How does the Humboldt penguin see?
The Humboldt penguin (Spheniscus humboldti) is a bird in the order Sphenisciformes. Its eyes belong to the vision type Penguin (underwater-tuned bird): blue-shifted cones, no UV cone, flat cornea for underwater focus.
Measured in this species: colour, field of view and night vision. Measured core: measured values on at least 3 of the 6 dials. Every value below carries its evidence level and sources; nothing is typed by hand.


What stands out
- It has 4 colour receptor classes; people have 3.
- Its sharpest vision resolves 18.93 cycles per degree: the finest stripe pattern it can tell apart from grey.
- Its eyes cover about 282° around the head, with 28° 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.[16][17]
- Activity pattern: diurnal.
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: 403 nm (VS/SWS (violet)), 450 nm (SWS (blue)), 499 nm (MWS (green)), 543 nm (LWS (long)) measured in this species | Measured | [1][2] |
| Sharpness | Acuity 18.93 cycles per degree median of 2 relatives in family Spheniscidae: Aptenodytes patagonicus, Eudyptula minor | Estimated | [3][4] |
| Field of view | Binocular overlap 28° species-v1.csv | Measured | [5][6] |
| Total field of view 282° species-v1.csv | Measured | [5][6] | |
| Blind area behind the head 78° blind area = 360 - total field | Derived | [6] | |
| Eye placement lateral frontal if binocular overlap >= 60 deg, else lateral | Derived | [6] | |
| Sharp zones (foveas) | Number of foveas 1 median of 48 relatives in class Aves: Branta canadensis, Cardinalis cardinalis, Passerina cyanea, Zenaida macroura, Cyanocitta cristata, Junco hyemalis | Group default | [7][8][9] |
| Fovea type single central fovea (displaced dorso-temporally from retinal centre) | Group default | [7][8][9] | |
| Night vision | Activity pattern diurnal mode of 5 rows (of 5 rows): cathemeral; diurnal; not_nocturnal | Measured (not re-verified) | [10][11][12][1][13] |
| Rods vs cones cone-dominated nocturnal -> rod-dominated; crepuscular / cathemeral / mixed -> mixed; diurnal -> cone-dominated | Derived | [10][11][12][1][13] | |
| 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 | [14][15][16][17][18] |
Related animals
- King penguin same vision type
- Little penguin same vision type
More birds: all birds with measured vision data.
Sources
- 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
- Frazer SA, Baghalian M, et al. 2024. Discovering genotype-phenotype relationships with machine learning and the Visual Physiology Opsin Database (VPOD). GigaScience 13:giae073; VPOD v1.3 data release. doi.org/10.5281/zenodo.19051998
- 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
- Hadden PW, Zhang J. 2023. An Overview of the Penguin Visual System. Vision (Basel, Switzerland) 7(1):6. doi.org/10.3390/vision7010006
- species_v1:Hadden & Zhang 2023 (Table 1, primary ref [47])
- 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
- Potier S, Mitkus M, Bonadonna F, Duriez O, Isard P-F, Dulaurent T, Mentek M, Kelber A 2017. Eye size, fovea, and foraging ecology in accipitriform raptors. Brain Behav Evol 90: 232-242. Supplementary material (Tables S1, S2).. doi.org/10.1159/000479783
- Rodrigues T, Matter MM, Chiodini A, et al. 2026. Foveal vision in fast-flying birds hunting on the wing. bioRxiv 2026.06.05.730304. doi.org/10.64898/2026.06.05.730304
- Anderson SR, Wiens JJ. 2017. Out of the dark: 350 million years of conservatism and evolution in diel activity patterns in vertebrates. Evolution 71:1944-1959. Dryad doi:10.5061/dryad.fg700. doi.org/10.5061/dryad.fg700
- Light conditions and the evolution of the visual system in birds (figshare dataset, SupplementaryDataset1). doi.org/10.6084/m9.figshare.22116371.v3
- 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
- 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?