INSIDE NATURE

December 2015 £3.99

Colour in Nature Ed Marshall:Photographer Uncovered

Into the woods: Squirrels in Action

COLOUR IN NATURE

ButterliesThe colouration of butterly wings has fascinated scientists for over 100 years. A lattice of scales makes up the wings of a butterly, with colour either being inluenced by structural or pigmentary mechanisms. Structural colour is created by an optical effect such as interference, refraction or diffraction. Different refractive indices in the wing give rise to different colours when exposed to light. Iridescence of the wing is caused by multiple slit interference. InInterference is due the interactions of light waves. Sunlight contains light of all wavelengths so when two light waves are aligned, interference will result, subsequently producing iridescence due to light hitting the wing interacting with light relected off the wing. In many butterlies, the two mechanisms are combined with structurally coloured butterly wings containing pigment that adjust the colour.

A prime example of structural colouration and iridescence is in the blue morpho butterly (Morpho peleides), found in Central & South America and Mexico. The blue Morpho butterly is among the largest butterlies in the world, with their wings spanning from 5-8 inches. The vivid blue colouring in the wings is a result of iridescence. So, how are these huge butterlies able to avoid predators with such conspicuous wing colouring?

The underside of the wings is a dull brown colour with numerous eye spots providing camoulage against predators when the wings are closed. Even in light, however, they manage to elude predators. As the butterlies continually move their wings, they seem to disappear and reappear at a distance, due to the exquisite lashes of blue light. This ability to change colour rapidly makes them a challenge for predators to pursue.

In comparison to the blue morpho butter-lies, their colouration is caused by a combination of structure and pigmentation. The scales act as a chirped multilayer relector but also contain papiliochrome pigments, which act as a spectral ilter. The combined structural and pigmentary effects tune the colouration of the scales. These tuned colours are important in mate recognition.

Sexual dimorphism is strong in this species with males being much brighter than ffemales and selected mate choice for brighter males. The bright colour is also used as a ‘warning’ to potential predators through aposematism.

Next to the morpho species, birdwing butterlies (belonging to the genus Ornithoptera and found in central and south Moluccas) are potentially the most amazingly coloured livingbutterly species.

Colour in nature is witnessed everywhere, from exquisite wing detail in butterlies through to seasonal changes in leaf colouration. I suppose the most pressing questions are: Through what means does colour arise in nature? And how do such vibrantly coloured animals persist when exposure to predators is so high?

ParrotsThe combination of pigmentary and structural coloration to achieve unique optical effects is also encountered in bird feathers such as parrots. Rainbow lorikeets (Trichoglossus haemahaematodus), featured below are parrot species, native to Australasia. Unlike the birdwing butterlies, they are not sexually dimorphic, with both sexes obtaining very bright, multi coloured plumage. They have deep blue heads with a distinct orange beak and red eyes. The bright plumage is still important in mate choice as bright colours are an indicator of health. The most colourful males have a higher sperm count and more colourful females will produce larger, healthier offspring. Birds that are infested with parasites will most likely have duller feathers. Surprisingly, this colouring that makes them stand out in the animal world is the same same feature that keeps them camoulaged from predators. The colour variation and vibrancy disrupts the outline of the parrot, making it dificult for predators to distinguish them.

Parrots in general, have pigments in their pigments in their feathers called psittacin or cartenoids but do not comprise pigments of all colours. Colours such as green are seen as a result of light scattering, relecting off the feather structure. This is called the called the Tyndall effect. There is also no pigment for the blue colouration and so this is seen as a mutation in birds with no red and yellow psittacin pigments. The amount of red and yellow psittacin in an indpsittacin in an individual bird partially determines the overall colour. Another element that inluences bird colour is melanin. This is also found in humans with the tanning of skin. In birds, melanin deciphers how dark the feathers are. These pigments apigments are black and brown protein structures in the feathers and affect the base colour of the bird. In pied birds with differing blocks of colour, such as the rainbow lorikeets, the rreduction of melanin varies on different parts of the feathers.

Structural colouration is also present in parrots as well as chemical components. Feather structure also plays a signiicant role with its layering, ordering, particle sizes and refractive indices. Changes in feather structure can change how light relects due to dark factors, which subsequently adjust the colour witnessed by the naked eye. As you can see, feather colour is ultimately determined by three elements- psittacin, melanin and feather structure. Such a huge array of colour variation is inluenced by so little elements.

The reds and purples are the result of an-other pigment called anthocyanin which unlike the cartenoids, is not present in the leaf all year round. Its formation depends on the breakdown of sugars as the phosphate level in leaves is reduced. The brighter the light during this period, the greater the production of anthocyanins, and the more vivid the colour displays.

LeavesThe use of pigment is also pThe use of pigment is also present in leaves. Leaves are green as a result of pigment known as chlorophyll. Green colour dominates and masks other pigments when chlorophyll is abundant in the growing season. The role of chlorophyll is to capture the sun’s rays and use the energy to manufacture plant food. As daylight hours shorten, veins in leaves that carry luids in and out of the leaf are blocked by a layer of cork cells. Mineral intake is therefore reduced, and chlorophyll decreases. As chlorophyll decreases, other pigments such as cartenoids begin to show through, giving rise to yellow, brown and orange.

ED MARSHALLNATURAL HISTORY PHOTOGRAPHER“I always want to capture a shot that shows something special. An image that makes me stand out from the ever-growing crowd, and to generate that little bit more interest in my work.” It is for the exact reason mentioned by Ed Marshall himself above that I was so inspired by his work. What struck me the most when exploring his photos was the extraordinary range of material he has been able to capture from dramatic coastal landscape panoramic images to the intricate detailed macro images of bumblebees on vibrant echium lowers. Every single image manages manages to convey a message or emotive expression which really draws the viewer into the photo.

Ed Marshall works fairly generally in natural history rather than focusing specically on wildlife as such, but over recent years has worked closely alongside people and conser-vation projects so has developed a style involving others around him but still enjoys getting out on his own and capturing shots that can make the long hours and tough weather conditions incredibly worth it. His main area of focus is on coastal natural history and feels his images in this setting are able to convey a story. The coastal images denitely inspired me the most. In fact, when scrolling these images, my initial reaction was almost always ‘wow’. Ed is able to capture the soft, silky, whitewash of waves incredibly well through merely just using a very slow shutter speed and a tripod. The contrasting colour in his work and the use of wide aperture in capturing animal portraits enhances the power the image is able to obtain. The natural, soft lighting in his images manages to amplify the subject outline and detail. When I look at phophotography, what often strikes me as a beautiful photo is actually in most cases, the most simplistic. Ed captures this aspect of photography incredibly well through the use of a clean, noise free background and a strong subject focus.

I

I feel the image I captured of this black headed gull ( (to the right) around the campus lake represents the image of the Fulmar well. This photo was taken during feeding time with a lot of ‘hustle and bustle’ occurring. I wanted to get a close up shot of one of the many birds, in light. Because the movement was so sporadic and rapid, it was challenging. However, through the use of a high shutter speed and multiple shots taken in situ, I feel I managed managed to capture what I was aiming for. Wintery weather conditions often mean light is low making it incredibly dificult to gain freeze shots of motion due to being unable to obtain a high enough shutter, but on this particular morning the su was shining and the light was perfect.

The two aspects of Ed’s Fulmar photograph that come across as most prominent are the full wing span, symmetry and the facial features, so I wanted a shot that illustrated this well. Besides the wings not being identical, due identical, due to shadowing, the symmetry is highlighted successfully, as a result of the spread of the tail feathers enhancing the overall shape. The highlights and shadows in this photo are more substantial than those of the Fulmar due to stronger natural sunlight and a higher exposure.

The highlights on the body of the gull really bring out the vibrant orange of the feet and beak, drawing the observer’s focus into the image. The shadows on the underside of the lower wing complement the highlights of the body well and magnify the body outline. They also create shading on the lower half of the bobody which, I feel adds to the image, demonstrating the gracefulness of the gull in light, despite their raucous behaviour on the ground. Because of the slightly differing angles in which our two images were shot, the wing structure of the gull is more noticeable. The shading gradient on the wing from light to dark is strong and the feather structure and organisation is bold. The overall composition of the image is relatively strong I feel as the frframe is illed and the background is clean. The similar background colouring in both photos helps enhance features of the birds well, especially the vibrant orange of the feet and beak in the gull. Aside from the higher exposure affecting the shadowing, I believe many aspects of my image represent Ed’s image successfully.

The photo of the fulmar in light, featured to the right, is the irst of Ed Marshall’s images that I decided to base my work upon. It is a prime example of the simplistic beauty that Ed Marshall manages to capture. The outline of the subject is strong and the composition of the photograph as a whole is captured well through the use of symmetry, simpliied background and the full frame subject. A high shutter speed was used in order to capture the frozen shot of motion. The facial features (i.e. the tubenose beak and eyes) are detailed and because the tubenose is the most important important feature of the fulmar, this photograph was captured well, highlighting every aspect and the eye gives a feeling of purpose and sincerity. Another prominent feature is the stiff wing structure and light passing through the wings highlights each individual feather. The combination of shadows and highlights on the wings, and the shading from light to dark from base to tips, enhances the clarity. The clean, blurred, ocean background puts emphasis on the streamlined light of the fulmar.

The light speckled, dark background is very effective. In fact, when irst capturing this image, there was a distracting horizontal brick layer in part of the background but through use of the clone stamp on photoshop, I managed managed to remove the distraction and successfully improve the image. Soft lighting is also achieved, bringing out the lufiness of the feathers. What I really love about this photo, is the use of texture and contrast of colour between the dark green background and the vivid bright green of the moss. I was concerned that I would ind it dificult to gain the powerful use of texture that Ed obtained but I was lucky in the sense that there happened to be moss patches covering the building. The rugged shape of the roof tiles, the sponginess of the moss and the soft feather structure of the sparrow all complement each other well. The speckled background particulaparticularly highlights the facial features of the bird and the colour patterning. In both photos, the facial expression of the bird is strong, with the emotive expression of the turnstone and the more startled look in the eyes of the sparrow.

Ed Marshall states that his inspiration and motivation stems from the work of other photographers as he is always learning. I stand by these words and Ed himself has given me the inspiration to continue to improve and have the patience to wait out in the rain for that perfect image. I think it’s the simplicity yet beauty of his images that truly stands out for me and I hope to be able to achieve this aspect well in my future images.

The second image I attempted to recreate was this breathtaking shot of a Turnstone, featured on the right. What this image portrays incredibly successfully is a strong composition due to a very wide aperture enhancing the subject and blurring both the background and foreground. It is the foreground blur that makes this image so striking and before now, I had never been able to create this effect. The viewer is drawn directly into the centre of the image, straight into the subject. The emotion in this photo is incredibly strong, with the speckled background resulting from the splashing of waves, creating a sense of calm, emphasising the solitary environment this bird appears to be in.

Soft liSoft lighting in this photo is used to the beneit of the subject, with the blurred whitewash increasing the strength of the subject outline. The feather structure and patterning of the bird is illustrated clearly and use of texture is strong. I think the comparison between the glimpse of slippery seaweed and the soft, plump feather layering in the bird is very striking. This image really captures the beauty of the turnstone and because it is taken at ground level it has a magniicent way of making the observer feel as if they are present at the scene. The image I obtained was taken on the roof of a building at Twycross zoo of a house sparrow, featured below. The prime focus of Ed’s image that I wanted to capture was that of both foreground and background blur, to enhance the subject and draw the eyes of the viewer straight into the centre of the image. I believe I managed to do this relatively successfully, the foreground blur of the roof brick is not as strong as the blur of the turnstone foreground but it still facilitates a striking subject enhancement.

Into the woods..

tranquil

Inquisitive

Apprehension Fear

Curiostiy

Tension Startled

Content