title: Ailanthus altissima

text: In addition to the tree of heaven's various uses, it has also been a part of Chinese culture for many centuries and has more recently attained a similar status in the west. Within the oldest extant Chinese dictionary, the Erya, written in the 3rd century BCE, the tree of heaven is mentioned second among a list of trees. It was mentioned again in a materia medica compiled during the Tang dynasty in 656 CE. Each work favoured a different character, however, and there is still some debate in the Chinese botanical community as to which character should be used. The current name, "chouchun" (), means "stinking tree", and is a relatively new appellation. People living near the lower Yellow River know it by the name "chunshu" (), meaning "spring tree". The name stems from the fact that "A. altissima" is one of the last trees to come out of dormancy, and as such its leaves coming out would indicate that winter was truly over.


title: Ailanthus altissima

text: In Chinese literature, ailanthus is often used for two rather extreme metaphors, with a mature tree representing a father and a stump being a spoiled child. This manifests itself occasionally when expressing best wishes to a friend's father and mother in a letter, where one can write "wishing your ailanthus and daylily are strong and happy", with ailanthus metaphorically referring to the father and daylily to the mother. Furthermore, one can scold a child by calling him a "good-for-nothing ailanthus stump sprout", meaning the child is irresponsible. This derives from the literature of Zhuangzi, a Taoist philosopher, who referred to a tree that had developed from a sprout at the stump and was thus unsuitable for carpentry due to its irregular shape. Later scholars associated this tree with ailanthus and applied the metaphor to children who, like stump sprouts of the tree, will not develop into a worthwhile human being if they don't follow rules or traditions.


title: Ailanthus altissima

text: The 1943 book "A Tree Grows in Brooklyn" by Betty Smith uses the tree of heaven as its central metaphor, using it as an analogy for the ability to thrive in a difficult environment. At that time as well as now, ailanthus was common in neglected urban areas. She writes:


title: Ailanthus altissima

text: In William Faulkner's novel, "Sanctuary", a "heaven-tree" stands outside the Jefferson jail, where Lee Goodwin and a "negro murderer" are incarcerated. The tree is associated with the black prisoner's despair in the face of his impending execution and the spirituals that he sings in chorus with other black people who keep a sort of vigil in the street below:


title: Ailanthus altissima

text: ...they sang spirituals while white people slowed and stopped in the leafed darkness that was almost summer, to listen to those who were sure to die and him who was already dead singing about heaven and being tired; or perhaps in the interval between songs a rich, sourceless voice coming out of the high darkness where the ragged shadow of the heaven-tree which snooded the street lamp at the corner fretted and mourned: "Fo days mo! Den dey ghy stroy de bes ba'yton singer in nawth Mississippi!"


title: Ailanthus altissima

text: Upon the barred and slitted wall the splotched shadow of the heaven-tree shuddered and pulsed monstrously in scarce any wind; rich and sad, the singing fell behind.


title: Ailanthus altissima

text: In the 2013 book "Teardown: Memoir of a Vanishing City" by journalist Gordon Young, the tree is referenced in a description of the Carriage Town neighborhood in Flint, Michigan.


title: Ailanthus altissima

text: Festive Victorian-era homes in various stages of restoration battled for supremacy with boarded-up firetraps and overgrown lots landscaped with weeds, garbage, and “ghetto palms,” a particularly hardy invasive species known more formally as Ailanthus altissima, or the tree of heaven, perhaps because only God can kill the things. Around the corner, business was brisk at a drug house where residents and customers alike weren't above casually taking a piss in the driveway.


title: Ailanthus altissima

text: Ailanthus is also sometimes counter-nicknamed "tree from hell" due to its prolific invasiveness and the difficulty in eradicating it. In certain parts of the United States, the species has been nicknamed the "ghetto palm" because of its propensity for growing in the inhospitable conditions of urban areas, or on abandoned and poorly maintained properties, such as in war-torn Afghanistan.


title: Ailanthus altissima

text: Until 26 March 2008, a -tall member of the species was a prominent "centerpiece" of the sculpture garden at the Noguchi Museum in the Astoria section in the borough of Queens in New York City. The tree had been spared by the sculptor Isamu Noguchi when in 1975 he bought the building which would become the museum and cleaned up its back lot. The tree was the only one he left in the yard, and the staff would eat lunch with Noguchi under it. "[I]n a sense, the sculpture garden was designed around the tree", said a former aide to Noguchi, Bonnie Rychlak, who later became the museum curator. By 2008, the old tree was found to be dying and in danger of crashing into the building, which was about to undergo a major renovation. The museum hired the Detroit Tree of Heaven Woodshop, an artists' collective, to use the wood to create benches, sculptures and other amenities in and around the building. The tree's rings were counted, revealing its age to be 75, and museum officials hoped it would regenerate from a sucker.


title: Ailanthus altissima

text: Ingo Vetter, a German artist and professor of fine arts at Umeå University in Sweden, was influenced by the idea of the "ghetto palm" and installed a living ailanthus tree taken from Detroit for an international art show called "Shrinking Cities" at the Kunst-Werke Institute for Contemporary Art in Berlin in 2004.


title: Robert Walker (actor, born 1918)

text: Robert Hudson Walker (October 13, 1918 – August 28, 1951) was an American actor who starred as the villain in Alfred Hitchcock's thriller "Strangers on a Train" (1951), which was released shortly before his early demise.


title: Robert Walker (actor, born 1918)

text: He started in youthful boy-next-door roles, often as a World War II soldier. One of these roles was opposite his first wife, Jennifer Jones, in the World War II epic "Since You Went Away" (1944). He also played Jerome Kern in "Till the Clouds Roll By". Twice divorced by 30, he suffered from alcoholism and mental illness, which were exacerbated by his painful separation and divorce from Jones.


title: Robert Walker (actor, born 1918)

text: Walker was born in Salt Lake City, Utah. Emotionally scarred by his parents' divorce when he was still a child, he subsequently developed an interest in acting, which led his maternal aunt, Hortense McQuarrie Odlum (then the president of Bonwit Teller), to offer to pay for his enrollment at the American Academy of Dramatic Arts in New York City in 1937. Walker lived in her home during his first year in the city.


title: Robert Walker (actor, born 1918)

text: While attending the American Academy of Dramatic Arts, Walker met fellow aspiring actress Phylis Isley, who later took the stage name Jennifer Jones. After a brief courtship, the couple married in Tulsa, Oklahoma, on January 2, 1939. Walker had some small unbilled parts in films such as "Winter Carnival" (1939), and two Lana Turner films at MGM: "These Glamour Girls" (1939) and "Dancing Co-Ed" (1939).


title: Robert Walker (actor, born 1918)

text: Walker's and Jennifer Jones' elder son Robert Walker Jr. (1940-2019) later became a successful movie actor, working with John Wayne, Robert Mitchum, Kirk Douglas and Walter Matthau among many others. Their other son, Michael Walker (1941-2007), was also an actor who appeared in films The Rogues (1964), Coronet Blue (1967) and Hell's Belles (1969) and several '60s TV series including Perry Mason: The Case of the Cheating Chancellor (1965).


title: Robert Walker (actor, born 1918)

text: Walker found work in radio while Isley stayed home and gave birth to two sons in quick succession - Robert Walker Jr. (1940–2019) and Michael Walker (1941–2007).


title: Robert Walker (actor, born 1918)

text: Walker co-starred in the weekly radio show "Maudie's Diary" from August 1941 to September 1942. Isley then returned to auditioning where her luck changed when she was discovered in 1941 by producer David O. Selznick, who changed her name to Jennifer Jones and groomed her for stardom.


title: Robert Walker (actor, born 1918)

text: The couple returned to Hollywood, and Selznick's connections helped Walker secure a contract with Metro-Goldwyn-Mayer, where he started work on the war drama "Bataan" (1943), playing a soldier who fights in the Bataan retreat.


title: Robert Walker (actor, born 1918)

text: He followed it with a supporting role in "Madame Curie" (1943). Both were notable commercial successes.


title: Robert Walker (actor, born 1918)

text: Walker's charming demeanor and boyish good looks caught on with audiences, and he was promoted to stardom with the title part of the romantic soldier in "See Here, Private Hargrove" (1944).


title: Robert Walker (actor, born 1918)

text: He also appeared in Selznick's "Since You Went Away" (1944), in which he and his wife portrayed doomed young lovers during World War II. By that time, Jones' affair with Selznick was common knowledge, and Jones and Walker separated in November 1943, in mid-production. The filming of their love scenes was torturous as Selznick insisted that Walker perform take after take of each love scene with Jones. She filed for divorce in April 1945. "Since You Went Away" was one of the most financially successful movies of 1944, earning over $7 million.


title: Robert Walker (actor, born 1918)

text: Back at MGM, Walker appeared alongside Spencer Tracy and Van Johnson in "Thirty Seconds Over Tokyo" (1944), the story of the Doolittle Raid. He played flight engineer and turret gunner David Thatcher, and it was another box office hit.


title: Robert Walker (actor, born 1918)

text: Walker starred as a GI preparing for overseas deployment in "The Clock" (1945")," with Judy Garland playing his love interest in her second non-musical film. (Garland’s first non-musical was "Life Begins for Andy Hardy" (1941). Although she recorded four songs for the picture, all were dropped before it was released.) Directed by her soon-to-be husband Vincente Minnelli, "The Clock" was profitable, though not as successful as Garland's musicals.


title: Robert Walker (actor, born 1918)

text: He then made a romantic comedy with Hedy Lamarr and June Allyson, "Her Highness and the Bellboy" (1945). Then he did a second Hargrove film, "What Next, Corporal Hargrove?" (1945) and a romantic comedy with June Allyson, "The Sailor Takes a Wife" (1945).


title: Robert Walker (actor, born 1918)

text: Walker starred in the musical "Till the Clouds Roll By" (1946), in which he played the popular composer Jerome Kern. This movie had rental receipts of over $6 million. He starred as another composer, Johannes Brahms, in "Song of Love" (1947), which co-starred Katharine Hepburn and Paul Henreid, which lost MGM over $1 million. In between, he made a film about the construction of the atomic bomb, "The Beginning or the End" (1946), which also resulted in a loss at the box office, and a Tracy-Hepburn drama directed by Elia Kazan, "The Sea of Grass" (1947), which was profitable.


title: Robert Walker (actor, born 1918)

text: In 1948, Walker was borrowed by Universal to star with Ava Gardner in the film "One Touch of Venus", directed by William A. Seiter. The film was a non-musical comedy adapted from a Broadway show with music by Kurt Weill. Walker married Barbara Ford, the daughter of director John Ford, in July 1948, but the marriage lasted only five months.


title: Robert Walker (actor, born 1918)

text: Back at MGM Walker was in two films that lost money, "Please Believe Me" (1950) with Deborah Kerr and "The Skipper Surprised His Wife" (1950) with Joan Leslie. More popular was a Western with Burt Lancaster, "Vengeance Valley" (1951), a notable hit.


title: Robert Walker (actor, born 1918)

text: In 1949, Walker spent time at the Menninger Clinic, where he was treated for a psychiatric disorder. Following his discharge, he was cast by director Alfred Hitchcock in "Strangers on a Train" (1951), for which he received acclaim for his performance as the charming psychopath Bruno Anthony.


title: Robert Walker (actor, born 1918)

text: In his final film, Walker played the title role of Leo McCarey's "My Son John" (1952), made at the height of the Red Scare. Despite the film's anti-Communist themes, Walker was allegedly neither liberal nor conservative, despite being a Republican, and took the job to work with McCarey and co-star Helen Hayes. Walker died before production finished, and so angles from his death scene in "Strangers" were spliced into a similar melodramatic death scene near the end of the film.


title: Robert Walker (actor, born 1918)

text: Walker was a registered Republican who supported Dwight Eisenhower's campaign in the 1952 presidential election, and was of the Mormon faith.


title: Robert Walker (actor, born 1918)

text: On the night of August 28, 1951, Walker's housekeeper reportedly found Walker in an emotional state. She called the actor's psychiatrist, Frederick Hacker, who arrived and administered amobarbital for sedation. Walker had allegedly been drinking before the outburst, and it is believed the combination of amobarbital and alcohol caused him to lose consciousness and stop breathing. Efforts to resuscitate Walker failed and he was pronounced dead shortly thereafter. He was aged 32. The loss was widely lamented.


title: Robert Walker (actor, born 1918)

text: In her biography of Walker and Jones, "Star-Crossed", author Beverly Linet quotes Walker's friend Jim Henaghan, who was not mentioned in official accounts of Walker's death, as saying that he was present at the time of the events leading to Walker's death. Henaghan, who was married to Gwen Verdon at the time, stated that he stopped by Walker's house in Los Angeles, where they played cards, and Walker was behaving normally. Walker's psychiatrist arrived and insisted that he receive an injection. When Walker refused, Henaghan held him down in order for the physician to administer it. Walker soon lost consciousness, and frantic efforts to revive him failed.


title: Medieval India

text: Medieval India refers to a long period of Post-classical history of the Indian subcontinent between the "ancient period" and "modern period". It is usually regarded as running approximately from the breakup of the Gupta Empire in the 6th century CE to the start of the Early modern period in 1526 with the start of the Mughal Empire, although some historians regard it as both starting and finishing later than these points. The medieval period is itself subdivided into the Early Medieval and Late Medieval eras.


title: Medieval India

text: In the Early Medieval period, there were more than 40 different states on the Indian subcontinent, which hosted a variety of cultures, languages, writing systems, and religions. At the beginning of the time period, Buddhism was predominant throughout the area, with the short-lived Pala Empire on the Indo Gangetic Plain sponsoring the Buddhist faith's institutions. One such institution was the Buddhist Nalanda University in modern-day Bihar, India, a centre of scholarship and brought a divided South Asia onto the global intellectual stage. Another accomplishment was the invention of the "Chaturanga" game which later was exported to Europe and became Chess.


title: Medieval India

text: In Southern India, the Tamil Hindu Kingdom of Chola gained prominence with an overseas empire that controlled parts of modern-day Sri Lanka, Malaysia, and Indonesia as oversees territories, and helped spread Hinduism and Buddhism into the historic cultural area of Southeast Asia. In this time period, neighboring regions such as Afghanistan, Tibet, and Southeast Asia were under South Asian influence.


title: Medieval India

text: During the Late Medieval period, a series of Turkic Islamic invasions from modern-day Central Asia Afghanistan and Iran conquered massive portions of Northern India, founding the Delhi Sultanate which ruled until the 16th century. As a consequence, Buddhism declined in South Asia, vanishing in many areas, but Hinduism survived and reinforced itself in areas conquered by Islamic invaders. In the far South, the Vijayanagara Empire was not conquered by any Muslim state in the period. The turn of the 16th century would see introduction of gunpowder and the rise of a new Islamic Empire—the Mughals, as well as the establishment of European trade posts by the Portuguese colonists. Mughal Empire was one of the three Islamic gunpowder empires, along with the Ottoman Empire and Safavid Persia. The subsequent cultural and technological developments transformed Indian society, concluding the Late Medieval period and beginning the Early modern period.


title: Medieval India

text: One definition includes the period from the 6th century, the first half of the 7th century, or the 8th century up to the 16th century, essentially coinciding with the Middle Ages of Europe. It may be divided into two periods: The 'early medieval period' which lasted from the 6th to the 13th century and the 'late medieval period' which lasted from the 13th to the 16th century, ending with the start of the Mughal Empire in 1526. The Mughal era, from the 16th century to the 18th century, is often referred to as the early modern period, but is sometimes also included in the 'late medieval' period.


title: Medieval India

text: An alternative definition, often seen in those more recent authors who still use the term at all, brings the start of the medieval times forward, either to about 1000 CE, or to the 12th century. The end may be pushed back to the 18th century, Hence, this period can be effectively considered as the beginning of Muslim domination to British India. Or the "early medieval" period as beginning in the 8th century, and ending with the 11th century.


title: Medieval India

text: The use of "medieval" at all as a term for periods in Indian history has often been objected to, and is probably becoming more rare (there is a similar discussion in terms of the history of China). It is argued that neither the start nor the end of the period really mark fundamental changes in Indian history, comparable to the European equivalents. Burton Stein still used the concept in his "A History of India" (1998), referring to the period from the Guptas to the Mughals, but most recent authors using it are Indian. Understandably, they often specify the period they cover within their titles.


title: Medieval India

text: The start of the period is typically taken to be the slow collapse of the Gupta Empire from about 480 to 550, ending the "classical" period, as well as "ancient India", although both these terms may be used for periods with widely different dates, especially in specialized fields such as the history of art or religion. Another alternative for the preceding period is "Early Historical" stretching "from the sixth century BC to the sixth century AD", according to Romila Thapar.


title: Medieval India

text: At least in northern India, there was no larger state until the Delhi Sultanate, or certainly the Mughal Empire, but there were several different dynasties ruling large areas for long periods, as well as many other dynasties ruling smaller areas, often paying some form of tribute to larger states. John Keay puts the typical number of dynasties within the subcontinent at any one time at between 20 and 40, not including local rajas.


title: Medieval India

text: This period follows the Muslim conquests of the Indian subcontinent and the decline of Buddhism, the eventual founding of the Delhi Sultanate and the creation of Indo-Islamic architecture, followed by the world's major trading nation, the Bengal Sultanate.


title: Medieval India

text: The start of the Mughal Empire in 1526 marked the beginning of the early modern period of Indian history, often referred to as the Mughal era. Sometimes, the Mughal era is also referred as the 'late medieval' period.


title: Medieval India

text: Modern historical works written on Medieval India have received some criticism from scholars studying the historiography of the period. E. Sreedharan argues that, after Indian independence up until the 1960s, Indian historians were often motivated by Indian nationalism. Peter Hardy notes that the majority of modern historical works on Medieval India up until then were written by British and Hindu historians, whereas the work of modern Muslim historians was under-represented. However, he argues that some of the modern Muslim historiography on Medieval India at the time was motivated by Islamic apologetics, attempting to justify "the life of medieval Muslims to the modern world."


title: Medieval India

text: Ram Sharan Sharma has criticised the simplistic manner in which Indian history is often divided into an ancient "Hindu" period, a medieval "Muslim" period, and a modern "British" period. He argues that there is no clear sharp distinction between when the ancient period ended and when the medieval period began, noting dates ranging from the 7th century to the 13th century.


title: Pteropus

text: Pteropus (suborder Yinpterochiroptera) is a genus of megabats which are among the largest bats in the world. They are commonly known as fruit bats or flying foxes, among other colloquial names.


title: Pteropus

text: They live in South Asia, Southeast Asia, Australia, East Africa, and some oceanic islands in the Indian and Pacific Oceans.


title: Pteropus

text: Flying foxes eat fruit and other plant matter, and occasionally consume insects as well. They locate resources with their keen sense of smell.


title: Pteropus

text: They have long life spans and low reproductive outputs, with females of most species producing only one offspring per year. Their slow life history makes their populations vulnerable to threats such as overhunting, culling, and natural disasters. Six flying fox species have been made extinct in modern times by overhunting. Flying foxes are often persecuted for their real or perceived role in damaging crops. They are ecologically beneficial by assisting in the regeneration of forests via . They benefit ecosystems and human interests by pollinating plants.


title: Pteropus

text: Like other bats, flying foxes are relevant to humans as a source of disease, as they are the reservoirs of rare but fatal disease agents including Australian bat lyssavirus, which causes rabies, and Hendra virus; seven known human deaths have resulted from these two diseases. Nipah virus is also transmitted by flying foxes—it affects more people, with over 100 attributed fatalities. They have cultural significance to indigenous people, with appearances in traditional art, folklore, and weaponry. Their fur and teeth were used as currency in the past. Some cultures still use their teeth as currency today.


title: Pteropus

text: Prior to 1998, genus authority was sometimes given to German naturalist Johann Christian Polycarp Erxleben. Although the Brisson publication (1762) predated the Erxleben publication (1777), thus giving him preference under the Principle of Priority, some authors gave preference to Erxleben as genus authority because Brisson's publication did not consistently use binomial nomenclature. In 1998, the International Commission on Zoological Nomenclature (ICZN) decided that Brisson's 1762 publication was a "rejected work" for nomenclatural purposes. Despite rejecting the majority of the publication, the ICZN decided to conserve a dozen generic names from the work and retain Brisson as authority, including "Pteropus".


title: Pteropus

text: The type species of the genus is the Mauritian flying fox, "Pteropus niger" (described as "Vespertilio vampyrus niger" by Robert Kerr in 1792).


title: Pteropus

text: The decision to designate "P. niger" as the type species was made by the ICZN through their plenary powers over biological nomenclature. ""Pteropus"" comes from Ancient Greek ""pterón"" meaning "wing" and ""poús"" meaning "foot." The phrase "flying fox" has been used to refer to "Pteropus" bats since at least 1759.


title: Pteropus

text: Flying fox species vary in body weight, ranging from . Across all species, males are usually larger than females.


title: Pteropus

text: The large flying fox has the longest forearm length and reported wingspan of any bat species, but some bat species exceed it in weight.


title: Pteropus

text: Its wingspan is up to , and it can weigh up to . The Indian and great flying foxes are heavier, at , respectively.


title: Pteropus

text: Outside this genus, the giant golden-crowned flying fox (genus "Acerodon") is the only bat with similar dimensions.


title: Pteropus

text: The pelage is long and silky with a dense underfur. In many species, individuals have a "mantle" of contrasting fur color on the back of their head, the shoulders, and the upper back. They lack tails. As the common name "flying fox" suggests, their heads resemble that of a small fox because of their small ears and large eyes. Females have one pair of mammae located in the chest region. Their ears are long and pointed at the tip and lack tragi. The outer margin of each ear forming an unbroken ring. The toes have sharp, curved claws. While microbats only have a claw on each thumb of their forelimbs, flying foxes additionally have a claw on each index finger.


title: Pteropus

text: The skulls of "Pteropus" species are composed of 24 bones, the snout is made of 7, the cranium of 16 and the mandible is a single bone. It has a large and bulbous braincase. Like all mammals, flying foxes have three middle ear ossicles which assist in transmitting sound to the brain. Flying fox skulls continue to develop after they are born. Compared to adults, young flying foxes have very short snouts; as they reach maturity, the maxilla elongates, gaining bone between the zygomatic processes and the canine teeth.


title: Pteropus

text: Based on the grey-headed flying fox's development, pups are born with some milk teeth already erupted: canines and incisors. By 9 days old, all the milk teeth have emerged, with a dental formula of and a total of 20 teeth. By 140 days old (4.6 months), all the milk teeth have fallen and been replaced by permanent teeth. The canines are usually replaced first, followed by the premolars, incisors, and then molars. The adult dental formula is for a total of 34 teeth. The occlusal surface of the molars is generally smooth but with longitudinal furrows.


title: Pteropus

text: Flying foxes have large hearts and a relatively fast heart rate: resting individuals have a heart rate of 100-400 beats per minute.


title: Pteropus

text: Flying foxes have simple digestive tracts; the time between ingestion and excretion is as short as 12 minutes. They lack both a cecum and an appendix. The stomach has marked cardiac and fundic regions.


title: Pteropus

text: The megabats, including flying foxes, have the greatest encephalization quotient (brain size relative to body size) of any bat family at 1.20.


title: Pteropus

text: This value is equivalent to that of domestic dogs. Flying foxes display behaviors that indicate a reliance on long-term information storage. Though they have wide-ranging movements and cover thousands of square kilometers annually, they are consistently able to locate the same resource patches and roosts. They will visit these resource patches consistently in a strategy known as trap-lining. They can also be conditioned to perform behaviors, such as one study where spectacled flying foxes were trained to pull a lever using juice as a reinforcement. In a follow-up to the initial study, individuals who had learned to pull the lever to receive juice still did so 3.5 years later.


title: Pteropus

text: They have large olfactory bulbs to process scents. They use scent to locate food, for mothers to locate their pups, and for mates to locate each other. Males have enlarged androgen-sensitive sebaceous glands on their shoulders that they use for scent-marking their territories, particularly during the mating season. The secretions of these glands vary by species—of the 65 chemical compounds isolated from the glands of four species, no compound was found in all species. Males also engage in "urine washing", meaning that they coat themselves in their own urine.


title: Pteropus

text: Flying foxes do not echolocate, and therefore rely on sight to navigate. Their eyes are relatively large and positioned on the front of their heads, giving them binocular vision.


title: Pteropus

text: Like most mammals, though not primates, they are dichromatic. They have both rods and cones; they have "blue" cones that detect short-wavelength light and "green" cones that detect medium-to-long-wavelengths. The rods greatly outnumber the cones, however, as cones comprise only 0.5% of photoreceptors. Flying foxes are adapted to seeing in low-light conditions.


title: Pteropus

text: Flying foxes are poorly represented in the fossil record. Relative to the current number of extant species, the Pteropodidae has one of the most incomplete fossil records of any bat group. As of 2014, no flying fox fossils are known from before the Holocene.


title: Pteropus

text: Many flying foxes live in the tropics, where conditions for fossilization are poor. Based on molecular evolution, flying foxes diverged from a common ancestor with "Rousettus" 28–18 million years ago and from their sister taxa "Neopteryx" and "Acerodon" 6.6–10.6 million years ago. "Neopteryx", "Acerodon", "Desmalopex", "Melonycteris", "Mirimiri", "Pteralopex", and "Styloctenium" are all relatively closely related to the flying foxes, as they are the other members of its subfamily Pteropodinae.


title: Pteropus

text: Phylogenetic analysis indicates that flying foxes diversified rapidly in an explosive evolutionary radiation, creating many taxa in a relatively short time frame. Most flying fox lineages emerged after the Zanclean, with two major clades created: one consisting of the Indian Ocean species and the other of the Melanesian, Micronesian, Australian, and insular Southeast Asian species. Flying foxes likely originated on mainland Asia; molecular data suggests that there were at least three colonization events into the Indian Ocean. One event resulted in Livingstone's fruit bat and the Pemba flying fox, which are the westernmost flying foxes. A second colonization event resulted in the Rodrigues flying fox to Rodrigues Island; while a third event resulted in several species diverging to Mauritius, the Seychelles, Madagascar, and Aldabra.


title: Pteropus

text: With one possible exception - the masked flying fox ("P. personatus"), flying foxes are likely monophyletic. There are over 60 extant species of flying fox. Flying foxes are now present from the western Indian Ocean midway through the Pacific Ocean as far east as the Cook Islands. They are found in tropical and subtropical climates.


title: Pteropus

text: Many species of flying fox are polygynandrous, meaning that each individual will mate with several other individuals. The Samoa flying fox is a notable exception because it is monogamous. Flying fox sexual behaviors include oral sex in addition to intercourse, with fellatio and cunnilingus observed between opposite sexes, as well as homosexual fellatio in at least one species, the Bonin flying fox. Opposite-sex oral sex is associated with increased duration of intercourse, while same-sex fellatio is hypothesized to encourage colony formation of otherwise-antagonistic males in colder climates.


title: Pteropus

text: Twins have been occasionally documented in some species, however. Twins can be fraternal, identical, or the result of superfetation. Pups are altricial and sparsely furred at birth, thereby dependent on their mothers for care. Pups are relatively small at birth, weighing approximately 12% of the mother's weight. Bats in other genera can have pups that weigh as much as 30% of the mother's weight at birth. They cling to their mothers' abdomens, gripping her fur with their thumb claws and teeth; females carry the pups for the first several weeks of life. After this, the females may leave the pups behind at the roost at night while they forage. As with nearly all bat species, males do not assist females in parental care. While male flying foxes of at least one species, the Bismarck masked flying fox, can lactate, it is unclear if the lactation is functional and males actually nurse pups or if it is a result of stress or malnutrition. Pups fledge beginning at 3 months old, but may not be weaned until 4–6 months old. Pups may stay with their mothers until age one. Flying foxes do not reach sexual maturity until 1.5–2 years old. Females can have up to two litters annually, though one is the norm due to the long weaning period. Most flying foxes are seasonal breeders and give birth in the spring, though the Mariana fruit bat seems to have aseasonal breeding with new pups documented throughout the year. Females remain fertile with no decrease in reproductive capability for at least the first 12 or 13 years of life.


title: Pteropus

text: Flying foxes, like all bats, are long-lived relative to their size. In the wild, average lifespans are likely 15 years. However, individuals part of populations that face excessive disturbance may have lifespans as short as 7.1 years. In captivity, individuals can live approximately 20–28 years. The longest-lived flying fox was an Indian flying fox named Statler, who was a resident at Bat World Sanctuary for his last few years. He was born at a zoo in 1987, and was 34 years old at the time of his death.


title: Pteropus

text: Most flying fox species are gregarious and form large aggregations of individuals called colonies or "camps." The large flying fox forms colonies of up to 15,000 individuals, while the little red flying fox forms colonies of up to 100,000 individuals. A few species and subspecies, such as Orii's flying fox ("P. dasymallus inopinatus") and the Ceram fruit bat, are solitary.


title: Pteropus

text: Colony size varies throughout the year in response to biological needs. The grey-headed flying fox forms harems during the breeding season consisting of one male and up to six females. These colonies break up after the breeding season is over. In the Bonin flying fox, colony formation is based on both the sex and age of individuals, as well as the season. In the winter breeding season, adult females will form colonies that include a few adult males (likely harems). Adult males who do not roost with females will form colonies with other adult and subadult males. Subadults will form mixed-sex "subadult groups" with each other. In the summer, however, individuals are solitary, with the exception of nursing females, who roost with their pups.


title: Pteropus

text: Flying foxes consume 25–35% of their body weight daily. They are generalists that will consume a variety of items to meet their nutritional needs. Food items include fruit, flowers, nectar, and leaves. They will sometimes deliberately consume insects such as cicadas as well.


title: Pteropus

text: In Australia, eucalypt blossoms and pollen are preferred food sources, followed by "Melaleuca" and "Banksia" flowers They feed on a wide variety of crops as well, causing conflicts with farmers. Crops eaten by flying foxes include sisal, cashew, pineapple, areca, breadfruit, jackfruit, neem, papaya, citrus, fig, mango, banana, avocado, guava, sugar cane, tamarind, grapes, and more.


title: Pteropus

text: In captivity, the recommended diet for flying foxes consists of two-thirds hard fruits like pears and apples and one-third soft fruits. Bananas and other high-fiber fruits should only be offered occasionally, as flying foxes are not adapted to high-fiber diets. Protein supplements are recommended for captive flying foxes; other supplements such as vitamin C, calcium, chondroitin sulfate, and glucosamine can be recommended periodically.


title: Pteropus

text: The majority of flying fox species are nocturnal and forage at night. A few island species and subspecies are diurnal, however, hypothesized as a response to a lack of predators. Diurnal taxa include "P. melanotus natalis", the Mauritian flying fox, the Caroline flying fox, "P. p. insularis", and the Seychelles fruit bat. Foraging resources are often far from roosts, with individuals traveling up to to reach them. Flying foxes can travel at for three hours or more, and can reach top speeds of . Some colonial species will forage in groups, especially when resources are abundant. Less social species will forage alone. When they land on a tree with food, they will hang onto the branch with their clawed hind feet and use their clawed thumbs to pull branches bearing flowers or fruits towards them. As they forage on fruit, flying foxes will compress the fruit against the palate with the tongue to squeeze out and consume the juices. The rest of the fruit is then discarded in "ejecta pellets."


title: Pteropus

text: Flying foxes have important roles as and pollinators. They help spread the seeds in the fruit they eat by discarding them in ejecta pellets or through their guano. In Madagascar, fig seeds have better germination success if they have passed through the gut of a flying fox, which is important because fig trees are a vital pioneer species in regenerating lost forest. Even though flying foxes can have a gut transit time as fast as 12 minutes, seeds can be retained in the gut for as long as 20 hours. As the flying foxes travel large distances, seeds can be deposited up to from the parent tree. They are particularly important in fragmented forests, as many other frugivores are terrestrial and often confined to forest fragments.


title: Pteropus

text: Flying foxes pollinate a variety of plants, including the economically valuable durian. They forage on its nectar in such a way that the flowers (and eventual fruit production) are not usually harmed. Flying fox pollination has a positive effect on durian reproductive success, suggesting that both flying foxes and durian trees benefit from this relationship.


title: Pteropus

text: Of the 62 flying fox species evaluated by the IUCN as of 2018, 3 are considered critically endangered: the Aru flying fox, Livingstone's fruit bat, and the Vanikoro flying fox. Another 7 species are listed as endangered; 20 are listed as vulnerable, 6 as near threatened, 14 as least concern, and 8 as data deficient. A further 4 are listed as extinct: the dusky flying fox, the large Palau flying fox, the small Mauritian flying fox, and the Guam flying fox. Over half of the species are threatened today with extinction, and in particular in the Pacific, a number of species have died out as a result of hunting, deforestation, and predation by invasive species. Six flying fox species are believed to have gone extinct from 1864 to 2014: the Guam, large Palau, small Mauritian, dusky, large Samoan, and the small Samoan flying foxes.


title: Pteropus

text: All species of "Pteropus" are placed on Appendix II of CITES and 10 on Appendix I, which restricts international trade. Individual species have different legal protections from hunting and domestic trade that reflect the environmental laws of the countries where they are found.


title: Pteropus

text: In some countries such as Bangladesh, Sri Lanka, and Thailand, flying foxes are absolutely protected from harm under the Wildlife Preservation and Security Act of 2012, Fauna and Flora Protection Ordinance of 1937, and Wildlife Protection and Reservation Act of 1992, respectively. However, in Thailand, flying fox poaching and the illegal bushmeat trade still occurs outside of protected areas. The large flying fox and the small flying fox are particularly prone to poaching and roost disturbance.


title: Pteropus

text: In other countries, such as Australia, Japan, and the United States, some species of conservation concern are protected under national environmental legislation, while others are not. In Australia, two flying foxes are listed under the Environment Protection and Biodiversity Conservation Act of 1999: the grey-headed and spectacled flying foxes are listed as "vulnerable." Farmers can apply for permits to kill flying foxes when they are causing crop damage.


title: Pteropus

text: Several flying fox species occur in Japan. The Bonin flying fox has been a Natural Monument of Japan since 1969, which means that it is illegal to capture or disturb them without appropriate permits. Two subspecies of the Ryukyu flying fox ("P. d. dasymallus" and "P. d. daitoensis") are also listed as Natural Monuments.


title: Pteropus

text: Flying foxes are not designated game species in Japan, and therefore cannot be legally hunted per the Wildlife Protection and Hunting Law. The Bonin flying fox and "P. d. daitoensis" are also listed as National Endangered Species, meaning that they cannot be killed or harmed; furthermore, the sale or transfer of live or dead individuals in whole or part is also prohibited without permits.


title: Pteropus

text: Despite not occurring in the continental United States, several species and subspecies are listed under its Endangered Species Act of 1973. "Pteropus mariannus mariannus"—a subspecies of the Mariana fruit bat—is listed as threatened while the Rodrigues flying fox and Guam flying fox are listed as endangered. Additionally, the U. S. Government has been petitioned to list the Aru flying fox and Bonin flying fox as threatened or endangered.


title: Pteropus

text: In countries such as India and Pakistan, flying foxes explicitly have no legal protection. In India, they are listed as "vermin" under the Wildlife Protection Act of 1972. Pakistan's only flying fox, the Indian flying fox, is listed under Schedule 4 of the Punjab Wildlife (Protection, Preservation, Conservation and Management) Act of 1974, meaning that it has no legal protections and can be hunted.


title: Pteropus

text: In Mauritius, flying foxes were formerly protected but are now legally culled at a large scale. In 2015, the Mauritian government passed the Native Terrestrial Biodiversity And National Parks Act, which legalized culling of the Mauritian flying fox. In Mauritius, over 40,000 Mauritian flying foxes were culled in a two-year period, reducing its population by an estimated 45%. This decision was viewed with controversy, with researchers stating "Because they spread seeds and pollinate flowers, flying foxes are vital for regenerating lost forests."


title: Pteropus

text: Legal protection can vary within a country as well, such as in Malaysia. Under the 1990 Protection of Wild Life Amendment Order, flying foxes can be hunted with a permit; each permit is good for killing up to 50 flying foxes. Permits cost U.S.$8 each. However, under the Protection of WildLife Act of 1972, flying foxes can be killed without permits if they are causing damage or if there is "reason to believe that it is about to cause serious damage" to crops. In 2012, the Malaysian state of Terengganu issued a moratorium on hunting flying foxes.


title: Pteropus

text: Flying foxes species are declining or going extinct as a result of several human impacts to their environments, in addition to natural phenomena. Their populations are especially vulnerable to threats because the litter size is usually only individual and females generally only have one litter per year. Even when nearly every female (90%) successfully produces and raises young, if a population's mortality rate exceeds 22% annually, then it will steadily decline.


title: Pteropus

text: Invasive species such as the brown tree snake can seriously impact populations; the brown tree snake consumes so many pups that it reduced the recruitment of the Guam population of the Mariana fruit bat to essentially zero.


title: Pteropus

text: Many flying fox species are threatened by overhunting. While they have long been a dietary component of indigenous people, expanding human population and more efficient weapons have resulted in population declines, local extinctions, and extinctions. Overhunting is believed to be the primary cause of extinction for the small Mauritian flying fox and the Guam flying fox.


title: Pteropus

text: Flying foxes are also threatened with excessive culling due to conflict with farmers. They are shot, beaten to death, or poisoned to reduce their populations. Mortality also occurs via accidental entanglement into netting used to prevent the bats from eating fruit. Culling can dramatically reduce flying fox populations.


title: Pteropus

text: In Mauritius, over 40,000 Mauritian flying foxes were culled in a two-year period, reducing its population by an estimated 45%. Flying foxes are also killed by electrocution. In one Australian orchard, it is estimated that over 21,000 bats were electrocuted to death in an 8-week period. Farmers construct electrified grids over their fruit trees to kill flying foxes before they can consume their crop. The grids are questionably effective at preventing crop loss, with one farmer who operated such a grid estimating that they still lost of fruit to flying foxes in a year. Some electrocution deaths are also accidental, such as when bats fly into overhead power lines.


title: Pteropus

text: Climate change causes flying fox mortality and a source of concern for species persistence. Extreme heat waves in Australia have been responsible for the deaths of more than 30,000 Australian flying foxes from 1994 to 2008. Females and young bats are most susceptible to extreme heat, which affects a population's ability to recover. Flying foxes are threatened by sea level rise associated with climate change, as several taxa are endemic to low-lying atolls.


title: Pteropus

text: Because many species are endemic to a single island, they are vulnerable to random events such as typhoons. A 1979 typhoon halved the remaining population of the Rodrigues flying fox. Typhoons result in indirect mortality as well: Because they defoliate the trees, flying foxes are more visible and easily hunted by humans. Food resources for the bats become scarce after major storms, and flying foxes resort to riskier foraging strategies such as consuming fallen fruit off the ground. There, they are more vulnerable to depredation by domestic cats, dogs, and pigs.


title: Pteropus

text: Flying foxes are also threatened by disease such as tick paralysis. Tick paralysis affects the spectacled flying fox, and is responsible for an estimated 1% of its annual mortality.


title: Pteropus

text: Several species of endangered flying fox are bred in captivity to augment their population sizes. Critically endangered Livingstone's fruit bats were taken from the wild starting in 1995 to create a captive breeding program. All captive individuals remain the property of the Comorian government. 17 individuals were collected from the wild; with breeding, there are 71 in captivity as of 2017. Individuals are held at the Jersey Zoo and the Bristol Zoo. Though the program has been successful in increasing the population, caretakers of the captive population have had to deal with husbandry issues such as obesity and cardiomyopathy. Relative to their wild counterparts, captive bats have a higher percentage of body fat and a lower percentage of muscle mass. The problem is pronounced in dominant males, which are the most sedentary. Addressing these concerns involves increasing flight space so that the animals can exercise adequately. Keepers are also exploring ways of distributing food within enclosures to encourage exercise.


title: Pteropus

text: The endangered Rodrigues flying fox has been bred in captivity with great success. By 1979, only 70–100 individuals were left in the world. In 1976, 25 individuals were removed from the wild by Durrell Wildlife Conservation Trust to begin a breeding program. In 1988, the breeding program was called "undoubtedly the most important chiropteran breeding project now in operation." By 2016, there were 180 individuals in 16 zoos across the United States alone. Worldwide, 46 zoos participate in the Rodrigues flying fox breeding program as of 2017.


title: Pteropus

text: Many flying foxes species are killed for bushmeat. The bushmeat harvest is often unsustainable, often resulting in severe population decline or local extinction. Flying foxes are killed and sold for bushmeat in several countries in Southeast Asia, South Asia, and Oceania, including Indonesia, Malaysia, Papua New Guinea, the Philippines, Bangladesh, China, Fiji, and Guam. Flying fox consumption is particularly common in countries with low food security and lack of environmental regulation. In some cultures in the region, however, eating flying fox meat is taboo. In Namoluk, locals are repulsed by the idea of eating flying foxes because the flying foxes urinate on themselves. In predominately Muslim regions such as much of Indonesia, flying foxes are rarely consumed because of halal dietary restrictions.


title: Pteropus

text: North Sulawesi has the greatest demand for flying fox bushmeat. Despite being in Muslim-majority Indonesia, North Sulawesi is predominately Christian; therefore, many locals do not follow halal guidelines prohibiting flying fox consumption. In Manado, most local people consume flying fox meat at least once a month. The frequency of flying fox consumption increases tenfold around holidays.


title: Pteropus

text: Locals believe that "unique meat" from undomesticated animals should be served on special occasions to "enliven the atmosphere." Suggestions to make the flying fox bushmeat trade more sustainable include enforcing a quota system for harvesting, encouraging hunters to release female and juvenile individuals, and providing economic alternatives to those who make a living selling flying fox bushmeat.


title: Pteropus

text: In Guam and the Commonwealth of the Northern Mariana Islands, consumption of the Mariana fruit bat exposes locals to the neurotoxin beta-Methylamino-L-alanine (BMAA) which may later lead to neurodegenerative diseases. BMAA may become biomagnified in humans who consume flying foxes; flying foxes are exposed to BMAA by eating cycad fruits.


title: Pteropus

text: Flying foxes are killed for use in traditional medicine. The Indian flying fox, for example, has many perceived medical uses.


title: Pteropus

text: Some believe that its fat is a treatment for rheumatism. Tribes in the Attappadi region of India eat the cooked flesh of the Indian flying fox to treat asthma and chest pain. Healers of the Kanda tribe of Bangladesh use hair from Indian flying foxes to create treatments for "fever with shivering."


title: Pteropus

text: Flying foxes are the natural reservoirs of several viruses, some of which can be transmitted to humans. Notably, flying foxes can transmit lyssaviruses, which cause rabies. In Australia the rabies virus is not naturally present; Australian bat lyssavirus is the only lyssavirus present. Australian bat lyssavirus was first identified in 1996; it is very rarely transmitted to humans. Transmission occurs from the bite or scratch of an infected animal, but can also occur from getting the infected animal's saliva in a mucous membrane or an open wound. Exposure to flying fox blood, urine, or feces is not a risk of exposure to Australian bat lyssavirus.


title: Pteropus

text: Since 1994, there have been three records of people getting infected with it—all three were in Queensland and each case was fatal.


title: Pteropus

text: Flying foxes are also reservoirs of henipaviruses such as Hendra virus and Nipah virus. Hendra virus was first identified in 1994; it also rarely occurs humans. From 1994 to 2013, there have been seven reported cases of Hendra virus affecting people, four of which were fatal. The hypothesized primary route of human infection is via contact with horses that have come into contact with flying fox urine.


title: Pteropus

text: There are no documented instances of direct transmission between flying foxes and humans. As of 2012, there is a vaccine available for horses to decrease the likelihood of infection and transmission.


title: Pteropus

text: Nipah virus was first identified in 1998 in Malaysia. Since 1998, there have been several Nipah outbreaks in Malaysia, Singapore, India, and Bangladesh, resulting in over 100 casualties. A 2018 outbreak in Kerala, India resulted in 19 humans infected, of which 17 died. The overall fatality rate is 40-75%. Humans can contract Nipah virus from direct contact with flying foxes or their fluids, through exposure to an intermediate host such as domestic pigs, or from contact with an infected person. A 2014 study of the Indian flying fox and Nipah virus found that while Nipah virus outbreaks are more likely in areas preferred by flying foxes, "the presence of bats in and of itself is not considered a risk factor for Nipah virus infection." Rather, the consumption of date palm sap is a significant route of transmission. The practice of date palm sap collection involves placing collecting pots at date palm trees. Indian flying foxes have been observed licking the sap as it flows into the pots, as well as defecating and urinating in proximity to the pots. In this way, humans who drink the palm sap can be exposed to the bats' viruses. The use of bamboo skirts on collecting pots lowers the risk of contamination from bat fluids.


title: Pteropus

text: Flying foxes can transmit several non-lethal diseases as well, such as Menangle virus and Nelson Bay virus. These viruses rarely affect humans and few cases have been reported. While other bat species have been suspected or implicated as the reservoir of diseases such as SARS and Ebola, flying foxes are not suspected as hosts for either causative virus.


title: Pteropus

text: Flying foxes are often considered pests due to the damage they cause to orchard crops. Flying foxes have been cited as particularly destructive to almonds, guavas, and mangoes in the Maldives; lychee in Mauritius; areca in India; and stone fruits in Australia. Orchard damages from other animals are often misattributed to flying foxes, though, and economic damage can be difficult to quantify or exaggerated. To prevent fruit damage, farmers may legally or illegally cull flying foxes. In the 1800s, the Australian government paid farmers bounties to kill flying foxes, though the practice has since been discontinued.


title: Pteropus

text: Alternatives to culling include placing barriers between the bats and fruit trees, such as netting, or harvesting fruit in a timely manner to avoid attracting as many flying foxes. Netting is the most effective way to prevent crop loss, though some farmers find it cost prohibitive. It costs US$4,400–44,000 to net of crops. Other methods of preventing fruit loss may also involve the use of scare guns, chemical deterrents, or night-time lights. Alternatively, planting Singapore cherry trees and other decoy crops next to an orchard can be effective, as flying foxes are much more attracted to their fruits than many other orchard crops.


title: Pteropus

text: The location of flying fox camps can be a disturbance to humans. In Batemans Bay, Australia, locals report being so disturbed by flying fox vocalizations in the morning that they lose sleep. Flying foxes can fly into power lines and cause electricity outages. Their guano and body odor are also unpleasant to smell. The presence of flying fox colonies can cause nearby property values to decline.


title: Pteropus

text: A folklore Dreamtime story from the New South Wales North Coast in Australia features an impatient flying fox wanting the Great Spirit to teach him how to be a bird, only to be hung upside down on a branch. They were also featured in Aboriginal cave art, as evinced by several surviving examples.


title: Pteropus

text: In Tonga, flying foxes are considered sacred. All flying foxes are the property of the king, meaning non-royal persons cannot harm them in any way. Tongan legend states that a colony of flying foxes at Kolovai are the descendants of a pair of flying foxes gifted to the King of Tonga by the Princess of Samoa.


title: Pteropus

text: In the Indian village of Puliangulam, a colony of Indian flying foxes roosts in a Banyan tree. Villagers believe that the flying foxes are under the protection of Muni, and do not harm the bats. A shrine to Muni is beneath the tree.


title: Pteropus

text: If locals believe that they have offended Muni by failing to protect the bats, they will pray and perform puja after offering sweet rice, coconut, and bananas to those attending the ceremony.


title: Pteropus

text: Flying foxes are also featured in folk stories from Papua New Guinea. Stories with flying foxes include a legend about a cockatoo stealing feathers from the flying fox, resulting in it becoming nocturnal. Another story features a flying fox that could transform into a young man; the flying fox stole a woman away from her husband to take as his wife. Another legend states that a flying fox-man was responsible for introducing yams to their people.


title: Pteropus

text: Indigenous societies in Oceania used parts of flying foxes for functional and ceremonial weapons. In the Solomon Islands, people created barbs out of their bones for use in spears. In New Caledonia, ceremonial axes made of jade were decorated with braids of flying fox fur. Flying fox wings were depicted on the war shields of the Asmat people of Indonesia; they believed that the wings offered protection to their warriors.


title: Pteropus

text: There are modern and historical references to flying fox byproducts used as currency. In New Caledonia, braided flying fox fur was once used as currency. On the island of Makira, which is part of the Solomon Islands, indigenous peoples still hunt flying foxes for their teeth as well as for bushmeat. The canine teeth are strung together on necklaces that are used as currency. Teeth of the insular flying fox are particularly prized, as they are usually large enough to drill holes in. The Makira flying fox is also hunted, though, despite its smaller teeth. Deterring local peoples from using flying fox teeth as currency may be detrimental to the species, with Lavery and Fasi noting, "Species that provide an important cultural resource can be highly treasured." Emphasizing sustainable hunting of flying foxes to preserve cultural currency may be more effective than encouraging the abandonment of cultural currency. Even if flying foxes were no longer hunted for their teeth, they would still be killed for bushmeat; therefore, retaining their cultural value may encourage sustainable hunting practices. Lavery stated, "It’s a positive, not a negative, that their teeth are so culturally valuable. The practice of hunting bats shouldn’t necessarily be stopped, it needs to be managed sustainably."


title: Pteropus

text: Flying foxes and other bat species in Southeast Asia are often killed and sold as "mummies". The mummified bodies or skeletons of these bats are often shipped to the United States where they are sold in souvenir or curiosity shops or online through vendors such as Etsy or eBay. From 2000 to 2013, over 100,000 dead bats were imported to the United States. Bat conservationist Merlin Tuttle wrote, "I've seen huge losses, mostly due to various kinds of over-harvesting, especially at cave entrances, either for food or for sale as mummies." Despite sometimes being advertised as "sustainable," the practice could lead to overharvesting and depletion of flying fox species, with Tuttle saying, "It is a virtual certainty that the bats you've seen advertised are not sustainably harvested."


title: Wallpaper

text: Wallpaper is a material used in interior decoration to decorate the interior walls of domestic and public buildings. It is usually sold in rolls and is applied onto a wall using wallpaper paste. Wallpapers can come plain as "lining paper" (so that it can be painted or used to help cover uneven surfaces and minor wall defects thus giving a better surface), textured (such as Anaglypta), with a regular repeating pattern design, or, much less commonly today, with a single non-repeating large design carried over a set of sheets. The smallest rectangle that can be tiled to form the whole pattern is known as the pattern repeat.


title: Wallpaper

text: Wallpaper printing techniques include surface printing, gravure printing, silk screen-printing, rotary printing, and digital printing. Wallpaper is made in long rolls which are hung vertically on a wall. Patterned wallpapers are designed so that the pattern "repeats", and thus pieces cut from the same roll can be hung next to each other so as to continue the pattern without it being easy to see where the join between two pieces occurs. In the case of large complex patterns of images this is normally achieved by starting the second piece halfway into the length of the repeat, so that if the pattern going down the roll repeats after 24 inches, the next piece sideways is cut from the roll to begin 12 inches down the pattern from the first. The number of times the pattern repeats horizontally across a roll does not matter for this purpose. A single pattern can be issued in several different colorways.


title: Wallpaper

text: The main historical techniques are: hand-painting, woodblock printing (overall the most common), stencilling, and various types of machine-printing. The first three all date back to before 1700.


title: Wallpaper

text: Wallpaper, using the printmaking technique of woodcut, gained popularity in Renaissance Europe amongst the emerging gentry. The social elite continued to hang large tapestries on the walls of their homes, as they had in the Middle Ages. These tapestries added color to the room as well as providing an insulating layer between the stone walls and the room, thus retaining heat in the room. However, tapestries were extremely expensive and so only the very rich could afford them. Less well-off members of the elite, unable to buy tapestries due either to prices or wars preventing international trade, turned to wallpaper to brighten up their rooms.


title: Wallpaper

text: Early wallpaper featured scenes similar to those depicted on tapestries, and large sheets of the paper were sometimes hung loosely on the walls, in the style of tapestries, and sometimes pasted as today. Prints were very often pasted to walls, instead of being framed and hung, and the largest sizes of prints, which came in several sheets, were probably mainly intended to be pasted to walls. Some important artists made such pieces - notably Albrecht Dürer, who worked on both large picture prints and also ornament prints - intended for wall-hanging. The largest picture print was "The Triumphal Arch" commissioned by the Holy Roman Emperor Maximilian I and completed in 1515. This measured a colossal 3.57 by 2.95 metres, made up of 192 sheets, and was printed in a first edition of 700 copies, intended to be hung in palaces and, in particular, town halls, after hand-coloring.


title: Wallpaper

text: Very few samples of the earliest repeating pattern wallpapers survive, but there are a large number of old master prints, often in engraving of repeating or repeatable decorative patterns. These are called ornament prints and were intended as models for wallpaper makers, among other uses.


title: Wallpaper

text: England and France were leaders in European wallpaper manufacturing. Among the earliest known samples is one found on a wall from England and is printed on the back of a London proclamation of 1509. It became very popular in England following Henry VIII's excommunication from the Catholic Church - English aristocrats had always imported tapestries from Flanders and Arras, but Henry VIII's split with the Catholic Church had resulted in a fall in trade with Europe. Without any tapestry manufacturers in England, English gentry and aristocracy alike turned to wallpaper.


title: Wallpaper

text: During the Protectorate under Oliver Cromwell, the manufacture of wallpaper, seen as a frivolous item by the Puritan government, was halted. Following the Restoration of Charles II, wealthy people across England began demanding wallpaper again - Cromwell's Puritan regime had imposed a repressive and restrictive culture on the population, and following his death, wealthy people began purchasing comfortable domestic items which had been banned under the Puritan state.


title: Wallpaper

text: In 1712, during the reign of Queen Anne, a wallpaper tax was introduced which was not abolished until 1836. By the mid-eighteenth century, Britain was the leading wallpaper manufacturer in Europe, exporting vast quantities to Europe in addition to selling on the middle-class British market. However this trade was seriously disrupted in 1755 by the Seven Years' War and later the Napoleonic Wars, and by a heavy level of duty on imports to France.


title: Wallpaper

text: In 1748 the British Ambassador to Paris decorated his salon with blue flock wallpaper, which then became very fashionable there. In the 1760s the French manufacturer Jean-Baptiste Réveillon hired designers working in silk and tapestry to produce some of the most subtle and luxurious wallpaper ever made. His sky blue wallpaper with fleurs-de-lys was used in 1783 on the first balloons by the Montgolfier brothers. The landscape painter Jean-Baptiste Pillement discovered in 1763 a method to use fast colours.


title: Wallpaper

text: Hand-blocked wallpapers like these use hand-carved blocks and by the 18th century designs include panoramic views of antique architecture, exotic landscapes and pastoral subjects, as well as repeating patterns of stylized flowers, people and animals.


title: Wallpaper

text: In 1785 Christophe-Philippe Oberkampf had invented the first machine for printing coloured tints on sheets of wallpaper. In 1799 Louis-Nicolas Robert patented a machine to produce continuous lengths of paper, the forerunner of the Fourdrinier machine. This ability to produce continuous lengths of wallpaper now offered the prospect of novel designs and nice tints being widely displayed in drawing rooms across Europe.


title: Wallpaper

text: Wallpaper manufacturers active in England in the 18th century included John Baptist Jackson and John Sherringham. Among the firms established in 18th-century America: J. F. Bumstead & Co. (Boston), William Poyntell (Philadelphia), John Rugar (New York).


title: Wallpaper

text: High-quality wallpaper made in China became available from the later part of the 17th century; this was entirely handpainted and very expensive. It can still be seen in rooms in palaces and grand houses including Nymphenburg Palace, Łazienki Palace, Chatsworth House, Temple Newsam, Broughton Castle, Lissan House, and Erddig. It was made up to 1.2 metres wide. English, French and German manufacturers imitated it, usually beginning with a printed outline which was coloured in by hand, a technique sometimes also used in later Chinese papers.


title: Wallpaper

text: Towards the end of the 18th century the fashion for scenic wallpaper revived in both America and France, leading to some enormous panoramas, like the 1804 20 strip wide panorama, "Sauvages de la Mer du Pacifique" (Savages of the Pacific), designed by the artist Jean-Gabriel Charvet for the French manufacturer Joseph Dufour et Cie showing the Voyages of Captain Cook. This famous so-called "papier peint" wallpaper is still in situ in Ham House, Peabody, Massachusetts. It was the largest panoramic wallpaper of its time, and marked the burgeoning of a French industry in panoramic wallpapers. Dufour realized almost immediate success from the sale of these papers and enjoyed a lively trade with America. The Neoclassical style currently in favour worked well in houses of the Federal period with Charvet's elegant designs. Like most 18th-century wallpapers, the panorama was designed to be hung above a dado.


title: Wallpaper

text: Beside Joseph Dufour et Cie (1797 - c. 1830) other French manufacturers of panoramic scenic and "trompe-l'œil" wallpapers, Zuber et Cie (1797–present) and Arthur et Robert exported their product across Europe and North America. Zuber et Cie's c. 1834 design "Views of North America" hangs in the Diplomatic Reception Room of the White House.


title: Wallpaper

text: Among the firms begun in France in the 19th century: Desfossé & Karth. In the United States: John Bellrose, Blanchard & Curry, Howell Brothers, Longstreth & Sons, Isaac Pugh in Philadelphia; Bigelow, Hayden & Co. in Massachusetts; Christy & Constant, A. Harwood, R. Prince in New York.


title: Wallpaper

text: The earliest known American wallpaper sample book that has survived to present day resides in the collection of Old Sturbridge Village in Sturbridge, MA. It was produced by the firm Janes & Bolles of Hartford, Connecticut, between 1821 and 1828.


title: Wallpaper

text: During the Napoleonic Wars, trade between Europe and Britain evaporated, resulting in the gradual decline of the wallpaper industry in Britain. However, the end of the war saw a massive demand in Europe for British goods which had been inaccessible during the wars, including cheap, colourful wallpaper. The development of steam-powered printing presses in Britain in 1813 allowed manufacturers to mass-produce wallpaper, reducing its price and so making it affordable to working-class people. Wallpaper enjoyed a huge boom in popularity in the nineteenth century, seen as a cheap and very effective way of brightening up cramped and dark rooms in working-class areas. It became almost the norm in most areas of middle-class homes, but remained relatively little used in public buildings and offices, with patterns generally being avoided in such locations. In the latter half of the century Lincrusta and Anaglypta, not strictly wallpapers, became popular competitors, especially below a dado rail. They could be painted and washed, and were a good deal tougher, though also more expensive.


title: Wallpaper

text: Wallpaper manufacturing firms established in England in the 19th century included Jeffrey & Co.; Shand Kydd Ltd.; Lightbown, Aspinall & Co.; John Line & Sons; Potter & Co.; Arthur Sanderson & Sons; Townshend & Parker. Designers included Owen Jones, William Morris, and Charles Voysey. In particular, many 19th century designs by Morris & Co and other Arts and Crafts designers remain in production.


title: Wallpaper

text: By the early twentieth century, wallpaper had established itself as one of the most popular household items across the Western world. Manufacturers in the USA included Sears; designers included Andy Warhol. Wallpaper has gone in and out of fashion since about 1930, but the overall trend has been for wallpaper-type patterned wallcoverings to lose ground to plain painted walls.


title: Wallpaper

text: In the early 21st century, wallpaper evolved into a lighting feature, enhancing the mood and the ambience through lights and crystals. Meystyle, a London-based company, invented LED-incorporated wallpaper. The development of digital printing allows designers to break the mould and combine new technology and art to bring wallpaper to a new level of popularity.


title: Wallpaper

text: Historical examples of wallpaper are preserved by cultural institutions such as the Deutsches Tapetenmuseum (Kassel) in Germany; the Musée des Arts Décoratifs (Paris) and Musée du Papier Peint (Rixheim) in France; the Victoria & Albert in the UK; the Smithsonian's Cooper-Hewitt, Historic New England, Metropolitan Museum of Art, U.S. National Park Service, and Winterthur in the USA. Original designs by William Morris and other English wallpaper companies are held by Walker Greenbank.


title: Wallpaper

text: In terms of methods of creation, wallpaper types include painted wallpaper, hand-printed blockwood wallpaper, hand-printed stencil wallpaper, machine-printed wallpaper, and flock wallpaper.


title: Wallpaper

text: Modern wallcoverings are diverse, and what is described as wallpaper may no longer actually be made from paper. Two of the most common factory trimmed sizes of wallpaper are referred to as "American" and "European" rolled goods. American rolled goods are by in length. European rolled goods are wide by in length, approximately . Most wallpaper borders are sold by length and with a wide range of widths therefore surface area is not applicable, although some may require trimming.


title: Wallpaper

text: The most common wall covering for residential use and generally the most economical is prepasted vinyl coated paper, commonly called "strippable" which can be misleading. Cloth backed vinyl is fairly common and durable. Lighter vinyls are easier to handle and hang. Paper backed vinyls are generally more expensive, significantly more difficult to hang, and can be found in wider untrimmed widths. Foil wallpaper generally has paper backing and can (exceptionally) be up to wide, and be very difficult to handle and hang. Textile wallpapers include silks, linens, grass cloths, strings, rattan, and actual impressed leaves. There are acoustical wall carpets to reduce sound. Customized wallcoverings are available at high prices and most often have minimum roll orders.


title: Wallpaper

text: Solid vinyl with a cloth backing is the most common commercial wallcovering and comes from the factory as untrimmed at approximately, to be overlapped and double cut by the installer. This same type can be pre-trimmed at the factory to approximately.


title: Wallpaper

text: Wallpaper also comes as 'borders', typically hung horizontally at the tops of walls, and above wainscotting. Bordering wallpaper comes in an array of colours and patterns, straight or shaped edges, and widths (sometimes called 'heights' due to its orientation), and is used to provide a finished look to walls already hung with printed wallpaper, or as an accent for painted or plain-papered walls. Some bordering wallpapers are decorated with pictures and even writing, which, when hung, can tell a simple story or a well-known theme, such as fairytales, poems, pictographs of alphabets or numerals, or religious works. In modern western homes, these are referred-to as 'friezes' and commonly adorn nurseries and children's bedrooms. They can also be found in classrooms and libraries.


title: Wallpaper

text: "Non-woven wallpaper:" Non-woven wallpaper is made from a mixture of chemical pulp and textile fibres, and is used on its own or as a backing for other types of wallpaper. When hanging this wallpaper, the paste is applied directly to the wall, after which the wallpaper will hang on without booking time.


title: Wallpaper

text: "Paper wallpaper:" Made of recyclable paper"." Is also used as backing material for other wallpapers. When using paper as wallpaper the booking time has to be considered.


title: Wallpaper

text: "Photo and metal wallpaper:" These Wallpapers are applied on a backing material like non-woven or paper wallpaper. When producing photo wallpaper, the picture will be printed on a paper backing. To create a metallic optic wallpaper, the coating of the backing material consist of metal foil like aluminium.


title: Wallpaper

text: "Liquid wallpaper:" Liquid wallpaper is decorative plaster. These wallpapers are presented in dry and liquid form, but the first option is more common. Liquid wallpaper can be applied directly to the plaster.


title: Wallpaper

text: New digital inkjet printing technologies using ultraviolet (UV) cured inks are being used for custom wallpaper production. Very small runs can be made, even a single wall. Photographs or digital art are output onto blank wallpaper material. Typical installations are corporate lobbies, restaurants, athletic facilities, and home interiors. This gives a designer the ability to give a space the exact look and feel desired.


title: Wallpaper

text: New types of wallpaper under development or entering the market in the early 21st century include wallpaper that blocks certain mobile phone and WiFi signals, in the interest of privacy. The wallpaper is coated with a silver ink which forms crystals that block outgoing signals.


title: Wallpaper

text: In 2012, scientists at the Institute of Solid Construction and Construction Material Technology at the Karlsruhe Institute of Technology announced that they had developed a wallpaper that can help keep a masonry wall from failing in an earthquake. The wallpaper uses glass fibre reinforcement in several directions and a special adhesive which forms a strong bond with the masonry when dry.


title: Wallpaper

text: Tsang Kin-Wah, one of Hong Kong's best-known painters, creates large-scale wallpaper installations that evoke the floral designs of William Morris in a style that has become known as word-art installation.


title: Wallpaper

text: Like paint, wallpaper requires proper surface preparation before application. Additionally wallpaper is not suitable for all areas. For example, bathroom wallpaper may deteriorate rapidly due to excessive steam (if is not sealed with a specific varnish). Proper preparation includes the repair of any defects in the drywall or plaster and the removal of loose material or old adhesives. For a better finish with thinner papers and poorer quality walls the wall can be cross-lined (horizontally) with lining paper first. Accurate room measurements (length, width, and height) along with number of window and door openings is essential for ordering wallpaper. Large drops, or repeats, in a pattern can be cut and hung more economically by working from alternating rolls of paper.


title: Wallpaper

text: After pre-pasted wallpaper is moistened, or dry wallpaper is coated with wet paste, the wet surface is folded onto itself and left for a few minutes to activate the glue, which is called "booking wallpaper."


title: Wallpaper

text: Besides conventional installation on interior walls and ceilings, wallpapers have been deployed as decorative covering for hatboxes, bandboxes, books, shelves, and window-shades.


title: Building material

text: Building material is material used for construction. Many naturally occurring substances, such as clay, rocks, sand, wood, and even twigs and leaves, have been used to construct buildings. Apart from naturally occurring materials, many man-made products are in use, some more and some less synthetic. The manufacturing of building materials is an established industry in many countries and the use of these materials is typically segmented into specific specialty trades, such as carpentry, insulation, plumbing, and roofing work. They provide the make-up of and structures including homes.


title: Building material

text: In history, there are trends in building materials from being natural to becoming more man-made and composite; biodegradable to imperishable; indigenous (local) to being transported globally; repairable to disposable; chosen for increased levels of fire-safety, and improved seismic resistance. These trends tend to increase the "initial" and "long term" economic, ecological, energy, and social costs of building materials.


title: Building material

text: Initial economic cost of building materials is the purchase price. This is often what governs decision making about what materials to use. Sometimes people take into consideration the energy savings or durability of the materials and see the value of paying a higher initial cost in return for a lower lifetime cost. For example, an asphalt shingle roof costs less than a metal roof to install, but the metal roof will last longer so the lifetime cost is less per year. Some materials may require more care than others, maintaining costs specific to some materials may also influence the final decision. Risks when considering lifetime cost of a material is if the building is damaged such as by fire or wind, or if the material is not as durable as advertised. The cost of materials should be taken into consideration to bear the risk to buy combustive materials to enlarge the lifetime. It is said that, "if it must be done, it must be done well".


title: Building material

text: Pollution costs can be macro and micro. The macro, environmental pollution of extraction industries building materials rely on such as mining, petroleum, and logging produce environmental damage at their source and in transportation of the raw materials, manufacturing, transportation of the products, retailing, and installation. An example of the micro aspect of pollution is the off-gassing of the building materials in the building or indoor air pollution. Red List building materials are materials found to be harmful. Also the carbon footprint, the total set of greenhouse gas emissions produced in the life of the material. A life-cycle analysis also includes the reuse, recycling, or disposal of construction waste. Two concepts in building which account for the ecological economics of building materials are green building and sustainable development.


title: Building material

text: the Initial energy costs include the amount of energy consumed to produce, deliver and install the material. The long term energy cost is the economic, ecological, and social costs of continuing to produce and deliver energy to the building for its use, maintenance, and eventual removal. The initial embodied energy of a structure is the energy consumed to extract, manufacture, deliver, install, the materials. The lifetime embodied energy continues to grow with the use, maintenance, and reuse/recycling/disposal of the building materials themselves "and" how the materials and design help minimize the life-time energy consumption of the structure.


title: Building material

text: Social costs are injury and health of the people producing and transporting the materials and potential health problems of the building occupants if there are problems with the building biology. Globalization has had significant impacts on people both in terms of jobs, skills, and self-sufficiency are lost when manufacturing facilities are closed and the cultural aspects of where new facilities are opened. Aspects of fair trade and labor rights are social costs of global building material manufacturing.


title: Building material

text: Brush structures are built entirely from plant parts and were used in primitive cultures such as Native Americans and pygmy peoples in Africa These are built mostly with branches, twigs and leaves, and bark, similar to a beaver's lodge. These were variously named wikiups, lean-tos, and so forth.


title: Building material

text: An extension on the brush building idea is the wattle and daub process in which clay soils or dung, usually cow, are used to fill in and cover a woven brush structure. This gives the structure more thermal mass and strength. Wattle and daub is one of the oldest building techniques. Many older timber frame buildings incorporate wattle and daub as non load bearing walls between the timber frames.


title: Building material

text: Snow and occasionally ice, were used by the Inuit peoples for igloos and snow is used to build a shelter called a quinzhee. Ice has also been used for ice hotels as a tourist attraction in northern climates.


title: Building material

text: Clay based buildings usually come in two distinct types. One being when the walls are made directly with the mud mixture, and the other being walls built by stacking air-dried building blocks called mud bricks.


title: Building material

text: Other uses of clay in building is combined with straws to create light clay, wattle and daub, and mud plaster.


title: Building material

text: Wet-laid, or damp, walls are made by using the mud or clay mixture directly without forming blocks and drying them first. The amount of and type of each material in the mixture used leads to different styles of buildings. The deciding factor is usually connected with the quality of the soil being used. Larger amounts of clay are usually employed in building with "cob", while low-clay soil is usually associated with "sod house" or "sod roof" construction. The other main ingredients include more or less sand/gravel and straw/grasses. "Rammed earth" is both an old and newer take on creating walls, once made by compacting clay soils between planks by hand; nowadays forms and mechanical pneumatic compressors are used.


title: Building material

text: Soil, and especially clay, provides good thermal mass; it is very good at keeping temperatures at a constant level. Homes built with earth tend to be naturally cool in the summer heat and warm in cold weather. Clay holds heat or cold, releasing it over a period of time like stone. Earthen walls change temperature slowly, so artificially raising or lowering the temperature can use more resources than in say a wood built house, but the heat/coolness stays longer.


title: Building material

text: People building with mostly dirt and clay, such as cob, sod, and adobe, created homes that have been built for centuries in western and northern Europe, Asia, as well as the rest of the world, and continue to be built, though on a smaller scale. Some of these buildings have remained habitable for hundreds of years.


title: Building material

text: "Mud-bricks", also known by their Spanish name "adobe" are ancient building materials with evidence dating back thousands of years BC. "Compressed earth blocks" are a more modern type of brick used for building more frequently in industrialized society since the building blocks can be manufactured off site in a centralized location at a brickworks and transported to multiple building locations. These blocks can also be monetized more easily and sold.


title: Building material

text: Structural mud bricks are almost always made using clay, often clay soil and a binder are the only ingredients used, but other ingredients can include sand, lime, concrete, stone and other binders. The formed or compressed block is then air dried and can be laid dry or with a mortar or clay slip.


title: Building material

text: Sand is used with cement, and sometimes lime, to make mortar for masonry work and plaster. Sand is also used as a part of the concrete mix. An important low-cost building material in countries with high sand content soils is the Sandcrete block, which is weaker but cheaper than fired clay bricks.


title: Building material

text: Rock structures have existed for as long as history can recall. It is the longest-lasting building material available, and is usually readily available. There are many types of rock, with differing attributes that make them better or worse for particular uses. Rock is a very dense material so it gives a lot of protection; its main drawback as a building material is its weight and the difficulty of working it. Its energy density is both an advantage and disadvantage. Stone is hard to warm without consuming considerable energy but, once warm, its thermal mass means that can retain heat for useful periods of time.


title: Building material

text: Dry-stone walls and huts have been built for as long as humans have put one stone on top of another. Eventually, different forms of mortar were used to hold the stones together, cement being the most commonplace now.


title: Building material

text: The granite-strewn uplands of Dartmoor National Park, United Kingdom, for example, provided ample resources for early settlers. Circular huts were constructed from loose granite rocks throughout the Neolithic and early Bronze Age, and the remains of an estimated 5,000 can still be seen today. Granite continued to be used throughout the Medieval period (see Dartmoor longhouse) and into modern times. Slate is another stone type, commonly used as roofing material in the United Kingdom and other parts of the world where it is found.


title: Building material

text: Stone buildings can be seen in most major cities, and some civilizations built predominantly with stone, such as the Egyptian and Aztec pyramids and the structures of the Inca civilization.


title: Building material

text: Thatch is one of the oldest of building materials known. "Thatch" is another word for "grass"; grass is a good insulator and easily harvested. Many African tribes have lived in homes made completely of grasses and sand year-round. In Europe, thatch roofs on homes were once prevalent but the material fell out of favor as industrialization and improved transport increased the availability of other materials. Today, though, the practice is undergoing a revival. In the Netherlands, for instance, many new buildings have thatched roofs with special ridge tiles on top.


title: Building material

text: Wood has been used as a building material for thousands of years in its natural state. Today, engineered wood is becoming very common in industrialized countries.


title: Building material

text: Wood is a product of trees, and sometimes other fibrous plants, used for construction purposes when cut or pressed into lumber and timber, such as boards, planks and similar materials. It is a generic building material and is used in building just about any type of structure in most climates. Wood can be very flexible under loads, keeping strength while bending, and is incredibly strong when compressed vertically. There are many differing qualities to the different types of wood, even among same tree species. This means specific species are better suited for various uses than others. And growing conditions are important for deciding quality.


title: Building material

text: "Timber" is the term used for construction purposes except the term "lumber" is used in the United States. Raw wood (a log, trunk, bole) becomes timber when the wood has been "converted" (sawn, hewn, split) in the forms of minimally-processed logs stacked on top of each other, timber frame construction, and light-frame construction. The main problems with timber structures are fire risk and moisture-related problems.


title: Building material

text: In modern times softwood is used as a lower-value bulk material, whereas hardwood is usually used for finishings and furniture. Historically timber frame structures were built with oak in western Europe, recently douglas fir has become the most popular wood for most types of structural building.


title: Building material

text: Many families or communities, in rural areas, have a personal woodlot from which the family or community will grow and harvest trees to build with or sell. These lots are tended to like a garden. This was much more prevalent in pre-industrial times, when laws existed as to the amount of wood one could cut at any one time to ensure there would be a supply of timber for the future, but is still a viable form of agriculture.


title: Building material

text: Bricks are made in a similar way to mud-bricks except without the fibrous binder such as straw and are "fired" ("burned" in a brick clamp or kiln) after they have air-dried to permanently harden them. Kiln fired clay bricks are a ceramic material. Fired bricks can be solid or have hollow cavities to aid in drying and make them lighter and easier to transport. The individual bricks are placed upon each other in courses using mortar. Successive courses being used to build up walls, arches, and other architectural elements. Fired brick walls are usually substantially thinner than cob/adobe while keeping the same vertical strength. They require more energy to create but are easier to transport and store, and are lighter than stone blocks. Romans extensively used fired brick of a shape and type now called Roman bricks. Building with brick gained much popularity in the mid-18th century and 19th centuries. This was due to lower costs with increases in brick manufacturing and fire-safety in the ever crowding cities.


title: Building material

text: The cinder block supplemented or replaced fired bricks in the late 20th century often being used for the inner parts of masonry walls and by themselves.


title: Building material

text: Cement bonded composites are made of hydrated cement paste that binds wood, particles, or fibers to make pre-cast building components. Various fiberous materials, including paper, fiberglass, and carbon-fiber have been used as binders.


title: Building material

text: Wood and natural fibers are composed of various soluble organic compounds like carbohydrates, glycosides and phenolics. These compounds are known to retard cement setting. Therefore, before using a wood in making cement bonded composites, its compatibility with cement is assessed.


title: Building material

text: Wood-cement compatibility is the ratio of a parameter related to the property of a wood-cement composite to that of a neat cement paste. The compatibility is often expressed as a percentage value. To determine wood-cement compatibility, methods based on different properties are used, such as, hydration characteristics, strength, interfacial bond and morphology. Various methods are used by researchers such as the measurement of hydration characteristics of a cement-aggregate mix; the comparison of the mechanical properties of cement-aggregate mixes and the visual assessment of microstructural properties of the wood-cement mixes. It has been found that the hydration test by measuring the change in hydration temperature with time is the most convenient method. Recently, Karade et al. have reviewed these methods of compatibility assessment and suggested a method based on the ‘maturity concept’ i.e. taking in consideration both time and temperature of cement hydration reaction.


title: Building material

text: Bricks were laid in lime mortar from the time of the Romans until supplanted by Portland cement mortar in the early 20th century. Cement blocks also sometimes are filled with grout or covered with a parge coat.


title: Building material

text: Concrete is a composite building material made from the combination of aggregate and a binder such as cement. The most common form of concrete is Portland cement concrete, which consists of mineral aggregate (generally gravel and sand), portland cement and water.


title: Building material

text: After mixing, the cement hydrates and eventually hardens into a stone-like material. When used in the generic sense, this is the material referred to by the term "concrete".


title: Building material

text: For a concrete construction of any size, as concrete has a rather low tensile strength, it is generally strengthened using steel rods or bars (known as rebars). This strengthened concrete is then referred to as reinforced concrete. In order to minimise any air bubbles, that would weaken the structure, a vibrator is used to eliminate any air that has been entrained when the liquid concrete mix is poured around the ironwork. Concrete has been the predominant building material in the modern age due to its longevity, formability, and ease of transport. Recent advancements, such as insulating concrete forms, combine the concrete forming and other construction steps (installation of insulation). All materials must be taken in required proportions as described in standards.


title: Building material

text: The tent is the home of choice among nomadic groups all over the world. Two well-known types include the conical teepee and the circular yurt. The tent has been revived as a major construction technique with the development of tensile architecture and synthetic fabrics. Modern buildings can be made of flexible material such as fabric membranes, and supported by a system of steel cables, rigid or internal, or by air pressure.


title: Building material

text: Recently, synthetic polystyrene or polyurethane foam has been used in combination with structural materials, such as concrete. It is lightweight, easily shaped, and an excellent insulator. Foam is usually used as part of a structural insulated panel, wherein the foam is sandwiched between wood or cement or insulating concrete forms.


title: Building material

text: Clear windows have been used since the invention of glass to cover small openings in a building. Glass panes provided humans with the ability to both let light into rooms while at the same time keeping inclement weather outside.


title: Building material

text: Glass is generally made from mixtures of sand and silicates, in a very hot fire stove called a kiln, and is very brittle. Additives are often included the mixture used to produce glass with shades of colors or various characteristics (such as bulletproof glass or lightbulbs).


title: Building material

text: The use of glass in architectural buildings has become very popular in the modern culture. Glass "curtain walls" can be used to cover the entire facade of a building, or it can be used to span over a wide roof structure in a "space frame". These uses though require some sort of frame to hold sections of glass together, as glass by itself is too brittle and would require an overly large kiln to be used to span such large areas by itself.


title: Building material

text: Gypsum concrete is a mixture of gypsum plaster and fibreglass rovings. Although plaster and fibres fibrous plaster have been used for many years, especially for ceilings, it was not until the early 1990s that serious studies of the strength and qualities of a walling system Rapidwall, using a mixture of gypsum plaster and 300mm plus fibreglass rovings, were investigated. With an abundance of gypsum (naturally occurring and by-product chemical FGD and phospho gypsums) available worldwide, Gypsum concrete-based building products, which are fully recyclable, offer significant environmental benefits.


title: Building material

text: Metal is used as structural framework for larger buildings such as skyscrapers, or as an external surface covering. There are many types of metals used for building. Metal figures quite prominently in prefabricated structures such as the Quonset hut, and can be seen used in most cosmopolitan cities. It requires a great deal of human labor to produce metal, especially in the large amounts needed for the building industries. Corrosion is metal's prime enemy when it comes to longevity.