The importance of colours
In nature, animals use colours in many different ways. Some animals use colours to camouflage themselves and blend in with their surroundings, while others use colours to make themselves visible. Strong colours can be useful when it’s time to mate. Usually males get bright colours, while females keep their normal colours.
Some animals use bright colors to blend in with their colorful surroundings, like this pygmy seahorse.
Photo: Rickard-Zerpe-CC-BY-SA
In many species, it's the males who have bright colors to attract mates. The male licorice gourami has spectacular colors and long, veil-like fins.
Photo: Martin-Fischer-CC-BY-SA
Male yellow-headed geckos are brightly orange-colored on their heads, to attract mates and display dominance over other males. Females are gray-colored and more camouflaged against their surroundings.
Photo: Geoff-Gallice-CC-BY
Displaying its colorful chin is a way for the anole lizard to both warn other males and attract mates.
Photo: Gailhampshire-CC-BY
During mating season, the male three-spined stickleback gets an intense red colour on its body. Once mating is over, he returns to his usual gray colour.
Photo: Piet-Spaans-CC-BY
Intense colours to instil fear
Some insects, fish and snakes use intense colours to signal that they taste bad, or are poisonous and dangerous. Usually, they are combinations of black and yellow or black and red, sometimes with touches of white. The red shell of the common ladybird with its black spots indicates that the bug is not tasty. The poison dart frogs of South America can be very brightly coloured to indicate just how poisonous they are.
Many insects have eye-like spots on their wings or abdomen to scare or confuse animals that want to eat them. Big eyes are always awe inspiring. A butterfly caterpillar with eye spots on its abdomen may resemble a snake.
A praying mantis in Tanzania has a coloration with eye spots as well as confusing patterns. But birds, fish, lizards and other animals also use intimidating eye spots to protect themselves.
The seven-spotted ladybird uses its colours to warn predators: "I taste bad!"
Photo: Dominik-Stodulski-CC-BY-SA
The small twenty-two spotted ladybug uses yellow and black as warning colours.
Photo: Olei-CC-BY-SA
Wasps also have colours that serve as a warning for their toxicity.
Photo: Richard-Bartz-CC-BY-SA
A colourful poison dart frog, warning with its colours.
The Peacock butterfly is a species with large, intimidating eye-spots on its wings.
Photo: Korall-CC-BY-SA
The spicebush swallowtail caterpillar also has eye-spots.
Photo: Michael-Hodge-CC-BY
The South American frog Physalaemus nattereri has large eye spots on the upper side of its body that scare both birds and other predators.
Photo: Felipe-Gomes-CC-BY-SA
This mantis in Tanzania has a confusing pattern and a scary eye-spot that protects it from predators.
Photo: Ngirilover-CC-BY-SA
Blue tits have colours in their plumage that are invisible to us humans, but which play a big role in the birds' choice of mate. In ultraviolet light, the differences between males and females can be seen clearly, and males use these colours to impress females and increase their chances of mating.
Photo: Luc-Viatour-CC-BY-SA
Hummingbirds have excellent colour vision and can perceive ultraviolet colours, which helps them locate nectar in flowers. Males also use their ultraviolet colours to impress females and capture their attention.
Photo: Marcial4-CC-BY-SA
When insects search for nectar in flowers, they often use the colours in UV light to find the right ones. The patterns and colours of flowers in UV light can also help insects find their way out of the flower, which is important for spreading pollen and preserving the flower's reproduction.
Photo: Plantsurfer-CC-BY-SA
Invisible UV light?
We like to think that humans have good eyesight. Based on the colours red, blue and green, we can see about 1,000,000 different shades of colour! But the ultraviolet shades are invisible to us. However, they are not invisible to birds, bees and many other insects. The colours of flowers are enhanced by UV light, making it easier for insects to access their nectar.
Many colours in the ultraviolet plumage of some birds are invisible to us, but play a major role in their selection of mates. To our eyes, male and female blue tits are very similar, but in UV light the differences are obvious for the birds themselves. Some hummingbirds actively use their UV colours when they want to impress a female. By flying at certain angles in relation to the sun’s rays, their colours become particularly prominent.