Eurasian jackdaw vision: the science and the numbers
Coloeus monedula · order Passeriformes · Birds: all the numbers
Its sharpest vision resolves 33 cycles per degree, against 63.75 for people in this dataset.[5] Both eyes see the same 22° in front of it.[8]
- 33cycles per degree (sharpness)Measured
- 22°seen by both eyesMeasured
The Eurasian jackdaw (Coloeus monedula) is a bird in the order Passeriformes. 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, 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 Eurasian jackdaw sees: colour receptors
What stands out
- Its sharpest vision resolves 33 cycles per degree: the finest stripe pattern it can tell apart from grey.
- Both eyes see the same 22° in front of it (binocular overlap), where depth is judged best.
- 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 2 receptor classes: 497 nm (MWS (green)), 565 nm (LWS (long)) receptor set of nearest measured relative Corvus frugilegus (same family Corvidae) | Estimated | [1] | Colour receptors: 3 receptor classes: 421.5 nm (VS/SWS (violet)), 532 nm (MWS (green)), 558.4 nm (LWS (long)) Measured (not re-verified)[1][2][3][4] |
| Sharpness | Acuity 33 cycles per degree median of 1 behavioural rows (method priority rule) | Measured | [5] | Acuity: 63.75 cycles per degree Measured[6][7] |
| Field of view | Binocular overlap 22° median of 1 rows (eyes-at-rest rows preferred) | Measured | [8] | Binocular overlap: 122.5° Measured[9][10] Total field of view: 200° Measured (not re-verified)[11] Blind area behind the head: 160° Derived[11] Eye placement: frontal Derived[9][10] |
| Total field of view 328.5° median total field (measured, or 360 - blind area) of relatives in family Corvidae: Corvus brachyrhynchos, Aphelocoma californica | Estimated | [12] | ||
| Sharp zones (foveas) | Number of foveas 1 median of 1 relatives in family Corvidae: Cyanocitta cristata | Estimated | [13] | Number of foveas: 1 Measured[14] Fovea type: fovea Measured[14] |
| Fovea type single central fovea (displaced dorso-temporally from retinal centre) | Estimated | [13] | ||
| Night vision | Activity pattern diurnal mode of 3 rows (of 3 rows): diurnal; not_nocturnal | Measured (not re-verified) | [15][16][17] | Activity pattern: diurnal Measured (not re-verified)[18][19][20][1][21][22][23][17] Pupil shape: vertical Group default[24][25] Reflective layer (tapetum): no Measured[26] Rods vs cones: cone-dominated Derived[18][19][20][1][21][22][23][17] |
| Rods vs cones cone-dominated nocturnal -> rod-dominated; crepuscular / cathemeral / mixed -> mixed; diurnal -> cone-dominated | Derived | [15][16][17] | ||
| Motion (flicker fusion) | Flicker fusion frequency 100 Hz median of 7 relatives in order Passeriformes: Passer domesticus, Taeniopygia guttata, Molothrus ater, Sturnus vulgaris, Cyanistes caeruleus, Ficedula albicollis | Group default | [27][28][29][30] | Flicker fusion frequency: 60 Hz Measured[28][29] |
Other senses
- magnetoreception: NOT RENDERED (no agreed visual percept) (Group default)
All birds side by side: Birds: every measurement. Method: how we know what animals see.
Sources
- 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
- Tyrrell et al. 2017
- Moore et al. 2017
- Kopania et al. 2025
- Light conditions and the evolution of…
- Wilman et al. 2014
- 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
- Boström et al. 2016
- 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.