How does the blue jay see?
The blue jay (Cyanocitta cristata) is a bird in the order Passeriformes. Its eyes belong to the vision type UV songbird, parrot and hummingbird: 4 cones with a true UV (UVS) cone and oil droplets, high CFF; UV plumage patterns visible.
Measured in this species: sharpness, 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 two colour receptor classes (a dichromat): reds and greens fall on one axis, as in red-green colour blindness in people.
- Its sharpest vision resolves 18.75 cycles per degree: the finest stripe pattern it can tell apart from grey.
- Its eyes cover about 328.5° around the head, with 16.5° seen by both eyes at once.
- It stops seeing flicker at 100 Hz, against 60 Hz for people in this dataset, so fast motion looks about 1.7 times slower to it.[12][13]
- 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.
| Dial | Value | Evidence | Sources |
|---|---|---|---|
| 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] |
| Sharpness | Acuity 18.75 cycles per degree median of 1 behavioural rows (method priority rule) | Measured | [2] |
| Field of view | Binocular overlap 16.5° median of 8 relatives in family Corvidae: Corvus albus, Corvus brachyrhynchos, Corvus corax, Corvus corone, Corvus frugilegus, Coloeus monedula | Estimated | [3][4] |
| Total field of view 328.5° median total field (measured, or 360 - blind area) of relatives in family Corvidae: Corvus brachyrhynchos, Aphelocoma californica | Estimated | [3] | |
| Blind area behind the head 31.5° | Estimated | [3] | |
| Eye placement lateral | Estimated | [3][4] | |
| Sharp zones (foveas) | Number of foveas 1 retinal topography | Measured (not re-verified) | [5] |
| Fovea type single central fovea (displaced dorso-temporally from retinal centre) | Measured (not re-verified) | [5] | |
| Night vision | Activity pattern diurnal mode of 5 rows (of 5 rows): diurnal; not_nocturnal; photopic | Measured (not re-verified) | [6][7][8][9][10] |
| Rods vs cones cone-dominated nocturnal -> rod-dominated; crepuscular / cathemeral / mixed -> mixed; diurnal -> cone-dominated | Derived | [6][7][8][9][10] | |
| 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 | [11][12][13][14] |
Other senses
- magnetoreception: NOT RENDERED (no agreed visual percept) (Group default)
Related animals
- European starling same vision type
- House sparrow same vision type
- American tree sparrow same vision type
- Brown-headed cowbird same vision type
- Chipping sparrow same vision type
- Dark-eyed junco 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
- 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
- Tyrrell LP, Moore BA, Loftis C, Fernandez-Juricic E 2017 (data 2017). The hawk-eyed songbird: retinal morphology, eye shape, and visual fields of an aerial insectivore. Am Nat 189(6). Dryad doi:10.5061/dryad.n7140.. doi.org/10.1086/691404
- Tyrrell LP, Fernandez-Juricic E 2017. Avian binocular vision: it's not just about what birds can see, it's also about what they can't. PLoS ONE 12(3): e0173235. S1 Table.. doi.org/10.1371/journal.pone.0173235
- Moore BA, Tyrrell LP, Pita D, Bininda-Emonds ORP, Fernandez-Juricic E 2017. Does retinal configuration make the head and eyes of foveate birds move? Sci Rep 7: 38406. Appendix 1.. doi.org/10.1038/srep38406
- 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
- 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 L, Motani R. 2011. Science 332:705-708, SOM. doi.org/10.1126/science.1200043
- 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
- Boström JE, Dimitrova M, Canton C, Håstad O, Qvarnström A, Ödeen A. 2016. Ultra-rapid vision in birds. PLoS ONE 11(3): e0151099. S1 Table. doi.org/10.1371/journal.pone.0151099
- 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
- 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
- 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
Every value cites its sources (all sources). Data: catalogue-v1, built 2026-09-29. Accuracy notes: how accurate is this?