How did we figure out the visual spectrum of different animals?

Question

Apparently hummingbirds can see in the ultraviolet range.

In: 4

Answer 1

We can look at the parts of their eyes (cones and rods and any other type of light-sensitive part) and figure out what happens when each part is exposed to different wavelengths of light. If the part reacts when exposed to a certain wavelength (especially by sending a signal down an optical nerve or similar structure), we can be confident that the part is sensitive to that wavelength. We can also expose live animals to different wavelengths and see how they react. Do this with enough precision and we can paint a pretty thorough picture of what they see and don’t see when it comes to light along the electromagnetic spectrum.