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Blary CLM, Duriez O, Bonadonna F, Mitkus M, Caro SP, Besnard A, Potier S. Low achromatic contrast sensitivity in birds: a common attribute shared by many phylogenetic orders. J Exp Biol 2024; 227:jeb246342. [PMID: 38099472 DOI: 10.1242/jeb.246342] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2023] [Accepted: 12/06/2023] [Indexed: 02/10/2024]
Abstract
Vision is an important sensory modality in birds, which can outperform other vertebrates in some visual abilities. However, sensitivity to achromatic contrasts - the ability to discern luminance difference between two objects or an object and its background - has been shown to be lower in birds compared with other vertebrates. We conducted a comparative study to evaluate the achromatic contrast sensitivity of 32 bird species from 12 orders using the optocollic reflex technique. We then performed an analysis to test for potential variability in contrast sensitivity depending on the corneal diameter to the axial length ratio, a proxy of the retinal image brightness. To account for potential influences of evolutionary relatedness, we included phylogeny in our analyses. We found a low achromatic contrast sensitivity for all avian species studied compared with other vertebrates (except small mammals), with high variability between species. This variability is partly related to phylogeny but appears to be independent of image brightness.
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Affiliation(s)
- Constance L M Blary
- CEFE, Univ Montpellier, CNRS, EPHE, IRD, 34293 Montpellier, France
- Agence de l'environnement et de la Maîtrise de l'Energie 20, 49004 Angers Cedex 01, France
| | - Olivier Duriez
- CEFE, Univ Montpellier, CNRS, EPHE, IRD, 34293 Montpellier, France
| | | | - Mindaugas Mitkus
- Institute of Biosciences, Life Sciences Center, Vilnius University, 10257 Vilnius, Lithuania
| | - Samuel P Caro
- CEFE, Univ Montpellier, CNRS, EPHE, IRD, 34293 Montpellier, France
| | - Aurélien Besnard
- CEFE, Univ Montpellier, CNRS, EPHE PSL University, IRD, 34293 Montpellier, France
| | - Simon Potier
- Lund Vision Group, Department of Biology, Lund University, Lund 22362, Sweden
- Les Ailes de l'Urga, 27320 Marcilly la Campagne, France
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2
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Potier S, Roulin A, Martin GR, Portugal SJ, Bonhomme V, Bouchet T, de Romans R, Meyrier E, Kelber A. Binocular field configuration in owls: the role of foraging ecology. Proc Biol Sci 2023; 290:20230664. [PMID: 37848065 PMCID: PMC10581762 DOI: 10.1098/rspb.2023.0664] [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: 03/20/2023] [Accepted: 09/12/2023] [Indexed: 10/19/2023] Open
Abstract
The binocular field of vision differs widely in birds depending on ecological traits such as foraging. Owls (Strigiformes) have been considered to have a unique binocular field, but whether it is related to foraging has remained unknown. While taking into account allometry and phylogeny, we hypothesized that both daily activity cycle and diet determine the size and shape of the binocular field in owls. Here, we compared the binocular field configuration of 23 species of owls. While we found no effect of allometry and phylogeny, ecological traits strongly influence the binocular field shape and size. Binocular field shape of owls significantly differed from that of diurnal raptors. Among owls, binocular field shape was relatively conserved, but binocular field size differed among species depending on ecological traits, with larger binocular fields in species living in dense habitat and foraging on invertebrates. Our results suggest that (i) binocular field shape is associated with the time of foraging in the daily cycle (owls versus diurnal raptors) and (ii) that binocular field size differs between closely related owl species even though the general shape is conserved, possibly because the field of view is partially restricted by feathers, in a trade-off with auditory localization.
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Affiliation(s)
- Simon Potier
- Department of Biology, Lund University, Sölvegatan 35, Lund S-22362, Sweden
- Les Ailes de l'Urga, 72 rue de la vieille route, 27320 Marcilly la Campagne, France
| | - Alexandre Roulin
- Department of Ecology and Evolution, University of Lausanne, Biophore 1015, Switzerland
| | - Graham R. Martin
- School of Biosciences, University of Birmingham, Edgbaston, Birmingham B15 2TT, UK
| | - Steven J. Portugal
- Department of Biological Science, School of Life and Environmental Sciences, Royal Holloway University of London, Egham, Surrey TW20 0EX, UK
| | - Vincent Bonhomme
- ISEM, Univ Montpellier, CNRS, EPHE, IRD, 34095 Montpellier, France
- Équipe Dynamique de la biodiversité, anthropo-écologie, Place Eugène Bataillon - CC065, 34095 Montpellier Cedex 5, France
| | - Thierry Bouchet
- Académie de Fauconnerie, SAS Puy du Fou France, 85500 Les Epesses, France
| | - Romuald de Romans
- Espace Rambouillet, Office National des Forêts, route du coin du bois, 78120 Sonchamp, France
| | - Eva Meyrier
- Les Aigles du Léman, Domaine de Guidou, 74140 Sciez sur Léman, France
| | - Almut Kelber
- Department of Biology, Lund University, Sölvegatan 35, Lund S-22362, Sweden
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3
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Cantlay JC, Martin GR, McClelland SC, Potier S, O'Brien MF, Fernández-Juricic E, Bond AL, Portugal SJ. Binocular vision and foraging in ducks, geese and swans (Anatidae). Proc Biol Sci 2023; 290:20231213. [PMID: 37670586 PMCID: PMC10510447 DOI: 10.1098/rspb.2023.1213] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2023] [Accepted: 08/02/2023] [Indexed: 09/07/2023] Open
Abstract
Wide variation in visual field configuration across avian species is hypothesized to be driven primarily by foraging ecology and predator detection. While some studies of selected taxa have identified relationships between foraging ecology and binocular field characteristics in particular species, few have accounted for the relevance of shared ancestry. We conducted a large-scale, comparative analysis across 39 Anatidae species to investigate the relationship between the foraging ecology traits of diet or behaviour and binocular field parameters, while controlling for phylogeny. We used phylogenetic models to examine correlations between traits and binocular field characteristics, using unidimensional and morphometric approaches. We found that foraging behaviour influenced three parameters of binocular field size: maximum binocular field width, vertical binocular field extent, and angular separation between the eye-bill projection and the direction of maximum binocular field width. Foraging behaviour and body mass each influenced two descriptors of binocular field shape. Phylogenetic relatedness had minimal influence on binocular field size and shape, apart from vertical binocular field extent. Binocular field differences are associated with specific foraging behaviours, as related to the perceptual challenges of obtaining different food items from aquatic and terrestrial environments.
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Affiliation(s)
- Jennifer C. Cantlay
- Department of Biological Sciences, School of Life and Environmental Sciences, Royal Holloway University of London, Egham, Surrey TW20 0EX, UK
| | - Graham R. Martin
- School of Biosciences, University of Birmingham, Edgbaston, Birmingham B15 2TT, UK
| | - Stephanie C. McClelland
- Department of Biological Sciences, School of Life and Environmental Sciences, Royal Holloway University of London, Egham, Surrey TW20 0EX, UK
| | - Simon Potier
- Department of Biology, Faculty of Science, Lund University, Sölvegatan 35, 223 62 Lund, Sweden
| | | | | | - Alexander L. Bond
- Bird Group, Department of Life Sciences, The Natural History Museum, Akeman Street, Tring, Hertfordshire HP23 6AP, UK
| | - Steven J. Portugal
- Department of Biological Sciences, School of Life and Environmental Sciences, Royal Holloway University of London, Egham, Surrey TW20 0EX, UK
- Bird Group, Department of Life Sciences, The Natural History Museum, Akeman Street, Tring, Hertfordshire HP23 6AP, UK
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4
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Liu Y, Jiang Y, Xu J, Liao W. Evolution of Avian Eye Size Is Associated with Habitat Openness, Food Type and Brain Size. Animals (Basel) 2023; 13:ani13101675. [PMID: 37238105 DOI: 10.3390/ani13101675] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2023] [Revised: 05/14/2023] [Accepted: 05/16/2023] [Indexed: 05/28/2023] Open
Abstract
The eye is the primary sensory organ that obtains information from the ecological environments and specifically bridges the brain with the extra environment. However, the coevolutionary relationships between eye size and ecological factors, behaviours and brain size in birds remain poorly understood. Here, we investigate whether eye size evolution is associated with ecological factors (e.g., habitat openness, food type and foraging habitat), behaviours (e.g., migration and activity pattern) and brain size among 1274 avian species using phylogenetically controlled comparative analyses. Our results indicate that avian eye size is significantly associated with habitat openness, food type and brain size. Species living in dense habitats and consuming animals exhibit larger eye sizes compared to species living in open habitats and consuming plants, respectively. Large-brained birds tend to possess larger eyes. However, migration, foraging habitat and activity pattern were not found to be significantly associated with eye size in birds, except for nocturnal birds having longer axial lengths than diurnal ones. Collectively, our results suggest that avian eye size is primarily influenced by light availability, food need and cognitive ability.
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Affiliation(s)
- Yating Liu
- School of Ecology and Nature Conservation, Beijing Forestry University, Beijing 100083, China
| | - Ying Jiang
- School of Ecology and Nature Conservation, Beijing Forestry University, Beijing 100083, China
| | - Jiliang Xu
- School of Ecology and Nature Conservation, Beijing Forestry University, Beijing 100083, China
| | - Wenbo Liao
- Key Laboratory of Southwest China Wildlife Resources Conservation (Ministry of Education), China West Normal University, Nanchong 637009, China
- Key Laboratory of Artificial Propagation and Utilization in Anurans of Nanchong City, China West Normal University, Nanchong 637009, China
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5
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Cunha F, Gutiérrez-Ibáñez C, Brinkman B, Wylie DR, Iwaniuk AN. The relative sizes of nuclei in the oculomotor complex vary by order and behaviour in birds. J Comp Physiol A Neuroethol Sens Neural Behav Physiol 2022; 209:341-360. [PMID: 36522507 DOI: 10.1007/s00359-022-01598-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2022] [Revised: 10/26/2022] [Accepted: 11/25/2022] [Indexed: 12/23/2022]
Abstract
Eye movements are a critical component of visually guided behaviours, allowing organisms to scan the environment and bring stimuli of interest to regions of acuity in the retina. Although the control and modulation of eye movements by cranial nerve nuclei are highly conserved across vertebrates, species variation in visually guided behaviour and eye morphology could lead to variation in the size of oculomotor nuclei. Here, we test for differences in the size and neuron numbers of the oculomotor nuclei among birds that vary in behaviour and eye morphology. Using unbiased stereology, we measured the volumes and numbers of neurons of the oculomotor (nIII), trochlear (nIV), abducens (nVI), and Edinger-Westphal (EW) nuclei across 71 bird species and analysed these with phylogeny-informed statistics. Owls had relatively smaller nIII, nIV, nVI and EW nuclei than other birds, which reflects their limited degrees of eye movements. In contrast, nVI was relatively larger in falcons and hawks, likely reflecting how these predatory species must shift focus between the central and temporal foveae during foraging and prey capture. Unexpectedly, songbirds had an enlarged EW and relatively more nVI neurons, which might reflect accommodation and horizontal eye movements. Finally, the one merganser we measured also has an enlarged EW, which is associated with the high accommodative power needed for pursuit diving. Overall, these differences reflect species and clade level variation in behaviour, but more data are needed on eye movements in birds across species to better understand the relationships among behaviour, retinal anatomy, and brain anatomy.
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Affiliation(s)
- Felipe Cunha
- Department of Neuroscience, University of Lethbridge, 4401 University Dr W, Lethbridge, AB, T1K 3M4, Canada
| | | | - Benjamin Brinkman
- Department of Neuroscience, University of Lethbridge, 4401 University Dr W, Lethbridge, AB, T1K 3M4, Canada
| | - Douglas R Wylie
- Department of Biological Sciences, University of Alberta, Edmonton, AB, Canada
| | - Andrew N Iwaniuk
- Department of Neuroscience, University of Lethbridge, 4401 University Dr W, Lethbridge, AB, T1K 3M4, Canada.
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6
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Perea-García JO, Ramarajan K, Kret ME, Hobaiter C, Monteiro A. Ecological factors are likely drivers of eye shape and colour pattern variations across anthropoid primates. Sci Rep 2022; 12:17240. [PMID: 36243745 PMCID: PMC9569326 DOI: 10.1038/s41598-022-20900-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2022] [Accepted: 09/20/2022] [Indexed: 01/06/2023] Open
Abstract
External eye appearance across primate species is diverse in shape and colouration, yet we still lack an explanation for the drivers of such diversity. Here we quantify substantial interspecific variation in eye shape and colouration across 77 primate species representing all extant genera of anthropoid primates. We reassess a series of hypotheses aiming to explain ocular variation in horizontal elongation and in colouration across species. Heavier body weight and terrestrial locomotion are associated with elongated eye outlines. Species living closer to the equator present more pigmented conjunctivae, suggesting photoprotective functions. Irises become bluer in species living further away from the equator, adding to existing literature supporting a circadian clock function for bluer irises. These results shift the current focus from communicative, to ecological factors in driving variation in external eye appearance in anthropoid primates. They also highlight the possibility that similar ecological factors contributed to selection for blue eyes in ancestral human populations living in northern latitudes.
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Affiliation(s)
- Juan Olvido Perea-García
- grid.4280.e0000 0001 2180 6431Department of Biological Sciences, National University of Singapore, Singapore, 117557 Singapore ,grid.5132.50000 0001 2312 1970Institute of Psychology, Cognitive Psychology Unit, Leiden University, Wassenaarseweg 52, 2333 AK Leiden, The Netherlands
| | - Kokulanantha Ramarajan
- grid.462738.c0000 0000 9091 4551School of Applied Sciences, Republic Polytechnic, Singapore, Singapore
| | - Mariska E. Kret
- grid.5132.50000 0001 2312 1970Institute of Psychology, Cognitive Psychology Unit, Leiden University, Wassenaarseweg 52, 2333 AK Leiden, The Netherlands
| | - Catherine Hobaiter
- grid.11914.3c0000 0001 0721 1626Centre for Social Learning and Cognitive Evolution and Scottish Primate Research Group, School of Psychology and Neuroscience, University of St Andrews, Fife, Scotland, UK
| | - Antónia Monteiro
- grid.4280.e0000 0001 2180 6431Department of Biological Sciences, National University of Singapore, Singapore, 117557 Singapore ,grid.463064.30000 0004 4651 0380Science Division, Yale-NUS College, Singapore, Singapore
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Luo H, Luo S, Fang W, Lin Q, Chen X, Zhou X. Genomic insight into the nocturnal adaptation of the black-crowned night heron (Nycticorax nycticorax). BMC Genomics 2022; 23:683. [PMID: 36192687 PMCID: PMC9531477 DOI: 10.1186/s12864-022-08904-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2022] [Accepted: 09/20/2022] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The black-crowned night heron (Nycticorax nycticorax) is an ardeid bird successfully adapted to the nocturnal environment. Previous studies had indicated that the eyes of the night herons have evolved several specialized morphological traits favoring nocturnal vision. However, the molecular mechanisms of the nocturnal vision adaptation of night herons remained inattentions. In this study, the whole genome of N. nycticorax was sequenced and comparative analyses were performed on the vision-related and olfactory receptor (OR) genes to understand the molecular mechanisms of the visual and olfactory adaptation of night herons. RESULTS The results indicated that a number of vision genes were under positive or relaxed selection in N. nycticorax, whereas a number of other vision genes were under relaxed or intensified selection in the boat-billed heron (Cochlearius cochlearius), which suggested that the two species adapt to nocturnality with different genetic mechanisms. The different selections acting on vision genes are probably associated with the enlargement of eye size and the enhancement of visual sensitivity in night herons. The analyses on olfactory receptor (OR) genes indicated that the total number of OR genes in the genomes of N. nycticorax and C. cochlearius were about half those in the little egret (Egretta garzetta), whereas the diversity of their OR genes was not remarkably different. Additionally, the number of expressed OR genes in the transcriptomes of N. nycticorax was also fewer than that in E. garzetta. These results suggest a reduced olfactory capability in night herons compared with E. garzetta. CONCLUSIONS Our results provided evidence that several vision genes of the night herons were subjected to different natural selections, which can contribute to a better understanding of the genetic mechanisms of visual adaptions of the night heron. In addition, the finding of the reduced number of total and expressed OR genes in night herons may reflect a trade-off between olfaction and vision.
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Affiliation(s)
- Haoran Luo
- Key Laboratory of Ministry of Education for Coastal and Wetland Ecosystems, College of the Environment and Ecology, Xiamen University, Xiamen, 361102, People's Republic of China
| | - Site Luo
- Key Laboratory of Ministry of Education for Coastal and Wetland Ecosystems, College of the Environment and Ecology, Xiamen University, Xiamen, 361102, People's Republic of China
| | - Wenzhen Fang
- Key Laboratory of Ministry of Education for Coastal and Wetland Ecosystems, College of the Environment and Ecology, Xiamen University, Xiamen, 361102, People's Republic of China
| | - Qingxian Lin
- Key Laboratory of Ministry of Education for Coastal and Wetland Ecosystems, College of the Environment and Ecology, Xiamen University, Xiamen, 361102, People's Republic of China
| | - Xiaolin Chen
- Key Laboratory of Ministry of Education for Coastal and Wetland Ecosystems, College of the Environment and Ecology, Xiamen University, Xiamen, 361102, People's Republic of China.
| | - Xiaoping Zhou
- Key Laboratory of Ministry of Education for Coastal and Wetland Ecosystems, College of the Environment and Ecology, Xiamen University, Xiamen, 361102, People's Republic of China.
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Zehtabvar O, Masoudifard M, Ekim O, Ghorbani F, Davudypoor S, Memarian I, Zarghami Dastjerdi P. Anatomical study of the scleral ring and eyeball of the long-eared owl (Asio otus) with anatomical methods and diagnostic imaging techniques. Vet Med Sci 2022; 8:1735-1749. [PMID: 35506884 PMCID: PMC9297753 DOI: 10.1002/vms3.823] [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] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The scleral ring in birds consists of ossicles that are fixed as small plates by cartilage joints and have no articulation to other parts of the skeleton. OBJECTIVE Due to inadequate examination of the scleral ring anatomy and its specific form in owls, this study aimed to investigate the exact structure of the scleral ring and some morphometric characteristics of the eyeball in a long-eared owl (Asio otus). METHODS The eyes of 20 alive and 10 dead male and female owls were examined. In addition to common anatomical methods, computed tomography scans and radiographic and ultrasonographic imaging techniques were used in this study. RESULTS The structure consisted of 15 ossicles. In the ventral part of the ring, these tubercles were observed in the scleral rings of all owls; in each ring, there were four bones with these tubercles. Additionally, there was no significant difference between the left and right eye parameters. Most ocular parameters in female owls were larger than those in males, but in the case of some parameters, such as optic nerve length and optic nerve sheath diameter, this difference was not observed. CONCLUSIONS According to this study, the scleral ring in the Asio otus has anterior and posterior parts, and the lens is in the immediate vicinity of the anterior part. The right and left scleral rings and eyeballs are bilaterally symmetrical in terms of the shape, size, and number of ossicles that form the ring.
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Affiliation(s)
- Omid Zehtabvar
- Anatomy Sector, Department of Basic Sciences, Faculty of Veterinary Medicine, University of Tehran, Tehran, Iran
| | - Majid Masoudifard
- Department of Surgery and Radiology, Faculty of Veterinary Medicine, University of Tehran, Tehran, Iran
| | - Okan Ekim
- Department of Anatomy, Faculty of Veterinary Medicine, Ankara University, Ankara, Turkey
| | - Faezeh Ghorbani
- Veterinary Radiologist, DVM, DVSc, Graduated from Faculty of Veterinary Medicine, University of Tehran, Tehran, Iran.,Graduated DVM Student, Faculty of Veterinary Medicine, University of Tehran, Tehran, Iran
| | - Somaye Davudypoor
- Veterinary Radiologist, DVM, DVSc, Graduated from Faculty of Veterinary Medicine, University of Tehran, Tehran, Iran
| | - Iman Memarian
- FPWC (Foundation for the Preservation of Wildlife Cultural Assets), IAR (International Animal Rescue), Felid Tag, Deer Tag, Persian Leopard and Cat Specialist Group (IUCN) Veterin Advisor, Tehran, Iran
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9
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Keirnan A, Worthy TH, Smaers JB, Mardon K, Iwaniuk AN, Weisbecker V. Not like night and day: the nocturnal letter-winged kite does not differ from diurnal congeners in orbit or endocast morphology. ROYAL SOCIETY OPEN SCIENCE 2022; 9:220135. [PMID: 35620001 PMCID: PMC9128852 DOI: 10.1098/rsos.220135] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/13/2022] [Accepted: 04/29/2022] [Indexed: 05/03/2023]
Abstract
Nocturnal birds display diverse adaptations of the visual system to low-light conditions. The skulls of birds reflect many of these and are used increasingly to infer nocturnality in extinct species. However, it is unclear how reliable such assessments are, particularly in cases of recent evolutionary transitions to nocturnality. Here, we investigate a case of recently evolved nocturnality in the world's only nocturnal hawk, the letter-winged kite Elanus scriptus. We employed phylogenetically informed analyses of orbit, optic foramen and endocast measurements from three-dimensional reconstructions of micro-computed tomography scanned skulls of the letter-winged kite, two congeners, and 13 other accipitrid and falconid raptors. Contrary to earlier suggestions, the letter-winged kite was not unique in any of our metrics. However, all species of Elanus have significantly higher ratios of orbit versus optic foramen diameter, suggesting high visual sensitivity at the expense of acuity. In addition, visual system morphology varies greatly across accipitrid species, likely reflecting hunting styles. Overall, our results suggest that the transition to nocturnality can occur rapidly and without changes to key hard-tissue indicators of vision, but also that hard-tissue anatomy of the visual system may provide a means of inferring a range of raptor behaviours, well beyond nocturnality.
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Affiliation(s)
- Aubrey Keirnan
- College of Science and Engineering, Flinders University, Adelaide, SA, Australia
| | - Trevor H. Worthy
- College of Science and Engineering, Flinders University, Adelaide, SA, Australia
| | | | - Karine Mardon
- Centre of Advanced Imaging, The University of Queensland, St. Lucia, QLD, Australia
| | - Andrew N. Iwaniuk
- Department of Neuroscience, University of Lethbridge, Lethbridge, Alberta, Canada
| | - Vera Weisbecker
- College of Science and Engineering, Flinders University, Adelaide, SA, Australia
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10
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Early evolution of diurnal habits in owls (Aves, Strigiformes) documented by a new and exquisitely preserved Miocene owl fossil from China. Proc Natl Acad Sci U S A 2022; 119:e2119217119. [PMID: 35344399 PMCID: PMC9169863 DOI: 10.1073/pnas.2119217119] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
SignificanceOwls, with their largely nocturnal habits, contrast strikingly with the vast majority of diurnal birds. A new spectacular late Miocene owl skeleton from China unexpectedly preserves the oldest evidence for daytime behavior in owls. The extinct owl is a member of the clade Surniini, which contains most living diurnal owl species. Analysis of the preserved eye bones documents them as consistent with diurnal birds, and phylogenetically constrained character mapping coincides with a reconstruction of an early evolutionary reversal away from nocturnal habits in this owl group. These results support a potential Miocene origin of nonnocturnal habits in a globally distributed owl group, which may be linked to steppe habitat expansion and climatic cooling in the late Miocene.
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11
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Currea JP, Frazer R, Wasserman SM, Theobald J. Acuity and summation strategies differ in vinegar and desert fruit flies. iScience 2022; 25:103637. [PMID: 35028530 PMCID: PMC8741510 DOI: 10.1016/j.isci.2021.103637] [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: 05/07/2021] [Revised: 09/16/2021] [Accepted: 12/14/2021] [Indexed: 11/11/2022] Open
Abstract
An animal's vision depends on terrain features that limit the amount and distribution of available light. Approximately 10,000 years ago, vinegar flies (Drosophila melanogaster) transitioned from a single plant specialist into a cosmopolitan generalist. Much earlier, desert flies (D. mojavensis) colonized the New World, specializing on rotting cactuses in southwest North America. Their desert habitats are characteristically flat, bright, and barren, implying environmental differences in light availability. Here, we demonstrate differences in eye morphology and visual motion perception under three ambient light levels. Reducing ambient light from 35 to 18 cd/m2 causes sensitivity loss in desert but not vinegar flies. However, at 3 cd/m2, desert flies sacrifice spatial and temporal acuity more severely than vinegar flies to maintain contrast sensitivity. These visual differences help vinegar flies navigate under variably lit habitats around the world and desert flies brave the harsh desert while accommodating their crepuscular lifestyle.
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Affiliation(s)
- John P. Currea
- Department of Psychology, Florida International University, Miami, FL 33199, USA
| | - Rachel Frazer
- Division of Neurobiology and Behavior, Columbia University, New York, NY 10027, USA
| | - Sara M. Wasserman
- Department of Neuroscience, Wellesley College, Wellesley, MA 02481, USA
| | - Jamie Theobald
- Department of Biological Sciences, Florida International University, Miami, FL 33199, USA
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12
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Tocco C, Dacke M, Byrne M. The finely defined shift work schedule of dung beetles and their eye morphology. Ecol Evol 2021; 11:15947-15960. [PMID: 34824802 PMCID: PMC8601928 DOI: 10.1002/ece3.8264] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2021] [Revised: 10/04/2021] [Accepted: 10/07/2021] [Indexed: 11/20/2022] Open
Abstract
In nature, nothing is wasted, not even waste. Dung, composed of metabolic trash and leftovers of food, is a high-quality resource and the object of fierce competition. Over 800 dung beetle species (Scarabaeinae) compete in the South African dung habitat and more than 100 species can colonize a single dung pat. To coexist in the same space, using the same food, beetles divide the day between them. However, detailed diel activity periods and associated morphological adaptations have been largely overlooked in these dung-loving insects. To address this, we used a high-frequency trapping design to establish the diel activity period of 44 dung beetle species in their South Africa communities. This allowed us to conclude that the dung beetles show a highly refined temporal partitioning strategy, with differences in peak of activity even within the diurnal, crepuscular, and nocturnal guilds, independent of nesting behavior and taxonomic classification. We further analyzed differences in eye and body size of our 44 model species and describe their variability in external eye morphology. In general, nocturnal species are bigger than crepuscular and diurnal species, and as expected, the absolute and relative eye size is greatest in nocturnal species, followed by crepuscular and then diurnal species. A more surprising finding was that corneal structure (smooth or facetted) is influenced by the activity period of the species, appearing flat in the nocturnal species and highly curved in the diurnal species. The role of the canthus-a cuticular structure that partially or completely divides the dung beetle eye into dorsal and ventral parts-remains a mystery, but the large number of species investigated in this study nevertheless allowed us to reject any correlation between its presence and the nesting behavior or time of activity of the beetles.
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Affiliation(s)
- Claudia Tocco
- Lund Vision GroupDepartment of BiologyLund UniversityLundSweden
- School of Animal, Plant and Environmental SciencesUniversity of the WitwatersrandWits, JohannesburgSouth Africa
| | - Marie Dacke
- Lund Vision GroupDepartment of BiologyLund UniversityLundSweden
- School of Animal, Plant and Environmental SciencesUniversity of the WitwatersrandWits, JohannesburgSouth Africa
| | - Marcus Byrne
- School of Animal, Plant and Environmental SciencesUniversity of the WitwatersrandWits, JohannesburgSouth Africa
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13
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Lisney TJ, Potier S, Isard PF, Mentek M, Mitkus M, Collin SP. Retinal topography in two species of flamingo (Phoenicopteriformes: Phoenicopteridae). J Comp Neurol 2020; 528:2848-2863. [PMID: 32154931 DOI: 10.1002/cne.24902] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2019] [Revised: 02/21/2020] [Accepted: 02/24/2020] [Indexed: 11/11/2022]
Abstract
In this study, we assessed eye morphology and retinal topography in two flamingo species, the Caribbean flamingo (Phoenicopterus ruber) and the Chilean flamingo (P. chilensis). Eye morphology is similar in both species and cornea size relative to eye size (C:A ratio) is intermediate between those previously reported for diurnal and nocturnal birds. Using stereology and retinal whole mounts, we estimate that the total number of Nissl-stained neurons in the retinal ganglion cell (RGC) layer in the Caribbean and Chilean flamingo is ~1.70 and 1.38 million, respectively. Both species have a well-defined visual streak with a peak neuron density of between 13,000 and 16,000 cells mm-2 located in a small central area. Neurons in the high-density regions are smaller and more homogeneous compared to those in medium- and low-density regions. Peak anatomical spatial resolving power in both species is approximately 10-11 cycles/deg. En-face images of the fundus in live Caribbean flamingos acquired using spectral domain optical coherence tomography (SD-OCT) revealed a thin, dark band running nasotemporally just dorsal to the pecten, which aligned with the visual streak in the retinal topography maps. Cross-sectional images (B-scans) obtained with SD-OCT showed that this dark band corresponds with an area of retinal thickening compared to adjacent areas. Neither the retinal whole mounts, nor the SD-OCT imaging revealed any evidence of a central fovea in either species. Overall, we suggest that eye morphology and retinal topography in flamingos reflects their cathemeral activity pattern and the physical nature of the habitats in which they live.
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Affiliation(s)
- Thomas J Lisney
- Oceans Graduate School, The University of Western Australia, Perth, Western Australia, Australia.,The Oceans Institute, The University of Western Australia, Perth, Western Australia, Australia.,CEFE UMR 5175, CNRS-Université de Montpellier-Université Paul-Valéry Montpellier-EPHE, Montpellier, France
| | - Simon Potier
- Department of Biology, Lund University, Lund, Sweden
| | - Pierre-François Isard
- Unité d'Ophtalmologie, Centre Hospitalier Vétérinaire, Saint-Martin-Bellevue, France
| | - Marielle Mentek
- Unité d'Ophtalmologie, Centre Hospitalier Vétérinaire, Saint-Martin-Bellevue, France
| | - Mindaugas Mitkus
- Department of Biology, Lund University, Lund, Sweden.,Institute of Biosciences, Life Sciences Center, Vilnius University, Vilnius, Lithuania
| | - Shaun P Collin
- Oceans Graduate School, The University of Western Australia, Perth, Western Australia, Australia.,The Oceans Institute, The University of Western Australia, Perth, Western Australia, Australia.,School of Life Sciences, La Trobe University, Bundoora, Victoria, Australia
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14
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Espíndola-Hernández P, Mueller JC, Carrete M, Boerno S, Kempenaers B. Genomic Evidence for Sensorial Adaptations to a Nocturnal Predatory Lifestyle in Owls. Genome Biol Evol 2020; 12:1895-1908. [PMID: 32770228 PMCID: PMC7566403 DOI: 10.1093/gbe/evaa166] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/05/2020] [Indexed: 12/17/2022] Open
Abstract
Owls (Strigiformes) evolved specific adaptations to their nocturnal predatory lifestyle, such as asymmetrical ears, a facial disk, and a feather structure allowing silent flight. Owls also share some traits with diurnal raptors and other nocturnal birds, such as cryptic plumage patterns, reversed sexual size dimorphism, and acute vision and hearing. The genetic basis of some of these adaptations to a nocturnal predatory lifestyle has been studied by candidate gene approaches but rarely with genome-wide scans. Here, we used a genome-wide comparative analysis to test for selection in the early history of the owls. We estimated the substitution rates in the coding regions of 20 bird genomes, including 11 owls of which five were newly sequenced. Then, we tested for functional overrepresentation across the genes that showed signals of selection. In the ancestral branch of the owls, we found traces of positive selection in the evolution of genes functionally related to visual perception, especially to phototransduction, and to chromosome packaging. Several genes that have been previously linked to acoustic perception, circadian rhythm, and feather structure also showed signals of an accelerated evolution in the origin of the owls. We discuss the functions of the genes under positive selection and their putative association with the adaptation to the nocturnal predatory lifestyle of the owls.
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Affiliation(s)
- Pamela Espíndola-Hernández
- Department of Behavioural Ecology and Evolutionary Genetics, Max Planck Institute for Ornithology, Seewiesen, Germany
| | - Jakob C Mueller
- Department of Behavioural Ecology and Evolutionary Genetics, Max Planck Institute for Ornithology, Seewiesen, Germany
| | - Martina Carrete
- Department of Physical, Chemical and Natural Systems, Universidad Pablo de Olavide, Sevilla, Spain
| | - Stefan Boerno
- Sequencing Core Facility, Max Planck Institute for Molecular Genetics, Berlin, Germany
| | - Bart Kempenaers
- Department of Behavioural Ecology and Evolutionary Genetics, Max Planck Institute for Ornithology, Seewiesen, Germany
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15
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Visual adaptations of diurnal and nocturnal raptors. Semin Cell Dev Biol 2020; 106:116-126. [DOI: 10.1016/j.semcdb.2020.05.004] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2020] [Revised: 05/06/2020] [Accepted: 05/06/2020] [Indexed: 02/06/2023]
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16
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Lisney TJ, Collin SP, Kelley JL. The effect of ecological factors on eye morphology in the western rainbowfish, Melanotaenia australis. J Exp Biol 2020; 223:jeb223644. [PMID: 32321751 DOI: 10.1242/jeb.223644] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2020] [Accepted: 04/12/2020] [Indexed: 11/20/2022]
Abstract
Ecological factors such as spatial habitat complexity and diet can explain variation in visual morphology, but few studies have sought to determine whether visual specialisation can occur among populations of the same species. We used a small Australian freshwater fish (the western rainbowfish, Melanotaenia australis) to determine whether populations showed variation in eye size and eye position, and whether this variation could be explained by environmental (light availability, turbidity) and ecological (predation risk, habitat complexity, invertebrate abundance) variables. We investigated three aspects of eye morphology - (1) eye size relative to body size, (2) pupil size relative to eye size and (3) eye position in the head - for fish collected from 14 sites in a major river catchment in northwest Western Australia. We found significant variation among populations in all three measures of eye morphology, but no effect of sex on eye size or eye position. Variation in eye diameter and eye position was best explained by the level of habitat complexity. Specifically, fish occurring in habitats with low complexity (i.e. open water) tended to have smaller, more dorsally located eyes than those occurring in more complex habitats (i.e. vegetation present). The size of the pupil relative to the size of the eye was most influenced by the presence of surrounding rock formations; fish living in gorge habitats had significantly smaller pupils (relative to eye size) than those occupying semi-gorge sites or open habitats. Our findings reveal that different ecological and environmental factors contribute to habitat-specific visual specialisations within a species.
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Affiliation(s)
- Thomas J Lisney
- Oceans Graduate School, The University of Western Australia, 35 Stirling Highway, Crawley, WA 6009, Australia
- The Oceans Institute (M470), The University of Western Australia, 35 Stirling Highway, Crawley, WA 6009, Australia
| | - Shaun P Collin
- Oceans Graduate School, The University of Western Australia, 35 Stirling Highway, Crawley, WA 6009, Australia
- The Oceans Institute (M470), The University of Western Australia, 35 Stirling Highway, Crawley, WA 6009, Australia
- School of Life Sciences, La Trobe University, Bundoora, VIC 3086, Australia
| | - Jennifer L Kelley
- School of Biological Sciences (M092), The University of Western Australia, 35 Stirling Highway, Crawley, WA 6009, Australia
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17
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Iwaniuk AN, Wylie DR. Sensory systems in birds: What we have learned from studying sensory specialists. J Comp Neurol 2020; 528:2902-2918. [PMID: 32133638 DOI: 10.1002/cne.24896] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2019] [Revised: 02/09/2020] [Accepted: 02/17/2020] [Indexed: 12/27/2022]
Abstract
"Diversity" is an apt descriptor of the research career of Jack Pettigrew as it ranged from the study of trees, to clinical conditions, to sensory neuroscience. Within sensory neuroscience, he was fascinated by the evolution of sensory systems across species. Here, we review some of his work on avian sensory specialists and research that he inspired in others. We begin with an overview of the importance of the Wulst in stereopsis and the need for further study of the Wulst in relation to binocularity across avian species. Next, we summarize recent anatomical, behavioral, and physiological studies on optic flow specializations in hummingbirds. Beyond vision, we discuss the first evidence of a tactile "fovea" in birds and how this led to detailed studies of tactile specializations in waterfowl and sensorimotor systems in parrots. We then describe preliminary studies by Pettigrew of two endemic Australian species, the plains-wanderer (Pedionomus torquatus) and letter-winged kite (Elanus scriptus), that suggest the evolution of some unique auditory and visual specializations in relation to their unique behavior and ecology. Finally, we conclude by emphasizing the importance of a comparative and integrative approach to understanding avian sensory systems and provide an example of one system that has yet to be properly examined: tactile facial bristles in birds. Through reviewing this research and offering future avenues for discovery, we hope that others also embrace the comparative approach to understanding sensory system evolution in birds and other vertebrates.
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Affiliation(s)
- Andrew N Iwaniuk
- Department of Neuroscience, University of Lethbridge, Lethbridge, Alberta, Canada
| | - Douglas R Wylie
- Department of Biological Sciences, University of Alberta, Edmonton, Alberta, Canada
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18
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Borges R, Fonseca J, Gomes C, Johnson WE, O'Brien SJ, Zhang G, Gilbert MTP, Jarvis ED, Antunes A. Avian Binocularity and Adaptation to Nocturnal Environments: Genomic Insights from a Highly Derived Visual Phenotype. Genome Biol Evol 2020; 11:2244-2255. [PMID: 31386143 PMCID: PMC6735850 DOI: 10.1093/gbe/evz111] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/20/2019] [Indexed: 01/04/2023] Open
Abstract
Typical avian eyes are phenotypically engineered for photopic vision (daylight). In contrast, the highly derived eyes of the barn owl (Tyto alba) are adapted for scotopic vision (dim light). The dramatic modifications distinguishing barn owl eyes from other birds include: 1) shifts in frontal orientation to improve binocularity, 2) rod-dominated retina, and 3) enlarged corneas and lenses. Some of these features parallel mammalian eye patterns, which are hypothesized to have initially evolved in nocturnal environments. Here, we used an integrative approach combining phylogenomics and functional phenotypes of 211 eye-development genes across 48 avian genomes representing most avian orders, including the stem lineage of the scotopic-adapted barn owl. Overall, we identified 25 eye-development genes that coevolved under intensified or relaxed selection in the retina, lens, cornea, and optic nerves of the barn owl. The agtpbp1 gene, which is associated with the survival of photoreceptor populations, was pseudogenized in the barn owl genome. Our results further revealed that barn owl retinal genes responsible for the maintenance, proliferation, and differentiation of photoreceptors experienced an evolutionary relaxation. Signatures of relaxed selection were also observed in the lens and cornea morphology-associated genes, suggesting that adaptive evolution in these structures was essentially structural. Four eye-development genes (ephb1, phactr4, prph2, and rs1) evolved in positive association with the orbit convergence in birds and under relaxed selection in the barn owl lineage, likely contributing to an increased reliance on binocular vision in the barn owl. Moreover, we found evidence of coevolutionary interactions among genes that are expressed in the retina, lens, and optic nerve, suggesting synergetic adaptive events. Our study disentangles the genomic changes governing the binocularity and low-light perception adaptations of barn owls to nocturnal environments while revealing the molecular mechanisms contributing to the shift from the typical avian photopic vision to the more-novel scotopic-adapted eye.
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Affiliation(s)
- Rui Borges
- CIIMAR/CIMAR, Interdisciplinary Centre of Marine and Environmental Research, University of Porto, Portugal.,Department of Biology, Faculty of Sciences, University of Porto, Portugal
| | - João Fonseca
- CIIMAR/CIMAR, Interdisciplinary Centre of Marine and Environmental Research, University of Porto, Portugal
| | - Cidália Gomes
- CIIMAR/CIMAR, Interdisciplinary Centre of Marine and Environmental Research, University of Porto, Portugal
| | - Warren E Johnson
- Smithsonian Conservation Biology Institute, National Zoological Park, Front Royal, Virginia.,Walter Reed Biosystematics Unit, Smithsonian Institution, Suitland, Maryland
| | - Stephen J O'Brien
- Theodosius Dobzhansky Center for Genome Bioinformatics, St. Petersburg State University, Russia.,Guy Harvey Oceanographic Center, Halmos College of Natural Sciences and Oceanography, Nova Southeastern University
| | - Guojie Zhang
- Section for Ecology and Evolution, Department of Biology, University of Copenhagen, Denmark.,China National GeneBank, BGI-Shenzen, Shenzhen, China.,State Key Laboratory of Genetic Resources and Evolution, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, China
| | - M Thomas P Gilbert
- Centre for GeoGenetics, Natural History Museum of Denmark, University of Copenhagen, Denmark
| | - Erich D Jarvis
- Laboratory of Neurogenetics of Language, Rockefeller University.,Howard Hughes Medical Institute, Chevy Chase, Maryland
| | - Agostinho Antunes
- CIIMAR/CIMAR, Interdisciplinary Centre of Marine and Environmental Research, University of Porto, Portugal.,Department of Biology, Faculty of Sciences, University of Porto, Portugal
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19
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Vasconcelos FTGRD, Naman MJV, Hauzman E, Baron J, Fix Ventura D, Bonci DMO. LWS visual pigment in owls: Spectral tuning inferred by genetics. Vision Res 2019; 165:90-97. [DOI: 10.1016/j.visres.2019.10.001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2018] [Revised: 09/30/2019] [Accepted: 10/03/2019] [Indexed: 11/30/2022]
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20
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Baden T, Euler T, Berens P. Understanding the retinal basis of vision across species. Nat Rev Neurosci 2019; 21:5-20. [PMID: 31780820 DOI: 10.1038/s41583-019-0242-1] [Citation(s) in RCA: 143] [Impact Index Per Article: 28.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/22/2019] [Indexed: 12/12/2022]
Abstract
The vertebrate retina first evolved some 500 million years ago in ancestral marine chordates. Since then, the eyes of different species have been tuned to best support their unique visuoecological lifestyles. Visual specializations in eye designs, large-scale inhomogeneities across the retinal surface and local circuit motifs mean that all species' retinas are unique. Computational theories, such as the efficient coding hypothesis, have come a long way towards an explanation of the basic features of retinal organization and function; however, they cannot explain the full extent of retinal diversity within and across species. To build a truly general understanding of vertebrate vision and the retina's computational purpose, it is therefore important to more quantitatively relate different species' retinal functions to their specific natural environments and behavioural requirements. Ultimately, the goal of such efforts should be to build up to a more general theory of vision.
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Affiliation(s)
- Tom Baden
- Sussex Neuroscience, School of Life Sciences, University of Sussex, Brighton, UK. .,Institute for Ophthalmic Research, University of Tübingen, Tübingen, Germany.
| | - Thomas Euler
- Institute for Ophthalmic Research, University of Tübingen, Tübingen, Germany.,Werner Reichardt Centre for Integrative Neuroscience, University of Tübingen, Tübingen, Germany
| | - Philipp Berens
- Institute for Ophthalmic Research, University of Tübingen, Tübingen, Germany.,Werner Reichardt Centre for Integrative Neuroscience, University of Tübingen, Tübingen, Germany.,Institute for Bioinformatics and Medical Informatics, University of Tübingen, Tübingen, Germany.,Bernstein Centre for Computational Neuroscience, University of Tübingen, Tübingen, Germany
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21
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Salazar J, Severin D, Vega-Zuniga T, Fernández-Aburto P, Deichler A, Sallaberry A. M, Mpodozis J. Anatomical Specializations Related to Foraging in the Visual System of a Nocturnal Insectivorous Bird, the Band-Winged Nightjar (Aves: Caprimulgiformes). BRAIN, BEHAVIOR AND EVOLUTION 2019; 94:27-36. [DOI: 10.1159/000504162] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/14/2019] [Accepted: 10/15/2019] [Indexed: 11/19/2022]
Abstract
Nocturnal animals that rely on their visual system for foraging, mating, and navigation usually exhibit specific traits associated with living in scotopic conditions. Most nocturnal birds have several visual specializations, such as enlarged eyes and an increased orbital convergence. However, the actual role of binocular vision in nocturnal foraging is still debated. Nightjars (Aves: Caprimulgidae) are predators that actively pursue and capture flying insects in crepuscular and nocturnal environments, mainly using a conspicuous “sit-and-wait” tactic on which pursuit begins with an insect flying over the bird that sits on the ground. In this study, we describe the visual system of the band-winged nightjar (Systellura longirostris), with emphasis on anatomical features previously described as relevant for nocturnal birds. Orbit convergence, determined by 3D scanning of the skull, was 73.28°. The visual field, determined by ophthalmoscopic reflex, exhibits an area of maximum binocular overlap of 42°, and it is dorsally oriented. The eyes showed a nocturnal-like normalized corneal aperture/axial length index. Retinal ganglion cells (RGCs) were relatively scant, and distributed in an unusual oblique-band pattern, with higher concentrations in the ventrotemporal quadrant. Together, these results indicate that the band-winged nightjar exhibits a retinal specialization associated with the binocular area of their dorsal visual field, a relevant area for pursuit triggering and prey attacks. The RGC distribution observed is unusual among birds, but similar to that of some visually dependent insectivorous bats, suggesting that those features might be convergent in relation to feeding strategies.
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22
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Martin GR. What Drives Bird Vision? Bill Control and Predator Detection Overshadow Flight. Front Neurosci 2017; 11:619. [PMID: 29163020 PMCID: PMC5682009 DOI: 10.3389/fnins.2017.00619] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2017] [Accepted: 10/23/2017] [Indexed: 11/27/2022] Open
Abstract
Although flight is regarded as a key behavior of birds this review argues that the perceptual demands for its control are met within constraints set by the perceptual demands of two other key tasks: the control of bill (or feet) position, and the detection of food items/predators. Control of bill position, or of the feet when used in foraging, and timing of their arrival at a target, are based upon information derived from the optic flow-field in the binocular region that encompasses the bill. Flow-fields use information extracted from close to the bird using vision of relatively low spatial resolution. The detection of food items and predators is based upon information detected at a greater distance and depends upon regions in the retina with relatively high spatial resolution. The tasks of detecting predators and of placing the bill (or feet) accurately, make contradictory demands upon vision and these have resulted in trade-offs in the form of visual fields and in the topography of retinal regions in which spatial resolution is enhanced, indicated by foveas, areas, and high ganglion cell densities. The informational function of binocular vision in birds does not lie in binocularity per se (i.e., two eyes receiving slightly different information simultaneously about the same objects) but in the contralateral projection of the visual field of each eye. This ensures that each eye receives information from a symmetrically expanding optic flow-field centered close to the direction of the bill, and from this the crucial information of direction of travel and time-to-contact can be extracted, almost instantaneously. Interspecific comparisons of visual fields between closely related species have shown that small differences in foraging techniques can give rise to different perceptual challenges and these have resulted in differences in visual fields even within the same genus. This suggests that vision is subject to continuing and relatively rapid natural selection based upon individual differences in the structure of the optical system, retinal topography, and eye position in the skull. From a sensory ecology perspective a bird is best characterized as "a bill guided by an eye" and that control of flight is achieved within constraints on visual capacity dictated primarily by the demands of foraging and bill control.
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Affiliation(s)
- Graham R. Martin
- School of Biosciences, University of Birmingham, Birmingham, United Kingdom
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23
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Floreana Island re-colonization potential of the Galápagos short-eared owl (Asio flammeus galapagoensis). CONSERV GENET 2017. [DOI: 10.1007/s10592-017-1007-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
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24
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Lau RK, Moresco A, Woods SJ, Reilly CM, Hawkins MG, Murphy CJ, Hollingsworth SR, Hacker D, Freeman KS. Presumptive keratoglobus in a great horned owl (Bubo virginianus). Vet Ophthalmol 2016; 20:560-567. [DOI: 10.1111/vop.12413] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Affiliation(s)
- Rachael K. Lau
- VCA West Lost Angeles; 1900 S Sepulveda Blvd. Los Angeles CA 90025 USA
| | - Anneke Moresco
- Wildlife Rehabilitation Hospital at Lindsay Wildlife Museum; 1931 First Ave. Walnut Creek CA 94597 USA
- Cincinnati Zoo and Botanical Gardens- Center for Conservation and Research of Endangered Wildlife (CREW); 3400 Vine St. Cincinnati OH 45220 USA
| | - Sarah J. Woods
- Department of Surgical and Radiological Sciences; School of Veterinary Medicine; University of California; Davis CA 95616 USA
| | - Christopher M. Reilly
- Department of Pathology, Microbiology and Immunology; University of California Davis School of Veterinary Medicine; One Shields Avenue Davis CA 95616 USA
| | - Michelle G. Hawkins
- Department of Medicine and Epidemiology; University of California Davis School of Veterinary Medicine; One Shields Avenue Davis CA 95616 USA
| | - Christopher J. Murphy
- Department of Ophthalmology & Vision Science; UC Davis Eye Center; School of Medicine; University of California; Davis CA 95616 USA
| | - Steven R. Hollingsworth
- Department of Surgical and Radiological Sciences; School of Veterinary Medicine; University of California; Davis CA 95616 USA
| | - Dennis Hacker
- Animal Eye Specialists; 10324 San Pablo Ave. El Cerrito CA 94530 USA
| | - Kate S. Freeman
- Veterinary Medical Teaching Hospital; School of Veterinary Medicine; University of California; Davis CA 95616 USA
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25
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González-Martín-Moro J, Hernández-Verdejo JL, Jiménez-Gahete AE. Surprising characteristics of visual systems of invertebrates. ACTA ACUST UNITED AC 2016; 92:19-28. [PMID: 27422478 DOI: 10.1016/j.oftal.2016.05.007] [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: 12/26/2015] [Revised: 05/23/2016] [Accepted: 05/26/2016] [Indexed: 10/21/2022]
Abstract
OBJECTIVE To communicate relevant and striking aspects about the visual system of some close invertebrates. MATERIAL AND METHODS Review of the related literature. RESULTS The capacity of snails to regenerate a complete eye, the benefit of the oval shape of the compound eye of many flying insects as a way of stabilising the image during flight, the potential advantages related to the extreme refractive error that characterises the ocelli of many insects, as well as the ability to detect polarised light as a navigation system, are some of the surprising capabilities present in the small invertebrate eyes that are described in this work. CONCLUSIONS The invertebrate eyes have capabilities and sensorial modalities that are not present in the human eye. The study of the eyes of these animals can help us to improve our understanding of our visual system, and inspire the development of optical devices.
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Affiliation(s)
- J González-Martín-Moro
- Departamento de Oftalmología, Hospital Universitario del Henares, Coslada, Madrid, España; Universidad Francisco de Vitoria, Madrid, España.
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26
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Mitkus M, Nevitt GA, Danielsen J, Kelber A. Vision on the high seas: spatial resolution and optical sensitivity in two procellariiform seabirds with different foraging strategies. J Exp Biol 2016; 219:3329-3338. [DOI: 10.1242/jeb.140905] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2016] [Accepted: 08/15/2016] [Indexed: 11/20/2022]
Abstract
Procellariiform or ‘tubenosed’ seabirds are challenged to find prey and orient over the seemingly featureless oceans. Previous studies have found that life history strategy (burrow vs. surface nesting) was correlated to foraging strategy. Burrow nesters tended to track prey using dimethyl sulphide (DMS), a compound associated with phytoplankton, whereas surface-nesting species did not. Burrow nesters also tended to be smaller and more cryptic, whereas surface nesters were larger with contrasting plumage coloration. Together these results suggested that differences in life history strategy might also be linked to differences in visual adaptations. Here, we used Leach's storm-petrel, a DMS-responder, and Northern fulmar, a non-responder, as model species to test this hypothesis on their sensory ecology. From the retinal ganglion cell density and photoreceptor dimensions, we determined that Leach's storm-petrels have six times lower spatial resolution than the Northern fulmars. However, the optical sensitivity of rod photoreceptors is similar between species. These results suggest that under similar atmospheric conditions Northern fulmars have six times the detection range for similarly sized objects. Both species have extended visual streaks with a central area of highest spatial resolution, but only the Northern fulmar has a central fovea. The prediction that burrow-nesting DMS responding procellariiforms should differ from non-responding species nesting in the open holds true for spatial resolution, but not for optical sensitivity. This result may reflect the fact that both species rely on olfaction for their nocturnal foraging activity, but that Northern fulmars might use vision more during daytime.
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Affiliation(s)
- Mindaugas Mitkus
- Lund Vision Group, Department of Biology, Lund University, Sölvegatan 35, 22364, Lund, Sweden
| | - Gabrielle A. Nevitt
- Department of Neurobiology, Physiology and Behavior, College of Biological Sciences, University of California, Davis, One Shields Avenue, Davis, CA 95616, USA
| | - Johannis Danielsen
- Department of Natural Sciences, University of the Faroe Islands, J. C. Svabos gøta 14, 100 Tórshavn, Faroe Islands
| | - Almut Kelber
- Lund Vision Group, Department of Biology, Lund University, Sölvegatan 35, 22364, Lund, Sweden
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27
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Lisney TJ, Wylie DR, Kolominsky J, Iwaniuk AN. Eye Morphology and Retinal Topography in Hummingbirds (Trochilidae: Aves). BRAIN, BEHAVIOR AND EVOLUTION 2015; 86:176-90. [DOI: 10.1159/000441834] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/18/2015] [Accepted: 10/15/2015] [Indexed: 11/19/2022]
Abstract
Hummingbirds are a group of small, highly specialized birds that display a range of adaptations to their nectarivorous lifestyle. Vision plays a key role in hummingbird feeding and hovering behaviours, yet very little is known about the visual systems of these birds. In this study, we measured eye morphology in 5 hummingbird species. For 2 of these species, we used stereology and retinal whole mounts to study the topographic distribution of neurons in the ganglion cell layer. Eye morphology (expressed as the ratio of corneal diameter to eye transverse diameter) was similar among all 5 species and was within the range previously documented for diurnal birds. Retinal topography was similar in Amazilia tzacatl and Calypte anna. Both species had 2 specialized retinal regions of high neuron density: a central region located slightly dorso-nasal to the superior pole of the pecten, where densities reached ∼45,000 cells·mm-2, and a temporal area with lower densities (38,000-39,000 cells·mm-2). A weak visual streak bridged the two high-density areas. A retina from Phaethornis superciliosus also had a central high-density area with a similar peak neuron density. Estimates of spatial resolving power for all 3 species were similar, at approximately 5-6 cycles·degree-1. Retinal cross sections confirmed that the central high-density region in C. anna contains a fovea, but not the temporal area. We found no evidence of a second, less well-developed fovea located close to the temporal retina margin. The central and temporal areas of high neuron density allow for increased spatial resolution in the lateral and frontal visual fields, respectively. Increased resolution in the frontal field in particular may be important for mediating feeding behaviors such as aerial docking with flowers and catching small insects.
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Krabichler Q, Vega-Zuniga T, Morales C, Luksch H, Marín GJ. The visual system of a Palaeognathous bird: Visual field, retinal topography and retino-central connections in the Chilean Tinamou (Nothoprocta perdicaria). J Comp Neurol 2014; 523:226-50. [DOI: 10.1002/cne.23676] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2014] [Revised: 09/05/2014] [Accepted: 09/09/2014] [Indexed: 02/05/2023]
Affiliation(s)
- Quirin Krabichler
- Chair of Zoology, Technische Universität München; Freising-Weihenstephan Germany
| | - Tomas Vega-Zuniga
- Chair of Zoology, Technische Universität München; Freising-Weihenstephan Germany
| | - Cristian Morales
- Laboratorio de Neurobiología y Biología del Conocer; Departamento de Biología; Facultad de Ciencias; Universidad de Chile; Santiago de Chile Chile
| | - Harald Luksch
- Chair of Zoology, Technische Universität München; Freising-Weihenstephan Germany
| | - Gonzalo J. Marín
- Laboratorio de Neurobiología y Biología del Conocer; Departamento de Biología; Facultad de Ciencias; Universidad de Chile; Santiago de Chile Chile
- Facultad de Medicina; Universidad Finis Terrae; Santiago de Chile Chile
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29
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Moritz GL, Melin AD, Tuh Yit Yu F, Bernard H, Ong PS, Dominy NJ. Niche convergence suggests functionality of the nocturnal fovea. Front Integr Neurosci 2014; 8:61. [PMID: 25120441 PMCID: PMC4110675 DOI: 10.3389/fnint.2014.00061] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2014] [Accepted: 07/08/2014] [Indexed: 11/24/2022] Open
Abstract
The fovea is a declivity of the retinal surface associated with maximum visual acuity. Foveae are widespread across vertebrates, but among mammals they are restricted to haplorhine primates (tarsiers, monkeys, apes, and humans), which are primarily diurnal. Thus primates have long contributed to the view that foveae are functional adaptations to diurnality. The foveae of tarsiers, which are nocturnal, are widely interpreted as vestigial traits and therefore evidence of a diurnal ancestry. This enduring premise is central to adaptive hypotheses on the origins of anthropoid primates; however, the question of whether tarsier foveae are functionless anachronisms or nocturnal adaptations remains open. To explore this question, we compared the diets of tarsiers (Tarsius) and scops owls (Otus), taxa united by numerous anatomical homoplasies, including foveate vision. A functional interpretation of these homoplasies predicts dietary convergence. We tested this prediction by analyzing stable isotope ratios that integrate dietary information. In Borneo and the Philippines, the stable carbon isotope compositions of Tarsius and Otus were indistinguishable, whereas the stable nitrogen isotope composition of Otus was marginally higher than that of Tarsius. Our results indicate that species in both genera consumed mainly ground-dwelling prey. Taken together, our findings support a functional interpretation of the many homoplasies shared by tarsiers and scops owls, including a retinal fovea. We suggest that the fovea might function similarly in tarsiers and scops owls by calibrating the auditory localization pathway. The integration of auditory localization and visual fixation during prey detection and acquisition might be critical at low light levels.
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Affiliation(s)
- Gillian L. Moritz
- Department of Biological Sciences, The Class of 1978 Life Sciences Center, Dartmouth CollegeHanover, NH, USA
| | - Amanda D. Melin
- Department of Anthropology, Washington University, St. LouisMO, USA
| | - Fred Tuh Yit Yu
- Research and Education Division, Zoology and EntomologyKota Kinabalu, Malaysia
| | - Henry Bernard
- Institute for Tropical Biology and Conservation, Universiti Malaysia SabahKota Kinabalu, Malaysia
| | - Perry S. Ong
- Institute of Biology, University of the Philippines DilimanQuezon City, Philippines
| | - Nathaniel J. Dominy
- Department of Biological Sciences, The Class of 1978 Life Sciences Center, Dartmouth CollegeHanover, NH, USA
- Department of Anthropology, Dartmouth CollegeHanover, NH, USA
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Coimbra JP, Collin SP, Hart NS. Topographic specializations in the retinal ganglion cell layer correlate with lateralized visual behavior, ecology, and evolution in cockatoos. J Comp Neurol 2014; 522:3363-85. [DOI: 10.1002/cne.23637] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2014] [Revised: 05/26/2014] [Accepted: 05/27/2014] [Indexed: 11/10/2022]
Affiliation(s)
- João Paulo Coimbra
- School of Animal Biology, The University of Western Australia; Crawley Western Australia 6009 Australia
- The Oceans Institute, The University of Western Australia; Crawley Western Australia 6009 Australia
- School of Anatomical Sciences, The University of the Witwatersrand; Parktown 2193 Johannesburg South Africa
| | - Shaun P. Collin
- School of Animal Biology, The University of Western Australia; Crawley Western Australia 6009 Australia
- The Oceans Institute, The University of Western Australia; Crawley Western Australia 6009 Australia
| | - Nathan S. Hart
- School of Animal Biology, The University of Western Australia; Crawley Western Australia 6009 Australia
- The Oceans Institute, The University of Western Australia; Crawley Western Australia 6009 Australia
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31
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Retinal ganglion cell topography and spatial resolution of two parrot species: budgerigar (Melopsittacus undulatus) and Bourke's parrot (Neopsephotus bourkii). J Comp Physiol A Neuroethol Sens Neural Behav Physiol 2014; 200:371-84. [PMID: 24677162 DOI: 10.1007/s00359-014-0894-2] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2014] [Revised: 02/17/2014] [Accepted: 02/20/2014] [Indexed: 10/25/2022]
Abstract
Retinal ganglion cell (RGC) isodensity maps indicate important regions in an animal's visual field. These maps can also be combined with measures of focal length to estimate the theoretical visual acuity. Here we present the RGC isodensity maps and anatomical spatial resolving power in three budgerigars (Melopsittacus undulatus) and two Bourke's parrots (Neopsephotus bourkii). Because RGCs were stacked in several layers, we modified the Nissl staining procedure to assess the cell number in the whole-mounted and cross-sectioned tissue of the same retinal specimen. The retinal topography showed surprising variation; however, both parrot species had an area centralis without discernable fovea. Budgerigars also had a putative area nasalis never reported in birds before. The peak RGC density was 22,300-34,200 cells/mm(2) in budgerigars and 18,100-38,000 cells/mm(2) in Bourke's parrots. The maximum visual acuity based on RGCs and focal length was 6.9 cyc/deg in budgerigars and 9.2 cyc/deg in Bourke's parrots. These results are lower than earlier behavioural estimates. Our findings illustrate that retinal topography is not a very fixed trait and that theoretical visual acuity estimations based on RGC density can be lower than the behavioural performance of the bird.
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Baumhardt PE, Moore BA, Doppler M, Fernández-Juricic E. Do American goldfinches see their world like passive prey foragers? A study on visual fields, retinal topography, and sensitivity of photoreceptors. BRAIN, BEHAVIOR AND EVOLUTION 2014; 83:181-98. [PMID: 24663005 DOI: 10.1159/000357750] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/08/2012] [Accepted: 12/04/2013] [Indexed: 11/19/2022]
Abstract
Several species of the most diverse avian order, Passeriformes, specialize in foraging on passive prey, although relatively little is known about their visual systems. We tested whether some components of the visual system of the American goldfinch (Spinus tristis), a granivorous bird, followed the profile of species seeking passive food items (small eye size relative to body mass, narrow binocular fields and blind areas, centrally located retinal specialization projecting laterally, ultraviolet-sensitive vision). We measured eye size, visual field configuration, the degree of eye movement, variations in the density of ganglion cells and cone photoreceptors, and the sensitivity of photoreceptor visual pigments and oil droplets. Goldfinches had relatively large binocular (46°) and lateral (134°) visual fields with a high degree of eye movement (66° at the plane of the bill). They had a single centrotemporally located fovea that projects laterally, but can be moved closer to the edge of the binocular field by converging the eyes. Goldfinches could also increase their panoramic vision by diverging their eyes while handling food items in head-up positions. The distribution of photoreceptors indicated that the highest density of single and double cones was surrounding the fovea, making it the center of chromatic and achromatic vision and motion detection. Goldfinches possessed a tetrachromatic ultraviolet visual system with visual pigment peak sensitivities of 399 nm (ultraviolet-sensitive cone), 442 nm (short-wavelength-sensitive cone), 512 nm (medium-wavelength-sensitive cone), and 580 nm (long-wavelength-sensitive cone). Overall, the visual system of American goldfinches showed characteristics of passive as well as active prey foragers, with a single-fovea configuration and a large degree of eye movement that would enhance food searching and handling with their relatively wide binocular fields.
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Affiliation(s)
- Patrice E Baumhardt
- Department of Biological Sciences, Purdue University, West Lafayette, Ind., USA
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Lisney TJ, Stecyk K, Kolominsky J, Graves GR, Wylie DR, Iwaniuk AN. Comparison of eye morphology and retinal topography in two species of New World vultures (Aves: Cathartidae). Anat Rec (Hoboken) 2013; 296:1954-70. [PMID: 24249399 DOI: 10.1002/ar.22815] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2013] [Revised: 08/11/2013] [Accepted: 08/26/2013] [Indexed: 11/08/2022]
Abstract
Vultures are highly reliant on their sensory systems for the rapid detection and localization of carrion before other scavengers can exploit the resource. In this study, we compared eye morphology and retinal topography in two species of New World vultures (Cathartidae), turkey vultures (Cathartes aura), with a highly developed olfactory sense, and black vultures (Coragyps atratus), with a less developed sense of olfaction. We found that eye size relative to body mass was the same in both species, but that black vultures have larger corneas relative to eye size than turkey vultures. However, the overall retinal topography, the total number of cells in the retinal ganglion cell layer, peak and average cell densities, cell soma area frequency distributions, and the theoretical peak anatomical spatial resolving power were the same in both species. This suggests that the visual systems of these two species are similar and that vision plays an equally important role in the biology of both species, despite the apparently greater reliance on olfaction for finding carrion in turkey vultures.
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Affiliation(s)
- Thomas J Lisney
- Department of Psychology, University of Alberta, Edmonton, AB, Canada
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34
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Lisney TJ, Stecyk K, Kolominsky J, Schmidt BK, Corfield JR, Iwaniuk AN, Wylie DR. Ecomorphology of eye shape and retinal topography in waterfowl (Aves: Anseriformes: Anatidae) with different foraging modes. J Comp Physiol A Neuroethol Sens Neural Behav Physiol 2013; 199:385-402. [DOI: 10.1007/s00359-013-0802-1] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2012] [Revised: 02/12/2013] [Accepted: 02/13/2013] [Indexed: 11/24/2022]
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35
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Gutiérrez-Ibáñez C, Iwaniuk AN, Lisney TJ, Wylie DR. Comparative study of visual pathways in owls (Aves: Strigiformes). BRAIN, BEHAVIOR AND EVOLUTION 2012; 81:27-39. [PMID: 23296024 DOI: 10.1159/000343810] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/09/2012] [Accepted: 08/27/2012] [Indexed: 11/19/2022]
Abstract
Although they are usually regarded as nocturnal, owls exhibit a wide range of activity patterns, from strictly nocturnal, to crepuscular or cathemeral, to diurnal. Several studies have shown that these differences in the activity pattern are reflected in differences in eye morphology and retinal organization. Despite the evidence that differences in activity pattern among owl species are reflected in the peripheral visual system, there has been no attempt to correlate these differences with changes in the visual regions in the brain. In this study, we compare the relative size of nuclei in the main visual pathways in nine species of owl that exhibit a wide range of activity patterns. We found marked differences in the relative size of all visual structures among the species studied, both in the tectofugal and the thalamofugal pathway, as well in other retinorecipient nuclei, including the nucleus lentiformis mesencephali, the nucleus of the basal optic root and the nucleus geniculatus lateralis, pars ventralis. We show that the barn owl (Tyto alba), a species widely used in the study of the integration of visual and auditory processing, has reduced visual pathways compared to strigid owls. Our results also suggest there could be a trade-off between the relative size of visual pathways and auditory pathways, similar to that reported in mammals. Finally, our results show that although there is no relationship between activity pattern and the relative size of either the tectofugal or the thalamofugal pathway, there is a positive correlation between the relative size of both visual pathways and the relative number of cells in the retinal ganglion layer.
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Hall MI, Kamilar JM, Kirk EC. Eye shape and the nocturnal bottleneck of mammals. Proc Biol Sci 2012; 279:4962-8. [PMID: 23097513 DOI: 10.1098/rspb.2012.2258] [Citation(s) in RCA: 77] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Most vertebrate groups exhibit eye shapes that vary predictably with activity pattern. Nocturnal vertebrates typically have large corneas relative to eye size as an adaptation for increased visual sensitivity. Conversely, diurnal vertebrates generally demonstrate smaller corneas relative to eye size as an adaptation for increased visual acuity. By contrast, several studies have concluded that many mammals exhibit typical nocturnal eye shapes, regardless of activity pattern. However, a recent study has argued that new statistical methods allow eye shape to accurately predict activity patterns of mammals, including cathemeral species (animals that are equally likely to be awake and active at any time of day or night). Here, we conduct a detailed analysis of eye shape and activity pattern in mammals, using a broad comparative sample of 266 species. We find that the eye shapes of cathemeral mammals completely overlap with nocturnal and diurnal species. Additionally, most diurnal and cathemeral mammals have eye shapes that are most similar to those of nocturnal birds and lizards. The only mammalian clade that diverges from this pattern is anthropoids, which have convergently evolved eye shapes similar to those of diurnal birds and lizards. Our results provide additional evidence for a nocturnal 'bottleneck' in the early evolution of crown mammals.
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Affiliation(s)
- Margaret I Hall
- Department of Anatomy, Arizona College of Osteopathic Medicine, Midwestern University, 19555 N 59th Avenue, Glendale, AZ 85308, USA.
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37
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Interspecifc variation in eye shape and retinal topography in seven species of galliform bird (Aves: Galliformes: Phasianidae). J Comp Physiol A Neuroethol Sens Neural Behav Physiol 2012; 198:717-31. [DOI: 10.1007/s00359-012-0742-1] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2012] [Revised: 06/05/2012] [Accepted: 06/20/2012] [Indexed: 12/24/2022]
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