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Wedge-tailed shearwater vision: the science and the numbers

Puffinus pacificus · order Procellariiformes · Birds: all the numbers

The wedge-tailed shearwater has four colour channels, including violet (406, 450, 503 and 566 nm).[1][2] Its eyes cover about 312.6° with 30.6° seen by both eyes.[9]

  • 4colour receptor classesMeasured
  • 312.6°field of viewEstimated

The wedge-tailed shearwater (Puffinus pacificus) 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, 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.

What the wedge-tailed shearwater sees: colour receptors

Wedge-tailed shearwater colour receptor peaks, 300 to 700 nmWedge-tailed shearwater: 4 receptor peaks at 406, 450, 503, 566 nm; you: 3 at 421.5, 532, 558.4 nm. ultraviolet300400500600700
Wedge-tailed shearwater: 406, 450, 503, 566 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 312.6° around the head, with 30.6° 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 wedge-tailed shearwater (Puffinus pacificus), catalogue-v1
DialValueEvidenceSourcesPeople
ColourColour receptors
4 receptor classes: 406 nm (VS/SWS (violet)), 450 nm (SWS (blue)), 503 nm (MWS (green)), 566 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)[2][3][4][5]
SharpnessAcuity
8.9 cycles per degree
median of 1 relatives in genus Puffinus: Puffinus puffinus
Estimated[6]Acuity: 63.75 cycles per degree Measured[7][8]
Field of viewBinocular overlap
30.6°
median of 1 rows (eyes-at-rest rows preferred)
Measured[9]Binocular overlap: 122.5° Measured[10][11]
Total field of view: 200° Measured (not re-verified)[12]
Blind area behind the head: 160° Derived[12]
Eye placement: frontal Derived[10][11]
Total field of view
312.6°
rule: total = 360 - blind area
Derived[9]
Blind area behind the head
47.4°
Measured[9]
Eye placement
lateral
frontal if binocular overlap >= 60 deg, else lateral
Derived[9]
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 3 rows (of 3 rows): cathemeral; diurnal; not_nocturnal
Measured (not re-verified)[17][2][18]Activity pattern: diurnal Measured (not re-verified)[19][20][21][2][22][23][24][18]
Pupil shape: vertical Group default[25][26]
Reflective layer (tapetum): no Measured[27]
Rods vs cones: cone-dominated Derived[19][20][21][2][22][23][24][18]
Rods vs cones
cone-dominated
nocturnal -> rod-dominated; crepuscular / cathemeral / mixed -> mixed; diurnal -> cone-dominated
Derived[17][2][18]
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[28][29][30][31][32]Flicker fusion frequency: 60 Hz Measured[30][31]

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

Sources

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