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Humboldt penguin vision: the science and the numbers

Spheniscus humboldti · order Sphenisciformes · Birds: all the numbers

The Humboldt penguin has four colour channels, including violet (403, 450, 499 and 543 nm).[1][2] Its eyes cover about 282° with 28° seen by both eyes.[10][11]

See it on your photoBack to How does the Humboldt penguin see?
  • 4colour receptor classesMeasured
  • 282°field of viewMeasured

The Humboldt penguin (Spheniscus humboldti) is a bird in the order Sphenisciformes. Its eyes belong to the vision type Penguin (underwater-tuned bird): cones shifted towards blue, no ultraviolet cone and a flat cornea for focusing under water. Measured in this species: colour, 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.

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 Humboldt penguin sees: colour receptors

Humboldt penguin colour receptor peaks, 300 to 700 nmHumboldt penguin: 4 receptor peaks at 403, 450, 499, 543 nm; you: 3 at 421.5, 532, 558.4 nm. ultraviolet300400500600700
Humboldt penguin: 403, 450, 499, 543 nmPeople: 421.5, 532, 558.4 nmWavelength in nanometres

What stands out

  • It has 4 colour receptor classes; people have 3.
  • Its eyes cover about 282° around the head, with 28° seen by both eyes at once.
  • 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 Humboldt penguin (Spheniscus humboldti), catalogue-v1
DialValueEvidenceSourcesPeople
ColourColour receptors
4 receptor classes: 403 nm (VS/SWS (violet)), 450 nm (SWS (blue)), 499 nm (MWS (green)), 543 nm (LWS (long))
measured in this species
Measured[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)[1][3][4][5]
SharpnessAcuity
18.93 cycles per degree
median of 2 relatives in family Spheniscidae: Aptenodytes patagonicus, Eudyptula minor
Estimated[6][7]Acuity: 63.75 cycles per degree Measured[8][9]
Field of viewBinocular overlap
28°
species-v1.csv
Measured[10][11]Binocular overlap: 122.5° Measured[12][13]
Total field of view: 200° Measured (not re-verified)[14]
Blind area behind the head: 160° Derived[14]
Eye placement: frontal Derived[12][13]
Total field of view
282°
species-v1.csv
Measured[10][11]
Blind area behind the head
78°
blind area = 360 - total field
Derived[11]
Eye placement
lateral
frontal if binocular overlap >= 60 deg, else lateral
Derived[11]
Binocular overlap (published value)
28° (approximate); approximately horizontal plane; eyes in relaxed (resting) position; head in typical posture for the species; alert live birds		Measured[15]
Binocular field, vertical extent
125° (approximate); approximately horizontal plane; eyes in relaxed (resting) position; head in typical posture for the species; alert live birds		Measured[15]
Field of one eye
155° (approximate); approximately horizontal plane; eyes in relaxed (resting) position; head in typical posture for the species; alert live birds		Measured[15]
Total field (published value)
282° (approximate); approximately horizontal plane; eyes in relaxed (resting) position; head in typical posture for the species; alert live birds		Measured[15]
Binocular field, widest at any elevation
45°; maximum binocular overlap (widest frontal binocular sector at any elevation); maximum binocular overlap (compiled)		Measured[16]
Field of one eye
123°; medium (air / water) as stated; horizontal plane in the plane of the optic axes; in water; method printed: histology, optical ray tracing (Martin & Young 1984)		Measured[17]
Blind area behind the head (published value)
114°; medium (air / water) as stated; horizontal plane in the plane of the optic axes; in water; histology, optical ray tracing		Measured[17]
Binocular overlap (published value)
0°; medium (air / water) as stated; horizontal plane in the plane of the optic axes; in water; histology, optical ray tracing		Measured[17]
Binocular field, vertical extent
77°; medium (air / water) as stated; horizontal plane in the plane of the optic axes; in water; histology, optical ray tracing		Measured[17]
Total field (published value)
246°; medium (air / water) as stated; horizontal plane in the plane of the optic axes; in water; histology, optical ray tracing		Measured[17]
Blind area behind the head (published value)
78°; medium (air / water) as stated; horizontal plane in the plane of the optic axes; in air; histology, optical ray tracing		Measured[17]
Sharp zones (foveas)Number of foveas
1
median of 48 relatives in class Aves: Branta canadensis, Cardinalis cardinalis, Passerina cyanea, Zenaida macroura, Cyanocitta cristata, Junco hyemalis
Group default[18][19][20]Number of foveas: 1 Measured[21]
Fovea type: fovea Measured[21]
Fovea type
single central fovea (displaced dorso-temporally from retinal centre)		Group default[18][19][20]
Night visionActivity pattern
diurnal
mode of 5 rows (of 5 rows): cathemeral; diurnal; not_nocturnal
Measured (not re-verified)[22][23][24][1][25]Activity pattern: diurnal Measured (not re-verified)[22][26][27][1][28][29][30][25]
Pupil shape: vertical Group default[31][32]
Reflective layer (tapetum): no Measured[33]
Rods vs cones: cone-dominated Derived[22][26][27][1][28][29][30][25]
Night sensitivity (optical, against people): S = 0.93 µm² sr, 1 times people (log10 ratio 0) Derived[34]
Rods vs cones
cone-dominated
nocturnal -> rod-dominated; crepuscular / cathemeral / mixed -> mixed; diurnal -> cone-dominated
Derived[22][23][24][1][25]
Motion (flicker fusion)Flicker fusion frequency
88.5 Hz
median of 17 relatives in class Aves: Bubo virginianus, Melopsittacus undulatus, Passer domesticus, Taeniopygia guttata, Columba livia, Calypte anna
Group default[35][36][37][38][39]Flicker fusion frequency: 60 Hz Measured[37][38]

All birds side by side: Birds: every measurement. Method: how we know what animals see.

Sources

  1. Longcore 2023
  2. Frazer et al. 2024
  3. Kirwan
  4. Müller et al. 2009
  5. Thermal Activation and Photoactivation of Visual… 2004
  6. Caves et al. 2018
  7. Caves et al. 2024
  8. Kirk et al. 2004
  9. Veilleux et al. 2014
  10. Hadden et al. 2023
  11. Hadden & Zhang 2023
  12. Heesy 2004
  13. Heffner et al. 1992
  14. Campbell & Green 1965
  15. Martin et al. 1999
  16. Troscianko et al. 2012
  17. Hadden et al. 2023
  18. Moore et al. 2017
  19. Potier et al. 2017
  20. Rodrigues et al. 2026
  21. Kopania et al. 2025
  22. Anderson et al. 2017
  23. Light conditions and the evolution of…
  24. Wilman et al. 2014
  25. Moura et al. 2024
  26. Borges et al. 2018
  27. Wilman et al. 2014
  28. Maor et al. 2017
  29. Jones et al. 2009
  30. Schmitz et al. 2011
  31. Banks et al. 2015
  32. Cervino et al. 2021
  33. Guareschi et al. 2025
  34. Brauburger et al. 2026
  35. Boström et al. 2016
  36. Haarlem et al. 2026
  37. Healy et al. 2013
  38. Inger et al. 2014
  39. 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.