Feather variations

Feathers are one of the epidermal growths that form the distinctive outer covering, or plumage, on birds and some non-avian theropod dinosaurs. They are considered the most complex integumentary structures found in vertebrates,^[1][2] and indeed a premier example of a complex evolutionary novelty.^[3] They are among the characteristics that distinguish the extant Aves from other living groups. Feathers have also been noticed in those Theropoda which have been termed feathered dinosaurs. Although feathers cover most parts of the body of birds, they arise only from certain well-defined tracts on the skin. They aid in flight, thermal insulation, waterproofing and coloration that helps in communication and protection.^[4]

Structure and characteristics[link]

Parts of a feather:
1. Vane
2. Rachis
3. Barb
4. Afterfeather
5. Hollow shaft, calamus

Feather structure of a Blue-and-yellow Macaw

Feathers are among the most complex integumentary appendages found in vertebrates and are formed in tiny follicles in the epidermis, or outer skin layer, that produce keratin proteins. The β-keratins in feathers, beaks and claws — and the claws, scales and shells of reptiles — are composed of protein strands hydrogen-bonded into β-pleated sheets, which are then further twisted and crosslinked by disulfide bridges into structures even tougher than the α-keratins of mammalian hair, horns and hoof.^[5][6] The exact signals that induce the growth of feathers on the skin are not known but it has been found that the transcription factor cDermo-1 induces the growth of feathers on skin and scales on the leg.^[7]

Feather microstructure showing interlocking barbules.

Classification[link]

There are two basic types of feather: vaned feathers which cover the exterior of the body, and down feathers which are underneath the vaned feathers. The pennaceous feathers are vaned feathers. Also called contour feathers, pennaceous feathers arise from tracts and cover the whole body. A third rarer type of feathers, filoplumes, is hairlike and (if present in a bird) grows along the fluffy down feathers. In some passerines, filoplumes arise exposed beyond the contour feathers on the neck.^[1] The remiges, or flight feathers of the wing, and rectrices, the flight feathers of the tail are the most important feathers for flight. A typical vaned feather features a main shaft, called the rachis. Fused to the rachis are a series of branches, or barbs; the barbs themselves are also branched and form the barbules. These barbules have minute hooks called barbicels for cross-attachment. Down feathers are fluffy because they lack barbicels, so the barbules float free of each other, allowing the down to trap much air and provide excellent thermal insulation. At the base of the feather, the rachis expands to form the hollow tubular calamus (or quill) which inserts into a follicle in the skin. The basal part of the calamus is without vanes. This part is embedded within the skin follicle and has an opening at the base (proximal umbilicus) and a small opening on the side (distal umbilicus).^[8]

Hatchling birds of some species have a special kind of natal down (neossoptiles) and these are pushed out when the normal feathers (teleoptiles) emerge.^[1]

Flight feathers are stiffened so as to work against the air in the downstroke but yield in other directions. It is noted that the pattern of orientation of β-keratin fibers in the feathers of flying birds differs from that in flightless birds. The fibers are better aligned in the middle of the feather and less aligned towards the tips.^[9][10]

Functions[link]

Feathers insulate birds from water and cold temperatures. They may also be plucked to line the nest and provide insulation to the eggs and young. The individual feathers in the wings and tail play important roles in controlling flight. Some species have a crest of feathers on their heads. Although feathers are light, a bird's plumage weighs two or three times more than its skeleton, since many bones are hollow and contain air sacs. Color patterns serve as camouflage against predators for birds in their habitats, and by predators looking for a meal. As with fish, the top and bottom colors may be different to provide camouflage during flight. Striking differences in feather patterns and colors are part of the sexual dimorphism of many bird species and are particularly important in selection of mating pairs. In some cases there are differences in the UV reflectivity of feathers across sexes even though no differences in color are noted in the visible range.^[11] The wing feathers of male Club-winged Manakins Machaeropterus deliciosus have special structures that are used to produce sounds by stridulation.^[12]

A contour feather from a Guinea fowl

Some birds have a supply of powder down feathers which grow continuously, with small particles regularly breaking off from the ends of the barbules. These particles produce a powder that sifts through the feathers on the bird's body and acts as a waterproofing agent and a feather conditioner. Powder down has evolved independently in several taxa and can be found in down as well as pennaceous feathers. They may be scattered in plumage in the pigeons and parrots or in localized patches on the breast, belly or flanks as in herons and frogmouths. Herons use their bill to break the feathers and to spread them while cockatoos may use their head as a powder puff to apply the powder.^[13] Waterproofing can be lost by exposure to emulsifying agents due to human pollution. Feathers can become waterlogged and birds may sink. It is also very difficult to clean and rescue birds whose feathers have been fouled by oil spills. The feathers of cormorants soak up water and help in reducing buoyancy and thereby allowing the birds to swim submerged.^[14]

Rictal bristles of a White-cheeked Barbet

Bristles are stiff, tapering feathers with a large rachis but few barbs. Rictal bristles are bristles found around the eyes and bill. They may serve a similar purpose to eyelashes and vibrissae in mammals. It has been suggested that they may aid insectivorous birds in prey capture or that it may have sensory functions, however there is no clear evidence.^[15] In one study, Willow Flycatchers (Empidonax traillii) were found to catch insects equally well before and after removal of the rictal bristles.^[16]

Grebes are peculiar in their habit of ingesting their own feathers and also feeding them to their young. Observations on the diet and feather eating frequency suggest that ingesting feathers particularly down from their flanks aids in forming easily ejectable pellets along with their diet of fish.^[17]

Distribution[link]

Feather tracts or pterylae and their naming

Contour feathers are not uniformly distributed on the skin of the bird except in some groups such as the Penguins, ratites and screamers.^[18] In most birds the feathers grow from specific tracts of skin called pterylae while there are regions which are free of feathers called apterylae. Filoplumes and down may arise from the apteriae, regions between the pterylae. The arrangement of these feather tracts, pterylosis or pterylography, varies across bird families and has been used in the past as a means for determining the evolutionary relationships of bird families.^[19][20]

Coloration[link]

Colors resulting from different feather pigments
Left: turacin (red) and turacoverdin (green, with some structural blue iridescence at lower end) on the wing of Tauraco bannermani
Right: carotenoids (red) and melanins (dark) on belly/wings of Ramphocelus bresilius

The colors of feathers are produced by the presence of pigments, or by microscopic refractive structures, or by a combination of both.

Most feather pigments are melanins (brown and beige pheomelanins, black and grey eumelanins) and carotenoids (red, yellow, orange); other pigments occur only in certain taxa – the yellow to red psittacofulvins^[21] (found in some parrots) and the red turacin and green turacoverdin (porphyrin pigments found only in turacos). Structural coloration^[4][22][23] is involved in the production of blue colors, iridescence, most ultraviolet reflectance and in the enhancement of pigmentary colors; structural iridescence has been reported^[24] in fossil feathers dating back 40 million years. White feathers lack pigment and scatter light diffusely; albinism in birds is caused by defective pigment production, though structural coloration will not be affected (as can be seen e.g. in blue-and-white budgerigars).

A feather with no pigment

For example, the blues and bright greens of many parrots are produced by constructive interference of light reflecting from different layers of the structures in feathers, in the case of green plumage in addition to the yellow pigments; the specific feather structure involved is sometimes called the Dyck texture.^[25][26] Melanin is often involved in the absorption of some of the light; in combination with yellow pigment it produces dull olive-greens.

In some birds, the feather colors may be created or altered by uropygial gland secretions. The yellow bill colors of many hornbills are produced by preen gland secretions. Other differences that may only be visible in the ultraviolet region have been suggested^[13] but studies have failed to find evidence.^[27] Uropygial oil secretion may also have an inhibitory effect on feather bacteria.^[28]

A bird's feathers undergo wear and tear and are replaced periodically during its life through molting. New feathers, known as blood, or pin feathers (depending on the stage of growth) when developing, are formed through the same follicle from which the old ones were fledged. The presence of melanin in feathers increases their resistance to abrasion.^[29] One study notes that melanin based feathers were observed to degrade more quickly under bacterial action, even compared to unpigmented feathers from the same species, than those unpigmented or with carotenoid pigments.^[30] However, another study the same year compared the action of bacteria on pigmentations of two song sparrow species and observed that the darker pigmented feathers were more resistant and they cited other research also published in 2004 that stated increased melanin provided greater resistance. They observed that the greater resistance of the darker birds confirmed Gloger's rule.^[31] The evolution of coloration is based on sexual selection and it has been suggested that carotenoid-based pigments may have evolved since they are likely to be more honest signals of fitness because they are derived from special diets,^[32][33] or because carotenoids are also required for immune function.^[34]

Parasites[link]

The feather surface is the home for some ectoparasites, notably feather lice (Phthiraptera) and feather mites. Feather lice typically live on a single host and can move only from parents to chicks or mating birds and occasionally by phoresy. This life history has resulted in most of the species being specific to the host and coevolving with the host, making them of interest in phylogenetic studies.^[35]

Feather holes are chewing traces of lice (most probably Brueelia spp. lice) on the wing and tail feathers. They were described on barn swallows, and because of easy countability, many evolutionary, ecological, and behavioral publications use them to quantify the intensity of infestation.

Interestingly, parasitic cuckoos which grow up in the nests of other species also have host specific feather lice and these seem to be transmitted only after they leave the host nest.^[36]

Birds maintain their feather condition by bathing in water, dust bathing and preening. A peculiar behavior of birds, anting, where ants are introduced into the plumage was suggested to help in reducing parasites but no supporting evidence has been found.^[37]

Human usage[link]

Part of Indian Peacock tail feather

Feathers have a number of utilitarian, cultural and religious uses.

Utilitarian functions[link]

Feathers are both soft and excellent at trapping heat; thus, they are sometimes used in high-class bedding, especially pillows, blankets, and mattresses. They are also used as filling for winter clothing, such as quilted coats and sleeping bags; goose and eider down have great loft, the ability to expand from a compressed, stored state to trap large amounts of compartmentalized, insulating air.^[38]

Bird feathers have long been used for fletching arrows. Colorful feathers such as those belonging to pheasants have been used to decorate fishing lures.

Feathers of large birds (most often geese) have been and are used to make quill pens. The word pen itself is derived from the Latin penna for feather.^[39] In French, plume can mean either feather or pen.

Feathers are also valuable in aiding the identification of species in forensic studies, particularly in bird strikes to aircraft. The ratios of hydrogen isotopes in feathers help in determining the geographic origins of birds.^[40] Feathers may also be useful in the non-destructive sampling of pollutants.^[41]

The poultry industry produces a large amount of feathers as waste, and like other forms of keratin, these are slow in their decomposition. Feather waste has been used in a number of industrial applications as a medium for culturing microbes,^[42] biodegradeable polymers,^[43] and production of enzymes.^[44] Feather proteins have been tried as an adhesive for wood board.^[45]

The hunting of birds for decorative and ornamentatal feathers (including in Victorian fashion) has endangered some species.^{[citation needed]}

In religion and culture[link]

Eagle feathers have great cultural and spiritual value to American Indians in the USA and First Nations peoples in Canada as religious objects. In the United States the religious use of eagle and hawk feathers are governed by the eagle feather law, a federal law limiting the possession of eagle feathers to certified and enrolled members of federally recognized Native American tribes.

In South America, brews made from the feathers of condors are used in traditional medications.^[46] In India, feathers of the Indian Peacock have been used in traditional medicine for snakebite, infertility and coughs.^[47][48]

During the 18th, 19th, and 20th centuries a booming international trade in plumes, to satisfy market demand in North America and Europe for extravagant head-dresses as adornment for fashionable women, caused so much destruction (for example, to egret breeding colonies) that a major campaign against it by conservationists led to the Lacey Act and caused the fashion to change and the market to finally collapse. Frank Chapman noted in 1886 that as many as 40 species of birds were used in about three-fourths of the 700 ladies' hats that he observed in New York City.^[49][50][51]

More recently, rooster plumage has become a popular trend as a hairstyle accessory, with feathers formerly used solely as fishing lures being now used to provide color and style to hair.^[52] Modern feather usage in fashion and also adorning military regimental headresses and cloths are derived as a waste product of farming of poultry birds, this includes chicken, geese, turkey, pheasant and ostrich. Feathers used for these purposes are deliberately modified through dyeing and manipulation to enhance the appearance of these poultry feathers, as they are naturally often dull in appearance compared to wild species which they are attempting to mimic. The number of feather products manufacturers in Europe has decreased enormously in the last 60 years mainly due to competition from Asia. One surviving company Jaffe et fils founded in 1946, formerly of London now based in Axminster, Devon is one of the last in Europe to dye and manufacture feather products for fashion, theatre and military regalia. Feathers have adorn hats at many prestigious events such as Weddings and Ladies day at Race courses(Royal Ascot). One milliner, Philip Treacy, has specialized in the use of feathers. He has created highly regarded hats notably for the Royal Family. One such as the hat was worn by the Camilla now the Duchess of Cornwall on her marriage to Prince Charles.

Evolution[link]

Fossil feather of Archaeopteryx

The functional view on the evolution of feathers has traditionally focused on insulation, flight and display. Discoveries of non-flying Late Cretaceous feathered dinosaurs in China however suggest that flight could not have been the original primary function.^[53] There have been suggestions that feathers may have had their original function in thermoregulation, waterproofing or even as sinks for metabolic wastes such as sulphur.^[54] Recent discoveries are claimed to support a thermoregulatory function, at least in smaller dinosaurs.^[55][56] While feathers have been suggested as having evolved from reptilian scales, there are numerous objections, and more recent explanations have arisen from the paradigm of evolutionary developmental biology.^[2] Theories of the scale-based origins of feathers suggest that the planar scale structure was modified for their development into feathers by splitting to form the webbing; however, the developmental process involves a tubular structure arising from a follicle and the tube splitting longitudinally to form the webbing.^[1][2] The number of feathers per unit area of skin is higher in smaller birds than in larger birds, and this trend indicates their important role in thermal insulation, since smaller birds lose more heat due to the relatively larger surface area in proportion to their body weight.^[4] The miniaturization of birds also played a role in the evolution of powered flight.^[57] The coloration of feathers is believed to be primarily evolved in response to sexual selection. In many cases the physiological condition of the birds (especially males) is indicated by the quality of their feathers and this is used (by the females) in mate choice.^[58][59]

Feathered dinosaurs[link]

Archaeopteryx lithographica (Berlin specimen)

Several non-avian dinosaurs had feathers on their limbs that would not have functioned for flight.^[2] One theory is that feathers originally evolved on dinosaurs as a result of insulation properties; those small dinosaurs that then grew longer feathers may have found them helpful in gliding, leading to the evolution of proto-birds like Archaeopteryx and Microraptor zhaoianus. Dinosaurs that had feathers or protofeathers include Pedopenna daohugouensis,^[60] and Dilong paradoxus, a tyrannosauroid which is 60 to 70 million years older than Tyrannosaurus rex.^[61]

The majority of dinosaurs known to have had feathers or protofeathers are saurischians, however featherlike "filamentous integumentary structures" are also known from the ornithischians Tianyulong and Psittacosaurus.^[62] The exact nature of these structures is still under study. However, it is believed that the stage 1 feathers such as those seen in these two ornithischians likely functioned in display.^[63]

Since the 1990s, dozens of feathered dinosaurs have been discovered in the clade Maniraptora, which includes the clade Avialae and the recent common ancestors of birds, Oviraptorosauria and Deinonychosauria. In 1998, the discovery of a feathered oviraptorosaurian, Caudipteryx zoui, challenged the notion that feathers were an exclusive structure of Avialae.^[64] Buried in the Yixian Formation in Liaoning, China, C. zoui lived during the Early Cretaceous Period. Present on the forelimbs and tails, their integumentary structure has been accepted as pennaceous vaned feathers based on the rachis and herringbone pattern of the barbs. In the clade Deinonychosauria, the continued divergence of feathers is also apparent in the families Troodontidae and Dromaeosauridae. Branched feathers with ranchis, barbs, and barbules were discovered in many members including Sinornithosaurus millenii, a dromaeosaurid found in the Yixian formation (124.6 MYA).^[65]

Previously, a temporal paradox existed in the evolution of feathers—theropods with highly derived bird-like characteristics occurred at a later time than Archaeopteryx—suggesting that the descendants of birds arose before the ancestor. However, this paradox was resolved in 2009 with the discovery of Anchiornis huxleyi, found in the Late Jurassic Tiaojishan Formation (160 MYA) in western Liaoning.^[66][67] By predating Archaeopteryx, Anchornis proves the existence of a modernly feathered theropod ancestor, providing insight into the dinosaur-bird transition. The specimen shows distribution of large pennaceous feathers on the forelimbs and tail, implying that pennaceous feathers spread to the rest of the body at an earlier stage in theropod evolution.^[68] The discovery, in 2011, of feathers preserved in amber, within samples dating to 80 mya, suggests the coexistence of theropods and birds, with both theropod and avian feather types commingled in the samples.^[69]

Evolutionary stages[link]

Diagram illustrating stages of evolution

Several studies of feather development in the embryos of modern birds, coupled with the distribution of feather types among various prehistoric bird precursors, have allowed scientists to attempt a reconstruction of the sequence in which feathers first evolved and developed into the types found on modern birds.

Feather evolution was broken down into the following stages by Xu and Guo in 2009:^[63]

1. Single filament
2. Multiple filaments joined at their base
3. Multiple filaments joined at their base to a central filament
4. Multiple filaments along the length of a central filament
5. Multiple filaments arising from the edge of a membranous structure
6. Pennaceous feather with vane of barbs and barbules and central rachis
7. Pennaceous feather with an asymmetrical rachis
8. Undifferentiated vane with central rachis

However, Foth (2011) showed that some of these purported stages (stages 2 and 5 in particular) are likely simply artifacts of preservation caused by the way fossil feathers are crushed and the feather remains or imprints are preserved. Foth re-interpreted stage 2 feathers as crushed or misidentified feathers of at least stage 3, and stage 5 feathers as crushed stage 6 feathers.^[70]

The following simplified diagram of dinosaur relationships follows these results, and shows the likely distribution of plumaceous (downy) and pennaceous (vaned) feathers among dinosaurs and prehistoric birds. The diagram follows one presented by Xu and Guo (2009) modified with the findings of Foth (2011).^[63] The numbers accompanying each name refer to the presence of specific feather stages. Note that 's' indicates the known presence of scales on the body.

See also[link]

• Pinioning

References[link]

External links[link]

Wikimedia Commons has media related to: Feather

• Chandler, Asa C. (1916). "A study of the structure of feathers, with reference to their taxonomic significance". University of Caliornia Publications in Zoology 13 (1): 243-446. http://archive.org/stream/cu31924000147953#page/n41/mode/1up/. </ref>
• McGraw, K. J. 2005. Polly want a pigment? Cracking the chemical code to red coloration in parrots. Australian Birdkeeper Magazine 18:608-611.
• DeMeo, Antonia M. Access to Eagles and Eagle Parts: Environmental Protection v. Native American Free Exercise of Religion (1995)
• Electronic Code of Federal Regulations (e-CFR), Title 50: Wildlife and Fisheries PART 22—EAGLE PERMITS
• U.S. v. Thirty Eight Golden Eagles (1986)
• Mechanical structure of feathers
• Documentary on the evolution of feathers
• Lecture notes on the avian integument
• U.S. National Fish and Wildlife Forensics Laboratory's Feather Atlas
• Federn.org

Henry John Deutschendorf, Jr. (December 31, 1943 – October 12, 1997), known professionally as John Denver, was an American singer/songwriter, activist, and humanitarian. After traveling and living in numerous locations while growing up in his military family, Denver began his music career in folk music groups in the late 1960s. His greatest commercial success was as a solo singer. Throughout his life Denver recorded and released approximately 300 songs, about 200 of which he composed. He performed primarily with an acoustic guitar and sang about his joy in nature, his enthusiasm for music, and relationship trials. Denver's music appeared on a variety of charts including country & western, the Billboard Hot 100, and adult contemporary, in all earning him 12 gold and 4 platinum albums with his signature songs "Sunshine on My Shoulders", "Take Me Home, Country Roads", "Leaving on a Jet Plane", "Rocky Mountain High", "Annie's Song", and "Calypso".

Denver further starred in films and several notable television specials in the 1970s and 1980s. In the following decades he continued to record, but also focused on calling attention to environmental issues, lent his vocal support to space exploration, and testified in front of Congress to protest censorship in music. He is known for his love of the state of Colorado, which he sang about numerous times. He lived in Aspen, Colorado, for much of his life, and influenced the governor to name him Poet Laureate of the state in 1974. The Colorado state legislature also adopted "Rocky Mountain High" as one of its state songs in 2007. He was an avid pilot, and died while flying his personal aircraft at the age of 53. Denver was one of the most popular acoustic artists of the 1970s.^[1]

Biography[link]

Early years[link]

Henry John Deutschendorf, Jr., was born in Roswell, New Mexico, to Erma Louise Swope and Lt. Col. Henry John Deutschendorf, Sr.,^[2] an Air Force Lieutenant Colonel (who set three speed records in the B-58 Hustler bomber and earned a place in the Air Force Hall of Fame). Henry Sr. was of German ancestry, and met and married his "Oklahoma Sweetheart".^[3] Denver's Irish Catholic and German maternal grandmother was the one who imbued Denver with his love of music. In his autobiography, Take Me Home, Denver described his life as the eldest son of a family shaped by a stern father who could not show his love for his children.

Because Denver's father was in the military, the family moved often, making it difficult for Denver to make friends and fit in with people of his own age. Constantly being the new kid was agony for the introverted child, and he grew up always feeling as if he should be somewhere else, but never knowing where that "right" place was.^[4] While living in Tucson, Arizona, Denver was a member of the Tucson Arizona Boys Chorus for two years. Denver was happy living in Tucson, but his father was transferred to Montgomery, Alabama, then in the midst of the Montgomery boycotts. The family later moved to Fort Worth, Texas, where Denver graduated from Arlington Heights High School. Attending high school in Fort Worth was a distressing experience for the disenfranchised Denver. In his third year of high school, he borrowed his father's car and ran away to California to visit family friends and begin his music career. His father flew to California to bring him back, and Denver unhappily returned to finish high school.^[5]

At the age of 11, Denver received an acoustic guitar from his grandmother.^[6] He learned to play well enough to perform at local clubs by the time he was in college. He adopted the surname "Denver" after the capital of his favorite state, Colorado. He decided to change his name when Randy Sparks, founder of The New Christy Minstrels, suggested that "Deutschendorf" wouldn't fit comfortably on a marquee.^[7] Denver attended Texas Tech University in Lubbock and sang in a folk-music group called "The Alpine Trio" while pursuing architecture studies.^[8] He was also a member of Delta Tau Delta Fraternity. Denver dropped out of the Texas Tech School of Engineering in 1963,^[6] and moved to Los Angeles, California, where he sang in folk clubs. In 1965, Denver joined the Chad Mitchell Trio, a folk group that had been renamed "The Mitchell Trio" prior to Chad Mitchell's departure and before Denver's arrival, and then "Denver, Boise, and Johnson" (John Denver, David Boise, and Michael Johnson).^[6]

Solo career[link]

In 1969, John Denver abandoned the band life to pursue a solo career and released his first album for RCA Records: Rhymes & Reasons. Two years prior Denver had made a self-produced demo recording of some of the songs he played at his concerts. He included in the demo a song called "Babe I Hate to Go," later renamed "Leaving on A Jet Plane." Denver made several copies and gave them out as presents for Christmas.^[9] Mitchell Trio manager Milt Okun brought the unreleased "Jet Plane" song to the high-profile folk group Peter, Paul and Mary. Their version of the song hit number one on the Billboard Hot 100.^[10]

Although RCA did not actively promote Rhymes & Reasons with a tour, Denver himself embarked on an impromptu supporting tour throughout the Midwest, stopping at towns and cities as the fashion took him, offering to play free concerts at local venues. When he was successful in convincing a school, college, American Legion Hall, or local coffee-house to let him play, he would spend a day or so postering the town and could usually be counted upon to show up at the local radio station, guitar in hand, offering himself for an interview.^{[citation needed]} With his foot-in-the-door of having authored "Leaving on a Jet Plane", he was often successful in gaining some valuable promotional airtime, usually featuring one or two songs performed live. Some venues would let him play for the "door"; others restricted him to selling copies of the album at intermission and after the show. After several months of this constant low-key touring schedule, however, he had sold enough albums to convince RCA to take a chance on extending his recording contract. He had also built a sizable and solid fan base, many of whom remained loyal throughout his career.^[6]

Denver recorded two more albums in 1970, Take Me to Tomorrow and Whose Garden Was This, including a mix of songs he had written and cover versions of other artists' compositions.

Career peak[link]

His next album, Poems, Prayers, and Promises (released in 1971), was a breakthrough for him in the U.S., thanks in part to the single "Take Me Home, Country Roads", which went to No.2 on the Billboard charts despite the first pressings of the track being distorted. Its success was due in part to the efforts of his new manager, future Hollywood producer Jerry Weintraub, who signed Denver in 1970. Weintraub insisted on a re-issue of the track and began a radio-airplay campaign that started in Denver, Colorado. Denver's career flourished from then on, and he had a series of hits over the next four years. In 1972, Denver scored his first Top Ten album with Rocky Mountain High, with its title track reaching the Top Ten in 1973.^[11] Between 1974 and 1975, Denver experienced an impressive chart dominance, with a string of four No.1 songs ("Sunshine on My Shoulders", "Annie's Song", "Thank God I'm a Country Boy", and "I'm Sorry") and three No.1 albums (John Denver's Greatest Hits, Back Home Again, and Windsong).^[12]

In the 1970s, Denver's onstage appearance included long blond hair, embroidered shirts emblazoned with images commonly associated with the American West (created by designer & appliqué artist Anna Zapp), and "granny" glasses. His manager, Jerry Weintraub, insisted on a significant number of television appearances, including a series of half-hour shows in England, despite Denver's protests at the time, "I've had no success in Britain...I mean none."^[13] Weintraub explained to Maureen Orth of Newsweek in December 1976, "I knew the critics would never go for John. I had to get him to the people."

After appearing as a guest on many shows, Denver went on to host his own variety/music specials, including several concerts from Red Rocks Amphitheatre near Denver. His seasonal special, Rocky Mountain Christmas, was watched by more than 60 million people and was the highest-rated show for the ABC network at that time.^{[citation needed]}

His live concert special, An Evening with John Denver, won the 1974–1975 Emmy for Outstanding Special, Comedy-Variety or Music.^[14] When Denver ended his business relationship because of Weintraub's focus on other projects, Weintraub threw Denver out of his office and called him a Nazi. Denver would later tell Arthur Tobier, when the latter transcribed his autobiography^{[citation needed]}, "...I'd bend my principles to support something he wanted of me. And of course every time you bend your principles – whether because you don't want to worry about it, or because you're afraid to stand up for fear of what you might lose – you sell your soul to the devil."^[15]

Denver was also a guest star on The Muppet Show, the beginning of the lifelong friendship between Denver and Jim Henson that spawned two television specials with The Muppets. He also tried his hand at acting, appearing in the The Colorado Cattle Caper episode of the McCloud television movie on February 24, 1974, and starring in the 1977 film Oh, God! opposite George Burns. Denver hosted the Grammy Awards five times in the 1970s and 1980s and guest-hosted The Tonight Show on multiple occasions.^[16] In 1975, Denver was awarded the Country Music Association's Entertainer of the Year award. At the ceremony, the outgoing Entertainer of the Year Charlie Rich presented the award to his successor, but in protest of what he considered the inappropriateness of Denver's selection, Rich set fire to the envelope containing the official notification of the award.^[17] However, Denver's music was defended by country singer Kathy Mattea, who told Alanna Nash of Entertainment Weekly, "A lot of people write him off as lightweight, but he articulated a kind of optimism, and he brought acoustic music to the forefront, bridging folk, pop, and country in a fresh way.... People forget how huge he was worldwide."

In 1977, Denver cofounded The Hunger Project with Werner Erhard and Robert W. Fuller. He served for many years and supported the organization until his death. Denver was also appointed by President Jimmy Carter to serve on the President's Commission on World Hunger, writing the song "I Want to Live" as its theme song. In 1979, Denver performed "Rhymes & Reasons" at the Music for UNICEF Concert. Royalties from the concert performances were donated to UNICEF.^[18] His father taught him to fly in the mid-1970s, which led to a reconciliation between father and son.^[8] In 1980, Denver and his father, Lt. Col. “Dutch” Deutschendorf, co-hosted an award winning television special, "The Higher We Fly: the History of Flight."^[3] It won the Osborn Award from the Aviation/Space Writers’ Association, and was honored by the Houston Film Festival.^[3]

Political activism[link]

Denver became outspoken in politics in the mid-1970s. In 1976, he campaigned for Jimmy Carter, who became a close friend and ally. Denver was a supporter of the Democratic Party and of a number of charitable causes for the environmental movement, the homeless, the poor, the hungry, and the African AIDS crisis. He founded the charitable Windstar Foundation in 1976, to promote sustainable living. His dismay at the Chernobyl disaster led to precedent-setting concerts in parts of communist Asia and Europe.^[8]

During the 1980s, Denver was critical of the Ronald Reagan Presidential Administration, but he remained active in his campaign against hunger, for which Reagan awarded Denver the Presidential World Without Hunger Award in 1985.^[8] Denver's criticism of the conservative politics of the 1980s was expressed in his autobiographical folk-rock ballad "Let Us Begin (What Are We Making Weapons For)." Denver was also critical of the Republican-dominated Congress and American Conservatism of the 1990s. He denounced the National Rifle Association (NRA) as a corrupt political machine that could buy off politicians, and in an open letter to the media, he wrote that he opposed oil drilling in the Arctic National Wildlife Refuge. Denver had battled to expand the refuge in the 1980s, and he praised President Bill Clinton for his opposition to the proposed drilling. The letter, which he wrote in the midst of the 1996 presidential election, was one of the last he ever wrote.^[8] Denver was also on the Board of Governors of the National Space Society for many years.

Later years and humanitarian work[link]

He had a few more U.S. Top 30 hits as the 1970s ended, but nothing to match his earlier success. He began to focus more on humanitarian and sustainability causes, focusing extensively on conservation projects. He made public expression of his acquaintances and friendships with ecological-design researchers such as Richard Buckminster Fuller and Amory Lovins, from whom he said he learned much. He also founded two environmental groups; the Windstar Foundation and Plant-It 2020 (originally Plant-It 2000). Denver had a keen interest in solutions to world hunger. He visited Africa during the 1980s to witness first-hand the suffering caused by starvation and to work with African leaders toward solutions.

John Denver testifies before the US Senate, 1985

Testimony continued

In 1983 and 1984, Denver hosted the annual Grammy Awards. In the 1983 finale, Denver was joined on stage by folk-music legend Joan Baez with whom he led an all-star version of "Blowin' in the Wind" and Let The Sunshine In, joined by such diverse musical icons as Jennifer Warnes, Donna Summer, and Rick James.

In 1984, Roone Arlidge, president of ABC Sports, asked Denver to compose and sing the theme song for the 1984 Winter Olympics in Sarajevo. Denver worked as both a performer and a skiing commentator (skiing was another avocation of Denver's). He had written "The Gold and Beyond", and sang it for the Olympic Games athletes, as well as local venues including many schools.^[3]

In 1985, Denver asked to participate in the singing of "We Are the World" but was turned down. According to Ken Kragen (who helped to produce the song), the reason that John Denver was turned down was that many people felt his image would hurt the credibility of the song as a pop-rock anthem. "I didn't agree" with this assessment, Kragen said, but reluctantly turned Denver down anyway.^[19]

For Earth Day 1990, Denver was the on-camera narrator of a well-received environmental TV program, "In Partnership With Earth," with then–EPA Administrator William K. Reilly.

With Denver's innate love of flying he was naturally attracted to NASA and became dedicated to America’s work in outer space. He conscientiously worked to help bring into being the “Citizens in Space” program. Denver received the NASA Public Service Medal, in 1985 for “helping to increase awareness of space exploration by the peoples of the world,” an award usually restricted to spaceflight engineers and designers. Also in 1985, Denver passed NASA’s rigorous physical exam and was in line for a space flight, a finalist for the first citizen’s trip on the Space Shuttle in 1986. He was not chosen. After the Challenger disaster with teacher Christa McAuliffe aboard, John dedicated his song “Flying for Me”, to all astronauts, and he continued to support NASA.^[3]

Denver testified before the Senate Labor and Commerce Committee on the topic of censorship during a Parents Music Resource Center hearing in 1985. Denver also toured Russia in 1985. His 11 Soviet Union concerts were the first by any American artist in more than 10 years, and they marked a very important cultural exchange that culminated in an agreement to allow other western artists to perform there.^[20] He returned two years later to perform at a benefit concert for the victims of the Chernobyl disaster. In October 1992, John undertook a multiple-city tour of the People's Republic of China. He also released a greatest-hits CD, "Homegrown," to raise money for homeless charities.

In 1994, he published his autobiography, Take Me Home, in which he candidly spoke of his marijuana, LSD, and cocaine use, his marital infidelities, history of domestic violence, and a suicide attempt in a London hotel room.^[21][22] In 1996, he was inducted into the Songwriters Hall of Fame.

In early 1997, Denver filmed an episode for the Nature series, centering on the natural wonders that inspired many of his best-loved songs. The episode contains his last song, "Yellowstone, Coming Home," which he composed while rafting along the Colorado River with his son and young daughter.^[23]

In the summer of 1997, Denver recorded a children's train album for Sony Wonder, entitled All Aboard!, produced by long-time friend Roger Nichols.^[24] The album consisted of old-fashioned swing, big band, folk, bluegrass, and gospel styles of music woven into a theme of railroad songs. This album won a posthumous Best Musical Album For Children Grammy for Denver, which was his only Grammy.^[25]

Personal life[link]

Denver's first marriage was to Annie Martell of St. Peter, Minnesota. Their wedding was held at the Christ Chapel at Gustavus Adolphus College. Annie was the subject of his hit Annie's Song, which he composed in only ten minutes while on a ski lift in 1974.^[8] The couple lived in Edina, Minnesota from 1968 to 1971. Following the success of "Rocky Mountain High," Denver purchased a residence in Colorado and owned one home in Colorado continuously until his death.^[26] He and Annie adopted a son, Zachary, and daughter, Anna Kate, who John would say were “meant to be” theirs.^[3] John once said, "I'll tell you the best thing about me. I'm some guy's dad; I'm some little gal's dad. When I die, Zachary John and Anna Kate's father, boy, that's enough for me to be remembered by. That's more than enough."^[27] Zachary was the subject of "A Baby Just Like You," a song that included the line "Merry Christmas, little Zachary" and which he wrote for Frank Sinatra. Denver and Annie Martell divorced in 1982 and the ensuing property settlement caused Denver to become so enraged he nearly choked his ex-wife, then used a chainsaw to cut the marital bed in half.^{[8][21][22][28]} Martell continues to live in Aspen, Colorado.

John Denver married Australian actress Cassandra Delaney in 1988, after a two-year courtship. Settling in Aspen, the couple had a daughter, Jesse Belle. Denver and Delaney separated in 1991 and divorced in 1993.^[8] Of his second marriage, Denver would later recall that "before our short-lived marriage ended in divorce, she managed to make a fool of me from one end of the valley to the other."^[22] In 1993, Denver pleaded guilty to a drunken driving charge, and was placed on probation.^[28] In August 1994, while still on probation, he was again charged with misdemeanor driving under the influence after crashing his Porsche into a tree in Aspen, Colorado.^[28] Though a jury trial in July 1997 resulted in a hung jury on the second DUI charge, prosecutors later decided to reopen the case, which was only closed after Denver's accidental death in October 1997.^[28][29] In 1996, the FAA decided that Denver could no longer fly a plane due to medical disqualification for failure to abstain from alcohol, a condition that the FAA had imposed in October 1995 after his prior drunk driving conviction.^[30][31]

Denver's talent extended beyond music. He was a painter as well but because of his limiting schedule, he pursued photography. He once said that "photography is a way to communicate a feeling." Denver was an avid skier and golfer. His love of flying was secondary only to his love for music.^[32] He collected vintage biplanes, and in 1974, he bought a Learjet, which he used to fly himself to concerts. He also bought a Christen Eagle aerobatic plane, two Cessna 210 and in 1997, an experimental, amateur-built Rutan Long-EZ.^[3][31][32]

A Long-EZ two seat canard plane similar to Denver's

Death[link]

On October 12, 1997, Denver was killed at the age of 53 when his experimental Rutan Long-EZ plane, aircraft registration number N555JD, crashed into the Pacific Ocean near Pacific Grove, California, while making a series of touch-and-go landings at the nearby Monterey Peninsula Airport.^[33] National Transportation Safety Board]] (NTSB) accident ID is LAX98FA008.^[34] As the crash badly disfigured Denver's head and body, making identification by dental records impossible, records of his fingerprints taken from his arrests for intoxicated driving were used to confirm that the fallen pilot was indeed the singer.^[35][36]

A pilot with over 2,700 hours of experience, Denver had single-engine land and sea, multi-engine land, glider, and instrument ratings. He also held a type rating in his Learjet. He had recently purchased the Long-EZ aircraft, and had taken a half-hour checkout flight with the aircraft the day before the accident.^[37] However, Denver did not possess a valid FAA medical certification.^[30][31] Denver was the sole occupant of the aircraft.^[38]

In 1996, nearly a year before the accident, the Federal Aviation Administration had learned of Denver's failure to abstain entirely from alcohol after his drunk driving arrests, and had previously revoked his medical certification.^[30][31] Since Denver was required by the FAA to have at least a third-class medical certification in order to exercise the privileges of his pilot certificate, he was not legally able to fly at the time of the accident. However, there was no trace of alcohol or drugs in Denver's body at autopsy.^[31]

Post-accident investigation by the NTSB showed that the experimental Rutan as built had an unusual reconfiguration of the fuel selector valve handle, which had been moved from the instrument panel to behind the left shoulder of the pilot.^[30][31] Wreckage examination by NTSB investigators revealed that the selector handle was not placarded or marked for any operating position.^[30][31] According to a pilot who had flown the aircraft in a prior checkout flight, the handle in the right position was for the left tank, the handle in the down position was for the right tank, and the off position was up.^[30][31] An NTSB interview with the aircraft mechanic servicing Denver's plane revealed that he and Denver had discussed the inaccessibility of the cockpit fuel selector valve handle and its resistance to being turned.^[30][31] Before the flight, Denver and the mechanic had attempted to extend the reach of the handle, using a pair of vice grip pliers.^[30][31] However, this did not solve the problem as the pilot could still not reach the handle while strapped into his seat.^[30][31] When investigators attempted to switch fuel tanks in a similar Long EZ, each time while an investigator turned his body the 90 degrees required to reach the valve, his natural tendency was to extend his right foot against the right rudder pedal to support his body as he turned in the seat, causing the aircraft to yaw and pitch up.^[30][31]

After the mechanic noted that the fuel sight gauges were only visible to the rear cockpit occupant, Denver asked him about the quantity of fuel shown.^[30][31] The mechanic told Denver that he had "less than half in the right tank and less than a quarter in the left tank".^[30][31] The mechanic then provided Denver with a shop inspection mirror so that he could look over his shoulder at the fuel sight gauges; the mirror was later recovered in the wreckage.^[30][31] Denver told the mechanic that he would use the autopilot inflight, if necessary, to hold the airplane level while he turned the fuel selector valve.^[30][31] Denver declined an offer to take on additional fuel, telling the mechanic that he would only be flying for about one hour.^[30][31]

Twenty witnesses to the accident were interviewed by the NTSB, some of whom observed the plane's crash into the ocean near Point Pinos.^[30][31] Four of the witnesses indicated that the airplane was originally heading west; five of them observed the airplane in a steep bank, with four of those five reporting the bank was to the right (north). Twelve witnesses saw the airplane in a steep nose-down descent, and 6 of them saw the airplane hit the water. Witnesses estimated the plane's height at 350 to 500 feet while heading toward the shoreline. Eight of the witnesses said that they heard a "pop" or "backfire," along with a reduction in the engine noise level just before the airplane descended into the water.

The National Transportation Safety Board determined the probable cause of the crash was the pilot's diversion of attention from the operation of the airplane and his inadvertent application of right rudder that resulted in the loss of airplane control while attempting to manipulate the fuel selector handle, resulting in a crash into the ocean.^[30][31] The Board also determined that the pilot's inadequate transition training, lack of total flight experience in type, and inadequate preflight planning and preparations, specifically his failure to refuel the airplane, were causal.^[30][31] The Board also singled out the aircraft builder's decision to locate the unmarked fuel selector handle in a hard-to-access position along with installing unmarked fuel quantity sight gauges as factors in the accident.^[30][31]