ADVERTISEMENTS:
The colour of an organism is an adaptation that helps it survive. In nature plants and animals use colour and patterns in different ways.
Two types of coloration are found in animals:
Type # 1. Deceptive Coloration:
Deceptive coloration is when an organism’s colour fools either its predators or prey. There are two types of deceptive coloration- camouflage and mimicry.
ADVERTISEMENTS:
a. Camouflage:
Camouflage helps an organism blend in with its surroundings. It can be colours or patterns or both. When organisms are camouflaged, they are not visible easily.
Some examples of camouflage are as follows:
i. The white fur of the polar bear represents solid colour and is perfect for an arctic environment. The tiger’s stripes help it to blend with the tall grass. Other big cats like the leopard and cheetah have spots that helps them to blend in to their environment
ADVERTISEMENTS:
ii. Another type of camouflage is called counter shading. Animals with counter shading have different colours on their backs and stomachs. The penguin’s exhibits counter shading. Penguins spend a lot of time in water. The dark feathers on their backs help camouflage them from predators that are swimming above them. Their white stomach feathers hide them from predators swimming below them.
iii. Cryptic coloration is when some organisms look like another object that they almost disappear.
For Example:
a. The walking stick looks so much like a twig that it is easy to overlook it.
b. The praying mantis can look like a leaf and a twig.
c. The larva of a geometrid moth resembles a thin stem.
iv. Some butterflies and moths have large eyespots. These eyespots trick birds into thinking that the butterfly or moth is much larger than it really is.
b. Mimicry:
The concept of mimicry was first proposed by H.W. Bates in 1862. The term has been derived from a greek word, ‘mimos’ that literally means ‘to mime’. The species that imitates is known as the ‘mimic’ and the one which is imitated is known as the ‘model’. Mimicry is another type of deceptive coloration. It can protect the mimic from predators or hide the mimic from prey.
ADVERTISEMENTS:
The different types of mimicry as explained briefly:
i. Batesian Mimicry:
In Batesian mimicry a harmless species mimics a toxic or dangerous species.
Some examples are as follows:
ADVERTISEMENTS:
a. The poisonous coral snake and the harmless king snake look a lot alike. Predators will avoid the king snake because they think it is poisonous.
b. Another example of Batesian mimicry is the monarch butterfly and the viceroy butterfly. They belong to two different species, but their colour pattern is strikingly similar. The monarch butterfly is inedible, while the viceroy butterfly is edible. Both live in the same area.
c. Several species of butterflies that mimic the toxic heliconid butterflies.
ii. Mullerian Mimicry:
ADVERTISEMENTS:
In this type two equally toxic species mimic each other for the purpose of protection. The moth and the wasp are inedible and resemble each other. Once a predator such as a bird has tasted a wasp it would automatically avoid a moth also. Thus both individuals are not destroyed by the bird. Similarly if a bird has tasted a moth it would avoid eating a wasp.
iii. Aggressive Mimicry:
This type of mimicry helps the organism to lure a prey. The frogfish or angler fish lures its prey with the help of a long antenna like extension on its head which wiggles. This deceives other fish and crustaceans to think it to be a little fish, which then comes close to the antenna with the intention of eating it. When they do, the anglerfish eats them.
Type # 2. Advertising Coloration:
ADVERTISEMENTS:
When animals and plants use colour to be noticed, it is called advertising coloration. Advertising coloration can be used to either warn or attract animals.
a. The bright colours of flowers and berries are the examples of advertising coloration that attract animals. Flowers need to be pollinated to reproduce. Bees and humming birds are attracted to bright colours and pollinate the flowers.
b. Some pollinated plants produce berries. These berries turn a bright colour when they are ripe. The bright colour lets berry-eating birds know the fruit is sweet and safe to eat. After birds eat the berries, the seeds will pass through their digestive system and be left behind. Some of the seeds left behind grow into new plants
c. Colour is also used to attract mates. Many male birds like the peacocks are brightly coloured to attract females. Female birds are naturally attracted to healthier males because they want their off-springs be healthier. Female birds on the other hand, are often less colourful. This helps camouflage them when they nest.
d. Advertising colour is also used to warn animals away. The ladybug has bright orange wings with black spots. Its colouring warns predators that the ladybug tastes awful.
e. The red-eyed tree frog may scare prey away with their colour. The bright red color of their eyes shocks the predator and gives the red-eyed frog time to hop away to safety.