How do Birds get their Color?



Birds have captivated us for time eternal, not only because of their ability to fly, but also because of the color they add to our lives. Ok, let me be clear that I’m not suggesting that ALL birds are colorful. Birds like Plain Chachalacas and Grey Catbirds hardly evoke images of stunning beauty. But a vast number of species DO exhibit dazzling displays of color. And these displays are not always what they might seem. Have you ever wondered why grackles look iridescent blue in good light and black in bad light? Or why the colorful gorgets of male hummingbirds appear and then disappear without warning? This is because color in birds is not a simple thing. But rather it is a complex concoction of some very specific recipes. There are two main ingredients that are essential in the making of color. The first is pigment and the second is keratin. And the ways in which these two fundamental ingredients are added to the color cooking pot are what produces the final colors that we see. Pigments are relatively simple color makers. There are three main pigments that give feathers their colors. The first pigment is called melanin and it produces black or dark brown coloration. Melanin is also very strong and is thus often reserved for the flight feathers. White feathers are caused by a lack of pigmentation and are much weaker than black feathers due to the lack of melanin. This might explain why many predominantly-white bird species have entirely black or black-tipped feathers in their wings. These feathers are exposed to the greatest wear
Pied Kingfisher, Ceryle rudis at Pilanesberg National Park, South Africa
and are required to be stronger than regular feathers. The second group of pigments are called carotenoids and they produce red, orange or yellow feathers. Carotenoids are produced by plants. When birds ingest either plant matter or something that has eaten a plant, they also ingest the carotenoids that produce the colors in their feathers. The pink color of flamingoes, for example, is derived
from carotenoids found in the crustaceans and algae that the birds sieve from the water. The third group of pigments are called porphyrins and these are essentially modified amino acids. Porphyrins can produce red, brown, pink and green colors. This pigment group is the rarest of the three pigment groups and is found in only a handful of bird families. The best-known example of porphyrins is the red pigment (often called turacin) that is found in many turaco species and turacoverdin, the green pigment found in
many of the same turaco species. Mixtures of pigments can also produce different and unusual color hues and shades. For example, the dull olive-green colors of certain forest birds is actually a mixture of yellow carotenoid pigments and dark-brown melanin pigments. Then we get to the second main ingredient that produces color: keratin. Keratin is the tough protein of which feathers are made. It also covers birds’ bills, feet and legs. Keratin is responsible for the iridescent coloring of many spectacular bird species. How keratin produces color is a rather complex process but, from what I’ve read on the subject, I shall attempt to simplify it as follows. Keratin produces color in two main ways: by layering and by scattering. Layering colors are produced when translucent keratin reflects short wave-lengths of colors like blues, violets, purples and greens. The other colors are absorbed by an underlying melanin (black) layer. The ways in which the keratin of the feathers are layered will dictate the color of the iridescence. Examples of layered coloring include the iridescence of glossy starlings and the speculums or wing patches of many duck species. Scattering is produced when the keratin of feathers is interspersed with tiny air pockets within the structure of the feathers themselves. These air pockets and the interspersed keratin scatter blue and green light and produce the shimmering colors of birds like kingfishers, rollers and bee-eaters.  The magnificence of some of these scattered colors is wonderfully exhibited in Adam
Guêpiers d'Europe
Riley’s post on the “Bee- eaters of Africa”. And like any really good dish, there are times when several ingredients need to be mixed  together to produce  a really good recipe. And both keratin and pigments can be combined to produce certain colors. The greens of many parrot species are caused by blue scattered light (produced by keratin) interacting with yellow carotenoids (produced by pigments in the feathers). Grey feathers are produced by the combination of scattered white light and melanin pigments. Learning a little about how color is produced in birds now presents me with an entirely new birding challenge when out in the field: figuring out the various color recipes that birds employ to dazzle! Source: Article, Images: flickr.com
Read More........

Rare Colorful Birds Around the World

The Guinea Turaco (Tauraco persa), also known as the Green Turaco, is a species of turaco, a group of near-passerines birds. It is found in forests of West and Central Africa, ranging from Senegal east to DR Congo and south to northern Angola. It lays two eggs in a tree platform nest. It formerly included the Livingstone'sSchalow'sKnysnaBlack-billed and Fischer's Turacos as subspecies. persa buffoni is the only subspecies of the Guinea Turaco without a white line below the eye The Guinea Turaco, often inconspicuous in the treetops, is approximately 43 cm long, including a long tail. The plumage is largely green and the tail and wings are dark purplish, except for the crimson primary feathers that are very distinct in flight. In the westernmost subspecies buffoni, which sometimes is known as the Buffon's Turaco, there is a white line above and in front of the eye and a black line below the eye. In the nominate subspecies of the central part of its range and zenkeri of the southeastern part there also is a second white line below the black line. Unlike similar turacos with red bills, even adult Guinea Turacos lack a white rear edge to the crest. This species is a common in climax forest with plentiful tall trees. It feeds on fruit and blossoms. Source: Article
The Wilson's Bird-of-paradise, Cicinnurus respublica, is a small, up to 21 cm long, passerine bird of the Paradisaeidae family. The male is a red and black bird-of-paradise, with a yellow mantle on its neck, light green mouth, rich blue feet and two curved violet tail feathers. The head is naked blue, with black double cross pattern on it. The female is a brownish bird with bare blue crown. In the field, the blue bare skin on the crown of the bird's head is so vivid that it is clearly visible by night; the deep scarlet back and velvet green breast are lush, the curlicue tail gleaming bright silver. An Indonesian endemic, the Wilson's Bird-of-paradise is distributed to the hill and lowland rainforests of Waigeo and Batanta Islands off West Papua. The diet consists mainly of fruits and small insects. The controversial scientific name of this species was given by Charles Lucien Bonaparte, Napoleon's nephew and a republican idealist, who described the bird from a badly damaged trade specimen purchased by British ornithologist Edward Wilson. In doing so, he beat John Cassin, who wanted to name the bird in honor of Wilson, by several months. Thirteen years later, in 1863, the German zoologist[term zoo studies] Heinrich Agathon Bernsteindiscovered the home grounds of the Wilson's Bird-of-paradise in Waigeo Island.  Due to ongoing habitat loss, limited range and exploitation, the Wilson's Bird-of-paradise is evaluated as Near Threatened on the IUCN Red List of Threatened Species. It is listed on Appendix II of CITES. The first footage of the Wilson's Bird-of-paradise ever to be filmed was recorded in 1996 by David Attenborough for the BBC documentary Attenborough in Paradise. He did so by dropping leaves on the forest floor, which irritated the bird into clearing them away. Source: Article
.Subscribe
The Red-bellied Pitta (Erythropitta erythrogaster) is a species of bird in the Pittidae family. It is found in Australia, Indonesia, Papua New Guinea, and the Philippines. Its natural habitat is subtropical or tropical moist lowland forestsSource: Article
The European Bee-eater (Merops apiaster) is a near passerine bird in the bee-eater family Meropidae. It breeds in southern Europe and in parts of north Africa and western Asia. It is strongly migratory, wintering in tropical Africa, India and Sri Lanka. This species occurs as a spring overshoot north of its range, with occasional breeding in northwest Europe. This is a bird which breeds in open country in warmer climates. Just as the name suggests, bee-eaters predominantly eat insects, especially bees, wasps and hornets which are caught in the air by sorties from an open perch. Before eating its meal, a European Bee-eater removes the sting by repeatedly hitting the insect on a hard surface. It eats some 250 bees daily.[citation needed] Lizards and frogs are also taken.[citation needed] The most important prey item in their diet are Hymenoptera, mostly Apis mellifera; a study in Spain found that these comprise 69.4% to 82% of the European bee-eaters' diet Their impact on bee populations however is small; they eat less than 1% of the worker bees in the area in which they live. A study found that European bee-eaters "convert food to body weight more efficiently if they are fed a mixture of bees and dragonflies than if they eat only bees or only dragonfiles. Source: Article
The Fiery-throated Hummingbird (Panterpe insignis) is a medium-sized hummingbird which breeds only in the mountains of Costa Rica and western Panama. It is the only member of the genus Panterpe. This is a common to abundant bird of montane forest canopy above 1400 m, and also occurs in scrub at the woodland edges and clearings. This bird is 11 cm long and weighs 5.7 g. It has a straight black bill and dusky feet. The adult Fiery-throated Hummingbird has shiny green body plumage, a blue tail, and a white spot behind the eye. It often looks dark, but when the light catches it at the right angle, it shows a brilliant blue crown, yellow-bordered bright orange throat, and blue chest patch. The sexes are similar, but young birds have rufous fringes to the head plumage. The call is a high-pitched twittering. The female Fiery-throated Hummingbird is entirely responsible for nest building and incubation. She lays two white eggs in a bulky plant-fibre cup nest 2–4 m high at the end of a descending bamboo stem or on a rootlet under a bank. Incubation takes 15–19 days, and fledging another 20-26. Very little color from the side. The food of this species is nectar, taken from a variety of small flowers, including epiphytic Ericaceae and bromeliads. Like other hummingbirds it also takes small insects as an essential source of protein. Male Fiery-throated Hummingbird defend flowers and scrubs in their feeding territories, and are dominant over most other hummingbirds. They will, however, allow females to share their food resources. Source
The flamebacks or goldenbacks are large woodpeckers which are resident breeders in tropical southern Asia. They derive their English names from their golden or crimson backs. However, the two flameback genera Dinopium and Chrysocolaptes are not particularly close relatives. The former are close to the enigmatic Meiglyptes and possibly Hemicircus woodpeckers, and the recently-reclassified Rufous Woodpecker (Micropternus brachyurus). Chrysocolaptes on the other hand appears to be a rather close relative of Campephilus, the genus of the famous Ivory-billed WoodpeckerSource: Article
The Golden Pheasant or "Chinese Pheasant", (Chrysolophus pictus) is a gamebird of the order Galliformes (gallinaceous birds) and the family Phasianidae. It is native to forests in mountainous areas of western China, but feral populations have been established in the United Kingdom and elsewhere. In England they may be found in East Anglia in the dense forest landscape of the Breckland. The adult male is 90–105 cm in length, its tail accounting for two-thirds of the total length. It is unmistakable with its golden crest and rump and bright red body. The deep orange "cape" can be spread in display, appearing as an alternating black and orange fan that covers all of the face except its bright yellow eye with a pinpoint black pupil. Males have a golden-yellow crest with a hint of red at the tip. The face, throat, chin, and the sides of neck are rusty tan. The wattles and orbital skin are both yellow in colour, and the ruff or cape is light orange. The upper back is green and the rest of the back and rump is golden-yellow. The tertiaries are blue whereas the scapulars are dark red. Other characteristics of the male plumage are the central tail feathers, black spotted with cinnamon, as well as the tip of the tail being a cinnamon buff. The upper tail coverts are the same colour as the central tail feathers. The male also has a scarlet breast, and scarlet and light chestnut flanks and underparts. Lower legs and feet are a dull yellow. The female (hen) is much less showy, with a duller mottled brown plumage similar to that of the female Common Pheasant. She is darker and more slender than the hen of that species, with a proportionately longer tail (half her 60–80 cm length). The female's breast and sides are barred buff and blackish brown, and the abdomen is plain buff. She has a buff face and throat. Some abnormal females may later in their lifetime get some male plumage. Lower legs and feet are a dull yellow. Both males and females have yellow legs and yellow bills. Despite the male's showy appearance, these hardy birds are very difficult to see in their natural habitat, which is dense, dark young conifer forests with sparse undergrowth. Consequently, little is known about their behaviour in the wild. They feed on the ground on grain, leaves and invertebrates, but they roost in trees at night. While they can fly, they prefer to run. If startled, they can suddenly burst upwards at great speed and with a distinctive wing sound. Although they can fly in short bursts, they are quite clumsy in flight and spend most of their time on the ground. Golden Pheasants lay 8-12 eggs at a time and will then incubate these for around 22–23 days. They tend to eat berries, grubs, seeds and other types of vegetation. The male has a metallic call in the breeding season. The Golden Pheasant is commonly found in zoos and aviaries, but often as impure specimens that have the similar Lady Amherst's Pheasant in their lineage. There are also different mutations of the Golden Pheasant known from birds in captivity, including the Dark-throated, Yellow, Cinnamon, Salmon, Peach, Splash, Mahogony and Silver. In aviculture, the wild type is referred to as "Red Golden" to differentiate it from these mutations. Source: Article1Article2
Read More........

Do Alien Civilizations Inevitably ‘Go Green’?

In the famous words of Arthur C. Clarke, “Any sufficiently advanced technology is indistinguishable from magic.” This phrase is often quoted to express the idea that an alien civilization which may be thousands or millions of years older than us would have technology so far ahead of ours that to us it would appear to be “magic.” Now, a variation of that thought has come from Canadian science fiction writer Karl Schroeder, who posits that ”any sufficiently advanced technology is indistinguishable from nature.” The reasoning is that if a civilization manages to exist that long, it would inevitably “go green” to such an extent that it would no longer leave any detectable waste products behind. Its artificial signatures would blend in with those of the natural universe, making it much more difficult to detect them by simply searching for artificial constructs versus natural ones. The idea has been proposed as an explanation for why we haven’t found them yet, based on the premise that such advanced societies would have visited and colonized our entire galaxy by now (known as the Fermi Paradox). The question becomes more interesting in light of the fact that astronomers now estimate that there are billions of other planets in our galaxy alone. If a civilization reaches such a “balance with nature” as a natural progression, it may mean that traditional methods of searching for them, like SETI, will ultimately fail. Of course, it is possible, perhaps even likely, that civilizations much older than us would have advanced far beyond radio technology anyway. SETI itself is based on the assumption that some of them may still be using that technology. Another branch of SETI is searching for light pulses such as intentional beacons as opposed to radio signals. But even other alternate searches, such as SETT (Search for Extraterrestrial Technology), may not pan out either, if this new scenario is correct. SETT looks for things like the spectral signature of nuclear fission waste being dumped into a star, or leaking tritium from alien fusion powerplants. Another solution to the Fermi Paradox states that advanced civilizations will ultimately destroy themselves. Before they do though, they could have already sent out robotic probes to many places in the galaxy. If those probes were technologically savvy enough to self-replicate, they could have spread themselves widely across the cosmos. If there were any in our solar system, we could conceivably find them. Yet this idea could also come back around to the new hypothesis – if these probes were advanced enough to be truly “green” and not leave any environmental traces, they might be a lot harder to find, blending in with natural objects in the solar system. It’s an intriguing new take on an old question. It can also be taken as a lesson – if we can learn to survive our own technological advances long enough, we can ultimately become more of a green civilization ourselves, co-existing comfortably with the natural universe around us. Source: Article.
Read More........