Figure 1
From: Evolution of ultraviolet vision in the largest avian radiation - the passerines
Examples of spectral sensitivities for VS and UVS birds. Normalised single cone spectral sensitivities (from left to right: SWS1, SWS2, MWS and LWS) of a VS bird (Indian Peafowl Pavo cristatus) [68] and a UVS bird (Eurasian Blue Tit Cyanistes caeruleus) [36] including the effects of ocular medium absorption. Human visible range is approximately 400-700 nm, with wavelengths shorter than 400 nm being ultraviolet.