Editing Visible spectrum (section)

===Birds===
{{see also|Bird vision#Ultraviolet sensitivity}}
Most other vertebrates (birds, lizards, fish, etc.) have retained their [[tetrachromacy]], including UVS opsins that extend further into the ultraviolet than humans' VS opsin.<ref name="Hunt-2001"/> The sensitivity of avian UVS opsins vary greatly, from 355–425&nbsp;nm, and LWS opsins from 560–570&nbsp;nm.<ref name="Hart-2007">{{cite journal |last1=Hart |first1=Nathan S. |last2=Hunt |first2=David M. |title=Avian Visual Pigments: Characteristics, Spectral Tuning, and Evolution |journal=The American Naturalist |date=January 2007 |volume=169 |issue=S1 |pages=S7–S26 |doi=10.1086/510141|pmid=19426092 |bibcode=2007ANat..169S...7H |s2cid=25779190 |citeseerx=10.1.1.502.4314 }}</ref> This translates to some birds with a visible spectrum on par with humans, and other birds with greatly expanded sensitivity to UV light. The LWS opsin of birds is sometimes reported to have a peak wavelength above 600&nbsp;nm, but this is an effective peak wavelength that incorporates the filter of avian [[oil droplet]]s.<ref name="Hart-2007"/> The peak wavelength of the LWS opsin alone is the better predictor of the long-wave limit. A possible benefit of avian UV vision involves sex-dependent markings on their [[plumage]] that are visible only in the ultraviolet range.<ref>{{cite book|last=Cuthill|first=Innes C |author-link=Innes Cuthill |editor=Peter J.B. Slater|title=Advances in the Study of Behavior|publisher=Academic Press|location=Oxford, England|year=1997|volume=29|chapter=Ultraviolet vision in birds|page=161|isbn=978-0-12-004529-7}}</ref><ref>{{cite book|last=Jamieson|first=Barrie G. M. |title=Reproductive Biology and Phylogeny of Birds|publisher=University of Virginia|location=Charlottesville VA|year=2007|page=128|isbn=978-1-57808-386-2}}</ref>