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Crab-eating macaque vision: the science and the numbers

Macaca fascicularis · order Primates · Mammals: all the numbers

The crab-eating macaque has 3 colour receptor classes (430, 531 and 561 nm), like most people.[1] Its sharpest vision resolves 46 cycles per degree, against 63.75 for people in this dataset.[5]

See it on your photoBack to How does the crab-eating macaque see?
  • 3colour receptor classesMeasured
  • 46cycles per degree (sharpness)Measured

The crab-eating macaque (Macaca fascicularis) is a mammal in the order Primates. Its eyes belong to the vision type Human-like trichromat: three cone types, sharp central vision and a wide zone seen by both eyes. Measured in this species: colour, sharpness, 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.

Method: How we know what animals see (the See Like Animals vision engine) · Sources · Last updated . Every value below carries its evidence level and sources; nothing is typed by hand.

What the crab-eating macaque sees: colour receptors

Crab-eating macaque colour receptor peaks, 300 to 700 nmCrab-eating macaque: 3 receptor peaks at 430, 531, 561 nm; you: 3 at 421.5, 532, 558.4 nm. ultraviolet300400500600700
Crab-eating macaque: 430, 531, 561 nmPeople: 421.5, 532, 558.4 nmWavelength in nanometres

What stands out

  • It has three colour receptor classes, like most people.
  • Its sharpest vision resolves 46 cycles per degree: the finest stripe pattern it can tell apart from grey.
  • 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.

Vision values for the crab-eating macaque (Macaca fascicularis), catalogue-v1
DialValueEvidenceSourcesPeople
ColourColour receptors
3 receptor classes: 430 nm (VS/SWS (violet)), 531 nm (MWS (green)), 561 nm (LWS (long))
measured in this species
Measured[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]
SharpnessAcuity
46 cycles per degree
median of 1 behavioural rows (method priority rule)
Measured[5]Acuity: 63.75 cycles per degree Measured[6][5]
Field of viewBinocular overlap
140°
median of 1 relatives in genus Macaca: Macaca mulatta
Estimated[7]Binocular overlap: 122.5° Measured[7][8]
Total field of view: 200° Measured (not re-verified)[9]
Blind area behind the head: 160° Derived[9]
Eye placement: frontal Derived[7][8]
Total field of view
200°
median species-v1 total field of order Primates: Homo sapiens
Group default[9]
Sharp zones (foveas)Number of foveas
1
fovea_present / area_centralis_type (retinal topography; count 1 = fovea present, 0 = none)
Measured[10]Number of foveas: 1 Measured[10]
Fovea type: fovea Measured[10]
Fovea type
fovea		Measured[10]
Night visionActivity pattern
diurnal
mode of 8 rows (of 8 rows): diurnal; photopic
Measured (not re-verified)[11][12][1][13][14][15][16]Activity pattern: diurnal Measured (not re-verified)[17][11][12][1][13][14][15][16]
Pupil shape: vertical Group default[18][19]
Reflective layer (tapetum): no Measured[20]
Rods vs cones: cone-dominated Derived[17][11][12][1][13][14][15][16]
Rods vs cones
cone-dominated
nocturnal -> rod-dominated; crepuscular / cathemeral / mixed -> mixed; diurnal -> cone-dominated
Derived[11][12][1][13][14][15][16]
Motion (flicker fusion)Flicker fusion frequency
73.5 Hz
median of 2 relatives in genus Macaca: Macaca mulatta, Macaca nemestrina
Estimated[21][22][23]Flicker fusion frequency: 60 Hz Measured[21][22]

All mammals side by side: Mammals: every measurement. Method: how we know what animals see.

Sources

  1. Longcore 2023
  2. Kirwan
  3. Müller et al. 2009
  4. Thermal Activation and Photoactivation of Visual… 2004
  5. Veilleux et al. 2014
  6. Kirk et al. 2004
  7. Heesy 2004
  8. Heffner et al. 1992
  9. Campbell & Green 1965
  10. Kopania et al. 2025
  11. Borges et al. 2018
  12. Wilman et al. 2014
  13. Maor et al. 2017
  14. Jones et al. 2009
  15. Schmitz et al. 2011
  16. Moura et al. 2024
  17. Anderson et al. 2017
  18. Banks et al. 2015
  19. Cervino et al. 2021
  20. Guareschi et al. 2025
  21. Healy et al. 2013
  22. Inger et al. 2014
  23. 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.