왜 초식공룡이 없었는지 읽어보시기 바랍니다. 원문 내용입니다.

[EU마이스터]

조류에 대한 견해 2011년 업데이타

BIRDS, THEIR HISTORY, COLORS, FEATHERS, FLIGHT, AERODYNAMICS AND WING SHAPE

Birds are feathered, warm-blood animals with backbones. They have two feet and two wings. Many animals such as bats, butterflies, and other insects have wings and fly. What distinguishes birds from other flying creatures are feathers. Birds are the only animals with feathers. Even bird that don't fly such as ostriches and kiwis have wings and feathers. [Source: David Attenborough, The Life of Birds, Princeton University Press, 1998]

Bird have the highest body temperatures of animals. Many species have a temperature over 110°F. This means they have very rapid metabolism and have to consume a lot of food relative to their body weight to keep themselves going.

빠른 신진대사를 만들어내는 것은 작은 새에게 가장 중요한 먹이는 기름진 음식입니다.

쥬라기의 숲에 곤충들의 발전이 어지지 않았다면 새들의 발전은 없을 것입니다. 그러나 쥬라기에 곤충은 도표는 일정한 양으로 유지되지만 실지 공룡들은 발전합니다.

숲의 공룡의 발전은 결국 곤충을 먹이로 한 발전을 말하고 있는 것입니다.

깃의 발전 역시 키틴질 유지로부터 나오는 머리카락의 기초 층인 유지가 형성되고, 만들어진 후에 깃의 발생이 하는 것입니다. 먹이에 대한 개념이 없는 아쉬움이 남는 것 같은 내용입니다.

As of 2004, there were 9,787 known species of birds. They are divided into 24 orders. One order, the Passeriformes (which includes songbirds) contains about half of the species. A total of 129 species of bird have become extinct, including the passenger pigeon and the dodo.

Americans spent $31 billion on birdwatching in 2007, which is $6 billion more than they spent on books. Bird provide humans with a number of symbols: wisdom (owls). peace (doves), stupidity (dodos), war (eagles and hawks), tackiness (pink flamingos), freedom (birds in flight), deprived of freedom (caged bird). Among the terms used to describes of birds are an exaltation of larks and a murder of crows.

Research has shown that 30 percent of the flying birds is done for fun.

Websites and Resources: ; Essays on Various Topics Related to Birds stanford.edu/group/stanfordbird ; Avibase avibase.bsc-eoc.org ; Avian Web avianweb.com/birdspecies ; Bird Species Birdlife.org birdlife.org ; Bird.com birds.com Wikipedia article on Birds Wikipedia ; Birdlife International birdlife.org ; National Audubon Society birds.audubon.org ; Cornell Lab of Ornithology birds.cornell.edu ; Ornithology ornithology.com ; Internet Bird Collection (videos and recordings of bird species) ibc.lynxeds.com ; International Field Guides /media.library.uiuc.edu ;

Websites and Resources on Animals: ARKive arkive.org Animal Info animalinfo.org ; Animal Picture Archives (do a Search for the Animal Species You Want) animalpicturesarchive ; BBC Animals Finder bbc.co.uk/nature/animals ; Animal Diversity Web animaldiversity.ummz.umich.edu ; International Field Guides media.library.uiuc.edu ; animals.com animals.com/tags/animals-z ; Encyclopedia of Life eol.org ; World Wildlife Fund (WWF) worldwildlife.org ; National Geographic National Geographic ; Animal Planet animal.discovery.com ; Wikipedia article on Animals Wikipedia ; Animals.com animals.com ; Endangered Animals iucnredlist.org ; Endangered Species Resource List ucblibraries.colorado.edu ; Biodiversity Heritage Library biodiversitylibrary.org

History of Birds

Birds evolved from reptiles about 140 million years ago. Transitional fossils are ones that show evolution from one group to another. Once called missing links they have ancestral features of the older species as well as novel traits of the descendant. Archaeopteryx is regarded as a transition fossil between dinosaurs and birds. Dated to 150 million years ago and discovered in Germany in 1861, this first bird retains traits such as a long bony tail and a full set of teeth. But is has birdlike wings and feathers. Its fingers are less fused and more open than in modern birds. Nine fossils of this magpie-size creatures have been found, including one with a velociraptor’s deadly claw. [Source: Newsweek, July 2, 2007]

Humboldt University Museum of Natural History in Berlin contains perhaps the world's most famous fossil, a sandstone imprint of the Archaeopteryx —the legendary 80-million-year-old “missing link” between dinosaurs and birds. Unfortunately the fossil is considered so valuable it is kept under lock and key in special vault and not displayed. A Japanese professor who was allowed to see it was so awestruck when he laid his eyes on it he fell down on his knees and nearly fainted.

Dinosaur-Era Birds from China

Confuciusornis sanctus, a 150-million-year-old bird found in Liaoning, is the earliest bird yet found. It had a toothless beak, feathered wings, claws that could be used to climb trees, feathers like modern birds and long tail feathers reminiscent of those found in some tropical birds and birds of paradise. Named in honor of the Chinese sage, Confuciusonris lived during the Jurassic period. Most early birds date back to the later Cretaceous period and scientist have speculated that they evolved from Jurassic age dinosaurs. For a long time the Archeareopteryx was the earliest known bird. Found in Germany, it lived 149 million years ago and is thought to have led to a dead end.

원래 초기에는 1억5천만년 바르게 이야기 되었던 내용이지만, 일부의 학자들이 거세게 깎아 내렸다가 이제 다시 복원된 새의 기원에 대한 내용입니다. 이 분기가 되는 시조새를 이미 저의 책에 담고 있습니다.

Sinosauropteryx ("Chinese dragon-bird”) is a small bipedal birdlike dinosaur found at Liaoning in 1996. It was the first nonbird whose fossil included featherlike structures. It has been offered as proof that birds evolved from dinosaurs.

Among the other species with birdlike features found in Liaoning are Protarchaeopteryx and Caudiperyx zoui, dinosaurs that looked like little velocirpators with featherlike filaments on their bodies, tails and arms. These creatures lived 120 million to 140 million years ago. Scientist have coined the name Dromeosaur to describe a group ro two legged predators that share a common ancestor with birds. Dromeosaurs in turn belong to a subgroup of dinosaurs called theropods that share about 1,000 anatomical features with birds, including wishbones, swiveling wrists and three forward-pointing toes.

드로마에오사우루스의 성장의 변화에 더 재미난 표현이 들어가 있습니다. 당연히 바꿔져야 했던 내용이 참 오랫동안 고비사막을 가지고 이야기한 내용입니다.

Fossils of a primitive bird called Protopteryx contains three different kinds of feathers: downy feathers on the head and body, true flight feathers and scalelike central tail feathers.

In June 2007, a birdlike dinosaur the size of tyrannosaur was found in the Erhain basin in Inner Mongolia. The five-meter-high, 1,400-kilogram dinosaur, called Gigantoraptor erlainensis, had a beak, slender legs and likely had feathers. Its discovery indicates tar the evolution of dinosaurs and birds was much more complicated than previously thought. Xu Xing, a scientists at the Chinese Academy of Sciences in Beijing who led the team that made the discovery, told AP, “This is like having a mouse that is the size of a horse or a cow. It is very important information for us in our efforts to trace the evolution process of dinosaurs to birds. Its more complicated than we imagined.”

참 부족한 답변 같습니다. 이것이 아마도 지금학자들의 사고의 한계성이 아닐까 싶습니다.

저가 제시하는 다양성을 찾아보신다면 이보다는 멋지게 내용이 잡힐 것으로 봅니다.

Missing Links Between Dinosaurs and Birds

Gigantoraptor, bird-like dinosaur In January 2003, Chinese scientist revealed the discovery of a “four-winged” dinosaur that had wings on its forelimbs and legs. The creature, given the name Microraptor, was about a meter long and appears to have “flown” by gliding using a method similar to that of flying squirrels. Xing Xu said, “The new fossils provide an example of the transition of dinosaurs to birds. They are the link between the flightless dinosaur and (flying) birds.”

Microraptor lived between 120 million and 110 million years ago. Xu and others argue that over time these creatures evolved into birds as their hind wings were lost. The existence of these creatures also offers evidence that the first flying bird-dinosaurs leapt off trees or other high places rather then getting a running start and taking off from the ground.

Sinoventor changi, another dinosaur discovered in the early 2000s in Liaoning, was a two-legged, chicken -size predator that probably had feathers and possessed a birdlike shoulder joint, a wishbone, and a pelvic bone that points backward. It was estimated to be about 130 million years old. Incisivosaurus gauhhieri lived about the same time. Described as a cross between a bird, a Tyrannosaurus rex and a beaver, it was the size of a turkey and had many birdlike features such as chisel-shaped teeth used for gnawing plants.

^^;;; 세종께서 혹세미문하지 말라 하셨는데, 간간히 두 개가 닮았다 하는 말 때문에 티라노를 새에 비유하는 사람들이 나오지요. 이런 말도 조심해서 써야지 무릇 우매한 자에게는 지식으로 바꿔지는 안타까움이 있네요.

A fossilized dinosaur pelvis containing two unlaid eggs was found in Jiangxi Province. The animal, a female oviraptorosaurian, was bipedal, lived 65 million years ago and had two potato-shaped, pineapple-size eggs inside her. Scientist say that its reproductive system was more like a bird’s than a reptiles and it laid successive pairs of eggs rather one large clutch all at once. Like a bird the eggs were produced by a single ovary but like a reptile more than one egg could be laid at a time. Birds can only lay one egg at a time. Reptiles like crocodiles have two ovaries and can lay several eggs at once. The discovery was announced in April 2005. The specimen was found some time ago and is kept at the National Museum of Natural Science in Taiwan.

Dinosaurs with Feathers from China

The Archaeoraptor liaoningensis, a creature found in 2000, has been described as the most definitive link between dinosaurs and birds because it had anatomical features found on dinosaurs and feathers. Scientists who made the discovery wrote in Nature, "It has things that are undeniably feathers...But is clearly a small vicious theropod similar to the velociraptors...in Jurassic Park."

This small duck-size dinosaur lied between 124 million and 147 million years ago. It had three different kinds of feathers: fuzz, hollow fibers of the head, plumlike "sprays" on the shoulders and filaments arranged in herring bone pattern in the backs of the arms and legs.

Scientist theorize the protofeathers could have first help keep the dinosaurs warm. Later their evolved into feather on the wings to help the creatures flap away like a chicken but nor truly fly so the could escape predators.

The fossil of a mei long, a species of dinosaur, was found with it head tucked under its forelimb. the position that birds adopt when they are sleeping to stay warm.

The Gigantoraptor is a giant birdlike dinosaur discovered in Inner Mongolia in 2007. Related to the oviraptorosaurs of the late Cretaceous Period—small 40-kilogram creatures with a toothless beak — it weighs more than one and half tons. It is not known what it ate with its large toothless beak or if it had feathers on its claw-tipped arms like other oviraptorosaurs.

A 124-million-year-old fossil of a sinosauropteryx , a small flesh-eating theropod, found in China has for the first time revealed the color of dinosaurs: reddish brown. In article published in Nature in February 2010, Mike Benton, a profesor of paleontology at Britain’s Bristol University, announced the discovery using internal cellular coloring agents — not the colors themselves — found fossilized tail feathers found in the fossil.

Theropods and Birds

In the last 1990s, fossils of three flightless dinosaurs were found in Liaoning and studied by a team lead of Stephen Czerkas of the Dinosaur Museum in Blanding Utah. What was interesting about them is that they were theropods, or meat eaters, and included a couple of eagle-size dromaeosaurs, small raptors like the ones in Jurassic Park, and a two-meter therizinosaur, with the arms of a bird and the tail of a dinosaur that was described by some as the missing link between dinosaurs and birds and gave credence to a theory first proposed by John Ostrom of Yale that birds evolved from theropods. [Source: Christopher P. Sloan, National Geographic, November 1999]

One dromaeosaur, named Sinornothosaurus, had a shoulder bone more similar to a bird than a dinosaur. Another dromaesoaur had feathers very much like those on birds, The therizinosaur is the largest known dinosaur found with feathers, which were more likely used for insulation than flight. All three creatures lived about 120 million years ago. The theory goes these theropods were the first dinosaurs to have feathers. The feathers were initially used for warmth but later they helped the dinosaurs make leaping escapes and jumps and this evolved into flight over time.

아마도 이 진화의 게임오버가 가장 중요한 말로 보입니다. ^^

In June 2009, a 155-million-year-old fossil was found in the Shishugu Formation in the Jungar Basin that provided important clues in understanding the evolution if bird-like dinosaurs. In a report in Nature, a team led by Chinese dinosaur expert Xing Xu said they discovered a young beaked herbivore—dubbed Limusaurus—that had feet configurations like those of birds, suggesting they have been early ancestors of birds.

In October 2009, British and Chinese scientists announced the discovery of the fossil of a 160-million-year-old pterosaur that they said provided a “missing link” in the understanding of flying dinosaurs also known as pterodactyls. The crow-size creature, dubbed Darwinopterus modularis in honor of Charles Darwin, lived 10 million years before the first bird and had wings and a head like other pterosaur but also had a long tail. The fossils were found in Zhucheng in Shandong Province.

아자 힘내자! 주첸

Bird Characteristics

All birds have beaks instead of jaws and teeth. Their wings correspond with the front legs of other animals, and their legs correspond with the rear legs of other animals. All birds lay eggs. Most make nests, which are used to care for eggs and young birds.

Birds have very large, strong hearts. They need them to pump large amounts of blood necessary to provide oxygen to the muscles needed for flight. Birds also have sophisticated breathing systems. Unlike mammals, which have lungs that are like inflating and deflating bags, bird lungs are comprised of a series a tubes, which draws in more oxygen.

Bird don't perspire. They have air sacs connected to their lungs that help keep the bird cool and lightens the bird. Bird also never get out breath. Their wing strokes expel air from the lungs. The faster a bird flaps its wings, the more carbon dioxide it need to expel, and the faster the air is expelled.

Most birds have three forward-facing toes and one backward-facing toe. Birds that spend most of their time on the ground tend to have long legs that they can use for running. Those that spend their time in trees have short, strong legs that ideal for perching, climbing and hopping. Those that spend a lot of time in the water have webbed feet that serve as paddles when the bird swims.

Bird Senses

Many birds, have keen eyesight. Most fly during the day and rely on eyesight to catch prey in mid air, avoid any obstacles and assess distance so they can land properly. Some species can see well in ultraviolet light and are better at distinguishing detail than humans.

The eyesight of predators is especially keen and is regarded as the most efficient and sensitive of all animals. A sparrow hawk can spot a grasshopper from a hundred meters up and swoop down, keeping its eye on the grasshopper the whole time. Some hawks have eyes that are larger than those of humans even though they are considerably smaller than humans.

Many birds, including starlings and parakeets, see plumage that reflects color only in the ultraviolet part of the spectrum, which humans can’t see. A starling that may look black to us but may look psychedelic to other starlings. Birds that colorful to us may look completely different to other birds who see ultraviolet light.

Bird have three eyelids. One is transparent and moves from side to side instead of up and down and helps protect the eyes from dust.

With the exception of vultures and other carrion eaters, most birds don't have a very developed sense of smell. Research indicates that some species anyway use their sense of smell to distinguish between members of their own kind. A study by U.S. and French researchers Francesco Bonadonna and Gabrielle Nevitt published in Nature found that some seabirds carry the scent of their partners on their nose and were able to locate their partners in colonies with thousands of birds after being separated for weeks.

Birds that lose their hearing often regain it in about a month.

Bird Feathers

Feathers are made of keratin, the same horny substance found in fingernails and lizard scales. They streamline the body, reducing friction and drag during flight, and are ideal for creating perfect airfoils, which give the birds lift n flight. Weight for weight, no devices has ever been produced by man or nature that act as a better airfoils. A bird’s colors come from both pigment and light reflecting structures in the feathers. A typical bird has 25,000 feathers.

Feathers have a central shaft with a hundred or so filaments on each side. Each filament is sided with a hundred or so smaller filaments or barbules. The barbules of flight feathers overlap and are hooked together so they create a continuous vane and give a feather its strength. There are several hundred hooks on each barbule and a million or so in a feather. Barbules that become unhooked are knocked back in place when a birds preens and strokes its feathers.

There are several different kinds of feathers. The two primary kinds are: 1) contour feathers, which are visible and help streamline a bird; and 2) down feathers, close to the body and found on chicks. Feather other than down emerge from tracts of skin called pterylae. Feathers are regularly replaced in a process called molting. Several birds have feathers that are toxic when touched or ingested.

Feathers are superb insulators, better than even fur. They are soft, fluffy and can trap air, keeping a bird warm and repel rain and water. Many water bird have down to keep warm. Unlike other feathers, down doesn't have a shaft with barbs. Instead branches come right out the skin. On cold days birds fluff out their feathers to stay warm. On hot days they flatten their feathers.

Feathers are also used to send a variety of other messages and identify species. During the breeding season some species such as bird of paradise's and cock of the rock's use their colorful feathers in courtship displays.

Feather Development

Bird feathers evolved from reptile scales. If you look at a bird embryo in its early stage of development you can see discs of cells called placodes scattered here and there. Some grow into scales like those that cover chickens. Others turn into feathers.

Research by Yale ornithologist Richard Prum suggests that feathers evolved in a series of steps, with old genes being borrowed for new uses. In reptiles specific genes mark off the front and back of each scale as it grows from the placode. In bird embryos each feather begins as a tube growing from a placode with the front and back genes at work in the feather evolution. Around 150 million years, ago, scientist estimate, these genes must have taken on a new role in dinosaurs causing some to sprout feathers and feather-like growths as seen in recent dinosaur fossils. [Source: Joel Zimmerman, National Geographic, November 2006]

Joel Zimmerman wrote in National Geographic, “The appearance of branch-like barbs was the next step in feather evolution, Prum argues, and the development of a baby bird’s downy feathers offers clues to how that happened. As a new feather tube grows, it is divided into strips, which eventually peel away into barbs. And once again, only a little tinkering with genes might have been required to get the tube to split. Prum has shown that the same genes that mark the front and back of reptile scales and feather tubes also mark the points around the tube where it will split.”

“Later, birds evolved the ability to turn these fluffy feathers into feathers with vanes, and then to lock the barbs together to make flight feathers, all with slight genetic changes...And by tweaking the growth of different parts of the feathers, birds evolved special plumage for hunting, swimming, courting and other activities.

Feather Care and Molting

Birds go through a great deal of trouble to tend and care for their feathers. Out of place feathers are repositioned. Ragged ones are restored with combing from the peak. Most birds have a large oil gland in their skin near their tail. The birds take oil with their beaks and use it to anoint their feathers and keep them water repellant. All this effort is rewarded with a more streamlined body and more perfect airfoils.

Fleas, lice and other parasites find feathers to be a warm cozy place to hang out. Many birds have parasite problem and constantly erecting their feathers and groom themselves to get rid of them. Some birds will even place ants and other insects in their plumage to get ride of parasites.

Feathers become damaged and wear out and need to be replaced. Most birds replace their feathers at least once year in a process called molting. Most species of bird molt over a long period of time, with a few feather replaced at a time so flying is not affected.

Molting usually takes in the spring or autumn. The old feather generally don't fall out until the new feathers emerge, so a bird can keep flying. This is not the case with many water bird who lose all their feathers at once and then grow new ones. Molting ducks are a sorry sight.

Bird Aerodynamics

The body of a flying bird is streamlined like the fuselage of an aircraft. The feathers all point backwards from the head to the tail. The legs are drawn up like the wheels of an airplane. There are no protruding ears and sometimes the nostrils point backwards. Air taken in through mouth goes out the nostrils like exhaust.

Birds are very light. Weight-saving adaptions that allow bird to fly include hollow bones supported by internal struts like those that strengthen wings on planes; a bony beak rather than a jaw and teeth; tail feathers instead of a tail; and a skeleton that is fused together like a fuselage frame. Their feathers are mostly air.

All flying birds have lungs that extend into air sacs in the body cavity, filling space in the lightest possible. Most bird have nine of these air sacs: in the neck, chest, and towards the back of the abdomen. These serve not only as lighteners they also supply the bird with the extra oxygen they need for flying, which required a lot of energy.

Bird Flight

Joel Zimmerman wrote in National Geographic, “As a feat of engineering, it’s hard to beat the flight feather of a bird. From the central vane sprout hundreds of filaments, some with grooves and some with hooks that zip the barbs together like velcro. They create a lightweight plane that can lift a bird into the sky. When the birds pull their feathers apart to clean them, the barbs simply zip back together by themselves.”

The flight mechanics of birds. In slow flight the down stroke of the wings occurs with the feathers compressed to produce lift. On the upstroke the feathers separate to allow air to pass through so the wing can return to upper position with a minimum of interference to flight.

After a flying bird—or flying insect or bat—makes a simple turns all its has to do to straighten out is start flapping its wings again. This finding was reported in an April 2009 in Science based experiments using high-speed film by a team lead by Tyson Hedrick of the University of North Carolina.

Wings: 아래의 새로운 견해와 키틴질을 분석한 새의 색을 분리한 내용이고, 이외 그리 큰 변화를 읽지 않은 내용이 지금 고생물의 취지에 속합니다.

The wings of birds developed from a single finger of their reptilian ancestors. The other finger have largely disappeared but most birds have the vestiges of ancestral thumbs as projections on the fore-edge of their wings which carries its own tuft of feathers.

Bird wings have curved leading edges and thin trailing edges that helps lift the bird the same way airplane wings lift a plane. Most birds take of by leaping into the wind and flapping their wings hard. They land by titling their wings at an angle to reduce speed and then throwing their bodies backwards and their legs forward.

The shape and sizes of wings allow different species of bird to do different things. Short, stubby, wings allow birds like tanagers to maneuver and swerve through the forest. Swept-back wings allow swifts and falcons to achieve great speeds while long extended wings of vultures and albatrosses allow them to glide and catch air currents. Fighter planes, supersonic planes and gliders follow the same principals.

The wings of a bird have more work to do than the wings of a plane. Not only do they have provide lift they must also serve as an engine. The muscles that operate the wings are the largest and strongest a bird possesses. The muscles that extend from wing joints to the deep keel on breast bone are the most powerful of all. They supply the power a bird needs to take off. The wing muscles of strong-flying birds such as pigeons account for half their total weight.

Wing Shape and Aircraft

Adam Summers, a professor of bioengineering at the University of California at Irvine, wrote in Natural History magazine ,“Structurally the wing resembles your arm, remove or fuse a few bones, add some feathers, and you just about have it. When the wings flap as when your arms do, chest muscles power their motions.”

The structure of bird wings, which are essentially two featherbed airfoils, is crucial to flapping flight. “One airfoil is made up of primary fight feathers attached to the wingtip bones. The other is formed by secondary flight feathers attached to forelimb bones,” Summer wrote.

Bird wings change shape when they fly. The U.S. military tried to employ this idea into the F-14 Tomcat fighter, which has a “swing-wing” that changes shape depending on whether the plane is taking off or not and how fast it is going. The idea didn’t pan out—in 2006 the Tomcat was retired—and some said the problem was that wing shapes have quite different affects on stationary wings and flapping ones.

These days, scientists are studying swifts for insights into aircraft wing development in part because they don’t flap their wings much when they glide or dive. Swift wings resemble long, thin, curved blades that taper off at the end sort of like a scythe. They gain added maneuverability by having an unusually larger proportion of their wings made up of the “hand” or wing tip bones. By changing the “wrist” angle between the “hand” and forelimb, the swift can change both the shape of the wing and its area, thereby maximizing their efficiency at various speeds.

Bird Colors

Many birds get their colors from melamine, the same substance that creates different skin colors and hair colors in humans. Some of the brighter hues are the product of diet. Many birds eat foods rich in carotenoids, the antioxidant chemicals that make fruits and vegetables orange, red and yellow. The color is often limited to a few choice locations such as the shoulder spots of the red-winged blackbird or the rouged cheek pads of the zebra finch. Some birds like cardinals are very efficient at extracting carotenoids from their food, and thus are covered in color and can maintain it even when carotenoids are lacking in their diets. Other birds such as house finches change color from yellow to red depending at their carotenoid intake.

Other birds get a metallic sheen and dazzling colors not from pigments but from optical features that reflect specific wavelengths of color. These structural colors, which don’t fade and are more brilliant than those produced by pigments, are of great interest to companies that make paint, cosmetics and holograms for credit cards.

Some birds owe their colors to the structural architecture of their feathers and skin which break up sunlight into colors. Bluebirds get their blue from light waves reflected by air bubbles trapped in their feathers. The green stripe above the eyes and beak of the velvet asity is produced by light reflected from collagen in the bird’s skin. The iridescence on a hummingbird’s throat is caused by a structural effect called coherent scattering.

Many of the most brilliantly-colored birds come from the tropics. Many are residents of the upper canopy of rain forests where they can display their colors to their optimum effect in the bright light. Other brightly-colored birds such as manakins and honey creepers spend most of their time in forest understories where only scattered rays of sunshine penetrates and do choreographed acrobatic mating displays in which they alternately flash and hide their colors as they move though the stippled sunshine, somewhat like dancer below a spinning disco ball.

Some of their brightest blue colors belong to birds that spend their time in the deep forest rather than in open habitats. Why does this occur when it seems like orange would be the most visible color? Research seems to show that many animals are visually sensitive to anything outside their usual habitats Since the dominant colors in a forest are green, brown, yellow and sometimes orange, blues and violets are rare background colors.

Beaks, Food and Bird Digestion

A beak is made of a horny sheath of keratin and weighs much less than jaw bones and teeth. "Chewing" is done in bird's gizzard, a special compartment of the stomach, which is located near a bird's center of gravity so it doesn't interfere with flying. Some birds can’t fly if they eat too much.

Beaks serve as both a mouth and hands and are used more for gathering food than eating it. Bird use them to pick up food, for defense and sometimes to build nests. Beaks are molded easily by evolution forces and over millions of years have developed to feed on particular food. See Darwin and finches.

Bird eats food rich in calories such as nuts, seeds, fruit, insect larvae and fish. They need all these calories because flying requires a lot of energy. Birds seem to care less about taste than other animals. A parrot has only 350 taste buds compared to 17,000 for a rabbit.

Food passes through the mouth into the gullet and then the crop, a thin-walled pocket that is used to store food for later digestion or regurgitation for feeding young. The crop is especially well pronounced in grain-eating birds. The gizzard is the avian equivalent of a stomach. It is connected to the intestines. Bird have no urinary tract. Nitrogenous wastes is excreted in the form of urea through an opening called the cloaca.

Many birds eat seeds and little else. Seeds are rich in food and nutrients but are surrounded by thick shells. To get around this many birds have strong muscles in their gizzards that break up the shells and swallow dirt and grit which function as an abrasive. Birds use a gizzard rather than teeth because gizzards are lighter.

Image Sources: 1) 2) 3) 4) 5) 6) 7) 8)

Text Sources: Mostly National Geographic articles. Also Life on Earth and The Life of Birds by David Attenborough (Princeton University Press), New York Times, Washington Post, Los Angeles Times, Smithsonian magazine, Natural History magazine, Discover magazine, Times of London, The New Yorker, Time, Newsweek, Reuters, AP, AFP, Lonely Planet Guides, Compton’s Encyclopedia and various books and other publications.

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이것은 쥬라기 숲이 만들어 놓은 발전이었지요. 그럼 강과 바다에 삶을 짚어볼 수 있는 정확한 견해는 쥬라기에 초식공룡을 없애버리게 됩니다. 우리는 쥬라기의 숲을 용각류나 혹은 말도되지 않는 초식공룡이라 생각하지만, 숲의 식생은 곤물과 개울의 물고기가 공룡들에게 주식입니다. 숲의 발전은 곤충의 발전으로 포유동물과 새를 만들어 낸 것이지요. 새와 공룡의 삶의 경쟁 이것이 쥬라기의 숲입니다. 지오그래픽사에서 이러한 제시는 이 문제에 이미 외국자본은 활 시위를 당긴 것인데, 우리네 출판사들은 잠자고 있습니다. 내 아무리 중요하다고 제출해도 박사들이 당신들이 동참하지 않는 문화 산업은 만들수 없어요.