See Like Animals Open the tool

Black rhinoceros vision: the science and the numbers

Diceros bicornis · order Perissodactyla · Mammals: all the numbers

Its sharpest vision resolves 6 cycles per degree, against 63.75 for people in this dataset.[5] Its activity pattern is cathemeral.[12][13][14][15][16]

  • 6cycles per degree (sharpness)Measured

The black rhinoceros (Diceros bicornis) is a mammal in the order Perissodactyla. Its eyes belong to the vision type Grazing ungulate panorama: two cone types, a horizontal band of sharp vision and a near-panoramic field with a blind area behind the head. Measured in this species: 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.

What the black rhinoceros sees: colour receptors

Black rhinoceros colour receptor peaks, 300 to 700 nmBlack rhinoceros: 2 receptor peaks at 428, 539 nm; you: 3 at 421.5, 532, 558.4 nm. ultraviolet300400500600700
Black rhinoceros: 428, 539 nmPeople: 421.5, 532, 558.4 nmWavelength in nanometres

What stands out

  • Its sharpest vision resolves 6 cycles per degree: the finest stripe pattern it can tell apart from grey.
  • Activity pattern: cathemeral.

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 black rhinoceros (Diceros bicornis), catalogue-v1
DialValueEvidenceSourcesPeople
ColourColour receptors
2 receptor classes: 428 nm (VS/SWS (violet)), 539 nm (MWS (green))
receptor set of nearest measured relative Equus caballus (same order Perissodactyla)
Group default[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
6 cycles per degree
median of 1 anatomical-ganglion rows (method priority rule)
Measured[5]Acuity: 63.75 cycles per degree Measured[6][5]
Field of viewBinocular overlap
42.5°
median of 1 relatives in order Perissodactyla: Equus caballus
Group default[7][8]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
350°
median species-v1 total field of order Perissodactyla: Equus caballus
Group default[10]
Sharp zones (foveas)Number of foveas
0
fovea_present / area_centralis_type (retinal topography; count 1 = fovea present, 0 = none)
Measured[11]Number of foveas: 1 Measured[11]
Fovea type: fovea Measured[11]
Fovea type
anakatabatic area, area centralis, horizontal streak
Measured[11]
Night visionActivity pattern
cathemeral
mode of 6 rows (of 6 rows): cathemeral; cathemeral (polyphasic); nocturnal/crepuscular; photopic
Measured (not re-verified)[12][13][14][15][16]Activity pattern: diurnal Measured (not re-verified)[17][18][13][1][14][19][15][16]
Pupil shape: vertical Group default[12][20]
Reflective layer (tapetum): no Measured[21]
Rods vs cones: cone-dominated Derived[17][18][13][1][14][19][15][16]
Rods vs cones
mixed
nocturnal -> rod-dominated; crepuscular / cathemeral / mixed -> mixed; diurnal -> cone-dominated
Derived[12][13][14][15][16]
Motion (flicker fusion)Flicker fusion frequency
60 Hz
median of 21 relatives in class Mammalia: Rattus norvegicus, Cavia porcellus, Mus musculus, Felis catus, Macaca mulatta, Macaca nemestrina
Group default[22][23][24][25]Flicker fusion frequency: 60 Hz Measured[23][24]

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. Timney & Keil 1992
  11. Kopania et al. 2025
  12. Banks et al. 2015
  13. Wilman et al. 2014
  14. Maor et al. 2017
  15. Schmitz et al. 2011
  16. Moura et al. 2024
  17. Anderson et al. 2017
  18. Borges et al. 2018
  19. Jones et al. 2009
  20. Cervino et al. 2021
  21. Guareschi et al. 2025
  22. Haarlem et al. 2026
  23. Healy et al. 2013
  24. Inger et al. 2014
  25. 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.