How does the barn owl see?
The barn owl (Tyto alba) 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: sharpness, field of view, foveas 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 three colour receptor classes, like most people.
- Its sharpest vision resolves 3.3 cycles per degree: the finest stripe pattern it can tell apart from grey.
- Its eyes cover about 201° around the head, with 36° seen by both eyes at once.
- It stops seeing flicker at 50 Hz, against 60 Hz for people in this dataset, so fast motion looks choppier to it.[16][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 3 receptor classes: 463 nm (SWS (blue)), 530 nm (MWS (green)), 555 nm (LWS (long)) receptor set of nearest measured relative Strix aluco (same order Strigiformes) | Group default | [1][2] |
| Sharpness | Acuity 3.3 cycles per degree median of 3 behavioural rows (method priority rule) | Measured | [3][4] |
| Field of view | Binocular overlap 36° median of 1 rows (eyes-at-rest rows preferred) | Measured | [5] |
| Total field of view 201° median species-v1 total field of order Strigiformes: Strix aluco | Group default | [6] | |
| Blind area behind the head 159° | Group default | [6] | |
| Eye placement lateral frontal if binocular overlap >= 60 deg, else lateral | Derived | [5] | |
| Sharp zones (foveas) | Number of foveas 1 species-v1.csv text: 1 (temporal area/shallow fovea) | Measured (not re-verified) | [7] |
| Fovea type temporal | Measured (not re-verified) | [7] | |
| Night vision | Activity pattern nocturnal mode of 7 rows (of 7 rows): nocturnal | Measured (not re-verified) | [8][9][10][11][12][13][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 | [8][9][10][11][12][13][14] | |
| Motion (flicker fusion) | Flicker fusion frequency 50 Hz median of 3 relatives in order Strigiformes: Bubo virginianus, Athene noctua, Asio flammeus | Group default | [16][17] |
Comparisons
Related animals
- Great horned owl same vision type
- Tawny 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
- 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
- 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
- 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
- species_v1:Harmening et al. 2009
- 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
- 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
- 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
- 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
- species_v1:Standard textbook knowledge
- 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
- 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
- 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?