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Manx shearwater vision: the science and the numbers

Puffinus puffinus · order Procellariiformes · Birds: all the numbers

The manx shearwater has four colour channels, including violet (402, 452, 503 and 566 nm).[1] Its sharpest vision resolves 8.9 cycles per degree, against 63.75 for people in this dataset.[5] Both eyes see the same 16° in front of it.[8]

See it on your photoBack to How does the manx shearwater see?
  • 4colour receptor classesMeasured
  • 8.9cycles per degree (sharpness)Measured
  • 16°seen by both eyesMeasured

The manx shearwater (Puffinus puffinus) is a bird in the order Procellariiformes. Its eyes belong to the vision type Panoramic grain-eater and wader: four cone types, low to moderate sharpness and an almost all-round field of view. Measured in this species: colour, 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.

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 manx shearwater sees: colour receptors

Manx shearwater colour receptor peaks, 300 to 700 nmManx shearwater: 4 receptor peaks at 402, 452, 503, 566 nm; you: 3 at 421.5, 532, 558.4 nm. ultraviolet300400500600700
Manx shearwater: 402, 452, 503, 566 nmPeople: 421.5, 532, 558.4 nmWavelength in nanometres

What stands out

  • It has 4 colour receptor classes; people have 3.
  • Its sharpest vision resolves 8.9 cycles per degree: the finest stripe pattern it can tell apart from grey.
  • Both eyes see the same 16° 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.

Vision values for the manx shearwater (Puffinus puffinus), catalogue-v1
DialValueEvidenceSourcesPeople
ColourColour receptors
4 receptor classes: 402 nm (VS/SWS (violet)), 452 nm (SWS (blue)), 503 nm (MWS (green)), 566 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
8.9 cycles per degree
median of 1 anatomical-ganglion rows (method priority rule)
Measured[5]Acuity: 63.75 cycles per degree Measured[6][7]
Field of viewBinocular overlap
16°
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
307°
median total field (measured, or 360 - blind area) of relatives in genus Puffinus: Puffinus bailloni, Puffinus pacificus
Estimated[12]
Blind area behind the head
53°		Estimated[12]
Eye placement
lateral
frontal if binocular overlap >= 60 deg, else lateral
Derived[8]
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[13][14][15]Number of foveas: 1 Measured[16]
Fovea type: fovea Measured[16]
Fovea type
single central fovea (displaced dorso-temporally from retinal centre)		Group default[13][14][15]
Night visionActivity pattern
diurnal
mode of 4 rows (of 4 rows): cathemeral; diurnal; not_nocturnal
Measured (not re-verified)[17][18][1][19]Activity pattern: diurnal Measured (not re-verified)[20][21][22][1][23][24][25][19]
Pupil shape: vertical Group default[26][27]
Reflective layer (tapetum): no Measured[28]
Rods vs cones: cone-dominated Derived[20][21][22][1][23][24][25][19]
Rods vs cones
cone-dominated
nocturnal -> rod-dominated; crepuscular / cathemeral / mixed -> mixed; diurnal -> cone-dominated
Derived[17][18][1][19]
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[29][30][31][32][33]Flicker fusion frequency: 60 Hz Measured[31][32]

All birds side by side: Birds: 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. Caves et al. 2024
  6. Kirk et al. 2004
  7. Veilleux et al. 2014
  8. Tyrrell et al. 2017
  9. Heesy 2004
  10. Heffner et al. 1992
  11. Campbell & Green 1965
  12. Lucas et al. 2024
  13. Moore et al. 2017
  14. Potier et al. 2017
  15. Rodrigues et al. 2026
  16. Kopania et al. 2025
  17. Light conditions and the evolution of…
  18. Wilman et al. 2014
  19. Moura et al. 2024
  20. Anderson et al. 2017
  21. Borges et al. 2018
  22. Wilman et al. 2014
  23. Maor et al. 2017
  24. Jones et al. 2009
  25. Schmitz et al. 2011
  26. Banks et al. 2015
  27. Cervino et al. 2021
  28. Guareschi et al. 2025
  29. Boström et al. 2016
  30. Haarlem et al. 2026
  31. Healy et al. 2013
  32. Inger et al. 2014
  33. 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.