of conspicuous colouration and burrowing in crayfish. Proc Biol Sci 2024; 291:20240632. [PMID: 38981529 PMCID: PMC11335007 DOI: 10.1098/rspb.2024.0632] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2023] [Revised: 05/02/2024] [Accepted: 06/14/2024] [Indexed: 07/11/2024] Open
Abstract
Conspicuous colours have fascinated biologists for centuries, leading to research on the evolution and functional significance of colour traits. In many cases, research suggests that conspicuous colours are adaptive and serve a function in sexual or aposematic signalling. In other cases, a lack of evidence for the adaptive value of conspicuous colours garners interest from biologists, such as when organisms that live underground and are rarely exposed to the surface are nevertheless colourful. Here, we use phylogenetic comparative methods to investigate colour evolution throughout freshwater crayfishes that vary in burrowing ability. Within the taxa we analysed, conspicuous colours have evolved independently over 50 times, and these colours are more common in semi-terrestrial crayfishes that construct extensive burrows. The intuitive but not evolutionarily justified assumption when presented with these results is to assume that these colours are adaptive. But contrary to this intuition, we discuss the hypothesis that colouration in crayfish is neutral. Supporting these ideas, the small population sizes and reduced gene flow within semi-terrestrial burrowing crayfishes may lead to the fixation of colour-phenotype mutations. Overall, our work brings into question the traditional view of animal colouration as a perfectly adapted phenotype.
Collapse
Affiliation(s)
- Zackary A. Graham
- Department of Organismal Biology, Ecology, and Zoo Science, West Liberty University, 208 University Drive, West Liberty, WV26074, USA
| | | |
Collapse
|
2
|
Hemingson CR, Cowman PF, Bellwood DR. Analysing biological colour patterns from digital images: An introduction to the current toolbox. Ecol Evol 2024; 14:e11045. [PMID: 38500859 PMCID: PMC10945235 DOI: 10.1002/ece3.11045] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2023] [Revised: 02/02/2024] [Accepted: 02/03/2024] [Indexed: 03/20/2024] Open
Abstract
Understanding the numerous roles that colouration serves in the natural world has remained a central focus in many evolutionary and ecological studies. However, to accurately characterise and then compare colours or patterns among individuals or species has been historically challenging. In recent years, there have been a myriad of new resources developed that allow researchers to characterise biological colours and patterns, specifically from digital imagery. However, each resource has its own strengths and weaknesses, answers a specific question and requires a detailed understanding of how it functions to be used properly. These nuances can make navigating this emerging field rather difficult. Herein, we evaluate several new techniques for analysing biological colouration, with a specific focus on digital images. First, we introduce fundamental background knowledge about light and perception to be considered when designing and implementing a study of colouration. We then show how numerous modifications can be made to images to ensure consistent formatting prior to analysis. After, we describe many of the new image analysis approaches and their respective functions, highlighting the type of research questions that they can address. We demonstrate how these various techniques can be brought together to examine novel research questions and test specific hypotheses. Finally, we outline potential future directions in colour pattern studies. Our goal is to provide a starting point and pathway for researchers wanting to study biological colour patterns from digital imagery.
Collapse
Affiliation(s)
- Christopher R. Hemingson
- The Research Hub for Coral Reef Ecosystem FunctionsJames Cook UniversityTownsvilleQueenslandAustralia
- College of Science and EngineeringJames Cook UniversityTownsvilleQueenslandAustralia
| | - Peter F. Cowman
- Biodiversity and Geosciences Program, Queensland Museum TropicsTownsvilleQueenslandAustralia
| | - David R. Bellwood
- The Research Hub for Coral Reef Ecosystem FunctionsJames Cook UniversityTownsvilleQueenslandAustralia
- College of Science and EngineeringJames Cook UniversityTownsvilleQueenslandAustralia
| |
Collapse
|
3
|
Weller HI, Hiller AE, Lord NP, Van Belleghem SM. recolorize: An R package for flexible colour segmentation of biological images. Ecol Lett 2024; 27:e14378. [PMID: 38361466 DOI: 10.1111/ele.14378] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2023] [Revised: 12/18/2023] [Accepted: 01/04/2024] [Indexed: 02/17/2024]
Abstract
Colour pattern variation provides biological information in fields ranging from disease ecology to speciation dynamics. Comparing colour pattern geometries across images requires colour segmentation, where pixels in an image are assigned to one of a set of colour classes shared by all images. Manual methods for colour segmentation are slow and subjective, while automated methods can struggle with high technical variation in aggregate image sets. We present recolorize, an R package toolbox for human-subjective colour segmentation with functions for batch-processing low-variation image sets and additional tools for handling images from diverse (high-variation) sources. The package also includes export options for a variety of formats and colour analysis packages. This paper illustrates recolorize for three example datasets, including high variation, batch processing and combining with reflectance spectra, and demonstrates the downstream use of methods that rely on this output.
Collapse
Affiliation(s)
- Hannah I Weller
- Department of Ecology, Evolution, and Organismal Biology, Brown University, Providence, Rhode Island, USA
- Helsinki Institute of Life Sciences, University of Helsinki, Helsinki, Finland
| | - Anna E Hiller
- Museum of Natural Science and Department of Biological Sciences, Louisiana State University, Baton Rouge, Louisiana, USA
| | - Nathan P Lord
- Department of Entomology, Louisiana State University Agricultural Center, Baton Rouge, Louisiana, USA
| | | |
Collapse
|
4
|
McMurry RS, Cavallaro MC, Shufran A, Hoback WW. Establishing Age-Based Color Changes for the American Burying Beetle, Nicrophorus americanus Olivier, with Implications for Conservation Efforts. INSECTS 2023; 14:844. [PMID: 37999043 PMCID: PMC10672208 DOI: 10.3390/insects14110844] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/07/2023] [Revised: 10/23/2023] [Accepted: 10/28/2023] [Indexed: 11/25/2023]
Abstract
The American burying beetle, Nicrophorus americanus Olivier, is a federally protected insect that once occupied most of eastern North America. Adult beetles feature distinct, recognizable markings on the pronotum and elytra, and color changes with age have been observed. Among the challenges faced by research scientists and conservation practitioners is the ability to determine beetle age in the field between and including teneral (young) and senescent (old) adult stages. Using 20 (10 male and 10 female) captive-bred beetles, we characterized the change in greyscale and red, green, and blue (RGB) color channels over the lifespan of each beetle for field-aging applications. Individual beetles were photographed at set intervals from eclosion to death, and color data were extracted using open-source ImageJ Version 1.54f software. A series of linear mixed-effects models determined that red color showed the steepest decrease among all color channels in the pronotum and elytral markings, with a more significant decrease in the pronotum. The change in greyscale between the pronotum and elytral markings was visibly different, with more rapid darkening in the pronotum. The resulting pronotum color chart was tested under field conditions in Oklahoma, aging 299 adult N. americanus, and six age categories (day range) were discernable by eye: teneral (0-15), late teneral (15-31), early mature (31-45), mature (45-59), early senescent (59-76), and senescent (76-90). The ability to more precisely estimate age will improve population structure estimates, laboratory breeding programs, and potential reintroduction efforts.
Collapse
Affiliation(s)
| | | | | | - William Wyatt Hoback
- Department of Entomology and Plant Pathology, Oklahoma State University, Stillwater, OK 74078, USA; (R.S.M.); (M.C.C.); (A.S.)
| |
Collapse
|
5
|
Russell BJ, Dierssen HM. Underwater spectral reflectance measurements: the reflectance standard submersion factor and its impact on derived target reflectance. APPLIED OPTICS 2023; 62:6299-6306. [PMID: 37706819 DOI: 10.1364/ao.493709] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/25/2023] [Accepted: 07/27/2023] [Indexed: 09/15/2023]
Abstract
For Earth observation remote sensing, high quality reflectance spectra are necessary for model input, algorithm development, and validation of derived products. In the aquatic environment, a common approach for making spectral reflectance measurements involves using a calibrated reflectance standard such as a Spectralon plaque underwater. The manufacturer provides a National Institute of Standards and Technology traceable reflectance curve with each standard, measured in air. Here, we demonstrate how the reflectance factor changes when submerged in water based on the standard albedo and viewing geometry. Target reflectances calculated incorrectly with the air calibrated values are 10%-60% lower than those estimated with submerged plaque calibrations. We provide guidelines for proper use and calibration of standards underwater.
Collapse
|
6
|
Szala K, Tobolka M, Surmacki A. Presence of the cloud cover and elevation angle of the sun affect measurements of eggshell coloration and patterning obtained from calibrated digital images. Ecol Evol 2023; 13:e10170. [PMID: 37435021 PMCID: PMC10329936 DOI: 10.1002/ece3.10170] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2023] [Revised: 05/15/2023] [Accepted: 05/24/2023] [Indexed: 07/13/2023] Open
Abstract
Calibrated digital photography is frequently used in studies focusing on avian eggshell appearance to measure colour and pattern features. Photographs are often taken in natural light conditions, yet little is known to what extent the normalisation process is able to control for varied light. Here, we photographed 36 blown eggs of the Japanese quail Coturnix japonica at five different elevation angles of the sun on both sunny and uniformly overcast days alongside grey standards. We normalised and processed the photographs in the MICA Toolbox software and checked how much noise was introduced by different natural light conditions to the colour and pattern measurements of the same set of eggs. Our results indicate that natural variation of light conditions affects eggshell colour and pattern measurements obtained by means of calibrated digital photography. Depending on a trait, the elevation angle of the sun had similar or even greater effect on the measurement than the presence of the cloud cover. Furthermore, measurements taken in cloudy conditions were more repeatable than those taken in sunny conditions. Based on the results, we propose practical guidelines regarding measuring colour and pattern of eggshells using calibrated digital photography in outdoor conditions.
Collapse
Affiliation(s)
- Klaudia Szala
- Department of Avian Biology and Ecology, Faculty of BiologyAdam Mickiewicz UniversityPoznańPoland
| | - Marcin Tobolka
- Department of ZoologyPoznań University of Life SciencesPoznańPoland
- Konrad Lorenz Institute of Ethology, University of Veterinary Medicine ViennaViennaAustria
| | - Adrian Surmacki
- Department of Avian Biology and Ecology, Faculty of BiologyAdam Mickiewicz UniversityPoznańPoland
| |
Collapse
|
7
|
Zhang G, Song S, Panescu J, Shapiro N, Dannemiller KC, Qin R. A novel systems solution for accurate colorimetric measurement through smartphone-based augmented reality. PLoS One 2023; 18:e0287099. [PMID: 37319291 PMCID: PMC10270580 DOI: 10.1371/journal.pone.0287099] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2022] [Accepted: 05/30/2023] [Indexed: 06/17/2023] Open
Abstract
Quantifying the colors of objects is useful in a wide range of applications, including medical diagnosis, agricultural monitoring, and food safety. Accurate colorimetric measurement of objects is a laborious process normally performed through a color matching test in the laboratory. A promising alternative is to use digital images for colorimetric measurement, due to their portability and ease of use. However, image-based measurements suffer from errors caused by the non-linear image formation process and unpredictable environmental lighting. Solutions to this problem often perform relative color correction among multiple images through discrete color reference boards, which may yield biased results due to the lack of continuous observation. In this paper, we propose a smartphone-based solution, that couples a designated color reference board with a novel color correction algorithm, to achieve accurate and absolute color measurements. Our color reference board contains multiple color stripes with continuous color sampling at the sides. A novel correction algorithm is proposed to utilize a first-order spatial varying regression model to perform the color correction, which leverages both the absolute color magnitude and scale to maximize the correction accuracy. The proposed algorithm is implemented as a "human-in-the-loop" smartphone application, where users are guided by an augmented reality scheme with a marker tracking module to take images at an angle that minimizes the impact of non-Lambertian reflectance. Our experimental results show that our colorimetric measurement is device independent and can reduce up to 90% color variance for images collected under different lighting conditions. In the application of reading pH values from test papers, we show that our system performs 200% better than human reading. The designed color reference board, the correction algorithm, and our augmented reality guiding approach form an integrated system as a novel solution to measure color with increased accuracy. This technique has the flexibility to improve color reading performance in systems beyond existing applications, evidenced by both qualitative and quantitative experiments on example applications such as pH-test reading.
Collapse
Affiliation(s)
- Guixiang Zhang
- Department of Civil, Environmental and Geodetic Engineering, The Ohio State University, Columbus, Ohio, United States of America
- Department of Electrical and Computer Engineering, The Ohio State University, Columbus, Ohio, United States of America
- Geospatial Data Analytics Lab, The Ohio State University, Columbus, Ohio, United States of America
| | - Shuang Song
- Department of Civil, Environmental and Geodetic Engineering, The Ohio State University, Columbus, Ohio, United States of America
- Geospatial Data Analytics Lab, The Ohio State University, Columbus, Ohio, United States of America
| | - Jenny Panescu
- Department of Civil, Environmental and Geodetic Engineering, The Ohio State University, Columbus, Ohio, United States of America
| | - Nicholas Shapiro
- Institute for Society and Genetics, University of California, Los Angeles, Los Angeles, California, United States of America
| | - Karen C. Dannemiller
- Department of Civil, Environmental and Geodetic Engineering, The Ohio State University, Columbus, Ohio, United States of America
- Environmental Health Sciences, The Ohio State University, Columbus, Ohio, United States of America
- Sustainability Institute, The Ohio State University, Columbus, Ohio, United States of America
| | - Rongjun Qin
- Department of Civil, Environmental and Geodetic Engineering, The Ohio State University, Columbus, Ohio, United States of America
- Department of Electrical and Computer Engineering, The Ohio State University, Columbus, Ohio, United States of America
- Geospatial Data Analytics Lab, The Ohio State University, Columbus, Ohio, United States of America
- Translational Data Analytics Institute, The Ohio State University, Columbus, Ohio, United States of America
| |
Collapse
|
8
|
Saiz E, Banicevic I, Espinoza Torres S, Bertata S, Picasso G, O'Brien M, Radu A. Portable, low-cost, Raspberry Pi-based optical sensor (PiSENS): continuous monitoring of atmospheric nitrogen dioxide. ANALYTICAL METHODS : ADVANCING METHODS AND APPLICATIONS 2023; 15:482-491. [PMID: 36606573 DOI: 10.1039/d2ay01433e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
We have developed a sensing system that utilizes a low-cost computer (Raspberry Pi) and its imaging camera as an optical sensing core for the continuous detection of NO2 in the air (PiSENS-A). The sensor is based on colour development as a consequence of the interaction of the gas with an absorbing solution. The PiSENS-A is thoroughly calibrated over the hourly mean which is used as one of the key metrics in evaluating air quality. The calibration was performed in the range of 0 < [NO2] < 476 μg m-3 chosen to contain the threshold used to determine compliance to the UK's Air Quality Standard Regulations (2010) expressed as a maximum of 18 permitted exceedances of [NO2]hourly mean = 200 μg per m3 per year. Lab-based measurements were evaluated against UV-vis. The average precision expressed as a relative standard deviation was: RSD% = 2.8%, while the correlation of mock samples was excellent (Pearson's r = 1.000). Field-based measurements were evaluated against chemiluminescence-based instrument exhibiting a correlation coefficient of R2 = 0.993. The PiSENS-A was also deployed as an independent air quality analyser at the Keele University campus.
Collapse
Affiliation(s)
- Ernesto Saiz
- Lennard-Jones Laboratories, Birchall Centre, Keele University, Keele, Staffordshire, ST5 5BG, UK.
| | - Ivana Banicevic
- Faculty of Technical Sciences, University of Montenegro, Montenegro
| | - Sergio Espinoza Torres
- Laboratory of Physical Chemistry Research, Faculty of Sciences, National University of Engineering, Av. Tupac Amaru 210, Lima 25, Peru
| | - Salma Bertata
- Lennard-Jones Laboratories, Birchall Centre, Keele University, Keele, Staffordshire, ST5 5BG, UK.
| | - Gino Picasso
- Laboratory of Physical Chemistry Research, Faculty of Sciences, National University of Engineering, Av. Tupac Amaru 210, Lima 25, Peru
| | - Matthew O'Brien
- Lennard-Jones Laboratories, Birchall Centre, Keele University, Keele, Staffordshire, ST5 5BG, UK.
| | - Aleksandar Radu
- School of Chemistry, Joseph Banks Laboratories, University of Lincoln, Green Lane, Lincoln, LN6 7DL, UK.
| |
Collapse
|
9
|
Taboada C, Delia J, Chen M, Ma C, Peng X, Zhu X, Jiang L, Vu T, Zhou Q, Yao J, O’Connell L, Johnsen S. Glassfrogs conceal blood in their liver to maintain transparency. Science 2022; 378:1315-1320. [PMID: 36548427 PMCID: PMC9984244 DOI: 10.1126/science.abl6620] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Transparency in animals is a complex form of camouflage involving mechanisms that reduce light scattering and absorption throughout the organism. In vertebrates, attaining transparency is difficult because their circulatory system is full of red blood cells (RBCs) that strongly attenuate light. Here, we document how glassfrogs overcome this challenge by concealing these cells from view. Using photoacoustic imaging to track RBCs in vivo, we show that resting glassfrogs increase transparency two- to threefold by removing ~89% of their RBCs from circulation and packing them within their liver. Vertebrate transparency thus requires both see-through tissues and active mechanisms that "clear" respiratory pigments from these tissues. Furthermore, glassfrogs' ability to regulate the location, density, and packing of RBCs without clotting offers insight in metabolic, hemodynamic, and blood-clot research.
Collapse
Affiliation(s)
- Carlos Taboada
- Biology Department, Duke University, Durham, NC, USA,Department of Biomedical Engineering, Duke University, Durham, NC, USA,Corresponding author.(C.T.);(J.D.);(J.Y.)
| | - Jesse Delia
- Department of Biomedical Engineering, Duke University, Durham, NC, USA,Department of Biology, Stanford University, Stanford, CA, USA,Division of Vertebrate Zoology and Richard Gilder Graduate School, American Museum of Natural History, New York, NY, USA,Corresponding author.(C.T.);(J.D.);(J.Y.)
| | - Maomao Chen
- Department of Biomedical Engineering, Duke University, Durham, NC, USA
| | - Chenshuo Ma
- Department of Biomedical Engineering, Duke University, Durham, NC, USA
| | - Xiaorui Peng
- Department of Biomedical Engineering, Duke University, Durham, NC, USA
| | - Xiaoyi Zhu
- Department of Biomedical Engineering, Duke University, Durham, NC, USA
| | - Laiming Jiang
- Department of Biomedical Engineering, University of Southern California, Los Angeles, CA 90089, USA
| | - Tri Vu
- Department of Biomedical Engineering, Duke University, Durham, NC, USA
| | - Qifa Zhou
- Department of Biomedical Engineering, University of Southern California, Los Angeles, CA 90089, USA,Department of Ophthalmology, University of Southern California, Los Angeles, CA 90033, USA,USC Ginsburg Institute for Biomedical Therapeutics, University of Southern California, Los Angeles, CA 90033, USA
| | - Junjie Yao
- Department of Biomedical Engineering, Duke University, Durham, NC, USA,Corresponding author.(C.T.);(J.D.);(J.Y.)
| | | | - Sönke Johnsen
- Biology Department, Duke University, Durham, NC, USA
| |
Collapse
|
10
|
Techniques for documenting and quantifying biofluorescence through digital photography and color quantization. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY 2022. [DOI: 10.1016/j.jpap.2022.100149] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
|
11
|
Rzhechitskiy Y, Gurkov A, Bolbat N, Shchapova E, Nazarova A, Timofeyev M, Borvinskaya E. Adipose Fin as a Natural “Optical Window” for Implantation of Fluorescent Sensors into Salmonid Fish. Animals (Basel) 2022; 12:ani12213042. [PMID: 36359166 PMCID: PMC9654777 DOI: 10.3390/ani12213042] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2022] [Revised: 10/27/2022] [Accepted: 11/03/2022] [Indexed: 11/09/2022] Open
Abstract
Simple Summary Novel optical sensors require implantation into the most transparent organs in order to ensure the most reliable and rapid monitoring of animal health. Widely farmed salmonid fish, such as rainbow trout, have highly translucent adipose fin, which we tested here and showed its high potential as the implantation site for the fluorescent sensors. The filamentous sensors were convenient to inject into the fin, and their optical signal was easily detectable using a simple hand-held device even without immobilization of the fish. Responsiveness of the sensors inside the adipose fin to bodily changes was shown under induced acidosis of fish fluids. The obtained results characterize adipose fin as the favorable site for implantation of optical sensors into salmonids for real-time tracking animal physiological status in basic research and aquaculture. Abstract Implantable optical sensors are emerging tools that have the potential to enable constant real-time monitoring of various internal physiological parameters. Such a possibility will open new horizons for health control not only in medicine, but also in animal husbandry, including aquaculture. In this study, we analyze different organs of commonly farmed rainbow trout (Oncorhynchus mykiss) as implantation sites for fluorescent sensors and propose the adipose fin, lacking an endoskeleton, as the optimal choice. The fin is highly translucent due to significantly thinner dermis, which makes the detectable fluorescence of an implanted sensor operating at the visible light range by more than an order of magnitude higher relative to the skin. Compared to the proximal parts of ray fins, the adipose fin provides easy implantation and visualization of the sensor. Finally, we tested fluorescent pH sensors inside the adipose fin and demonstrated the possibility of acquiring their signal with a simple hand-held device and without fish anesthesia. All these features will most likely make the adipose fin the main “window” into the internal physiological processes of salmonid fish with the help of implantable optical sensors.
Collapse
Affiliation(s)
| | - Anton Gurkov
- Institute of Biology, Irkutsk State University, 664025 Irkutsk, Russia
- Baikal Research Centre, 664003 Irkutsk, Russia
| | - Nadezhda Bolbat
- Institute of Biology, Irkutsk State University, 664025 Irkutsk, Russia
| | - Ekaterina Shchapova
- Institute of Biology, Irkutsk State University, 664025 Irkutsk, Russia
- Baikal Research Centre, 664003 Irkutsk, Russia
| | - Anna Nazarova
- Institute of Biology, Irkutsk State University, 664025 Irkutsk, Russia
| | - Maxim Timofeyev
- Institute of Biology, Irkutsk State University, 664025 Irkutsk, Russia
| | - Ekaterina Borvinskaya
- Institute of Biology, Irkutsk State University, 664025 Irkutsk, Russia
- Correspondence:
| |
Collapse
|
12
|
Ospina-Rozo L, Roberts A, Stuart-Fox D. A generalized approach to characterize optical properties of natural objects. Biol J Linn Soc Lond 2022. [DOI: 10.1093/biolinnean/blac064] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Abstract
To understand the diversity of ways in which natural materials interact with light, it is important to consider how their reflectance changes with the angle of illumination or viewing and to consider wavelengths beyond the visible. Efforts to characterize these optical properties, however, have been hampered by heterogeneity in measurement techniques, parameters and terminology. Here, we propose a standardized set of measurements, parameters and terminology to describe the optical properties of natural objects based on spectrometry, including angle-dependent effects, such as iridescence and specularity. We select a set of existing measurements and parameters that are generalizable to any wavelength range and spectral shape, and we highlight which subsets of measures are relevant to different biological questions. As a case study, we have applied these measures to 30 species of Christmas beetles, in which we observed previously unrealized diversity in visible and near-infrared reflectance. As expected, reflection of short wavelengths was associated with high spectral purity and angle dependence. In contrast to simple, artificial structures, iridescence and specularity were not strongly correlated, highlighting the complexity and modularity of natural materials. Species did not cluster according to spectral parameters or genus, suggesting high lability of optical properties. The proposed standardization of measures and parameters will improve our understanding of biological adaptations for manipulating light by facilitating the systematic comparison of complex optical properties, such as glossy or metallic appearances and visible or near-infrared iridescence.
Collapse
Affiliation(s)
- Laura Ospina-Rozo
- School of Biosciences, University of Melbourne , VIC 3010 , Australia
| | - Ann Roberts
- ARC Centre of Excellence for Transformative Meta-Optical Systems, School of Physics, University of Melbourne , VIC 3010 , Australia
| | - Devi Stuart-Fox
- School of Biosciences, University of Melbourne , VIC 3010 , Australia
| |
Collapse
|
13
|
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.
Collapse
|
14
|
Evaluating different metrics to study small color differences: the red bill and plumage of common waxbills as a case study. Behav Ecol Sociobiol 2022. [DOI: 10.1007/s00265-022-03236-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
|
15
|
Yu Y, Yang Z, Jiang Y, Wang L, Wu Y, Liao J, Yang R, Zhang L. Inheritance and QTL Mapping for Flower Color in Salvia miltiorrhiza Bunge. J Hered 2022; 113:248-256. [PMID: 35259262 DOI: 10.1093/jhered/esac012] [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: 01/26/2022] [Accepted: 03/04/2022] [Indexed: 11/12/2022] Open
Abstract
Salvia miltiorrhiza Bunge is an outcross-pollinated plant with diverse flower colors, ranging from white to purple. To clarify the genetic basis of S. miltiorrhiza flower color, we crossed white-flowered S. miltiorrhiza f. alba with dark violet-flowered S. miltiorrhiza, and selfed F1 to obtain an F2 population. The RGB color system was used to describe the flower color of the parents, F1 progeny, and F2 individuals. Afterward, we used genotyping-by-sequencing (GBS) technology to construct a high-density linkage map of S. miltiorrhiza based on the F2 population. Finally, the linkage map was used to locate the QTLs of the genes that control flower color in S. miltiorrhiza. Through measurement and cluster analysis of the R, G, and B values of flowers from the parents, F1, and F2 individuals, it was found that the purple flower color of S. miltiorrhiza is a quantitative trait controlled by two loci of major genes. The genetic map contained 605 SNPs with a total length of 738.3 cM in eight linkage groups (LGs), and the average distance between two markers was 1.22 cM. Based on the constructed genetic map and the flower R, G, B, and R+G+B values, two QTLs were detected for flower color, located on LG4 and LG5. The results of this study lay the foundation for cloning genes that control flower color and studying the molecular mechanism of flower color regulation in S. miltiorrhiza.
Collapse
Affiliation(s)
- Yan Yu
- College of Sciences, Sichuan Agricultural University, Ya'an, 625014, Sichuan, China.,College of Life Science, China West Normal University, Nanchong, 637009, Sichuan, China
| | - Zaijun Yang
- College of Life Science, China West Normal University, Nanchong, 637009, Sichuan, China
| | - Yuanyuan Jiang
- College of Sciences, Sichuan Agricultural University, Ya'an, 625014, Sichuan, China.,Featured Medicinal Plants Sharing and Service Platform of Sichuan Province, Sichuan Agricultural University, Ya'an, 625014, Sichuan, China
| | - Long Wang
- College of Sciences, Sichuan Agricultural University, Ya'an, 625014, Sichuan, China.,Featured Medicinal Plants Sharing and Service Platform of Sichuan Province, Sichuan Agricultural University, Ya'an, 625014, Sichuan, China
| | - Yichao Wu
- College of Life Science, China West Normal University, Nanchong, 637009, Sichuan, China
| | - Jinqiu Liao
- Featured Medicinal Plants Sharing and Service Platform of Sichuan Province, Sichuan Agricultural University, Ya'an, 625014, Sichuan, China
| | - Ruiwu Yang
- Featured Medicinal Plants Sharing and Service Platform of Sichuan Province, Sichuan Agricultural University, Ya'an, 625014, Sichuan, China
| | - Li Zhang
- College of Sciences, Sichuan Agricultural University, Ya'an, 625014, Sichuan, China.,Featured Medicinal Plants Sharing and Service Platform of Sichuan Province, Sichuan Agricultural University, Ya'an, 625014, Sichuan, China
| |
Collapse
|
16
|
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.
Collapse
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
| |
Collapse
|
17
|
|
18
|
Comparison of digital photography and spectrometry for evaluating colour perception in humans and other trichromatic species. Behav Ecol Sociobiol 2021. [DOI: 10.1007/s00265-021-03071-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
|
19
|
Trunschke J, Lunau K, Pyke GH, Ren ZX, Wang H. Flower Color Evolution and the Evidence of Pollinator-Mediated Selection. FRONTIERS IN PLANT SCIENCE 2021; 12:617851. [PMID: 34381464 PMCID: PMC8350172 DOI: 10.3389/fpls.2021.617851] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/15/2020] [Accepted: 05/14/2021] [Indexed: 06/01/2023]
Abstract
The evolution of floral traits in animal-pollinated plants involves the interaction between flowers as signal senders and pollinators as signal receivers. Flower colors are very diverse, effect pollinator attraction and flower foraging behavior, and are hypothesized to be shaped through pollinator-mediated selection. However, most of our current understanding of flower color evolution arises from variation between discrete color morphs and completed color shifts accompanying pollinator shifts, while evidence for pollinator-mediated selection on continuous variation in flower colors within populations is still scarce. In this review, we summarize experiments quantifying selection on continuous flower color variation in natural plant populations in the context of pollinator interactions. We found that evidence for significant pollinator-mediated selection is surprisingly limited among existing studies. We propose several possible explanations related to the complexity in the interaction between the colors of flowers and the sensory and cognitive abilities of pollinators as well as pollinator behavioral responses, on the one hand, and the distribution of variation in color phenotypes and fitness, on the other hand. We emphasize currently persisting weaknesses in experimental procedures, and provide some suggestions for how to improve methodology. In conclusion, we encourage future research to bring together plant and animal scientists to jointly forward our understanding of the mechanisms and circumstances of pollinator-mediated selection on flower color.
Collapse
Affiliation(s)
- Judith Trunschke
- CAS Key Laboratory for Plant Diversity and Biogeography of East Asia, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, China
| | - Klaus Lunau
- Institute of Sensory Ecology, Heinrich-Heine-University, Düsseldorf, Germany
| | - Graham H. Pyke
- CAS Key Laboratory for Plant Diversity and Biogeography of East Asia, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, China
- Department of Biological Sciences, Macquarie University, Ryde, NSW, Australia
| | - Zong-Xin Ren
- CAS Key Laboratory for Plant Diversity and Biogeography of East Asia, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, China
| | - Hong Wang
- CAS Key Laboratory for Plant Diversity and Biogeography of East Asia, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, China
| |
Collapse
|
20
|
John L, Rick IP, Vitt S, Thünken T. Body coloration as a dynamic signal during intrasexual communication in a cichlid fish. BMC ZOOL 2021; 6:9. [PMID: 37170176 PMCID: PMC10127425 DOI: 10.1186/s40850-021-00075-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2020] [Accepted: 04/13/2021] [Indexed: 11/10/2022] Open
Abstract
Abstract
Background
Intrasexual competition over access to resources can lead to aggression between individuals. Because overt aggression, i.e. fights, can be costly for contestants, the communication of aggressive motivation prior to engagement in a physical fight is often mediated by conventional signals. Animals of various taxa, including fishes, display visual signals such as body coloration that can dynamically be adjusted depending on the individual’s motivation. Male individuals of the West African cichlid Pelvicachromis taeniatus express a yellow body coloration displayed during courtship but also in an intrasexual competition context.
Results
Within-individual variation in male yellow body coloration, as quantified with standardized digital photography and representation in a CIELab color space, was examined in a mating context by exposing males to a female and in a competitive intrasexual context, i.e. in a dyadic contest. Additionally, spectrometric reflectance measurements were taken to obtain color representations in a physiological color space based on spectral sensitivities of our model species. Exposure to females did not significantly affect male color expression. However, analysis of body coloration revealed a change in within-individual color intensity and colored area after interaction with a male competitor. In dominant males, extension of coloration was positively correlated with restrained aggression, i.e. displays, which in turn explained dominance established between the two contestants.
Conclusion
Body coloration in male P. taeniatus is a dynamic signal that is used in concert with display behavior in communication during intrasexual competition.
Collapse
|
21
|
Laitly A, Callaghan CT, Delhey K, Cornwell WK. Is color data from citizen science photographs reliable for biodiversity research? Ecol Evol 2021; 11:4071-4083. [PMID: 33976795 PMCID: PMC8093748 DOI: 10.1002/ece3.7307] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2020] [Revised: 01/09/2021] [Accepted: 01/12/2021] [Indexed: 12/31/2022] Open
Abstract
Color research continuously demands better methods and larger sample sizes. Citizen science (CS) projects are producing an ever-growing geo- and time-referenced set of photographs of organisms. These datasets have the potential to make a huge contribution to color research, but the reliability of these data need to be tested before widespread implementation.We compared the difference between color extracted from CS photographs with that of color extracted from controlled lighting conditions (i.e., the current gold standard in spectrometry) for both birds and plants. First, we tested the ability of CS photographs to quantify interspecific variability by assessing > 9,000 CS photographs of 537 Australian bird species with controlled museum spectrometry data. Second, we tested the ability of CS photographs to quantify intraspecific variability by measuring petal color data for two plant species using seven methods/sources with varying levels of control.For interspecific questions, we found that by averaging out variability through a large sample size, CS photographs capture a large proportion of across species variation in plumage color within the visual part of the spectrum (R2 = 0.68-0.71 for RGB space and 0.72-0.77 for CIE-LAB space). Between 12 and 14 photographs per species are necessary to achieve this averaging effect for interspecific studies. Unsurprisingly, the CS photographs taken with commercial cameras failed to capture information in the UV part of the spectrum. For intraspecific questions, decreasing levels of control increase the color variation but averaging larger sample sizes can partially mitigate this, aside from particular issues related to saturation and irregularities in light capture.CS photographs offer a very large sample size across space and time which offers statistical power for many color research questions. This study shows that CS photographs contain data that lines up closely with controlled measurements within the visual spectrum if the sample size is large enough, highlighting the potential of CS photographs for both interspecific and intraspecific ecological or biological questions. With regard to analyzing color in CS photographs, we suggest, as a starting point, to measure multiple random points within the ROI of each photograph for both patterned and unpatterned patches and approach the recommended sample size of 12-14 photographs per species for interspecific studies. Overall, this study provides groundwork in analyzing the reliability of a novel method, which can propel the field of studying color forward.
Collapse
Affiliation(s)
- Alexandra Laitly
- Evolution and Ecology Research CentreSchool of Biological, Earth and Environmental SciencesUniversity of New South WalesSydneyNSWAustralia
| | - Corey T. Callaghan
- Evolution and Ecology Research CentreSchool of Biological, Earth and Environmental SciencesUniversity of New South WalesSydneyNSWAustralia
| | - Kaspar Delhey
- Max Planck Institute for OrnithologySeewiesenGermany
- School of Biological SciencesMonash UniversityClaytonVic.Australia
| | - William K. Cornwell
- Evolution and Ecology Research CentreSchool of Biological, Earth and Environmental SciencesUniversity of New South WalesSydneyNSWAustralia
| |
Collapse
|
22
|
Kertész K, Bálint Z, Piszter G, Horváth ZE, Biró LP. Multi-instrumental techniques for evaluating butterfly structural colors: A case study on Polyommatus bellargus (Rottemburg, 1775) (Lepidoptera: Lycaenidae: Polyommatinae). ARTHROPOD STRUCTURE & DEVELOPMENT 2021; 61:101010. [PMID: 33486292 DOI: 10.1016/j.asd.2020.101010] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Revised: 11/13/2020] [Accepted: 11/16/2020] [Indexed: 06/12/2023]
Abstract
Color is an important communication channel for day-flying butterflies. Chemical (pigmentary) coloration is often supplemented by physical color generated by photonic nanostructures. These nanoarchitectures - which are characteristic for a given species - exhibit wavelength ranges in which light propagation is forbidden. The photonic nanoarchitectures are located in the lumen of the wing scales and are developed individually by each scale during metamorphosis. This self-assembly process is governed by the genes in the nucleus of the scale producing cell. It is crucial to establish well-defined measurement methods for the unambiguous characterization and comparison of colors generated in such a complex manner. Owing to the intricate architecture ordered at multiple levels (from centimeters to tens of nanometers), the precise quantitative determination of butterfly wing coloration is not trivial. In this paper, we present an overview of several optical spectroscopy measurement methods and illustrate techniques for processing the obtained data, using the species Polyommatus bellargus as a test case, the males of which exhibit a variation in their blue structural color that is easily recognizable to the naked eye. The benefits and drawbacks of these optical methods are discussed and compared. Furthermore, the origin of the color differences is explained in relation to differences in the wing scale nanomorphology revealed by electron microscopy. This in turn is tentatively associated with the unusually large genetic drift reported for this species in the literature.
Collapse
Affiliation(s)
- Krisztián Kertész
- Institute of Technical Physics and Materials Science, Centre for Energy Research, P.O. Box 49, H-1525 Budapest, Hungary.
| | - Zsolt Bálint
- Hungarian Natural History Museum, Baross utca 13, H-1088 Budapest, Hungary
| | - Gábor Piszter
- Institute of Technical Physics and Materials Science, Centre for Energy Research, P.O. Box 49, H-1525 Budapest, Hungary
| | - Zsolt Endre Horváth
- Institute of Technical Physics and Materials Science, Centre for Energy Research, P.O. Box 49, H-1525 Budapest, Hungary
| | - László Péter Biró
- Institute of Technical Physics and Materials Science, Centre for Energy Research, P.O. Box 49, H-1525 Budapest, Hungary
| |
Collapse
|
23
|
Wei N, Tian Y, Liao Y, Komatsu N, Gao W, Lyuleeva-Husemann A, Zhang Q, Hussain A, Ding EX, Yao F, Halme J, Liu K, Kono J, Jiang H, Kauppinen EI. Colors of Single-Wall Carbon Nanotubes. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2021; 33:e2006395. [PMID: 33314478 DOI: 10.1002/adma.202006395] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/18/2020] [Revised: 10/29/2020] [Indexed: 06/12/2023]
Abstract
Although single-wall carbon nanotubes (SWCNTs) exhibit various colors in suspension, directly synthesized SWCNT films usually appear black. Recently, a unique one-step method for directly fabricating green and brown films has been developed. Such remarkable progress, however, has brought up several new questions. The coloration mechanism, potentially achievable colors, and color controllability of SWCNTs are unknown. Here, a quantitative model is reported that can predict the specific colors of SWCNT films and unambiguously identify the coloration mechanism. Using this model, colors of 466 different SWCNT species are calculated, which reveals a broad spectrum of potentially achievable colors of SWCNTs. The calculated colors are in excellent agreement with existing experimental data. Furthermore, the theory predicts the existence of many brilliantly colored SWCNT films, which are experimentally expected. This study shows that SWCNTs as a form of pure carbon, can display a full spectrum of vivid colors, which is expected to complement the general understanding of carbon materials.
Collapse
Affiliation(s)
- Nan Wei
- Department of Applied Physics, Aalto University School of Science, Aalto, 00076, Finland
| | - Ying Tian
- Department of Physics, Dalian Maritime University, Dalian, 116026, China
| | - Yongping Liao
- Department of Applied Physics, Aalto University School of Science, Aalto, 00076, Finland
| | - Natsumi Komatsu
- Department of Electrical and Computer Engineering, Rice University, Houston, TX, 77005, USA
| | - Weilu Gao
- Department of Electrical and Computer Engineering, Rice University, Houston, TX, 77005, USA
| | | | - Qiang Zhang
- Department of Applied Physics, Aalto University School of Science, Aalto, 00076, Finland
| | - Aqeel Hussain
- Department of Applied Physics, Aalto University School of Science, Aalto, 00076, Finland
| | - Er-Xiong Ding
- Department of Applied Physics, Aalto University School of Science, Aalto, 00076, Finland
| | - Fengrui Yao
- School of Physics, Academy for Advanced Interdisciplinary Studies, Collaborative Innovation Center of Quantum Matter, Peking University, Beijing, 100871, China
| | - Janne Halme
- Department of Applied Physics, Aalto University School of Science, Aalto, 00076, Finland
| | - Kaihui Liu
- School of Physics, Academy for Advanced Interdisciplinary Studies, Collaborative Innovation Center of Quantum Matter, Peking University, Beijing, 100871, China
| | - Junichiro Kono
- Department of Electrical and Computer Engineering, Rice University, Houston, TX, 77005, USA
- Department of Physics and Astronomy, Rice University, Houston, TX, 77005, USA
- Department of Materials Science and NanoEngineering, Rice University, Houston, TX, 77005, USA
| | - Hua Jiang
- Department of Applied Physics, Aalto University School of Science, Aalto, 00076, Finland
| | - Esko I Kauppinen
- Department of Applied Physics, Aalto University School of Science, Aalto, 00076, Finland
| |
Collapse
|
24
|
Parikh A, Nirupama DN, Naveen DN, Sindhu J, Nainan M. Spectrophotometric analysis of crown discoloration induced by various intracanal medicaments: An in vitro study. ENDODONTOLOGY 2021. [DOI: 10.4103/endo.endo_59_19] [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] Open
|
25
|
Yamamoto N, Sota T. Evolutionary fine-tuning of background-matching camouflage among geographical populations in the sandy beach tiger beetle. Proc Biol Sci 2020; 287:20202315. [PMID: 33323087 PMCID: PMC7779511 DOI: 10.1098/rspb.2020.2315] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2020] [Accepted: 11/20/2020] [Indexed: 11/12/2022] Open
Abstract
Background-matching camouflage is a widespread adaptation in animals; however, few studies have thoroughly examined its evolutionary process and consequences. The tiger beetle Chaetodera laetescripta exhibits pronounced variation in elytral colour pattern among sandy habitats of different colour in the Japanese Archipelago. In this study, we performed digital image analysis with avian vision modelling to demonstrate that elytral luminance, which is attributed to proportions of elytral colour components, is fine-tuned to match local backgrounds. Field predation experiments with model beetles showed that better luminance matching resulted in a lower attack rate and corresponding lower mortality. Using restriction site-associated DNA (RAD) sequence data, we analysed the dispersal and evolution of colour pattern across geographical locations. We found that sand colour matching occurred irrespective of genetic and geographical distances between populations, suggesting that locally adapted colour patterns evolved after the colonization of these habitats. Given that beetle elytral colour patterns presumably have a quantitative genetic basis, our findings demonstrate that fine-tuning of background-matching camouflage to local habitat conditions can be attained through selection by visual predators, as predicted by the earliest proponent of natural selection.
Collapse
Affiliation(s)
- Nayuta Yamamoto
- Department of Zoology, Graduate School of Science, Kyoto University, Sakyo, Kyoto 606-8502, Japan
| | - Teiji Sota
- Department of Zoology, Graduate School of Science, Kyoto University, Sakyo, Kyoto 606-8502, Japan
| |
Collapse
|
26
|
Potash AD, Greene DU, Foursa GA, Mathis VL, Conner LM, McCleery RA. A comparison of animal color measurements using a commercially available digital color sensor and photograph analysis. Curr Zool 2020; 66:601-606. [PMID: 33391358 PMCID: PMC7769579 DOI: 10.1093/cz/zoaa016] [Citation(s) in RCA: 4] [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: 02/14/2020] [Accepted: 03/21/2020] [Indexed: 11/14/2022] Open
Abstract
An animal's pelage, feather, or skin color can serve a variety of functions, so it is important to have multiple standardized methods for measuring color. One of the most common and reliable methods for measuring animal coloration is the use of standardized digital photographs of animals. New technology in the form of a commercially available handheld digital color sensor could provide an alternative to photography-based animal color measurements. To determine whether a digital color sensor could be used to measure animal coloration, we tested the ability of a digital color sensor to measure coloration of mammalian, avian, and lepidopteran museums specimens. We compared results from the sensor to measurements taken using traditional photography methods. Our study yielded significant differences between photography-based and digital color sensor measurements of brightness (light to dark) and colors along the green to red spectrum. There was no difference between photographs and the digital color sensor measurements for colors along the blue to yellow spectrum. The average difference in recorded color (ΔE) by the 2 methods was above the threshold at which humans can perceive a difference. There were significant correlations between the sensor and photographs for all measurements indicating that the sensor is an effective animal coloration measuring tool. However, the sensor's small aperture and narrow light spectrum range designed for human-vision limit its value for ecological research. We discuss the conditions in which a digital color sensor can be an effective tool for measuring animal coloration in both laboratory settings and in the field.
Collapse
Affiliation(s)
- Alex D Potash
- Department of Wildlife Ecology and Conservation, University of Florida Institute of Food and Agricultural Science, Gainesville, FL 32611, USA
| | - Daniel U Greene
- Weyerhaeuser Company, Environmental Research South, Columbus, MS 39701, USA
| | - Gabrielle A Foursa
- Department of Biology, University of Florida, Gainesville, FL 32611, USA
| | - Verity L Mathis
- Florida Museum of Natural History, University of Florida, Gainesville, FL 32611, USA
| | | | - Robert A McCleery
- Department of Wildlife Ecology and Conservation, University of Florida Institute of Food and Agricultural Science, Gainesville, FL 32611, USA
| |
Collapse
|
27
|
Nokelainen O, Sreelatha LB, Brito JC, Campos JC, Scott-Samuel NE, Valkonen JK, Boratyński Z. Camouflage in arid environments: the case of Sahara-Sahel desert rodents. JOURNAL OF VERTEBRATE BIOLOGY 2020. [DOI: 10.25225/jvb.20007] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Affiliation(s)
- Ossi Nokelainen
- Department of Biological and Environmental Science, University of Jyväskylä, Jyväskylä, Finland; e-mail:
| | - Lekshmi B. Sreelatha
- CIBIO-InBIO Associate Laboratory, Research Center in Biodiversity and Genetic Resources, University of Porto, Vairão, Portugal; e-mail:
| | - José Carlos Brito
- CIBIO-InBIO Associate Laboratory, Research Center in Biodiversity and Genetic Resources, University of Porto, Vairão, Portugal; e-mail:
| | - João C. Campos
- CIBIO-InBIO Associate Laboratory, Research Center in Biodiversity and Genetic Resources, University of Porto, Vairão, Portugal; e-mail:
| | | | - Janne K. Valkonen
- Department of Biological and Environmental Science, University of Jyväskylä, Jyväskylä, Finland; e-mail:
| | - Zbyszek Boratyński
- CIBIO-InBIO Associate Laboratory, Research Center in Biodiversity and Genetic Resources, University of Porto, Vairão, Portugal; e-mail:
| |
Collapse
|
28
|
Bian L, Cai XM, Luo ZX, Li ZQ, Chen ZM. Foliage Intensity is an Important Cue of Habitat Location for Empoasca onukii. INSECTS 2020; 11:insects11070426. [PMID: 32659987 PMCID: PMC7412280 DOI: 10.3390/insects11070426] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/10/2020] [Revised: 07/06/2020] [Accepted: 07/06/2020] [Indexed: 11/02/2022]
Abstract
For many herbivorous insects, vision is more important than olfaction in the prealighting stage of host habitat location. Tea leafhoppers, Empoasca onukii (Hemiptera, Cicadellidae), are serious pests that preferentially inhabit the tender leaves of tea plants across China. Here, we investigated whether tea leafhoppers could distinguish foliage colors associated with different leaf ages and use this visual cue to guide suitable habitat location from short distances. Similar to honeybees, the adult E. onukii has an apposition type of compound eye, and each ommatidium has eight retinular cells, in which three spectral types of photoreceptors are distributed, with peak sensitivities at 356 nm (ultraviolet), 435 nm (blue), and 542 nm (green). Both changes in spectral intensity and hue of reflectance light of the host foliage were correlated with varying leaf age, and the intensity linearly decreased with increasing leaf age. Behavioral responses also showed that adult E. onukii could discriminate between the simulated colors of host foliage at different leaf ages without olfactory stimuli and selected the bright colors that strongly corresponded to those of tender leaves. The results suggest that, compared with the spectral composition (hue), the intensity of light reflectance from leaves at different ages is more important for adult leafhoppers when discriminating host foliage and could guide them to tender leaves at the top of tea shoots.
Collapse
Affiliation(s)
- Lei Bian
- Tea Research Institute, Chinese Academy of Agricultural Science, 9 Meiling South Road, Xihu District, Hangzhou 310008, China; (L.B.); (X.M.C.); (Z.X.L.); (Z.Q.L.)
- Key Laboratory of Tea Biology and Resource Utilization, Ministry of Agriculture, 9 Meiling South Road, Xihu District, Hangzhou 310008, China
| | - Xiao Ming Cai
- Tea Research Institute, Chinese Academy of Agricultural Science, 9 Meiling South Road, Xihu District, Hangzhou 310008, China; (L.B.); (X.M.C.); (Z.X.L.); (Z.Q.L.)
- Key Laboratory of Tea Biology and Resource Utilization, Ministry of Agriculture, 9 Meiling South Road, Xihu District, Hangzhou 310008, China
| | - Zong Xiu Luo
- Tea Research Institute, Chinese Academy of Agricultural Science, 9 Meiling South Road, Xihu District, Hangzhou 310008, China; (L.B.); (X.M.C.); (Z.X.L.); (Z.Q.L.)
- Key Laboratory of Tea Biology and Resource Utilization, Ministry of Agriculture, 9 Meiling South Road, Xihu District, Hangzhou 310008, China
| | - Zhao Qun Li
- Tea Research Institute, Chinese Academy of Agricultural Science, 9 Meiling South Road, Xihu District, Hangzhou 310008, China; (L.B.); (X.M.C.); (Z.X.L.); (Z.Q.L.)
- Key Laboratory of Tea Biology and Resource Utilization, Ministry of Agriculture, 9 Meiling South Road, Xihu District, Hangzhou 310008, China
| | - Zong Mao Chen
- Tea Research Institute, Chinese Academy of Agricultural Science, 9 Meiling South Road, Xihu District, Hangzhou 310008, China; (L.B.); (X.M.C.); (Z.X.L.); (Z.Q.L.)
- Key Laboratory of Tea Biology and Resource Utilization, Ministry of Agriculture, 9 Meiling South Road, Xihu District, Hangzhou 310008, China
- Correspondence: ; Tel.: +86-571-86650100
| |
Collapse
|
29
|
Dračková T, Smolinský R, Hiadlovská Z, Dolinay M, Martínková N. Quantifying colour difference in animals with variable patterning. JOURNAL OF VERTEBRATE BIOLOGY 2020. [DOI: 10.25225/jvb.20029] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Affiliation(s)
- Tereza Dračková
- Institute of Biostatistics and Analyses, Masaryk University, Brno, Czech Republic; e-mail:
| | - Radovan Smolinský
- Department of Biology, Faculty of Education, Masaryk University, Brno, Czech Republic; e-mail:
| | - Zuzana Hiadlovská
- Institute of Animal Physiology and Genetics, Czech Academy of Sciences, Brno, Czech Republic; e-mail:
| | - Matej Dolinay
- Institute of Vertebrate Biology, Czech Academy of Sciences, Brno, Czech Republic; e-mail:
| | - Natália Martínková
- Institute of Vertebrate Biology, Czech Academy of Sciences, Brno, Czech Republic; e-mail:
| |
Collapse
|
30
|
Didion JE, Smith K, Layne JE. Modifying twisted nematic LCD screens to create dichromatic visual stimuli with LEDs. Methods Ecol Evol 2020. [DOI: 10.1111/2041-210x.13375] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Jeremiah E. Didion
- Department of Biological Sciences University of Cincinnati Cincinnati OH USA
| | - Karleigh Smith
- Department of Biological Sciences University of Cincinnati Cincinnati OH USA
| | - John E. Layne
- Department of Biological Sciences University of Cincinnati Cincinnati OH USA
| |
Collapse
|
31
|
Caves EM, Nowicki S, Johnsen S. Von Uexküll Revisited: Addressing Human Biases in the Study of Animal Perception. Integr Comp Biol 2020; 59:1451-1462. [PMID: 31127268 DOI: 10.1093/icb/icz073] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
More than 100 years ago, the biologist Jakob von Uexküll suggested that, because sensory systems are diverse, animals likely inhabit different sensory worlds (umwelten) than we do. Since von Uexküll, work across sensory modalities has confirmed that animals sometimes perceive sensory information that humans cannot, and it is now well-established that one must account for this fact when studying an animal's behavior. We are less adept, however, at recognizing cases in which non-human animals may not detect or perceive stimuli the same way we do, which is our focus here. In particular, we discuss three ways in which our own perception can result in misinformed hypotheses about the function of various stimuli. In particular, we may (1) make untested assumptions about how sensory information is perceived, based on how we perceive or measure it, (2) attribute undue significance to stimuli that we perceive as complex or striking, and (3) assume that animals divide the sensory world in the same way that we as scientists do. We discuss each of these biases and provide examples of cases where animals cannot perceive or are not attending to stimuli in the same way that we do, and how this may lead us to mistaken assumptions. Because what an animal perceives affects its behavior, we argue that these biases are especially important for researchers in sensory ecology, cognition, and animal behavior and communication to consider. We suggest that studying animal umwelten requires integrative approaches that combine knowledge of sensory physiology with behavioral assays.
Collapse
Affiliation(s)
| | | | - Sönke Johnsen
- Biology Department, Duke University, Durham, NC, USA
| |
Collapse
|
32
|
Performance Evaluation of Two Commercially Available Portable Spectrometers to Non-Invasively Determine Table Grape and Peach Quality Attributes. AGRONOMY-BASEL 2020. [DOI: 10.3390/agronomy10010148] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Near-infrared (NIR) spectroscopy has been used to non-destructively and rapidly evaluate the quality of fresh agricultural produce. In this study, two commercially available portable spectrometers (F-750: Felix Instruments, WA, USA; and SCiO: Consumer Physics, Tel Aviv, Israel) were evaluated in the wavelength range between 740 and 1070 nm to non-invasively predict quality attributes, including the dry matter (DM), and total soluble solids (TSS) content of three fresh table grape cultivars (‘Autumn Royal’, ‘Timpson’, and ‘Sweet Scarlet’) and one peach cultivar (‘Cassie’). Prediction models were developed using partial least-square regression (PLSR) to correlate the NIR absorbance spectra with the invasive quality measurements. In regard to grapes, the best DM prediction models yielded an R2 of 0.83 and 0.81, a ratio of standard error of performance to standard deviation (RPD) of 2.35 and 2.29, and a root mean square error of prediction (RMSEP) of 1.40 and 1.44; and the best TSS prediction models generated an R2 of 0.97 and 0.95, an RPD of 5.95 and 4.48, and an RMSEP of 0.53 and 0.70 for the F-750 and SCiO spectrometers, respectively. Overall, PLSR prediction models using both spectrometers were promising to predict table grape quality attributes. Regarding peach, the PLSR prediction models did not perform as well as in grapes, as DM prediction models resulted in an R2 of 0.81 and 0.67, an RPD of 2.24 and 1.74, and an RMSEP of 1.28 and 1.66; and TSS resulted in an R2 of 0.62 and 0.55, an RPD of 1.55 and 1.48, and an RMSEP of 1.19 and 1.25 for the F-750 and SCiO spectrometers, respectively. Overall, the F-750 spectrometer prediction models performed better than those generated by using the SCiO spectrometer data.
Collapse
|
33
|
Engelbrecht‐Wiggans E, Tumulty JP. “Reverse” sexual dichromatism in a Neotropical frog. Ethology 2019. [DOI: 10.1111/eth.12942] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
| | - James P. Tumulty
- Department of Ecology, Evolution, and Behavior University of Minnesota St. Paul MN USA
| |
Collapse
|
34
|
Burkle LA, Runyon JB. Floral volatiles structure plant–pollinator interactions in a diverse community across the growing season. Funct Ecol 2019. [DOI: 10.1111/1365-2435.13424] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Laura A. Burkle
- Department of Ecology Montana State University Bozeman Montana
| | - Justin B. Runyon
- Rocky Mountain Research Station USDA Forest Service Bozeman Montana
| |
Collapse
|
35
|
Use of plumage and gular pouch color to evaluate condition of oil spill rehabilitated California brown pelicans (Pelecanus occidentalis californicus) post-release. PLoS One 2019; 14:e0211932. [PMID: 30811430 PMCID: PMC6392258 DOI: 10.1371/journal.pone.0211932] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2018] [Accepted: 01/24/2019] [Indexed: 11/19/2022] Open
Abstract
Sublethal effects of oil spills may dampen seabird rehabilitation success due to lingering negative impacts of contamination and stress on reproduction and long-term survival. These effects can be difficult to measure while birds are in care as well as once birds are released. Expression of sexually selected traits that are sensitive to condition can provide information on physiological status of birds. We evaluated plumage molt and gular pouch skin color of California brown pelicans (Pelecanus occidentalis californicus) following oil contamination and rehabilitation to test for differences between previously oiled and rehabilitated (post-spill) and presumably uncontaminated pelicans. Post-spill pelicans released with either color leg bands alone, or bands plus harness-mounted satellite GPS tags, were relocated and visually assessed in the field at non-breeding communal roosts and compared to surrounding unmarked pelicans in the general population. Non-oiled pelicans bearing GPS tags were also included in the study. Post-spill pelicans lagged the general population in molt of ornamental yellow crown feathers but hind neck transition into white plumage was not significantly different. Both post-spill and non-oiled pelicans wearing GPS tags had lower gular redness scores than the unmarked, non-oiled population. Pre-breeding gular pouch redness of post-spill pelicans was more strongly influenced by wearing of a GPS tag than a history of oil contamination and rehabilitation. Gular pouch redness of post-spill pelicans in the first 18 months after release was positively correlated with long term survivorship. If gular pouch color is a condition-dependent sexual signal and overall health influences plumage molt progression, our results indicate that many post-spill pelicans marked with bands alone were in relatively good condition going into the next breeding season, but those released with electronic tags experienced additional stress due to wearing the equipment, introducing a confounding variable to the post-release study.
Collapse
|
36
|
Affiliation(s)
- Rafael Maia
- Department of Ecology, Evolution and Environmental Biology, Columbia University, New York, NY, USA
| | - Thomas E White
- School of Life and Environmental Sciences, University of Sydney, Camperdown, Sydney, NSW, Australia
| |
Collapse
|
37
|
Bergeron ZT, Fuller RC. Using Human Vision to Detect Variation in Avian Coloration: How Bad Is It? Am Nat 2018; 191:269-276. [DOI: 10.1086/695282] [Citation(s) in RCA: 45] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
|
38
|
Robledo-Ospina LE, Escobar-Sarria F, Troscianko J, Rao D. Two ways to hide: predator and prey perspectives of disruptive coloration and background matching in jumping spiders. Biol J Linn Soc Lond 2017. [DOI: 10.1093/biolinnean/blx108] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
|
39
|
Badiane A, Pérez i de Lanuza G, García‐Custodio MDC, Carazo P, Font E. Colour patch size and measurement error using reflectance spectrophotometry. Methods Ecol Evol 2017. [DOI: 10.1111/2041-210x.12801] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Affiliation(s)
- Arnaud Badiane
- Department of Biological Sciences Macquarie University Sydney NSW 2109 Australia
- Ethology Lab Cavanilles Institute of Biodiversity and Evolutionary Biology University of Valencia Valencia APDO 22085, 46071 Spain
| | - Guillem Pérez i de Lanuza
- CIBIO, Research Centre in Biodiversity and Genetic Resources, InBIO, University of Porto, Institute of Agrarian Sciences of Vairão R. Padre Armando Quintas 4485‐661 Vairão Portugal
| | - María del Carmen García‐Custodio
- Ethology Lab Cavanilles Institute of Biodiversity and Evolutionary Biology University of Valencia Valencia APDO 22085, 46071 Spain
| | - Pau Carazo
- Ethology Lab Cavanilles Institute of Biodiversity and Evolutionary Biology University of Valencia Valencia APDO 22085, 46071 Spain
| | - Enrique Font
- Ethology Lab Cavanilles Institute of Biodiversity and Evolutionary Biology University of Valencia Valencia APDO 22085, 46071 Spain
| |
Collapse
|
40
|
Boyer JF, Swierk L. Rapid body color brightening is associated with exposure to a stressor in an Anolis lizard. CAN J ZOOL 2017. [DOI: 10.1139/cjz-2016-0200] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Many species use color change to optimize body coloration to changing environmental conditions, and drivers of rapid color change in natural populations are numerous and poorly understood. We examined factors influencing body coloration in the Water Anole (Anolis aquaticus Taylor, 1956), a lizard possessing color-changing stripes along the length of its body. We quantified the color of three body regions (the eye stripe, lateral stripe, and dorsum) before and after exposure to a mild stressor (handling and restraint). Based on current understanding of the genus Anolis Daudin, 1802, we hypothesized that exposure to a stressor would generate genus-typical skin darkening (i.e., increased melanism). Contrary to expectations, stress consistently brightened body coloration: eye and lateral stripes transitioned from brown to pale blue and green and the dorsum became lighter brown. Sex, size, and body temperature did not correlate with any aspect of body coloration, and a laboratory experiment confirmed that light exposure did not drive brightening. We propose that color change may serve to reduce conspicuousness through disruptive camouflage; lizards tended to display brighter stripes on mottled green–brown substrates. Together, these results improve our understanding of Anolis color change diversity and emphasize the need for a broader interpretation of the mechanism and functions of color change across taxa.
Collapse
Affiliation(s)
- Jane F.F. Boyer
- Division of Natural Sciences, University of Guam, Mangilao, Guam 96923
| | - Lindsey Swierk
- Las Cruces Biological Station, Organization for Tropical Studies, Apartado 73-8257, San Vito de Coto Brus, Costa Rica
| |
Collapse
|
41
|
Tedore C, Johnsen S. Using RGB displays to portray color realistic imagery to animal eyes. Curr Zool 2017; 63:27-34. [PMID: 29491960 PMCID: PMC5804149 DOI: 10.1093/cz/zow076] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2016] [Revised: 02/27/2016] [Accepted: 06/03/2016] [Indexed: 11/13/2022] Open
Abstract
RGB displays effectively simulate millions of colors in the eyes of humans by modulating the relative amount of light emitted by 3 differently colored juxtaposed lights (red, green, and blue). The relationship between the ratio of red, green, and blue light and the perceptual experience of that light has been well defined by psychophysical experiments in humans, but is unknown in animals. The perceptual experience of an animal looking at an RGB display of imagery designed for humans is likely to poorly represent an animal's experience of the same stimulus in the real world. This is due, in part, to the fact that many animals have different numbers of photoreceptor classes than humans do and that their photoreceptor classes have peak sensitivities centered over different parts of the ultraviolet and visible spectrum. However, it is sometimes possible to generate videos that accurately mimic natural stimuli in the eyes of another animal, even if that animal's sensitivity extends into the ultraviolet portion of the spectrum. How independently each RGB phosphor stimulates each of an animal's photoreceptor classes determines the range of colors that can be simulated for that animal. What is required to determine optimal color rendering for another animal is a device capable of measuring absolute or relative quanta of light across the portion of the spectrum visible to the animal (i.e., a spectrometer), and data on the spectral sensitivities of the animal's photoreceptor classes. In this article, we outline how to use such equipment and information to generate video stimuli that mimic, as closely as possible, an animal's color perceptual experience of real-world objects. Key words: color vision, computer animation, perception, video playback, virtual reality.
Collapse
Affiliation(s)
- Cynthia Tedore
- Department of Biology, Lund University, Sölvegatan 35, Lund 223 62, SwedenDepartment of Biology, Duke University, Durham, 125 Science Drive, NC 27708, USA
| | - Sönke Johnsen
- Department of Biology, Lund University, Sölvegatan 35, Lund 223 62, SwedenDepartment of Biology, Duke University, Durham, 125 Science Drive, NC 27708, USA
| |
Collapse
|
42
|
Variation of outdoor illumination as a function of solar elevation and light pollution. Sci Rep 2016; 6:26756. [PMID: 27272736 PMCID: PMC4895134 DOI: 10.1038/srep26756] [Citation(s) in RCA: 86] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2016] [Accepted: 05/03/2016] [Indexed: 12/29/2022] Open
Abstract
The illumination of the environment undergoes both intensity and spectral changes during the 24 h cycle of a day. Daylight spectral power distributions are well described by low-dimensional models such as the CIE (Commission Internationale de l’Éclairage) daylight model, but the performance of this model in non-daylight regimes is not characterised. We measured downwelling spectral irradiance across multiple days in two locations in North America: One rural location (Cherry Springs State Park, PA) with minimal anthropogenic light sources, and one city location (Philadelphia, PA). We characterise the spectral, intensity and colour changes and extend the existing CIE model for daylight to capture twilight components and the spectrum of the night sky.
Collapse
|