Anna's hummingbird vision: the science and the numbers
Calypte anna · order Apodiformes · Birds: all the numbers
Its sharpest vision resolves 6 cycles per degree, against 63.75 for people in this dataset.[6] The Anna's hummingbird stops seeing flicker at 75 Hz, against 60 Hz for people.[38]
- 6cycles per degree (sharpness)Measured
- 75hertz flicker fusion (motion)Measured
The Anna's hummingbird (Calypte anna) is a bird in the order Apodiformes. Its eyes belong to the vision type UV songbird, parrot and hummingbird: four cone types including a true ultraviolet cone, coloured oil droplets and fast motion vision. Measured in this species: sharpness, night vision and motion (flicker fusion). 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 Anna's hummingbird sees: colour receptors
What stands out
- Its sharpest vision resolves 6 cycles per degree: the finest stripe pattern it can tell apart from grey.
- It stops seeing flicker at 75 Hz, against 60 Hz for people in this dataset, so fast motion looks about 1.3 times slower to it.[39][40]
- 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: 417.5 nm (VS/SWS (violet)), 452 nm (SWS (blue)), 501 nm (MWS (green)), 570 nm (LWS (long)) receptor set of nearest measured relative Anas platyrhynchos (same class Aves) | Group default | [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 6 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 27.5° median of 133 relatives in class Aves: Accipiter cooperii, Spatula clypeata, Mareca penelope, Anas platyrhynchos, Ardeola ralloides, Baeolophus bicolor | Group default | [9][10][11][12][13][14][15][16][17] | Binocular overlap: 122.5° Measured[18][19] Total field of view: 200° Measured (not re-verified)[20] Blind area behind the head: 160° Derived[20] Eye placement: frontal Derived[18][19] |
| Eye placement lateral | Group default | [9][10][11][12][13][14][15][16][17] | ||
| Sharp zones (foveas) | Number of foveas 1 median of 1 relatives in order Apodiformes: Apus apus | Group default | [21] | Number of foveas: 1 Measured[22] Fovea type: fovea Measured[22] |
| Fovea type temporal fovea only (no central pit) | Group default | [21] | ||
| Night vision | Activity pattern diurnal mode of 7 rows (of 7 rows): diurnal; not_nocturnal | Measured (not re-verified) | [23][24][25][26][27][28][29] | Activity pattern: diurnal Measured (not re-verified)[23][30][31][2][32][33][34][29] Pupil shape: vertical Group default[35][36] Reflective layer (tapetum): no Measured[37] Rods vs cones: cone-dominated Derived[23][30][31][2][32][33][34][29] |
| Rods vs cones cone-dominated nocturnal -> rod-dominated; crepuscular / cathemeral / mixed -> mixed; diurnal -> cone-dominated | Derived | [23][24][25][26][27][28][29] | ||
| Motion (flicker fusion) | Flicker fusion frequency 75 Hz median of 1 bright-light rows (behavioural/whole-eye ERG rows; all rows: [75.0]) | Measured | [38] | Flicker fusion frequency: 60 Hz Measured[39][40] |
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. 2024
- Kirk et al. 2004
- Veilleux et al. 2014
- Cantlay et al. 2023
- Lucas et al. 2024
- Vision et al. 2026
- Pecsics et al. 2023
- Portugal et al. 2023
- Potier et al. 2018
- Potier et al. 2023
- Tyrrell et al. 2017
- Tyrrell et al. 2017
- Heesy 2004
- Heffner et al. 1992
- Campbell & Green 1965
- Rodrigues et al. 2026
- Kopania et al. 2025
- Anderson et al. 2017
- 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
- 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.