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Optical Differences in Color Vision between a Human Eye and Avian Eye

It is well known that birds have greater light wavelength sensitivity in their eyes, making their vision better than that of humans. It has been found that the avian eye can detect ultraviolet wavelengths, and evidence has shown that this perception plays an important role in their foraging habits.

An experiment was conducted to see the effect of the removal of “1) UV wavelengths and 2) wavebands in the human-visible region on the frequency-dependent seed preferences of zebra finches” (Church, 2001). It was discovered that removing UV wavelengths changed the direction and strength of frequency-dependence. Although ultraviolet wavelengths are still strongly suspected to be very significant to avian vision, wavelengths in the human-visible spectrum are considered to be dominant.

Color perception is very significant in the human world, but it is known that there are wavelengths that cannot be detected by the human eye. The structure of the avian eye, for example, gives birds a more colorful world. There is evidence that the ability of birds to see ultraviolet wavelengths is very useful to them in the detection of objects. There are many optical differences, involving color vision, in a human eye and a bird eye, which affect their sight and behavior.

The human eye is trichromatic, meaning it contains three classes of cones. On the other hand, birds have tetrachromatic vision with four classes of cones. The extra class of cones in an avian eye enables birds to see twice as many colors as humans as well as ultraviolet light. Birds use ultraviolet wavelengths to search for insects, berries, seeds, and mammals.

Even though it has been proven that birds can detect ultraviolet wavelengths, in experiments, ultraviolet light did not seem to make as much of a difference as was hoped. Possibly, if there were other variables in the experiments, the importance and use of UV light in avian eyes would be more obvious. To understand avian sight better, it may be more worthwhile to consider the whole range of wavelengths that birds see, rather than concentrating on just one waveband. It can be easily realized that birds have better vision than humans through observation of their behavior, especially in predator-prey situations.

However, now we humans still wonder exactly how well they can see.

Information for this page provided by the link below

https://cosmos.ucdavis.edu/