Red-tailed hawk vision: the science and the numbers
Buteo jamaicensis · order Accipitriformes · Birds: all the numbers
Their sharpest vision resolves 16.8 cycles per degree, against 63.75 for people in this dataset.[6] Their eyes cover about 278° with 25.5° seen by both eyes.[9]
- 16.8cycles per degree (sharpness)Measured
- 278°field of viewEstimated
The red-tailed hawk (Buteo jamaicensis) is a bird in the order Accipitriformes. Its eyes belong to the vision type Raptor telephoto: four cone types, two foveas and very high sharpness. Measured in this species: sharpness, field of view, foveas 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 red-tailed hawks see: colour receptors
What stands out
- Its sharpest vision resolves 16.8 cycles per degree: the finest stripe pattern it can tell apart from grey.
- Its eyes cover about 278° around the head, with 25.5° 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)), 449 nm (SWS (blue)), 504 nm (MWS (green)), 567 nm (LWS (long)) receptor set of nearest measured relative Buteo buteo (same genus Buteo) | Estimated | [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 16.8 cycles per degree median of 1 behavioural rows (method priority rule) | Measured | [6] | Acuity: 63.75 cycles per degree Measured[7][8] |
| Field of view | Binocular overlap 25.5° median of 2 rows (eyes-at-rest rows preferred) | Measured | [9][10] | Binocular overlap: 122.5° Measured[11][12] Total field of view: 200° Measured (not re-verified)[13] Blind area behind the head: 160° Derived[13] Eye placement: frontal Derived[11][12] |
| Total field of view 278° rule: total = 360 - blind area | Derived | [9] | ||
| Blind area behind the head 82° | Measured | [9] | ||
| Eye placement lateral frontal if binocular overlap >= 60 deg, else lateral | Derived | [9][10] | ||
| Sharp zones (foveas) | Number of foveas 2 species-v1.csv text: 2 (central deep + temporal shallow) | Measured (not re-verified) | [14] | Number of foveas: 1 Measured[15] Fovea type: fovea Measured[15] |
| Fovea type central fovea, temporal | Measured (not re-verified) | [14] | ||
| Night vision | Activity pattern diurnal mode of 7 rows (of 7 rows): diurnal; not_nocturnal | Measured (not re-verified) | [16][17][18][19][2][20][21] | Activity pattern: diurnal Measured (not re-verified)[22][23][24][2][25][26][27][21] Pupil shape: vertical Group default[28][29] Reflective layer (tapetum): no Measured[30] Rods vs cones: cone-dominated Derived[22][23][24][2][25][26][27][21] |
| Rods vs cones cone-dominated nocturnal -> rod-dominated; crepuscular / cathemeral / mixed -> mixed; diurnal -> cone-dominated | Derived | [16][17][18][19][2][20][21] | ||
| Motion (flicker fusion) | Flicker fusion frequency 77.7 Hz median of 1 relatives in family Accipitridae: Parabuteo unicinctus | Estimated | [31] | Flicker fusion frequency: 60 Hz Measured[32][33] |
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
- Tyrrell et al. 2017
- Heesy 2004
- Heffner et al. 1992
- Campbell & Green 1965
- Potier et al. 2017
- 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
- Lafitte et al. 2022
- Healy et al. 2013
- Inger et al. 2014
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.