How does the tundra swan see?
The tundra swan (Cygnus columbianus) is a bird in the order Anseriformes. Its eyes belong to the vision type Panoramic grain-eater and wader.
Measured in this species: field of view and night vision. One measured dial: a value other than colour or sharpness is measured in this species; colour and sharpness are not measured here. Every value below carries its evidence level and sources; nothing is typed by hand.
See your photo as the tundra swanThis species is part of the full catalogue in the tool (full unlock). Your photo stays on your device.
What stands out
- It has 4 colour receptor classes; people have 3.
- Its sharpest vision resolves 11.2 cycles per degree: the finest stripe pattern it can tell apart from grey.
- Its eyes cover about 306° around the head, with 23.5° seen by both eyes at once.
- It stops seeing flicker at 88.5 Hz, against 60 Hz for people in this dataset, so fast motion looks about 1.5 times slower to it.[15][16]
- Activity pattern: cathemeral.
The six dials
Evidence levels: how the tiers work. "Measured" means a value measured in this species; "Estimated" values come from a close relative or an eye-size formula.
| Dial | Value | Evidence | Sources |
|---|---|---|---|
| Colour | Colour receptors 4 receptor classes: 417.5 nm (VS/SWS (violet)), 452 nm (SWS (blue)), 501 nm (MWS (green)), 570 nm (LWS (long)) receptor set of nearest measured relative Anas platyrhynchos (same family Anatidae) | Estimated | [1][2] |
| Sharpness | Acuity 11.2 cycles per degree median of 7 relatives in family Anatidae: Spatula clypeata, Anas platyrhynchos, Mareca strepera, Aythya affinis, Aythya marila, Branta canadensis | Estimated | [3][4] |
| Field of view | Binocular overlap 23.5° median of 1 rows (eyes-at-rest rows preferred) | Measured | [5] |
| Total field of view 306° median total field (measured, or 360 - blind area) of relatives in family Anatidae: Mergus merganser | Estimated | [6] | |
| Sharp zones (foveas) | Number of foveas 1 median of 1 relatives in family Anatidae: Branta canadensis | Estimated | [7] |
| Fovea type single central fovea (displaced dorso-temporally from retinal centre) | Estimated | [7] | |
| Night vision | Activity pattern cathemeral mode of 5 rows (of 5 rows): cathemeral; diurnal; not_nocturnal | Measured (not re-verified) | [8][9][10][11][12] |
| Rods vs cones mixed nocturnal -> rod-dominated; crepuscular / cathemeral / mixed -> mixed; diurnal -> cone-dominated | Derived | [8][9][10][11][12] | |
| Motion (flicker fusion) | Flicker fusion frequency 88.5 Hz median of 17 relatives in class Aves: Bubo virginianus, Melopsittacus undulatus, Passer domesticus, Taeniopygia guttata, Columba livia, Calypte anna | Group default | [13][14][15][16][17] |
Related animals
- Canada goose same vision type
- Mallard same vision type
- Greater scaup same vision type
- Lesser scaup same vision type
- Northern shoveler same vision type
- American black duck same vision type
More birds: all birds with measured vision data.
Sources
- Lind O, Mitkus M, Olsson P, Kelber A. 2014. Ultraviolet vision in birds: the importance of transparent eye media. Proc R Soc B 281:20132209. Table 1. doi.org/10.1098/rspb.2013.2209
- Longcore T. 2023. A compendium of photopigment peak sensitivities and visual spectral response curves of terrestrial wildlife to guide design of outdoor nighttime lighting. Basic Appl Ecol 73:40-50. doi:10.1016/j.baae.2023.09.002. doi.org/10.5281/zenodo.8432720
- Caves EM, Brandley NC, Johnsen S (2018) Visual acuity and the evolution of signals. Trends Ecol Evol 33:358-372. Supplementary Tables S1-S3.. doi.org/10.1016/j.tree.2018.03.001
- Caves EM, Fernandez-Juricic E, Kelley LA (2024) Ecological and morphological correlates of visual acuity in birds. J Exp Biol 227(2): jeb246063. Supplementary Table S1.. doi.org/10.1242/jeb.246063
- Cantlay JC, Martin GR, McClelland SC, Potier S, O'Brien MF, Fernandez-Juricic E, Bond AL, Portugal SJ 2023. Binocular vision and foraging in ducks, geese and swans (Anatidae). Proc R Soc B 290: 20231213. ESM full data set (figshare collection 6781097).. doi.org/10.1098/rspb.2023.1213
- Pecsics T, Csorgo T. 2023. Ornis Hungarica 31(2):110-124. doi.org/10.2478/orhu-2023-0023
- Moore BA, Tyrrell LP, Pita D, Bininda-Emonds ORP, Fernandez-Juricic E 2017. Does retinal configuration make the head and eyes of foveate birds move? Sci Rep 7: 38406. Appendix 1.. doi.org/10.1038/srep38406
- Angielczyk KD, Schmitz L 2014. Nocturnality in synapsids predates the origin of mammals by over 100 million years. Proc R Soc B 281: 20141642. Dryad doi:10.5061/dryad.1v8kj.. doi.org/10.1098/rspb.2014.1642
- Choiniere JN, Neenan JM, Schmitz L, Ford DP, Chapelle KEJ, Balanoff AM, Sipla JS, Georgi JA, Walsh SA, Norell MA, Xu X, Clark JM, Benson RBJ. 2021. Evolution of vision and hearing modalities in theropod dinosaurs. Science 372:610-613. doi:10.1126/science.abe7941. Data: https://osf.io/teq73/. doi.org/10.1126/science.abe7941
- Wilman H, Belmaker J, Simpson J, de la Rosa C, Rivadeneira MM, Jetz W. 2014. EltonTraits 1.0: species-level foraging attributes of the world's birds and mammals. Ecology 95:2027. BirdFuncDat.txt. doi.org/10.6084/m9.figshare.3559887.v1
- Schmitz & Motani 2011. Nocturnality in dinosaurs inferred from scleral ring and orbit morphology. Science 332:705. Comparative data redeposited in Xing et al. 2020 supplementary information (Zenodo).. doi.org/10.5281/zenodo.3591994
- Moura et al. 2024. A phylogeny-informed characterisation of global tetrapod traits addresses data gaps and biases. PLoS Biol 22:e3002658. TetrapodTraits v3.0.1.. doi.org/10.5281/zenodo.22536349
- Boström JE, Dimitrova M, Canton C, Håstad O, Qvarnström A, Ödeen A. 2016. Ultra-rapid vision in birds. PLoS ONE 11(3): e0151099. S1 Table. doi.org/10.1371/journal.pone.0151099
- Haarlem CS, Hynes C, Jackson AL, Mitchell KJ, O'Connell RG, Healy K. 2026. Pace of ecology drives the tempo of visual perception across the animal kingdom. Nature Ecology & Evolution (doi:10.1038/s41559-026-02994-7). Figshare dataset 10.6084/m9.figshare.30556475. doi.org/10.6084/m9.figshare.30556475
- Healy K, McNally L, Ruxton GD, Cooper N, Jackson AL. 2013. Metabolic rate and body size are linked with perception of temporal information. Animal Behaviour 86:685-696. Table 1. doi.org/10.1016/j.anbehav.2013.06.018
- Inger R, Bennie J, Davies TW, Gaston KJ. 2014. Potential biological and ecological effects of flickering artificial light. PLoS ONE 9(5): e98631. Table 3. doi.org/10.1371/journal.pone.0098631
- Lafitte A, Sordello R, Legrand M, Nicolas V, Obein G, Reyjol Y. 2022. A flashing light may not be that flashy: A systematic review on critical fusion frequencies. PLoS ONE 17(12): e0279718. S10 File (CFF database). doi.org/10.1371/journal.pone.0279718
Every value cites its sources (all sources). Data: catalogue-v1, built 2026-09-29. Accuracy notes: how accurate is this?