Editing Hummingbird (section)

===Visual cues of foraging===

Hummingbirds have exceptional visual acuity providing them with discrimination of food sources while foraging.<ref name=lisney/> Although hummingbirds are thought to be attracted to color while seeking food, such as red flowers or artificial feeders, experiments indicate that location and flower nectar quality are the most important "[[beacon]]s" for foraging.<ref name="audubon">{{Cite web |date=28 May 2013 |title=Hummingbirds See Red |url=http://www.audubon.org/news/hummingbirds-see-red |access-date=23 April 2017 |publisher=US National Audubon Society}}</ref><ref>{{Cite web |date=16 March 2012 |title=Hummingbirds take no notice of flower color |url=https://phys.org/news/2012-03-hummingbirds.html |access-date=22 April 2017 |publisher=Phys.org}}</ref> Hummingbirds depend little on visual cues of flower color to beacon to nectar-rich locations, but rather they use surrounding landmarks to find the nectar reward.<ref>{{Cite journal |last1=Hurly |first1=T.A. |last2=Franz |first2=S |last3=Healy |first3=S.D. |year=2010 |title=Do rufous hummingbirds (''Selasphorus rufus'') use visual beacons? |journal=Animal Cognition |volume=13 |issue=2 |pages=377–383 |doi=10.1007/s10071-009-0280-6 |pmid=19768647 |s2cid=9189780}}</ref><ref>{{Cite journal |last1=Hurly |first1=T.A. |last2=Fox |first2=T.A.O. |last3=Zwueste |first3=D.M. |last4=Healy |first4=S.D. |year=2014 |title=Wild hummingbirds rely on landmarks not geometry when learning an array of flowers |url=https://research-repository.st-andrews.ac.uk/bitstream/10023/6422/1/Hurly_et_al_Anim_Cog_14.pdf |journal=Animal Cognition |volume=17 |issue=5 |pages=1157–165 |doi=10.1007/s10071-014-0748-x |pmid=24691650 |hdl-access=free |hdl=10023/6422 |s2cid=15169177}}</ref><ref name="Hornsby">{{cite journal |last1=Hornsby |first1=Mark A.W. |last2=Healy |first2=Susan D. |last3=Hurly |first3=T. Andrew |title=Wild hummingbirds can use the geometry of a flower array |journal=Behavioural Processes |volume=139 |year=2017|pmid=28161360|issn=0376-6357 |doi=10.1016/j.beproc.2017.01.019 |pages=33–37|hdl=10023/12652 |s2cid=10692583 |hdl-access=free }}</ref>

In at least one hummingbird species &ndash; the [[green-backed firecrown]] (''Sephanoides sephaniodes'') &ndash; flower colors preferred are in the red-green wavelength for the bird's visual system, providing a higher [[contrast (vision)|contrast]] than for other flower colors.<ref name="herrera">{{Cite journal |last1=Herrera |first1=G |last2=Zagal |first2=J. C. |last3=Diaz |first3=M |last4=Fernández |first4=M. J. |last5=Vielma |first5=A |last6=Cure |first6=M |last7=Martinez |first7=J |last8=Bozinovic |first8=F |last9=Palacios |first9=A. G. |year=2008 |title=Spectral sensitivities of photoreceptors and their role in colour discrimination in the green-backed firecrown hummingbird (''Sephanoides sephaniodes'') |journal=Journal of Comparative Physiology A |volume=194 |issue=9 |pages=785–794 |doi=10.1007/s00359-008-0349-8 |pmid=18584181 |hdl-access=free |hdl=10533/142104 |s2cid=7491787|url=http://americanae.aecid.es/americanae/es/registros/registro.do?tipoRegistro=MTD&idBib=3262327 }}</ref> Further, the crown plumage of firecrown males is highly iridescent in the red wavelength range (peak at 650 nanometers), possibly providing a competitive advantage of [[dominance (ethology)|dominance]] when foraging among other hummingbird species with less colorful plumage.<ref name=herrera/> The ability to discriminate colors of flowers and plumage is enabled by a visual system having four single [[cone cell]]s and a double cone screened by [[photoreceptor cell|photoreceptor]] [[oil droplet]]s which enhance color discrimination.<ref name=audubon/><ref name=herrera/>