How does the great horned owl see?
The great horned owl (Bubo virginianus) is a bird in the order Strigiformes. Its eyes belong to the vision type Owl and night bird: tubular forward eyes (owls) or tiny eyes (kiwi), rod-dominated, low acuity, fixed eyes.
Measured in this species: colour, sharpness, field of view, night vision and motion (flicker fusion). 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, including ultraviolet; people have 3.
- Its sharpest vision resolves 7.125 cycles per degree: the finest stripe pattern it can tell apart from grey.
- Its eyes cover about 201° around the head, with 41° seen by both eyes at once.
- It stops seeing flicker at 40 Hz, against 60 Hz for people in this dataset, so fast motion looks choppier to it.[17][18]
- Activity pattern: nocturnal.
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: 373 nm (UVS), 454 nm (SWS (blue)), 504 nm (MWS (green)), 555 nm (LWS (long)) measured in this species | Measured | [1][2][3] |
| Ultraviolet yes: at least one receptor peaks in the ultraviolet | Measured | ||
| Sharpness | Acuity 7.125 cycles per degree median of 2 behavioural rows (method priority rule) | Measured (not re-verified) | [4][5] |
| Field of view | Binocular overlap 41° median of 1 rows (eyes-at-rest rows preferred) | Measured | [6] |
| Total field of view 201° median species-v1 total field of family Strigidae: Strix aluco | Estimated | [7] | |
| Blind area behind the head 159° | Estimated | [7] | |
| 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 | [8][9][10] |
| Fovea type single central fovea (displaced dorso-temporally from retinal centre) | Group default | [8][9][10] | |
| Night vision | Activity pattern nocturnal mode of 5 rows (of 5 rows): diurnal; nocturnal | Measured (not re-verified) | [11][12][13][2][14] |
| Reflective layer (tapetum) no | Measured (not re-verified) | [15] | |
| Rods vs cones rod-dominated nocturnal -> rod-dominated; crepuscular / cathemeral / mixed -> mixed; diurnal -> cone-dominated | Derived | [11][12][13][2][14] | |
| Motion (flicker fusion) | Flicker fusion frequency 40 Hz median of 1 bright-light rows (behavioural/whole-eye ERG rows; all rows: [40.0]); cff_hz: dim-light rows (bright-light rows used) set aside (labelled alternative: 45) | Measured | [16] |
Comparisons
Related animals
- Tawny owl same vision type
- Barn owl same vision type
- Little owl same vision type
- Great grey owl same vision type
- Snowy owl same vision type
- Australian masked owl 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
- VPOD in-vivo (MSP / single-cell) lambda max compendium, file scp_cleaned.csv, VPOD GitHub (Frazer et al. 2025 bioRxiv 10.1101/2025.08.22.671864). github.com/VisualPhysiologyDB/visual-physiology-opsin-db/tree/main/scripts_n_notebooks/vpod_ML_workflows/mine_n_match/data_sources/lmax/vpod
- 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
- Potier S, Mitkus M, Kelber A (2020) Visual adaptations of diurnal and nocturnal raptors. Semin Cell Dev Biol 106:156-164. Table 1.. doi.org/10.1016/j.semcdb.2020.05.004
- Potier S, Roulin A, Martin GR, Portugal SJ, Bonhomme V, Bouchet T, de Romans R, Meyrier E, Kelber A. 2023. Binocular field configuration in owls: the role of foraging ecology. Proc R Soc B 290: 20230664. Data figshare.. doi.org/10.1098/rspb.2023.0664
- species_v1:Martin 1984
- 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
- Light conditions and the evolution of the visual system in birds (figshare dataset, SupplementaryDataset1). doi.org/10.6084/m9.figshare.22116371.v3
- 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
- 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
- species_v1:Healy et al. 2013
- 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
- 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
Every value cites its sources (all sources). Data: catalogue-v1, built 2026-09-29. Accuracy notes: how accurate is this?