Written by
| Powered by phpBay Pro |
How do scientists find what colors an animal can see and in general what type of vision do animals/birds have?
For example, I read on Wiki that Cat's night vision is superior to humans but day vision is inferior. Also, a hen can see only some specific colors (not the whole spectrum). Also, an eagle has a telescopic vision etc. How are these things found? They probably can't get cats or hens to respond to some specific colors etc I guess!
It's actually a combination of what the first two posters wrote. Microscopic examination of the retina provides information on the density of visual cells and the proportions of one kind to another. More rods than cones indicates better night vision, for example. Testing the visal pigments from the retinal cells for their responses to light determines the wavelength sensitivities of the different types of cells, which establishes how well an animal should be able to discriminate colors. Behavioral studies can establish the animal's real life ability to discriminate among colors and at see objects at various light levels.
Cats have trouble seeing some of the colors that normal human eyes can see because they have only 2 kinds of cone cells to our 3. Chickens, like most birds, have cone cells with 4 different visual pigments plus color-filtering oil droplets and are able to see many times more colors than we can, even into the ultraviolet range. Eagles actually have high-def vision, not telescopic vision, because the foveal pit, an area of densely packed cells in their retinas, creates a high resolution image.
Items Recently Purchased From This Site:
| Powered by phpBay Pro |
