Because cats and dogs are slightly color blind (they only have blue and green cones), people tend to think that birds are also color blind. However, in this article, you will discover that is quite the opposite in most cases!
Quite the contrary! Birds can actually see way better than us. Their eyes are so sensitive they are capable of seeing ultraviolet colors that are invisible to human eyes.
Do birds see in color? How well do birds see?
Yes, they do! Bird of prey and raptors have excellent vision.
The cell in the eyes responsible for color perception are called cones and they are located in the retina. While humans have three cones, birds can have four types of cones. Every cone represents a selective filter for certain colors. This wavelength filter allows avians to see more contrast in their surroundings.
Bald eagles, for instance, have incredibly powerful eyes. They have five times more nerve density in their retinas, being able to transfer more data to their brains. Their vision can be 4-8 times more powerful than the human eye.
In general, raptors’ eyes act like cameras that have both a macro lens and a zoom lens. One lens lets them focus on objects that are far away whereas the other zeros it on finding fine details.
Their extraordinary vision is necessary for them to gather their prey easily. For instance, an eagle can spot a mouse on the ground from a thousand feet in the air. They can see fish swimming just beneath the surface of a body of water and swoop them down with their powerful talons.
Birds also have Pecten oculi, a structure of blood vessels that keep their vision clear, even under fast-changing light conditions while they are flying and hunting.
Birds can see ultraviolet light
To demonstrate that birds can see colors and even ultraviolet, Mary Caswell Stoddard, an assistant professor in the Princeton University Department of Ecology and Evolutionary Biology, made an experiment using hummingbirds to discover how birds really use color in their day-to-day life.
There were two feeders with a LED tube inside signaling different colors. One with common water and another with sugar. The hummingbirds were to choose which feeder to keep hoovering at. The reward (sugar) was given depending on which feeder the bird tried to collect nectar. Over the course of several hours, the birds learned to feed at the rewarding feeder that lit a different color at each experiment. The scientists even used two colors that are identical to the human eye, such as ultraviolet+green, but the birds were able to distinguish them.
Pigeons also have amazing eyesight, binocular vision, and a great memory. They can understand foreground an background. Can distinguish letter of the alphabet, a cat or a dog, and even the difference between a Monet and a Picasso painting.
They are used in Search and Rescue because they can spot the bright orange of a life-raft when it’s still out of range of human vision.
Pigeons helping the fight against cancer
Scientists saw this useful skill spot identifying vision as an advantage for identifying cancer in radiology images. They trained pigeons to spot differences in the radiology images (cancer) by pecking in a touch-sensitive screen and giving them a food reward.
The pigeons were able to identify cancer correctly 85% of the time. That happened only in 15 days of training. When grouped into flocks to analyze averages, their accuracy rate jumped to 99%, the same level of accuracy of cancer radiology experts.
What colors are birds attracted to?
In general, birds tend to be commonly attracted to the colors red and yellow. Hummingbirds, for instance, have a profound fondness of red flowers, and that’s the reason why feeders are red-colored.
Natural camouflage colors, like gray, brown, and green are good options to attract birds with more nervous temperaments, such as doves, quails, etc.
While bright colors usually attract birds, white, however, is the one color to be avoided. Apparently, birds see it as a warning color.
Why colors are important for birds?
Color is important for birds because it helps them choosing mates, as well as locating food.
Brighter plumage colors indicate the onset of the breeding season. Brighter colors can also indicate that a mate is mature and healthy.
Food and environmental cues
- Bright colors can be a warning against toxic plants and strong predators
- For hummingbirds, the brighter flowers, the more nectar they contain
- Bright-colored fruits are usually ready to eat and are at the peak of their nutritious content.
- Change in the foliage means that’s time for migration
What colors can birds not see?
Nocturne birds have limited color vision when compared to diurnal birds. Owls for instance have blurry vision during the day and can see a limited number of colors.
However, at nighttime, their vision is incredible. Nocturn birds have a special vision that allows them to capture more light and see even in low light conditions.
Owls have a reflective surface behind their retina known as the tapetum lucidum. This allows the light to reflect back into the animal’s eye after it’s already passed through, giving the bird two chances to collect an adequate amount of light.
How do birds migrate at night if they can’t see?
Scientists discovered that birds can do long migrations and fly at night because they are capable of seeing Earth’s magnetic field.
The Earth’s magnetic field is a result of the movement or convection of liquid iron in the outer core. As the liquid metal in the outer core moves, it generates electric currents, which lead to a magnetic field. The continual movement of liquid metal through this magnetic field creates stronger electrical currents and thus a stronger magnetic field.
As it turns out, birds see the magnetic field as some sort of blue wave light, that acts like a compass they are trying to guide themselves up in the air.
To resume, birds have excellent vision! They can spot contrast in colors from distance and see even more colors than we do.