Colour Vision: A Unique Experience for Every Creature
Tigers and deer do not see the world the way we do. Each species has developed color vision suited to its environment. Our eyes are equipped with a unique system to detect and process light, made possible through the combination of our eyes and brain. Different animal groups have developed their vision based on their needs. Predatory animals, such as tigers and leopards, rely more on the movement of their prey and therefore do not require a wide range of colors. They have binocular vision, which helps them gauge depth and distance accurately. On the other hand, prey animals, such as deer and rabbits, need to survey a larger area to detect predators. Hence, their eyes are positioned on the sides of their heads, allowing them to have a wider field of view.
The ability to perceive colours depends on light-sensitive cells in the eye called photoreceptors. These are mainly of two types: rod cells, which help in low-light vision and detect brightness, and cone cells, which assist in recognizing colours and details. Humans have three types of cone cells, providing trichromatic vision, allowing us to perceive blue, green, and red colours, resulting in a broad colour spectrum. In contrast, tigers have only two types of cone cells, enabling them to see only blue and green colours distinctly. Red and orange appear as dull brown or faded shades to them. Tigers rely more on motion and contrast, which aids them in hunting at night and during twilight. Similarly, deer also have dichromatic vision but can see blue and yellow hues more effectively. Red and orange appear as shades of brown or grey to them. Consequently, deer cannot distinctly see a tiger’s orange fur, allowing the tiger to blend seamlessly into the forest.
Some creatures, such as birds, have tetrachromatic vision, enabling them to perceive UV light, while mantis shrimp possess hyperspectral vision with 16 types of photoreceptors, allowing them to see UV, infrared, and polarized light. Humans cannot see infrared and UV light as our eye lenses filter out UV rays. However, some reports suggest that individuals who have undergone lens surgery may develop the ability to perceive UV light.
Birds have developed several adaptations to protect their eyes from UV radiation. The lenses and corneas of their eyes are capable of filtering UV light, preventing intense UV rays from directly reaching the retina. Additionally, their eyes contain special types of oil-filled colored droplets that help filter harmful wavelengths of light and enhance color recognition. Some birds also use their eyelids and third eyelid (nictitating membrane) for UV protection, which not only helps in retaining moisture and shielding from dust but also reduces the impact of UV light on their eyes.
Choosing the right clothing colours is crucial if you want to attract less attention from animals in the jungle. Bright green, white, black, blue, and purple are more visible to animals, while brown, khaki, and grey blend well with the natural surroundings. Orange appears dull brown to deer and other mammals but can be highly attractive to birds. Therefore, to avoid drawing the attention of birds, it is best to avoid red, orange, and yellow colours.
Each species experiences colour vision differently. Tigers and deer do not perceive colours as we do, but movement and brightness play a more vital role in their vision. Wearing brown, khaki, and grey clothing is the best way to blend into the jungle environment.
