How does the California sea lion see?
The California sea lion (Zalophus californianus) is a mammal in the order Carnivora. Its eyes belong to the vision type Marine mammal cone monochromat.
Measured in this species: colour, sharpness and night vision. Measured core: measured values on at least 3 of the 6 dials. Every value below carries its evidence level and sources; nothing is typed by hand.
See your photo as the California sea lionThis species is part of the full catalogue in the tool (full unlock). Your photo stays on your device.
What stands out
- It has one receptor class for colour, so it sees brightness but no hue.
- Its sharpest vision resolves 5.625 cycles per degree: the finest stripe pattern it can tell apart from grey.
- Its eyes cover about 250° around the head, with 88.5° seen by both eyes at once.
- It stops seeing flicker at 76.25 Hz, against 60 Hz for people in this dataset, so fast motion looks about 1.3 times slower to it.[14][15]
- 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.
| Dial | Value | Evidence | Sources |
|---|---|---|---|
| Colour | Colour receptors 1 receptor class: 501.3 nm (MWS (green)) measured in this species | Measured (not re-verified) | [1] |
| Sharpness | Acuity 5.625 cycles per degree median of 2 behavioural rows (method priority rule) | Measured | [2][3] |
| Field of view | Binocular overlap 88.5° median of 4 relatives in order Carnivora: Canis lupus, Felis catus, Mustela putorius, Mustela nivalis | Group default | [4][5] |
| Total field of view 250° median species-v1 total field of order Carnivora: Canis familiaris | Group default | [6] | |
| Sharp zones (foveas) | Number of foveas 0 median of 10 relatives in order Carnivora: Canis lupus, Vulpes lagopus, Acinonyx jubatus, Felis catus, Crocuta crocuta, Enhydra lutris | Group default | [7] |
| Fovea type area centralis, horizontal streak | Group default | [7] | |
| Night vision | Activity pattern cathemeral mode of 4 rows (of 6 rows): aquatic; cathemeral; diurnal; mixed (nocturnal/crepuscular, cathemeral, crepuscular or diurnal/crepuscular); nocturnal/crepuscular | Measured (not re-verified) | [8][9][10][11][12] |
| Rods vs cones mixed nocturnal -> rod-dominated; crepuscular / cathemeral / mixed -> mixed; diurnal -> cone-dominated | Derived | [8][9][10][11][12] | |
| Motion (flicker fusion) | Flicker fusion frequency 76.25 Hz median of 4 relatives in order Carnivora: Felis catus, Canis lupus, Pagophilus groenlandicus, Canis familiaris | Group default | [13][14][15][16] |
Related animals
- Harbour seal same vision type
- Northern elephant seal same vision type
- Pacific walrus same vision type
- Harp seal same vision type
- Northern fur seal same vision type
- Steller's sea lion same vision type
More mammals: all mammals with measured vision data.
Sources
- Murphy MJ, Westerman EL. 2022. Evolutionary history limits species' ability to match colour sensitivity to available habitat light. Proc R Soc B 289:20220612. Electronic supplementary Table S1. doi.org/10.1098/rspb.2022.0612
- de Sousa AA et al. 2022. A natural history of vision loss: insight from evolution for human visual function. Neurosci Biobehav Rev 134:104550 (mmc, acuity compilation). doi.org/10.1016/j.neubiorev.2022.104550
- Kirk EC, Kay RF 2004. The evolution of high visual acuity in the Anthropoidea. In Anthropoid Origins, Table 1 (behavioural acuity). doi.org/10.1007/978-1-4419-8873-7_20
- Heesy CP 2004. On the relationship between orbit orientation and binocular visual field overlap in mammals. Anat Rec 281A:1104, Table 1. doi.org/10.1002/ar.a.20116
- Heffner RS, Heffner HE 1992. Visual factors in sound localization in mammals. J Comp Neurol 317:219, Table 1 (via Evo-M1 sensory merge). doi.org/10.1002/cne.903170302
- species_v1:Miller & Murphy 1995
- Kopania EEK, Clark NL. 2025. Mammalian retinal specializations for high acuity vision evolve in response to both foraging strategies and morphological constraints. Evolution Letters 9: qrae072. Supplementary Tables S1-S2.. doi.org/10.1093/evlett/qrae072
- Borges R, Johnson WE, O'Brien SJ, Gomes C, Heesy CP, Antunes A (2018) Adaptive genomic evolution of opsins reveals that early mammals flourished in nocturnal environments. BMC Genomics 19:121
- Wilman et al. 2014 EltonTraits 1.0, MamFuncDat.txt. doi.org/10.6084/m9.figshare.3559887.v1
- Maor R, Dayan T, Ferguson-Gow H, Jones KE. 2017. Temporal niche expansion in mammals from a nocturnal ancestor after dinosaur extinction. Nature Ecology & Evolution 1:1889-1895. Supplementary Table 1. doi.org/10.1038/s41559-017-0366-5
- Jones KE et al. 2009. PanTHERIA: a species-level database of life history, ecology, and geography of extant and recently extinct mammals. Ecology 90:2648. Ecological Archives E090-184. doi.org/10.1890/08-1494.1
- Moura et al. 2024. A phylogeny-informed characterisation of global tetrapod traits addresses data gaps and biases. PLoS Biol 22:e3002658. TetrapodTraits v3.0.1.. doi.org/10.5281/zenodo.22536349
- Haarlem CS, Hynes C, Jackson AL, Mitchell KJ, O'Connell RG, Healy K. 2026. Pace of ecology drives the tempo of visual perception across the animal kingdom. Nature Ecology & Evolution (doi:10.1038/s41559-026-02994-7). Figshare dataset 10.6084/m9.figshare.30556475. doi.org/10.6084/m9.figshare.30556475
- Healy K, McNally L, Ruxton GD, Cooper N, Jackson AL. 2013. Metabolic rate and body size are linked with perception of temporal information. Animal Behaviour 86:685-696. Table 1. doi.org/10.1016/j.anbehav.2013.06.018
- Inger R, Bennie J, Davies TW, Gaston KJ. 2014. Potential biological and ecological effects of flickering artificial light. PLoS ONE 9(5): e98631. Table 3. doi.org/10.1371/journal.pone.0098631
- Lafitte A, Sordello R, Legrand M, Nicolas V, Obein G, Reyjol Y. 2022. A flashing light may not be that flashy: A systematic review on critical fusion frequencies. PLoS ONE 17(12): e0279718. S10 File (CFF database). doi.org/10.1371/journal.pone.0279718
Every value cites its sources (all sources). Data: catalogue-v1, built 2026-09-29. Accuracy notes: how accurate is this?