Colours in Birds
 |
 |
| Every bird species has a different colouring. The reason for this colour diversity is due to the light shifts in feathers and the presence of a pigment substance, called keratin, in the structure of the feather. |
One of the most important features of the multicoloured feathers of birds is that they are lifeless structures. The reason why a feather maintains its colour exactly, even after it is shed, is that a fully developed feather is completely lifeless.
Rich colour diversity in birds is basically due to the presence of pigments in the feathers, which were stored during the initial development phases of the feather, or the light shifts which occur depending on the structural characteristics of the feathers.
Since these formations, which are made up of the substance keratin, are soon worn down by environmental conditions, they are regularly renewed. Yet, each time, the bird regains its colourful feathers. This is because the feathers of birds continue to grow until they fully reach the necessary length, and the characteristic colour and pattern of that specific kind.
Due to their different structure, feathers can have an appearance similar to that obtained by a glass prism breaking light into different colours. Colours that are formed through refraction of light in this way are brighter and more metallic than those that are coloured by pigments. The colours of these feathers shift from blue to green, and from orange to red. Generally, the green, blue, and metallic colours in birds are formed through the reflection and refraction of light. Yet, some of the colours of feathers come from pigments.39
There are mainly three kinds of pigments in birds. These are melanin pigments that produce black, brown or dull yellow, lipochrome pigments that produce red, yellow or orange, and carotenoids. Blue, green and some other bright colours in birds are created by microscopic bubbles in the keratin of the feathers that refract the light. The feathers absorbing the full spectrum of light and only reflecting blue, on the other hand, creates the blue colour of some birds.40
Hormones also play an important role in colour change in birds. The colour difference between the male and female members of some species is caused by sex hormones. The different colourings and feather shapes of cocks and hens, for example, depend on the oestrogen hormone.
The colours of birds are important for their adaptation to their habitat as well as for male and female members' recognition of each other and the males' courtship of females in the mating season. In addition, pigments, which give colour to feathers, enhance the strength of the feathers, store energy coming from the sun and prevent harmful ultraviolet rays from entering the body.
Butterflies
Butterflies are known for the beauty of their wings that have surfaces that are relatively much wider than their thorax. How, then, do these spectacular patterns and colours in the wings of butterflies come about?
 |
| A close-up of the scales on the wings of butterflies |
Butterflies have a pair of membranous wings, which are in fact transparent. Since these are covered with scales of varying thickness, the transparency of the membranous wings goes unnoticed. These scales increase the aerodynamic qualities of the butterflies' wings, and give them their colour. The scales, which are so delicate as to fall from their places as soon as they are touched, have sharply-pointed ends sticking into the wings of the butterfly. In this way, the scales remain attached without falling off. Each of these tiny scales, which seem like overlapping shingles on a roof, take on a colour either by chemical pigments or by its structure which refracts the light falling onto it into rainbow colours as does a soap bubble.41 In addition, laboratory research has shown that different colours depend on different chemical substances. The by-products of a colouring substance called pteridine, for example, create the pink, white, and yellow colours that are commonly seen in butterflies. Melanin, which is a very common colouring substance, exists in the black spots in the wings. Interestingly, the colours in the wings of butterflies are not always as they seem to be. For example, green scales are in reality a mixture of black and yellow scales. Recent research conducted on butterfly wings has demonstrated that pigments are synthesised in the scales and that the enzymes necessary for melanin production lie in the upper skin of the scales. Colouring substances are not the only cause of these highly volatile colours in butterflies. The structure and the order of the scales on the wings of the butterfly cause various tricks of light, such as reflection, refraction, and finally the formation of colours of dazzling beauty. For instance, Stilpnotio Salicis butterflies have semi-transparent scales, which contain bubbles. Although there is no colouring substance in these scales, the light passing through the scales give the butterfly a satin-like appearance.
  |
| The large Indonesian butterfly (left) has two large spots resembling eyes on its wings, which it uses to startle its enemies. It is a satisfactory defence for these butterflies. Other species such as Monarch butterflies, on the other hand, take recourse to other methods (right). With their dark orange wings with black patterns, they send "bad taste" warning to their enemies. |
The surface of the scales on the Argynnis butterfly's wings is unbelievably soft, which creates silvery reflections. In some butterflies, the different arrangement of two overlapping rows of scales may also create different reflections of light, for example, causing a butterfly to look blue instead of black or brown.
When we examine the structure of butterfly wings even by considering their colourings alone, we come across lots of wonders. The existence of such an extraordinary beauty is undoubtedly evidence of the exalted might and endless artistry of Allah, Who has created all these.
It also must be stated that besides their being created as adornment, the colours and patterns on the wings of butterflies have many other crucial functions for these creatures.
False Eyes of Butterflies
In many butterflies, there are round dark-coloured patterns that remind us of the eyes of a large creature. These eyes, which again consist of coloured scales on the wings, embody a most important defence mechanism for butterflies. Butterflies keep their wings closed when they rest. If they meet an enemy, or are disturbed by a slight touch, the wings instantly open, and large, bright, intensely coloured eyespots on the wing surface appear. In this way, the required message is delivered to the predator.
 |
 |
| The butterflies seen in the photographs utilise camouflage both with colour and pattern. Allah created the eye motifs on the wings, not lacking even the sparkles in the eye. | |
Camouflage of Butterflies
Butterflies' camouflaging skills are as impressive as their false eyes. It is as if camouflaging butterflies see the colour of the bush, make an evaluation of the environment, analyse it, and imitate the colour of the bush with the colours they produce in their bodies' highly effective systems. Another species, aware of the tastes of its predator, gives warning signals to it by imitating colours that repel it by suggesting that the butterfly would taste bad or even be poisonous. It is by no means possible for a butterfly alone to perform these acts. We can make it clearer with an example:
Suppose that you are trying to produce a colour in a laboratory. If you have little knowledge of this subject, you will not be able to achieve the definite result that you wish, no matter how advanced your laboratory equipment or facilities. Then consider trying to achieve the quality of colours such as those of the butterflies, which, by developing the same colours and patterns as the environment, become almost invisible. You would not be able to develop even a single meaningful colour. The situation being so, it would be certainly an unscientific and irrational approach to claim that this glorious system in butterflies has come into existence by chance free of conscious design.
If there is a design somewhere, there is also a designer. The flawless design on the earth belongs to Allah, the Compassionate. What falls to people with reason is to reflect upon Allah's attribute of creating in detail. In Surat an-Nahl, Allah states as follows:
(He has made subservient to you) also the things of varying colours He has created for you in the earth. There is certainly a Sign in that for people who pay heed. (Surat an-Nahl: 13)
  |
| The colours of the butterflies seen in the photographs are in fact very striking. However, both live in safety due to the harmonious they blend in with the substratum on which they pose. |
Black Spots that Absorb Light
In some butterflies, especially on the parts of their wings that are near to the body, there are large, dark coloured spots that consist of scales. These spots, placed on both wings symmetrically, have a very important function for butterflies. Butterflies make use of these spots in order to reach the body temperature that is required to fly. How do they do this?
Scales have the properties of modifying heat to minimum or maximum levels depending on their colours. We have all seen butterflies opening and closing their wings under the sun as if they are trying to find a certain angle. The black spots in their wings help those butterflies, which try to attract sunlight by this movement. A butterfly that needs to warm up its body opens and closes its wings so that the sunlight falls directly on these spots, and therefore warms up its body.
Butterflies that live in open lands exposed to sun have lighter colours while those that live in wooded areas have darker colours.
Some species of Lepidoptera butterflies have no scales on their wings, cannot reflect light, and so are transparent. Though it is possible to see these butterflies while they fly, it is almost impossible to locate them when they alight somewhere. This provides a perfect protection for the butterfly. Just as all other creatures, butterflies have also been created with the systems with which they can meet all their needs. Moreover, all these are interdependent systems in which one cannot exist without the other.
Like all other creatures in the universe, Allah created butterflies too with all the details they possess and endowed them with all the systems they need.
  |
| The brown colour and spots under the wings of the blue Morpho butterflies provide an excellent means of camouflage for hiding in the bush. Butterflies may all of a sudden become invisible in the bush. |
39. David Attenborough, The Life of
Birds, Princeton University Press, New Jersey, 1998, p.158 
40. David Attenborough, The Life of Birds,
Princeton
University Press, New Jersey, 1998, p.158
41. Ranger Rick, May 1999
