Common ostrich vision: the science and the numbers
Struthio camelus · order Struthioniformes · Birds: all the numbers
The common ostrich has four colour channels, including violet (405, 444, 505 and 570 nm).[1][2] Its sharpest vision resolves 19.32 cycles per degree, against 63.75 for people in this dataset.[6] Its eyes cover about 290° with 20° seen by both eyes.[13]
- 4colour receptor classesMeasured
- 19.32cycles per degree (sharpness)Measured
- 290°field of viewMeasured
The common ostrich (Struthio camelus) is a bird in the order Struthioniformes. Its eyes belong to the vision type Panoramic grain-eater and wader: four cone types, low to moderate sharpness and an almost all-round field of view. Measured in this species: colour, sharpness, field of view and night vision. Measured core: measured values on at least 3 of the 6 dials.
This is a simulation built from published eye measurements, not what the animal experiences.
What the common ostrich sees: colour receptors
What stands out
- It has 4 colour receptor classes; people have 3.
- Its sharpest vision resolves 19.32 cycles per degree: the finest stripe pattern it can tell apart from grey.
- Its eyes cover about 290° around the head, with 20° seen by both eyes at once.
- 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. The last column gives the values for people from the same catalogue.
| Dial | Value | Evidence | Sources | People |
|---|---|---|---|---|
| Colour | Colour receptors 4 receptor classes: 405 nm (VS/SWS (violet)), 444 nm (SWS (blue)), 505 nm (MWS (green)), 570 nm (LWS (long)) measured in this species | Measured | [1][2] | Colour receptors: 3 receptor classes: 421.5 nm (VS/SWS (violet)), 532 nm (MWS (green)), 558.4 nm (LWS (long)) Measured (not re-verified)[2][3][4][5] |
| Sharpness | Acuity 19.32 cycles per degree median of 1 anatomical-ganglion rows (method priority rule) | Measured | [6] | Acuity: 63.75 cycles per degree Measured[7][8] |
| Field of view | Binocular overlap 20° median of 1 rows (eyes-at-rest rows preferred) | Measured | [9] | Binocular overlap: 122.5° Measured[10][11] Total field of view: 200° Measured (not re-verified)[12] Blind area behind the head: 160° Derived[12] Eye placement: frontal Derived[10][11] |
| Total field of view 290° measured in this species (extension 2026-10, fov-verified.csv) | Measured | [13] | ||
| Blind area behind the head 70° 360 - total field | Derived | [13] | ||
| Eye placement lateral frontal if binocular overlap >= 60 deg, else lateral | Derived | [9] | ||
| Binocular field, vertical extent 80° (approximate); approximately horizontal plane; eyes in relaxed (resting) position; head in typical posture for the species; alert live birds | Measured | [13] | ||
| Field of one eye 155° (approximate); approximately horizontal plane; eyes in relaxed (resting) position; head in typical posture for the species; alert live birds | Measured | [13] | ||
| Total field (published value) 290° (approximate); approximately horizontal plane; eyes in relaxed (resting) position; head in typical posture for the species; alert live birds | Measured | [13] | ||
| 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 | [14][15][16] | Number of foveas: 1 Measured[17] Fovea type: fovea Measured[17] |
| Fovea type single central fovea (displaced dorso-temporally from retinal centre) | Group default | [14][15][16] | ||
| Night vision | Activity pattern diurnal mode of 7 rows (of 7 rows): cathemeral; diurnal; not_nocturnal | Measured (not re-verified) | [18][19][20][21][2][22][23] | Activity pattern: diurnal Measured (not re-verified)[24][25][26][2][27][28][29][23] Pupil shape: vertical Group default[30][31] Reflective layer (tapetum): no Measured[32] Rods vs cones: cone-dominated Derived[24][25][26][2][27][28][29][23] Night sensitivity (optical, against people): S = 0.93 µm² sr, 1 times people (log10 ratio 0) Derived[33] |
| Rods vs cones cone-dominated nocturnal -> rod-dominated; crepuscular / cathemeral / mixed -> mixed; diurnal -> cone-dominated | Derived | [18][19][20][21][2][22][23] | ||
| 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 | [34][35][36][37][38] | Flicker fusion frequency: 60 Hz Measured[36][37] |
All birds side by side: Birds: every measurement. Method: how we know what animals see.
Sources
- Lind et al. 2014
- Longcore 2023
- Kirwan
- Müller et al. 2009
- Thermal Activation and Photoactivation of Visual… 2004
- Caves et al. 2018
- Kirk et al. 2004
- Veilleux et al. 2014
- Tyrrell et al. 2017
- Heesy 2004
- Heffner et al. 1992
- Campbell & Green 1965
- Martin et al. 1999
- Moore et al. 2017
- Potier et al. 2017
- Rodrigues et al. 2026
- Kopania et al. 2025
- Angielczyk et al. 2014
- Light conditions and the evolution of…
- Choiniere et al. 2021
- Wilman et al. 2014
- Schmitz et al. 2011
- Moura et al. 2024
- Anderson et al. 2017
- Borges et al. 2018
- Wilman et al. 2014
- Maor et al. 2017
- Jones et al. 2009
- Schmitz et al. 2011
- Banks et al. 2015
- Cervino et al. 2021
- Guareschi et al. 2025
- Brauburger et al. 2026
- Boström et al. 2016
- Haarlem et al. 2026
- Healy et al. 2013
- Inger et al. 2014
- Lafitte et al. 2022
Every value cites its sources (all sources). Values were extracted from these works and converted (units, medians, derived values); changes are ours, and the listed sources do not endorse this site. Data: catalogue-v1, built 2026-09-29. Accuracy notes: how accurate is this? Method: how we know.