title: Mỹ Lai massacre

text: More than a thousand people turned out on 16 March 2008, forty years after the massacre. The Sơn Mỹ Memorial drew survivors and families of victims and some returning U.S. veterans. One woman (an 8-year-old at the time) said, ""Everyone in my family was killed in the Mỹ Lai massacre—my mother, my father, my brother and three sisters. They threw me into a ditch full of dead bodies. I was covered with blood and brains."" The U.S. was unofficially represented by a volunteer group from Wisconsin called Madison Quakers, who in 10 years built three schools in Mỹ Lai and planted a peace garden.


title: Mỹ Lai massacre

text: On 19 August 2009, Calley made his first public apology for the massacre in a speech to the Kiwanis club of Greater Columbus, Georgia:"There is not a day that goes by that I do not feel remorse for what happened that day in Mỹ Lai", he told members of the club. "I feel remorse for the Vietnamese who were killed, for their families, for the American soldiers involved and their families. I am very sorry...If you are asking why I did not stand up to them when I was given the orders, I will have to say that I was a 2nd lieutenant getting orders from my commander and I followed them—foolishly, I guess."


title: Mỹ Lai massacre

text: Trần Văn Đức, who was seven years old at the time of the Mỹ Lai massacre and now resides in Remscheid, Germany, called the apology "terse". He wrote a public letter to Calley describing the plight of his and many other families to remind him that time did not ease the pain, and that grief and sorrow over lost lives will forever stay in Mỹ Lai.


title: Mỹ Lai massacre

text: Altogether, 14 officers directly and indirectly involved with the operation, including two generals, were investigated in connection with the Mỹ Lai massacre, except for LTC Frank A. Barker, CPT Earl Michaels, and 2LT Stephen Brooks, who all died before the beginning of the investigation.


title: Mỹ Lai massacre

text: Before being shipped to South Vietnam, all of Charlie Company's soldiers went through an advanced infantry training and basic unit training at Pohakuloa Training Area in Hawaii. At Schofield Barracks they were taught how to treat POWs and how to distinguish VC guerrillas from civilians by a Judge Advocate.


title: Mỹ Lai massacre

text: A photographer and a reporter from the 11th Brigade Information Office were attached to Task Force Barker and landed with Charlie Company in Sơn Mỹ on 16 March 1968. Neither the "Americal News Sheet" published 17 March 1968, nor the "Trident", 11th Infantry Brigade newsletter from 22 March 1968, reported the deaths of noncombatants in Mỹ Lai. The "Stars and Stripes" published a laudatory piece, "U.S. troops Surrounds Red, Kill 128", on March 18.


title: Mỹ Lai massacre

text: On 12 April 1968, the "Trident" wrote, "The most punishing operations undertaken by the brigade in Operation Muscatine's area involved three separate raids into the village and vicinity of My Lai, which cost the VC 276 killed". On 4 April 1968, the information office of the 11th Brigade issued a press-release, "Recent Operations in Pinkville," without reporting mass casualties among civilians. Subsequent criminal investigation found that, "Both individuals failed to report what they had seen, the reporter wrote a false and misleading account of the operation, and the photographer withheld and suppressed from proper authorities the photographic evidence of atrocities he had obtained."


title: Mỹ Lai massacre

text: The first reporting of the Mỹ Lai massacre appeared in the American media after Fort Benning issued a press release related to the charges pressed against Lieutenant William Calley. This was issued on 5 September 1969.


title: Mỹ Lai massacre

text: Consequently, NBC aired on 10 September 1969 a segment in the "Huntley-Brinkley Report" which reported the killings of numerous civilians in South Vietnam. Following that, Ronald Ridenhour decided to disobey the Army's order to withhold the information from the media. He approached reporter Ben Cole of the "Phoenix Republic", who chose not to handle the scoop. Charles Black from the "Columbus Enquirer" uncovered the story on his own but also decided to put it on hold. Two major national news press outlets—"The New York Times" and "The Washington Post"—received some tips with partial information but did not act on them.


title: Mỹ Lai massacre

text: Ridenhour called Seymour Hersh on 22 October 1969. The freelance investigative journalist conducted an independent inquiry, and published to break the wall of silence that was surrounding the Mỹ Lai massacre. Hersh initially tried to sell the story to "Life" and "Look" magazines; both turned it down. Hersh went to the small, Washington-based Dispatch News Service, which sent it to fifty major American newspapers; thirty accepted it for publication. "New York Times" reporter Henry Kamm investigated further and found several survivors of the Mỹ Lai massacre in South Vietnam. He estimated the number of civilians killed as 567.


title: Mỹ Lai massacre

text: Next, Ben Cole published an article about Ronald Ridenhour, a helicopter gunner and an Army whistleblower, who was among the first who started to uncover the truth about the Mỹ Lai massacre. Joseph Eszterhas of "The Plain Dealer", a friend of Ron Haeberle, knew about the photo evidence of the massacre; he published the grisly images of the dead bodies of old men, women, and children on 20 November 1969. "Time Magazine"<nowiki>'</nowiki>s article on 28 November 1969 and in "Life" magazine on 5 December 1969, finally brought Mỹ Lai to the fore of the public debate about Vietnam War.


title: Mỹ Lai massacre

text: Richard L. Strout, the "Christian Science Monitor" political commentator, wrote: "American press self-censorship thwarted Mr. Ridenhour's disclosures for a year. 'No one wanted to go into it', his agent said of telegrams sent to "Life", "Look", and "Newsweek" magazines outlining allegations..."


title: Mỹ Lai massacre

text: Afterward, interviews and stories connected to the Mỹ Lai massacre started to appear regularly in the American and international press.


title: Mỹ Lai massacre

text: Concluding an ABC television news broadcast, anchor man Frank Reynolds said to his audience that, as a consequence of the allegations, ‘‘our spirit as a people is scarred.’’ The massacre, he believed, offered ‘‘the most compelling argument yet advanced for America to end its involvement in Vietnam, not alone because of what the war is doing to the Vietnamese or to our reputation abroad, but because of what it is doing to us.’’


title: Mỹ Lai massacre

text: Following the massacre a Pentagon task force called the Vietnam War Crimes Working Group (VWCWG) investigated alleged atrocities which were committed against South Vietnamese civilians by U.S. troops and created a secret archive of some 9,000 pages which documents 320 alleged incidents from 1967–1971 including 7 massacres in which at least 137 civilians died; 78 additional attacks targeting noncombatants in which at least 57 were killed, 56 were wounded and 15 were sexually assaulted; and 141 incidents of U.S. soldiers torturing civilian detainees or prisoners of war. 203 U.S. personnel were charged with crimes, 57 of them were court-martialed and 23 of them were convicted. The VWCWG also investigated over 500 additional alleged atrocities but it could not verify them.


title: Mỹ Lai massacre

text: Over 100 songs were released about the My Lai massacre and Lt. William Calley, identified by the Vietnam War Song Project. During the war years (from 1969–1973), around half of the songs displayed support for Calley, while around half took an anti-war position and criticized the actions of Calley. All the songs in the post-war era were critical of the actions of Calley and his platoon. Commercially, the most successful song was "The Battle Hymn of Lt. Calley" by Terry Nelson, which peaked at No. 37 in the "Billboard" Hot 100 on 1 May 1971, selling over 1 million records. Despite success, Tex Ritter cancelled his cover of the song because his record label, Capitol, viewed it as controversial. John Deer's cover of the song bubbled under the "Billboard" Hot 100 on 1 May 1971, at No. 114.


title: Mỹ Lai massacre

text: "The Lieutenant" is a 1975 Broadway rock opera that concerns the Mỹ Lai massacre and resulting courts martial. It was nominated for four Tony Awards including Best Musical and Best Book of a Musical.


title: Mỹ Lai massacre

text: The Mỹ Lai massacre, like many other events in Vietnam, was captured on camera by U.S. Army personnel. The most published and graphic images were taken by Ronald Haeberle, a U.S. Army Public Information Detachment photographer who accompanied the men of Charlie Company that day.


title: Mỹ Lai massacre

text: In 2009, Haeberle said that he destroyed a number of photographs he took during the massacre. Unlike the photographs of the dead bodies, the destroyed photographs depicted Americans in the actual process of murdering Vietnamese civilians. According to M. Paul Holsinger, the "And babies" poster, which used a Haeberle photo, was "easily the most successful poster to vent the outrage that so many felt about the human cost of the conflict in Southeast Asia. Copies are still frequently seen in retrospectives dealing with the popular culture of the Vietnam War era or in collections of art from the period."


title: Mỹ Lai massacre

text: Another soldier, John Henry Smail of the 3rd Platoon, took at least 16 color photographs depicting U.S. Army personnel, helicopters, and aerial views of Mỹ Lai. These, along with Haeberle's photographs, were included in the "Report of the Department of the Army review of the Preliminary Investigations into the My Lai Incident". Former First Lieutenant (1LT) Roger L. Alaux Jr., a forward artillery observer, who was assigned to Charlie Company during the combat assault on Mỹ Lai 4, also took some photographs from a helicopter that day, including aerial views of Mỹ Lai, and of the Charlie Company's landing zone.


title: Mỹ Lai massacre

text: A Sơn Mỹ Memorial dedicated to victims of the Sơn Mỹ (Mỹ Lai) massacre was created in the village of Tịnh Khê, Sơn Tịnh District, Quảng Ngãi Province, Vietnam. The graves with headstones, signs on the places of killing and a museum are all located on memorial site. The War Remnants Museum in Ho Chi Minh City has an exhibition on Mỹ Lai.


title: Mỹ Lai massacre

text: On the 30th anniversary of the massacre, 16 March 1998, a groundbreaking ceremony for the Mỹ Lai Peace Park was held away from the site of the massacre. Veterans, including Hugh Thompson Jr. and Lawrence Colburn from the helicopter rescue crew, attended the ceremony. Mike Boehm, a veteran who was instrumental in the peace park effort, said, "We cannot forget the past, but we cannot live with anger and hatred either. With this park of peace, we have created a green, rolling, living monument to peace."


title: Mỹ Lai massacre

text: On 16 March 2001, the Mỹ Lai Peace Park was dedicated, a joint venture of the Quảng Ngãi Province Women's Union, the Madison Quakers' charitable organization, and the Vietnamese government.


title: Troye Sivan

text: Troye Sivan Mellet ( ; born 5 June 1995) is a South African-born Australian singer-songwriter, actor and YouTuber. After gaining popularity as a singer on YouTube and in Australian talent competitions, Sivan signed with EMI Australia in 2013 and released his third extended play, "TRXYE" (2014), which peaked at number five on the US "Billboard" 200. Its lead single, "Happy Little Pill", reached number ten on Australian music charts. In 2015, he released his fourth extended play "Wild" followed by his debut studio album "Blue Neighbourhood", whose lead single "Youth" became Sivan's first single to enter the top 40 of the "Billboard" Hot 100 chart, peaking at number 23. His second studio album "Bloom" (2018) reached number three in Australia, and number four on the "Billboard" 200 chart. Its lead single, "My My My!", became Sivan's second number-one single on the "Billboard" Dance Club Songs chart. In 2020, his EP "In a Dream" was released.


title: Troye Sivan

text: As an actor, Sivan portrayed the younger Wolverine in "" (2009) and starred as the titular character in the "Spud" film trilogy. As a YouTube personality, Sivan used to upload video blogs regularly and, as of 2021, has over 7.3million subscribers and over 1.3billion total views. In 2014, "Time" named Sivan as one of the "25 Most Influential Teens of 2014". In 2017, he became the youngest recipient to receive a GLAAD Stephen F. Kolzak Award.


title: Troye Sivan

text: In 2018, he received a Golden Globe nomination for Best Original Song for "Revelation", from the film "Boy Erased", in which he also had a supporting acting role. In 2022, he starred in the movie "Three Months".


title: Troye Sivan

text: Sivan was born in Johannesburg, South Africa, the son of Laurelle Mellet, a homemaker and former model, and Shaun Mellet, an entrepreneur and real estate agent. Sivan grew up in Perth, Western Australia, with his parents and three siblings. He was raised in an Orthodox Jewish family, though he does not consider himself to be religious—his father was born to a Jewish family of Lithuanian-Jewish descent and his mother converted to Judaism. Sivan attended Carmel School, a private Modern Orthodox school, until 2009, when he started distance education. His middle name turned surname Sivan is a Hebrew calendar month.


title: Troye Sivan

text: Sivan's musical career started when he sang at the 2006, 2007 and 2008 Channel Seven Perth Telethon. His 2006 performance included a duet with "Australian Idol" winner Guy Sebastian. Sivan made it to the finals of "StarSearch" 2007. His debut EP "Dare to Dream" was released in June 2007. In February 2010, Sivan opened "We Are the World 25 for Haiti (YouTube Edition)", the collaborative music charity video produced by Lisa Lavie to help raise money for the victims of the 2010 Haiti earthquake.


title: Troye Sivan

text: On 5 June 2013, Sivan was signed to EMI Australia, a Universal Music Australia label, but kept it a secret until a year later. On 15 August 2014 he released a five-song EP entitled "TRXYE", led by its first single "Happy Little Pill", which was released on 25 July 2014. "TRXYE" debuted at No. 1 on iTunes in over 55 countries. The EP debuted at No. 5 on the "Billboard" 200 the following week, scoring Sivan his first Top 10 album. "Happy Little Pill" peaked at number 10 on the ARIA Singles Chart and was certified gold by the Australian Recording Industry Association for shipments exceeding 35,000 copies. Sivan released his second major-label EP, "Wild", on 4 September 2015. The EP was supported by a music video trilogy entitled "Blue Neighbourhood", comprising the three songs "Wild", "Fools" and "Talk Me Down" and released from September 2015 to December 2015. Additionally, the EP served as an introduction to his debut studio album "Blue Neighbourhood", which was released on 4 December 2015. The single "Youth" reached number 23 in the "Billboard" Hot 100. Sivan supported "Blue Neighbourhood" and "Wild" with his first tour, 2015's Troye Sivan Live. He further supported "Blue Neighbourhood" with 2016's Blue Neighbourhood Tour and Suburbia Tour. On 26 May 2017, Troye collaborated with Martin Garrix to produce the song "There for You".


title: Troye Sivan

text: On 10 January 2018, Sivan released the single "My My My!", along with an accompanying music video. He confirmed that his second album was inspired by his then-boyfriend, American model Jacob Bixenman. The song was described as a departure from his earlier work, with "Pitchfork" calling his vocals "assured" and "NPR Music" describing it as "an infectious celebration of sexual desire". "NPR" also noted the significance of the song and music video displaying confidence in Sivan's sexuality, writing "[i]t's not every day you see a young, skinny, queer kid get to be completely himself in a music video, and Sivan makes us want to dance along with him." Sivan's first live performance of the song was on 20 January as the musical guest on "Saturday Night Live" in an episode hosted by Jessica Chastain. Sivan later confirmed that his new album would feature a collaboration with long-time friend Ariana Grande, titled "Dance to This". On 16 March, his song "Strawberries & Cigarettes" from the "Love, Simon" soundtrack was released. It received a nomination for the 2018 Satellite Awards for Best Original Song. "Bloom" was released as the third single on 2 May 2018, following "The Good Side". That month, he announced that his second studio album is titled "Bloom", while accompanying Taylor Swift as a guest performer at a concert in Pasadena, California, during her Reputation Stadium Tour. The album was released on 31 August 2018. The album's final pre-release track, "Animal", was launched on 9 August 2018.


title: Troye Sivan

text: That same year, Sivan received a Golden Globe nomination for Best Original Song for "Revelation", which he recorded and co-wrote for the film "Boy Erased". He was also shortlisted for an Academy Award for the song. In October 2018, Sivan collaborated with British singer-songwriter Charli XCX on the single "1999"; the two also performed the single together live on "The Tonight Show Starring Jimmy Fallon". A sequel collaboration, titled "2099", was debuted on 6 June 2019 at the two artists' LA Pride event "Go West Fest" and released as a promotional single from Charli XCX's album "Charli" on 10 September 2019. In January 2019, Sivan released the single "I'm So Tired..." with American singer-songwriter Lauv.


title: Troye Sivan

text: On 1 April 2020, Sivan released "Take Yourself Home", his first single from his fifth EP "In a Dream". Sivan worked with freelance artists in need of work during the COVID-19 pandemic to create the visual art for his single. The artists, who Sivan met on Instagram, also designed t-shirts for the single, and all net proceeds were donated to the WHO COVID-19 Solidarity Response Fund and Spotify's COVID-19 Music Relief Project. On 15 July, Sivan released the single "Easy" and announced the release of the concept EP "In a Dream". The EP was released on 21 August 2020. In June 2021, he performed songs from the EP for Grubhub's virtual concert series "Sound Bites". For every comment on the livestream, Grubhub donated $10 to support the NGLCC's efforts in assisting LGBT-owned restaurants during the COVID-19 pandemic.


title: Troye Sivan

text: On 16 April 2021, his collaboration "You" with Regard and Tate McRae was released. The song topped the Hot Dance Electronic Songs Chart for eight weeks. On 27 August, Sivan announced his single "Angel Baby", which was released on 10 September. It reached the top 5 in several countries in Southeast Asia.


title: Troye Sivan

text: On 2 February 2022, it was announced that Sivan had written two original songs for the upcoming film "Three Months," which was scheduled for release on 23 February. On 18 February 2022, Sivan announced that in "Three Months", he would portray Caleb, a 17-year-old infected with HIV following a one-night fling on the eve of his high school graduation. The film explores the ongoing stigma that HIV-positive persons experience.


title: Troye Sivan

text: Sivan's music videos frequently feature LGBTQ relationships between the characters. "Blue Neighbourhood"s trilogy followed the narrative of two gay teenagers in a secret relationship while "Youth" featured Sivan with another male love interest. His music video for "Heaven" features footage of historical LGBTQ movements and couples, as well as sensual shots with him and an anonymous man with the running taglines "Without losing a piece of me, how do I get to Heaven?" and "If I'm losing a piece of me, maybe I don't want Heaven". The singer says these portrayals are important to him, especially when he considers his younger life when he remembers "such vivid memories of the few times I saw any type of LGBTQ relationship on TV or in music videos".


title: Troye Sivan

text: On 16 July 2020, Sivan released a self-directed music video for his second song, "Easy", from his EP "In a Dream". A remix of "Easy", featuring country singer-songwriter Kacey Musgraves and producer Mark Ronson, was released alongside a second music video in December 2020.


title: Troye Sivan

text: In 2007, Sivan starred as Oliver Twist in a production of "Oliver!" at the Regal Theatre. In 2008, Sivan was cast in a Western Australian short film, "Betrand the Terrible". In February 2008, Sivan was cast as young James Howlett in "". Sivan got the part after videos of his telethon performance were posted on YouTube, catching the attention of a Hollywood agent who contacted Sivan and asked him to send in an audition tape. Though Kodi Smit-McPhee was already cast for this role, he was unable to be a part of the film, due to his other film, "The Road". In July 2009, he auditioned successfully for the lead role in "Spud", a film adaptation of the 2005 novel by South African author John van de Ruit. Filming took place in South Africa from early March to mid-April 2010. The film was released in South Africa on 3 December 2010 and was later nominated for six SAFTAs, including a Best Lead Actor in a Feature Film nomination for Sivan.


title: Troye Sivan

text: Sivan appeared in the Western Australian season of Samuel Beckett's absurdist play "Waiting for Godot" which opened on 28 May 2010. Sivan shared the role of "Boy" with Craig Hyde-Smith, alternating nights. In June 2012, Sivan returned to South Africa to film "", which was released in South Africa on 21 June 2013. Sivan also starred in the third film in the series, "", released on 28 November 2014.


title: Troye Sivan

text: Sivan had a supporting role in the 2018 film "Boy Erased". In 2022, he starred as Caleb in the feature film "Three Months".


title: Troye Sivan

text: In September 2012, Sivan began creating video blogs on the video sharing site YouTube, after having only sung on the site since 2007. At the time of posting his first vlog, Sivan had accumulated 27,000 subscribers in his five years since joining YouTube on 1 October 2007. A YouTube video Sivan made with fellow YouTuber Tyler Oakley, titled "The 'Boyfriend' Tag", earned them a Teen Choice Award in the "Choice Web Collaboration" category. As of June 2022, Sivan had over 7million subscribers and over 1billion total views across his YouTube videos.


title: Troye Sivan

text: In 2018, Sivan was the face of Valentino's Spring/Summer 2018 collection. In 2019, he was an ambassador for MAC's Viva Glam campaign. He also appeared in Calvin Klein's #MyCalvins and #CK50 compaigns that year. Since 2020, he has been a Cartier ambassador. In February 2021, Sivan's capsule t-shirt collection that he designed with Uniqlo was released. On 24 September 2021, he was featured as a model in the third volume of Rihanna's "Savage X Fenty Show". In early 2022, he was involved in Beyoncé's Ivy Park's campaign for her capsule collection with Adidas. In June 2022, it was announced that he was an ambassador for YSL Beauty.


title: Troye Sivan

text: Sivan's favourite artists include Amy Winehouse, Taylor Swift and Lorde. MTV Artists cites Michael Jackson and Frank Ocean as additional influences. He told "Wonderland" magazine in 2018, "When I think about the songs that I grew up listening to that made me feel ... gay, it was mostly straight women: Cher, Madonna, Miley, Robyn, Lady Gaga. Those are my gay icons, which is a bit strange. I would have loved to have had more queer music growing up. That would have been nice." Sivan also cites Ariana Grande and Christina Aguilera as his inspirations, as his music video for "My My My!" was directly influenced by the one for "Dirrty" (2002).


title: Troye Sivan

text: Sivan's music has been described as "layered electropop with constant tinges of EDM". His baritone voice has received widespread praise, and his work has been compared to that of Lorde and Taylor Swift. In December 2020, Sivan was listed at number 34 in "Rolling Stone Australia"s "50 Greatest Australian Artists of All Time" issue.


title: Troye Sivan

text: Sivan came out publicly as gay via a YouTube video on 7 August 2013, three years after coming out to his family. He has a mild form of Marfan syndrome.


title: USB hardware

text: The initial versions of the USB standard specified connectors that were easy to use and that would have acceptable life spans; revisions of the standard added smaller connectors useful for compact portable devices. Higher-speed development of the USB standard gave rise to another family of connectors to permit additional data paths. All versions of USB specify cable properties; version 3.x cables include additional data paths. The USB standard included power supply to peripheral devices; modern versions of the standard extend the power delivery limits for battery charging and devices requiring up to 100 watts. USB has been selected as the standard charging format for many mobile phones, reducing the proliferation of proprietary chargers.


title: USB hardware

text: The three sizes of USB connectors are the default or "standard" format intended for desktop or portable equipment, the "mini" intended for mobile equipment, which was deprecated when it was replaced by the thinner "micro" size, all of which were deprecated with the release of Type-C. There are five speeds for USB data transfer: Low Speed, Full Speed, High Speed (from version 2.0 of the specification), SuperSpeed (from version 3.0), and SuperSpeed+ (from version 3.1). The modes have differing hardware and cabling requirements. USB devices have some choice of implemented modes, and USB version is not a reliable statement of implemented modes. Modes are identified by their names and icons, and the specification suggests that plugs and receptacles be colour-coded (SuperSpeed is identified by blue).


title: USB hardware

text: Unlike other data buses (such as Ethernet), USB connections are directed; a host device has "downstream" facing ports that connect to the "upstream" facing ports of devices. Only downstream facing ports provide power; this topology was chosen to easily prevent electrical overloads and damaged equipment. Thus, USB cables have different ends: A and B, with different physical connectors for each. Each format has a plug and receptacle defined for each of the A and B ends. A USB cable, by definition, has a plug on each end—one A (or C) and one B (or C)—and the corresponding receptacle is usually on a computer or electronic device. The mini and micro formats may connect to an AB receptacle, which accepts either an A or a B plug, that plug determining the behavior of the receptacle.


title: USB hardware

text: The connectors the USB committee specifies support a number of USB's underlying goals, and reflect lessons learned from the many connectors the computer industry has used. The connector mounted on the host or device is called the "receptacle", and the connector attached to the cable is called the "plug". The official USB specification documents also periodically define the term "male" to represent the plug, and "female" to represent the receptacle, though these uses are inconsistent with established definitions of connector gender.


title: USB hardware

text: By design, it is difficult to insert a USB plug into its receptacle incorrectly. The USB specification requires that the cable plug and receptacle be marked so the user can recognize the proper orientation. The USB-C plug however is reversible. USB cables and small USB devices are held in place by the gripping force from the receptacle, with no screws, clips, or thumb-turns as other connectors use.


title: USB hardware

text: The different A and B plugs prevent accidentally connecting two power sources. However, some of this directed topology is lost with the advent of multi-purpose USB connections (such as USB On-The-Go in smartphones, and USB-powered Wi-Fi routers), which require A-to-A, B-to-B, and sometimes Y/splitter cables. See the USB On-The-Go connectors section below for a more detailed summary description.


title: USB hardware

text: There are so-called "cables" with A plugs on both ends, which may be valid if the "cable" includes, for example, a USB host-to-host transfer device with two ports. This is, by definition, a device with two logical B ports, each with a captive cable, not a cable with two A ends.


title: USB hardware

text: The standard connectors were designed to be more robust than many past connectors. This is because USB is hot-swappable, and the connectors would be used more frequently, and perhaps with less care, than previous connectors.


title: USB hardware

text: Standard USB has a minimum rated lifetime of 1,500 cycles of insertion and removal, the mini-USB receptacle increases this to 5,000 cycles, and the newer Micro-USB and USB-C receptacles are both designed for a minimum rated lifetime of 10,000 cycles of insertion and removal. To accomplish this, a locking device was added and the leaf-spring was moved from the jack to the plug, so that the most-stressed part is on the cable side of the connection. This change was made so that the connector on the less expensive cable would bear the most wear.


title: USB hardware

text: In standard USB, the electrical contacts in a USB connector are protected by an adjacent plastic tongue, and the entire connecting assembly is usually protected by an enclosing metal shell.


title: USB hardware

text: The shell on the plug makes contact with the receptacle before any of the internal pins. The shell is typically grounded, to dissipate static electricity and to shield the wires within the connector.


title: USB hardware

text: The USB standard specifies tolerances for compliant USB connectors to minimize physical incompatibilities in connectors from different vendors. The USB specification also defines limits to the size of a connecting device in the area around its plug, so that adjacent ports are not blocked. Compliant devices must either fit within the size restrictions or support a compliant extension cable that does.


title: USB hardware

text: USB 2.0 uses two wires for power (V and GND), and two for differential serial data signals. Mini and micro connectors have their GND connections moved from pin #4 to pin #5, while their pin #4 serves as an ID pin for the On-The-Go host/client identification.


title: USB hardware

text: USB 3.0 provides two additional differential pairs (four wires, SSTx+, SSTx−, SSRx+ and SSRx−), providing full-duplex data transfers at "SuperSpeed", which makes it similar to Serial ATA or single-lane PCI Express.


title: USB hardware

text: USB ports and connectors are often color-coded to distinguish their different functions and USB versions. These colors are not part of the USB specification and can vary between manufacturers; for example, USB 3.0 specification mandates appropriate color-coding while it only recommends blue inserts for standard-A USB 3.0 connectors and plugs.


title: USB hardware

text: USB connector types multiplied as the specification progressed. The original USB specification detailed standard-A and standard-B plugs and receptacles. The connectors were different so that users could not connect one computer receptacle to another. The data pins in the standard plugs are recessed compared to the power pins so that the device can power up before establishing a data connection. Some devices operate in different modes depending on whether the data connection is made. Charging docks supply power and do not include a host device or data pins, allowing any capable USB device to charge or operate from a standard USB cable. Charging cables provide power connections, but not data. In a charge-only cable, the data wires are shorted at the device end, otherwise, the device may reject the charger as unsuitable.


title: USB hardware

text: The maximum allowed cross-section of the "overmold boot" (which is part of the connector used for its handling) is for the standard-A plug type, while for the type-B it is .


title: USB hardware

text: Mini-USB connectors were introduced together with USB 2.0 in April 2000, for use with smaller devices such as digital cameras, smartphones, and tablet computers. The Mini-A connector and the Mini-AB receptacle connector have been deprecated since May 2007. Mini-B connectors are still supported, but are not On-The-Go-compliant; the Mini-B USB connector was standard for transferring data to and from the early smartphones and PDAs. Both Mini-A and Mini-B plugs are approximately .


title: USB hardware

text: Micro-USB connectors, which were announced by the USB-IF on 4 January 2007, have a similar width to Mini-USB, but approximately half the thickness, enabling their integration into thinner portable devices. The Micro-A connector is with a maximum overmold boot size of , while the Micro-B connector is with a maximum overmold size of .


title: USB hardware

text: The thinner Micro-USB connectors were intended to replace the Mini connectors in devices manufactured since May 2007, including smartphones, personal digital assistants, and cameras.


title: USB hardware

text: The Micro plug design is rated for at least 10,000 connect-disconnect cycles, which is more than the Mini plug design. The Micro connector is also designed to reduce the mechanical wear on the device; instead, the easier-to-replace cable is designed to bear the mechanical wear of connection and disconnection. The "Universal Serial Bus Micro-USB Cables and Connectors Specification" details the mechanical characteristics of Micro-A plugs, Micro-AB receptacles (which accept both Micro-A and Micro-B plugs), Double-Sided Micro USB, and Micro-B plugs and receptacles, along with a Standard-A receptacle to a Micro-A plug adapter.


title: USB hardware

text: Micro-USB was endorsed as the standard connector for data and power on mobile devices by the cellular phone carrier group Open Mobile Terminal Platform (OMTP) in 2007.


title: USB hardware

text: Micro-USB was embraced as the "Universal Charging Solution" by the International Telecommunication Union (ITU) in October 2009.


title: USB hardware

text: In Europe, micro-USB became the defined common external power supply (EPS) for use with smartphones sold in the EU, and 14 of the world's largest mobile phone manufacturers signed the EU's common EPS Memorandum of Understanding (MoU). Apple, one of the original MoU signers, makes Micro-USB adapters available—as permitted in the Common EPS MoU—for its iPhones equipped with Apple's proprietary 30-pin dock connector or (later) Lightning connector. according to the CEN, CENELEC, and ETSI.


title: USB hardware

text: USB 3.0 introduced Type-A SuperSpeed plugs and receptacles as well as micro-sized Type-B SuperSpeed plugs and receptacles. The 3.0 receptacles are backward-compatible with the corresponding pre-3.0 plugs.


title: USB hardware

text: USB 3.x and USB 1.x Type-A plugs and receptacles are designed to interoperate. To achieve USB 3.0's SuperSpeed (and SuperSpeed+ for USB 3.1 Gen 2), 5 extra pins are added to the unused area of the original 4 pin USB 1.0 design, making USB 3.0 Type-A plugs and receptacles backward compatible to those of USB 1.0.


title: USB hardware

text: On the device side, a modified Micro-B plug (Micro-B SuperSpeed) is used to cater for the five additional pins required to achieve the USB 3.0 features (USB-C plug can also be used). The USB 3.0 Micro-B plug effectively consists of a standard USB 2.0 Micro-B cable plug, with an additional 5 pins plug "stacked" to the side of it. In this way, cables with smaller 5 pin USB 2.0 Micro-B plugs can be plugged into devices with 10 contact USB 3.0 Micro-B receptacles and achieve backward compatibility.


title: USB hardware

text: USB cables exist with various combinations of plugs on each end of the cable, as displayed below in the "USB cables matrix".


title: USB hardware

text: USB On-The-Go (OTG) introduces the concept of a device performing both master and slave roles. All current OTG devices are required to have one, and only one, USB connector: a Micro-AB receptacle. (In the past, before the development of Micro-USB, On-The-Go devices used "Mini"-AB receptacles).


title: USB hardware

text: The Micro-AB receptacle is capable of accepting both Micro-A and Micro-B plugs, attached to any of the legal cables and adapters as defined in revision 1.01 of the Micro-USB specification.


title: USB hardware

text: To enable Type-AB receptacles to distinguish which end of a cable is plugged in, plugs have an "ID" pin in addition to the four contacts in standard-size USB connectors. This ID pin is connected to GND in Type-A plugs, and left unconnected in Type-B plugs. Typically, a pull-up resistor in the device is used to detect the presence or absence of an ID connection.


title: USB hardware

text: The OTG device with the A-plug inserted is called the A-device and is responsible for powering the USB interface when required, and by default assumes the role of host. The OTG device with the B-plug inserted is called the B-device and by default assumes the role of peripheral. An OTG device with no plug inserted defaults to acting as a B-device. If an application on the B-device requires the role of host, then the Host Negotiation Protocol (HNP) is used to temporarily transfer the host role to the B-device.


title: USB hardware

text: OTG devices attached either to a peripheral-only B-device or a standard/embedded host have their role fixed by the cable, since in these scenarios it is only possible to attach the cable one way.


title: USB hardware

text: Developed at roughly the same time as the USB 3.1 specification, but distinct from it, the USB-C Specification 1.0 was finalized in August 2014 and defines a new small reversible-plug connector for USB devices. The USB-C plug connects to both hosts and devices, replacing various Type-A and Type-B connectors and cables with a standard meant to be future-proof.


title: USB hardware

text: The 24-pin double-sided connector provides four power–ground pairs, two differential pairs for USB 2.0 data (though only one pair is implemented in a USB-C cable), four pairs for SuperSpeed data bus (only two pairs are used in USB 3.1 mode), two "sideband use" pins, V +5 V power for active cables, and a configuration pin for cable orientation detection and dedicated biphase mark code (BMC) configuration data channel. Type-A and Type-B adaptors and cables are required for older hosts and devices to plug into USB-C hosts and devices. Adapters and cables with a USB-C receptacle are not allowed.


title: USB hardware

text: Full-featured USB-C 3.1 cables are electronically marked cables that contain a full set of wires and a chip with an ID function based on the configuration data channel and vendor-defined messages (VDMs) from the USB Power Delivery 2.0 specification. USB-C devices also support power currents of 1.5 A and 3.0 A over the 5 V power bus in addition to baseline 900 mA; devices can either negotiate increased USB current through the configuration line or they can support the full Power Delivery specification using both BMC-coded configuration line and legacy BFSK-coded V line.


title: USB hardware

text: USB plugs fit one receptacle with notable exceptions for USB On-The-Go "AB" support and the general backward compatibility of USB 3.0 as shown.


title: USB hardware

text: Manufacturers of personal electronic devices might not include a USB standard connector on their product for technical or marketing reasons. Some manufacturers such as Apple provide proprietary cables that permit their devices to physically connect to a USB standard port. Full functionality of proprietary ports and cables with USB standard ports is not assured; for example, some devices only use the USB connection for battery charging and do not implement any data transfer functions.


title: USB hardware

text: The D± signals used by low, full, and high speed are carried over a twisted pair (typically unshielded) to reduce noise and crosstalk. SuperSpeed uses separate transmit and receive differential pairs, which additionally require shielding (typically, shielded twisted pair but twinax is also mentioned by the specification). Thus, to support SuperSpeed data transmission, cables contain twice as many wires and are thus larger in diameter.


title: USB hardware

text: The USB 1.1 standard specifies that a standard cable can have a maximum length of with devices operating at full speed (12 Mbit/s), and a maximum length of with devices operating at low speed (1.5 Mbit/s).


title: USB hardware

text: USB 2.0 provides for a maximum cable length of for devices running at high speed (480 Mbit/s). The primary reason for this limit is the maximum allowed round-trip delay of about 1.5 μs. If USB host commands are unanswered by the USB device within the allowed time, the host considers the command lost. When adding USB device response time, delays from the maximum number of hubs added to the delays from connecting cables, the maximum acceptable delay per cable amounts to 26 ns. The USB 2.0 specification requires that cable delay be less than (, ), which is close to the maximum achievable transmission speed for standard copper wire.


title: USB hardware

text: The USB 3.0 standard does not directly specify a maximum cable length, requiring only that all cables meet an electrical specification: for copper cabling with AWG 26 wires the maximum practical length is .


title: USB hardware

text: The tolerance on V_BUS at an upstream (or host) connector was originally ±5% (ie. could lie anywhere in the range 4.75 V to 5.25 V). With the release of the USB Type-C specification in 2014 and its 3 A power capability, the USB-IF elected to increase the upper voltage limit to 5.5 V to combat voltage droop at higher currents. The USB 2.0 specification (and therefore implicitly also the USB 3.x specifications) was also updated to reflect this change at that time. A number of extensions to the USB Specifications have progressively further increased the maximum allowable V_BUS voltage: starting with 6.0V with USB BC 1.2, to 21.5 V with USB PD 2.0 and 50.9 V with USB PD 3.1, while still maintaining backwards compatibility with USB 2.0 by requiring various forms of handshake before increasing the nominal voltage above 5 V.


title: USB hardware

text: USB PD continues the use of the bilateral 5% tolerance, with allowable voltages of ±5% ±0.5 V (eg. for a PDO of 9.0 V, the maximum and minimum limits are 9.95 V and 8.05 V, respectively).


title: USB hardware

text: There are several minimum allowable voltages defined at different locations within a chain of connectors, hubs, and cables between an upstream host (providing the power) and a downstream device (consuming the power). To allow for voltage drops, the voltage at the host port, hub port, and device are specified to be at least 4.75 V, 4.4 V, and 4.35 V respectively by USB 2.0 for low-power devices, but must be at least 4.75 V at all locations for high-power devices (however, high-power devices are required to operate as a low-powered device so that they may be detected and enumerated if connected to a low-power upstream port). The USB 3.x specifications require that all devices must operate down to 4.00 V at the device port.


title: USB hardware

text: Unlike USB 2.0 and USB 3.2, USB4 does not define its own VBUS-based power model. Power for USB4 operation is established and managed as defined in the USB Type-C Specification and the USB PD Specification.


title: USB hardware

text: The limit to device power draw is stated in terms of a "unit load" which is 100 mA for USB 2.0, or 150 mA for SuperSpeed (ie USB 3.x) devices. Low-power devices may draw at most 1 unit load, and all devices must act as low-power devices before they are configured. A high-powered device must be configured, after which it may draw up to 5 unit loads (500 mA), or 6 unit loads (900 mA) for SuperSpeed devices, as specified in its configuration because the maximum power may not always be available from the upstream port.


title: USB hardware

text: A bus-powered hub is a high-power device providing low-power ports. It draws 1 unit load for the hub controller and 1 unit load for each of at most 4 ports. The hub may also have some non-removable functions in place of ports. A self-powered hub is a device that provides high-power ports by supplementing the power supply from the host with its own external supply. Optionally, the hub controller may draw power for its operation as a low-power device, but all high-power ports must draw from the hub's self-power.


title: USB hardware

text: Where devices (for example, high-speed disk drives) require more power than a high-power device can draw, they function erratically, if at all, from bus power of a single port. USB provides for these devices as being self-powered. However, such devices may come with a Y-shaped cable that has two USB plugs (one for power and data, the other for only power), so as to draw power as two devices. Such a cable is non-standard, with the USB compliance specification stating that "use of a 'Y' cable (a cable with two A-plugs) is prohibited on any USB peripheral", meaning that "if a USB peripheral requires more power than allowed by the USB specification to which it is designed, then it must be self-powered."


title: USB hardware

text: USB Battery Charging (BC) defines a "charging port", which may be a "charging downstream port" (CDP), with data, or a "dedicated charging port" (DCP) without data. Dedicated charging ports can be found on USB power adapters to run attached devices and battery packs. Charging ports on a host with both kinds will be labelled.


title: USB hardware

text: The charging device identifies a charging port by non-data signaling on the D+ and D− terminals. A dedicated charging port places a resistance not exceeding 200 Ω across the D+ and D− terminals.


title: USB hardware

text: Per the base specification, any device attached to a "standard downstream port" (SDP) must initially be a low-power device, with high-power mode contingent on later USB configuration by the host. Charging ports, however, can immediately supply between 0.5 and 1.5 A of current. The charging port must not apply current limiting below 0.5 A, and must not shut down below 1.5 A or before the voltage drops to 2 V.


title: USB hardware

text: Since these currents are larger than in the original standard, the extra voltage drop in the cable reduces noise margins, causing problems with High Speed signaling. Battery Charging Specification 1.1 specifies that charging devices must dynamically limit bus power current draw during High Speed signaling; 1.2 specifies that charging devices and ports must be designed to tolerate the higher ground voltage difference in High Speed signaling.


title: USB hardware

text: Revision 1.2 of the specification was released in 2010. It made several changes, and increased limits including allowing 1.5 A on charging downstream ports for unconfigured devices—allowing High Speed communication while having a current up to 1.5 A. Also, support was removed for charging port detection via resistive mechanisms.


title: USB hardware

text: Before the Battery Charging Specification was defined, there was no standardized way for the portable device to inquire how much current was available. For example, Apple's iPod and iPhone chargers indicate the available current by voltages on the D− and D+ lines. When D+ = D− = 2.0 V, the device may pull up to 900 mA. When D+ = 2.0 V and D− = 2.8 V, the device may pull up to 1 A of current. When D+ = 2.8 V and D− = 2.0 V, the device may pull up to 2 A of current.


title: USB hardware

text: Portable devices having a USB On-The-Go port may want to charge and access a USB peripheral simultaneously, yet having only a single port (both due to On-The-Go and space requirement) prevents this. "Accessory charging adapters (ACA)" are devices that provide portable charging power to an On-The-Go connection between host and peripheral.


title: USB hardware

text: ACAs have three ports: the OTG port for the portable device, which is required to have a Micro-A plug on a captive cable; the accessory port, which is required to have a Micro-AB or type-A receptacle; and the charging port, which is required to have a Micro-B receptacle, or type-A plug or charger on a captive cable. The ID pin of the OTG port is not connected within plug as usual, but to the ACA itself, where signals outside the OTG floating and ground states are used for ACA detection and state signaling. The charging port does not pass data, but does use the D± signals for charging port detection. The accessory port acts as any other port. When appropriately signaled by the ACA, the portable device can charge from the bus power as if there were a charging port present; any OTG signals over bus power are instead passed to the portable device via the ID signal. Bus power is also provided to the accessory port from the charging port transparently.


title: USB hardware

text: In July 2012, the USB Promoters Group announced the finalization of the USB Power Delivery (USB-PD) specification (USB PD rev. 1), an extension that specifies using certified "PD aware" USB cables with standard USB Type-A and Type-B connectors to deliver increased power (more than 7.5 W) to devices with greater power demands. (USB-PD A and B plugs have a mechanical mark while Micro plugs have a resistor or capacitor attached to the ID pin indicating the cable capability.) USB-PD Devices can request higher currents and supply voltages from compliant hosts—up to 2 A at 5 V (for a power consumption of up to 10 W), and optionally up to 3 A or 5 A at either 12 V (36 W or 60 W) or 20 V (60 W or 100 W). In all cases, both host-to-device and device-to-host configurations are supported.


title: USB hardware

text: The intent is to permit uniformly charging laptops, tablets, USB-powered disks and similarly higher-power consumer electronics, as a natural extension of existing European and Chinese mobile telephone charging standards. This may also affect the way electric power used for small devices is transmitted and used in both residential and public buildings. The standard is designed to coexist with the previous USB Battery Charging specification.


title: USB hardware

text: The first Power Delivery specification defined six fixed power profiles for the power sources. PD-aware devices implement a flexible power management scheme by interfacing with the power source through a bidirectional data channel and requesting a certain level of electrical power, variable up to 5 A and 20 V depending on supported profile. The power configuration protocol can use BMC coding over the CC wire if one is present, or a 24 MHz BFSK-coded transmission channel on the V line.


title: USB hardware

text: The USB Power Delivery specification revision 2.0 (USB PD Rev. 2.0) has been released as part of the USB 3.1 suite. It covers the USB-C cable and connector with a separate configuration channel, which now hosts a DC coupled low-frequency BMC-coded data channel that reduces the possibilities for RF interference. Power Delivery protocols have been updated to facilitate USB-C features such as cable ID function, Alternate Mode negotiation, increased V currents, and V-powered accessories.


title: USB hardware

text: As of USB Power Delivery specification revision 2.0, version 1.2, the six fixed power profiles for power sources have been deprecated. USB PD Power Rules replace power profiles, defining four normative voltage levels at 5 V, 9 V, 15 V, and 20 V. Instead of six fixed profiles, power supplies may support any maximum source output power from 0.5 W to 100 W.


title: USB hardware

text: The USB Power Delivery specification revision 3.0 defines an optional Programmable Power Supply (PPS) protocol that allows granular control over V power, allowing a range of 3.3 to 21 V in 20 mV steps to facilitate constant-current or constant-voltage charging. Revision 3.0 also adds extended configuration messages and fast role swap and deprecates the BFSK protocol.


title: USB hardware

text: On 8 January 2018 USB-IF announced "Certified USB Fast Charger" logo for chargers that use "Programmable Power Supply" (PPS) protocol from the USB Power Delivery 3.0 specification.


title: USB hardware

text: In May 2021, the USB PD promoter group launched revision 3.1 of the specification. Revision 3.1 adds Extended Power Range (EPR) mode which allows higher voltages of 28, 36, and 48 V, providing up to 240 W of power (48 V at 5 A), and the "Adjustable Voltage Supply" (AVS) protocol which allows specifying the voltage from a range of 15 to 48 V in 100 mV steps. Higher voltages require electronically marked EPR cables that support 5 A operation and incorporate mechanical improvements required by the USB Type-C standard rev. 2.1; existing power modes are retroactively renamed Standard Power Range (SPR). In October 2021 Apple introduced a 140 W (28 V 5 A) GaN USB PD charger with new Macbooks.


title: USB hardware

text: Prior to Power Delivery, mobile phone vendors used custom protocols to exceed the 7.5 W cap on USB-BCS. For example, Qualcomm's Quick Charge 2.0 is able to deliver 18 W at a higher voltage, and VOOC delivers 20 W at the normal 5 V. Some of these technologies, such as Quick Charge 4, eventually became compatible with USB PD again.


title: USB hardware

text: Sleep-and-charge USB ports can be used to charge electronic devices even when the computer that hosts the ports is switched off. Normally, when a computer is powered off the USB ports are powered down. This feature has also been implemented on some laptop docking stations allowing device charging even when no laptop is present. On laptops, charging devices from the USB port when it is not being powered from AC drains the laptop battery; most laptops have a facility to stop charging if their own battery charge level gets too low.


title: USB hardware

text: On Dell, HP and Toshiba laptops, sleep-and-charge USB ports are marked with the standard USB symbol with an added lightning bolt or battery icon on the right side. Dell calls this feature "PowerShare", and it needs to be enabled in the BIOS. Toshiba calls it "USB Sleep-and-Charge". On Acer Inc. and Packard Bell laptops, sleep-and-charge USB ports are marked with a non-standard symbol (the letters "USB" over a drawing of a battery); the feature is called "Power-off USB". Lenovo calls this feature "Always On USB".


title: USB hardware

text: , all new mobile phones applying for a license in China are required to use a USB port as a power port for battery charging. This was the first standard to use the convention of shorting D+ and D− in the charger.


title: USB hardware

text: In September 2007, the Open Mobile Terminal Platform group (a forum of mobile network operators and manufacturers such as Nokia, Samsung, Motorola, Sony Ericsson, and LG) announced that its members had agreed on Micro-USB as the future common connector for mobile devices.


title: USB hardware

text: The GSM Association (GSMA) followed suit on 17 February 2009, and on 22 April 2009, this was further endorsed by the CTIA – The Wireless Association, with the International Telecommunication Union (ITU) announcing on 22 October 2009 that it had also embraced the Universal Charging Solution as its "energy-efficient one-charger-fits-all new mobile phone solution," and added: "Based on the Micro-USB interface, UCS chargers will also include a 4-star or higher efficiency rating—up to three times more energy-efficient than an unrated charger."


title: USB hardware

text: In June 2009, many of the world's largest mobile phone manufacturers signed an EC-sponsored Memorandum of Understanding (MoU), agreeing to make most data-enabled mobile phones marketed in the European Union compatible with a common External Power Supply (common EPS). The EU's common EPS specification (EN 62684:2010) references the USB Battery Charging Specification and is similar to the GSMA/OMTP and Chinese charging solutions. In January 2011, the International Electrotechnical Commission (IEC) released its version of the (EU's) common EPS standard as IEC 62684:2011. The European Union and its members should adopt a resolution during 2022 for the global adoption of USB Type C chargers for all mobile products on the European market.


title: USB hardware

text: A variety of (non-USB) standards support charging devices faster than the USB Battery Charging standard. When a device doesn't recognize the faster-charging standard, generally the device and the charger fall back to the USB battery-charging standard of 5 V at 1.5 A (7.5 W). When a device detects it is plugged into a charger with a compatible faster-charging standard, the device pulls more current or the device tells the charger to increase the voltage or both to increase power (the details vary between standards).


title: USB hardware

text: Some USB devices require more power than is permitted by the specifications for a single port. This is common for external hard and optical disc drives, and generally for devices with motors or lamps. Such devices can use an external power supply, which is allowed by the standard, or use a dual-input USB cable, one input of which is for power and data transfer, the other solely for power, which makes the device a non-standard USB device. Some USB ports and external hubs can, in practice, supply more power to USB devices than required by the specification but a standard-compliant device may not depend on this.


title: USB hardware

text: In addition to limiting the total average power used by the device, the USB specification limits the inrush current (i.e., the current used to charge decoupling and filter capacitors) when the device is first connected. Otherwise, connecting a device could cause problems with the host's internal power. USB devices are also required to automatically enter ultra low-power suspend mode when the USB host is suspended. Nevertheless, many USB host interfaces do not cut off the power supply to USB devices when they are suspended.


title: USB hardware

text: Some non-standard USB devices use the 5 V power supply without participating in a proper USB network, which negotiates power draw with the host interface. Examples include USB-powered keyboard lights, fans, mug coolers and heaters, battery chargers, miniature vacuum cleaners, and even miniature lava lamps. In most cases, these items contain no digital circuitry, and thus are not standard-compliant USB devices. This may cause problems with some computers, such as drawing too much current and damaging circuitry. Prior to the USB Battery Charging Specification, the USB specification required that devices connect in a low-power mode (100 mA maximum) and communicate their current requirements to the host, which then permits the device to switch into high-power mode.


title: USB hardware

text: Some devices, when plugged into charging ports, draw even more power (10 watts at 2.1 amperes) than the Battery Charging Specification allows—the iPad is one such device; it negotiates the current pull with data pin voltages. Barnes & Noble Nook Color devices also require a special charger that runs at 1.9 amperes.


title: USB hardware

text: PoweredUSB is a proprietary extension that adds four pins supplying up to 6 A at 5 V, 12 V, or 24 V. It is commonly used in point of sale systems to power peripherals such as barcode readers, credit card terminals, and printers.


title: Beaver

text: Beavers are large, semiaquatic rodents in the genus Castor native to the temperate Northern Hemisphere. There are two extant species: the North American beaver ("Castor canadensis") and the Eurasian beaver ("C. fiber"). Beavers are the second-largest living rodents after the capybaras. They have stout bodies with large heads, long chisel-like incisors, brown or gray fur, hand-like front feet, webbed back feet and flat, scaly tails. The two species differ in the shape of the skull and tail and fur color. Beavers can be found in a number of freshwater habitats, such as rivers, streams, lakes and ponds. They are herbivorous, consuming tree bark, aquatic plants, grasses and sedges.


title: Beaver

text: Beavers build dams and lodges using tree branches, vegetation, rocks and mud; they chew down trees for building material. Dams impound water and lodges serve as shelters. Their infrastructure creates wetlands used by many other species, and because of their effect on other organisms in the ecosystem, they are considered a keystone species. Adult males and females live in monogamous pairs with their offspring. When they are old enough, the young will help their parents repair dams and lodges and may also help raise newly born offspring. Beavers hold territories and mark them using scent mounds made of mud, debris and castoreum, a liquid substance excreted through the beaver's castor sacs. Beavers can also recognize their kin by their anal gland secretions and are more likely to tolerate them as neighbors.


title: Beaver

text: Historically, beavers have been hunted for their fur, meat and castoreum. Castoreum has been used in medicine, perfume and food flavoring, while beaver pelts have been a major driver of the fur trade. Before protections began in the 19th and early 20th centuries, overhunting had nearly exterminated both species. Their populations have rebounded, and they are both listed as least concern by the IUCN Red List of mammals. In human culture, the beaver symbolizes industriousness and is the national animal of Canada.


title: Beaver

text: The English word "beaver" comes from the Old English word "beofor" or "befor" and is connected to the German word "Biber" and the Dutch word "bever". The ultimate origin of the word is from an Indo-European root for "brown". The genus name "Castor" has its origin in the Greek "kastor" and translates as "beaver". The name "beaver" is the source for several names of places in Europe including "Beverley", "Bièvres", "Biberbach", "Biebrich", "Bibra", "Bibern", "Bibrka", "Bobr", "Bjurbäcker", "Bjurfors", "Bober", "Bóbrka" and "Bjurlund".


title: Beaver

text: There are two extant species: the North American beaver ("Castor canadensis") and the Eurasian beaver ("C. fiber"). The Eurasian beaver is slightly longer with a more lengthened skull, triangular nasal cavities—as opposed to the square ones of the North American species—, lighter fur color and a narrower tail.


title: Beaver

text: Carl Linnaeus coined the genus "Castor" in 1758; he also coined the specific (species) epithet "fiber". German zoologist Heinrich Kuhl coined "C. canadensis" in 1820. However, they were not confirmed to be separate species until the 1970s when chromosomal evidence became available. (The Eurasian has 48 chromosomes, versus the North American's 40.) Prior to that, many considered them the same species. The difference in chromosome numbers prevents them from interbreeding. 25 subspecies have been classified for "C. canadensis" and nine for "C. fiber".


title: Beaver

text: Beavers belong to the rodent suborder Castorimorpha, along with Heteromyidae (kangaroo rats and kangaroo mice), and the gophers. Modern beavers are the only extant members of the family Castoridae. They originated in North America in the late Eocene and colonized Eurasia via the Bering Land Bridge in the early Oligocene, coinciding with the "Grande Coupure", a time of significant changes in animal species around 33million years ago (mya).


title: Beaver

text: The more basal castorids had several unique features; more complex occlusion between cheek teeth, parallel rows of upper teeth, premolars being only slightly smaller than molars, the presence of a third set of premolars (P3), a hole in the stapes of the inner ear, a smooth palatine bone (with the palatine opening closer to the rear end of the bone), and a longer snout. More derived castorids have less complex occlusion, upper tooth rows that create a V-shape towards the back, larger second premolars compared to molars, absence of a third premolar set and stapes hole, a more grooved palatine (with the opening shifted towards the front), and reduced incisive foramen. Members of the subfamily "Palaeocastorinae" appeared in late Oligocene North America. This group consisted primarily of smaller animals with relatively large front legs, a flattened skull and a reduced tail, all features of a fossorial (burrowing) lifestyle.


title: Beaver

text: In the early Miocene (about 24 mya), castorids evolved a semiaquatic lifestyle. Members of the subfamily Castoroidinae are considered to be a sister group to modern beavers, and included giants like "Castoroides" of North America and "Trogontherium" of Eurasia. "Castoroides" is estimated to have had a length of and a weight of . Fossils of one genus in Castoroidinae, "Dipoides", have been found near piles of chewed wood, though it appears to have been an inferior woodcutter compared to "Castor". Researchers suggest that modern beavers and Castoroidinae shared a bark-eating common ancestor. Dam and lodge-building likely developed from bark-eating, and allowed beavers to survive in the harsh winters of the subarctic. There is no conclusive evidence for this behavior occurring in non-"Castor" species.


title: Beaver

text: The genus "Castor" likely originated in Eurasia; The earliest fossil remains appear to be "C. neglectus", found in Germany and dated 12–10 mya. Mitochondrial DNA studies place the common ancestor of the two living species at around 8 mya. The ancestors of the North American beaver would have crossed the Bering Land Bridge around 7.5 mya. "Castor" may have competed with members of Castoroidinae, which led to niche differentiation. The fossil species "C. praefiber" was likely the ancestor of the Eurasian beaver. "C. californicus" from the Early Pleistocene of North America was similar to but larger than the extant North American beaver.


title: Beaver

text: Beavers are the second-largest living rodents, after the capybaras. They have a head-body length of , with a tail, a shoulder height of and a weight of . Males and females are almost identical externally. Their bodies are streamlined like marine mammals and their robust build allows them to pull heavy loads. A beaver coat has 12,000–23,000 hairs/cm (77,000–148,000 per in) and functions to keep the animal warm, to help it float in water, and to protect it against predators. Guard hairs are long and typically reddish brown, but can range from yellowish brown to nearly black; while the underfur is long and dark gray. Beavers molt every summer.


title: Beaver

text: Beavers have large skulls and powerful chewing muscles. They have four chisel-shaped incisors they keep growing throughout their lives. The incisors are covered in a thick enamel colored orange or reddish-brown by iron compounds. The lower incisors have roots that are almost as long as the entire lower jaw. Beavers have one premolar and three molars on all four sides of the jaws, adding up to 20 teeth. The molars have meandering ridges for grinding woody material. The eyes, ears and nostrils are arranged so that they can remain above water when the rest of the body submerges. The nostrils and ears have valves that close underwater while nictitating membranes cover the eyes. To protect the larynx and trachea from water flow, the epiglottis is contained within the nasal cavity instead of the throat. In addition, the back of the tongue can rise and create a waterproof seal. A beaver's lips can close behind the incisors, preventing water from entering their mouths as they cut and bite onto things while submerged.


title: Beaver

text: The beaver's front feet are dexterous, allowing them to grasp and manipulate objects and food, as well as dig. The hind feet are larger and have webbing between the toes, and the second innermost toe has a "double nail" used for grooming. Beavers can swim at ; only their webbed hind feet are used while the front feet fold under the chest. On the surface, the hind limbs thrust one after the other while underwater, they move at the same time. Beavers are awkward on land but can move quickly when they feel threatened. They can carry objects while walking on their hind legs. The beaver's distinctive tail consists of a conical, muscular, hairy base; and a flat, scaly end that makes up two-thirds of the appendage. The tail has multiple functions; it provides support for the animal when it is upright (such as when chewing down a tree), acts as a rudder when it is swimming and stores fat for winter. It also has a countercurrent blood vessel system which allows the animal to lose heat in warm temperatures and retain heat in cold temperatures.


title: Beaver

text: The beaver's sex organs are inside the body, and the male's penis has a cartilaginous baculum. They have only one opening, a cloaca, for reproduction, scent-marking, defecation and urination. The cloaca evolved secondarily, as mammals have lost this feature, and may reduce the area vulnerable to infection in dirty water. The beaver's intestine is six times longer than its body, and the caecum is double the volume of its stomach. Microorganisms in the caecum allow them to process around 30 percent of the cellulose they eat. A beaver defecates in the water, leaving behind balls of sawdust. Female beavers have four mammary glands; these produce milk with 19 percent fat, higher than in other rodents. Beavers have two pairs of glands, castor sacs, which are part of the urethra, and anal glands. The castor sacs secrete castoreum, a liquid substance used mainly for marking territory. Anal glands produce an oily substance which the beaver uses as a waterproof ointment for its coat. The substance plays a role in individual and family recognition. Anal secretions are darker in females than males among Eurasian beavers, while the reverse is true for the North American species.


title: Beaver

text: Compared to many other rodents, a beaver's brain has a hypothalamus that is much smaller than the cerebrum; this indicates a relatively advanced brain with higher intelligence. The cerebellum is large, allowing the animal to move within a three-dimensional space (such as underwater) similar to tree-climbing squirrels. The neocortex is devoted mainly to touch and hearing. Touch is more advanced in the lips and hands than the whiskers and tail. Vision in the beaver is comparably poor, and the beaver eye cannot see as well underwater as that of an otter. Beavers have a good sense of smell, which they use for inspecting scent marks, food and other individuals, and for detecting land predators.


title: Beaver

text: Beavers can hold their breath for as long as 15 minutes. However, they typically remain underwater for no more than five or six minutes. Dives typically last less than 30 seconds and are usually no more than deep. When diving, their heart rate decreases to 60 beats per minute, only half its normal beat, and blood flow is directed more to the brain. A beaver's body also has a high tolerance for carbon dioxide. When surfacing, the animal can replace 75 percent of the air in its lungs in one breath, compared to 15 percent for a human.


title: Beaver

text: The IUCN Red List of mammals lists both beaver species as least concern. The North American beaver is widespread throughout most of the United States and Canada and can be found in northern Mexico. The species was introduced to Finland in 1937 (and then spread to northwestern Russia) and to Tierra del Fuego, Patagonia, in 1946. The introduced population in Finland has been moving closer to the habitat of the Eurasian beaver as of 2019. Historically, the North American beaver was trapped and nearly extirpated because its fur was highly sought after. Protections have allowed the beaver population on the continent to rebound to an estimated 6–12million by the late 20th century; still far lower than the originally estimated 60–400million North American beavers before the days of the fur trade. The introduced population in Tierra del Fuego is estimated at 35,000–50,000 individuals as of 2016.


title: Beaver

text: The Eurasian beaver's range historically included much of Eurasia, but was decimated by hunting by the early 20th century. In Europe, beavers were reduced to fragmented populations in the Rhône of France, the Elbe in Germany, southern Norway, the Neman river and Dnieper Basin in Belarus and the Voronezh river in Russia with combined numbers estimated at 1,200 individuals. The beaver has since recolonized parts of its former range aided by conservation policies and reintroductions. Beaver populations now range across western, central and eastern Europe, western Russia and the Scandinavian Peninsula. Beginning in 2009, beavers have been reintroduced successfully to parts of Great Britain. In 2020, the total Eurasian beaver population in Europe was estimated at over one million. Small native populations are also present in Mongolia and northwestern China; their numbers were estimated at 150 and 700 respectively as of 2016. Under New Zealand's Hazardous Substances and New Organisms Act 1996, beavers are classed as a "prohibited new organism" preventing them from being introduced into the country.


title: Beaver

text: Beavers live in freshwater ecosystems such as rivers, streams, lakes and ponds. Water is the most important part of beaver habitat; they swim and dive in it, and it provides them a refuge from land predators, restricts access to their homes and allows them to move building objects more easily. Beavers prefer to use slower moving streams, typically with a gradient or steepness of one percent, though they have been recorded using streams with gradients as high as 15 percent. Beavers are found in wider streams more than narrower ones. They also prefer areas with no regular flooding and may abandon a location for years after a significant flood.


title: Beaver

text: Beavers typically select flat landscapes with diverse vegetation close to the water. North American beavers prefer trees being or less from the water, but will roam several hundred meters to find more. Beavers have also been recorded in mountainous areas. Dispersing beavers will use certain habitats temporarily before finding their ideal home. These include small streams, temporary swamps, ditches and backyards. These sites lack important resources, so the animals keep moving. Beavers have settled increasingly at or near human-made environments, including agricultural areas, suburbs, golf courses and shopping malls.


title: Beaver

text: Beavers have a herbivorous and a generalist diet. During the spring and summer, they mainly feed on herbaceous plant material such as leaves, roots, herbs, ferns, grasses, sedges, water lilies, water shields, rushes and cattails. During the fall and winter, they eat more bark and cambium of woody plants; tree and shrub species used include aspen, birch, oak, dogwood, willow and alder. There is some disagreement about why beaver select specific woody plants; some research has shown that beaver more frequently select species which are more easily digested, while others suggest beaver principally select forage based upon size. Beavers may cache their food for the winter, piling up wood in the deepest part of their pond where it cannot be reached by other browsers. This is known as a "raft" the top of which becomes frozen creating a "cap". The animal accesses the raft by swimming under the ice. Many populations of Eurasian beaver do not make rafts but forage on land during winter.


title: Beaver

text: Beavers usually live up to 10 years. Felids, canids and bears may prey upon them. Beavers are protected from predators when in their lodges and prefer to stay near water. Their parasites include the bacteria "Francisella tularensis", which causes tularemia; the protozoan "Giardia duodenalis", which causes giardiasis (beaver fever); and the beaver beetle and mites of the genus "Schizocarpus". They have also been recorded with the rabies virus.


title: Beaver

text: Beavers need trees and shrubs as building material for dams, which impound flowing water to create a pond for them to live in, and lodges, which act as shelters and refuges from predators and the elements. Without such material, beavers dig burrows into a bank to live. Construction begins in late summer or early fall, and they repair them whenever needed. Beavers can cut down trees wide or less in under 50 minutes. Thicker trees, at wide or more, may not fall for hours. When chewing down a tree, beavers switch between biting with the left and right side of the mouth. Tree branches are then cut and carried to their destination with the powerful jaw and neck muscles. Other building materials, like mud and rocks, are held by the forelimbs and tucked between the chin and chest.


title: Beaver

text: Beaver start building dams when they hear running water, and the sound of a leak in a dam triggers them to repair it. To build a dam, beavers stack up relatively long and thick logs between the banks and facing opposite directions. Heavy rocks hold down the poles, with grass packed between them. Beavers continue to pile on more material until the dam slopes in a direction facing upstream. Dams can range in height from to tall and can stretch from to several hundred meters long. Beaver dams are more effective in trapping and slowly leaking water than man-made concrete dams. Lake-dwelling beavers do not need to build dams.


title: Beaver

text: Beavers make two types of lodges: bank lodges and open-water lodges. Bank lodges are burrows dug along the shore and covered in sticks. The more complex freestanding, open-water lodges are built over a platform of piled-up sticks. The lodge is mostly sealed with mud except for a hole at the top which acts as an air vent. Both types are accessed by underwater entrances. The above-water space inside the lodge is known as the "living chamber" and a "dining area" may exist close to the water entrance. Families routinely clean out old plant material inside the lodge and bring in new ones.


title: Beaver

text: North American beavers build more open-water lodges than Eurasian beavers. Beaver lodges built by new settlers are typically small and sloppy. More experienced families can build structures with height of and around (above water). One sturdy enough to withstand the coming winter can be finished in just two nights. Both lodge types can be present at a beaver site. During the summer, beavers tend to use the bank lodges to keep cool. They use open-water lodges during the winter. The air vent provides ventilation, and new carbon dioxide can empty out in an hour. The lodge remains consistent in both oxygen and carbon dioxide levels from season to season.


title: Beaver

text: Beavers in some areas will dig canals connected to their ponds. The canals fill up with groundwater and give beavers access and easier transport of resources, as well as allow them to escape predators. These canals can stretch up to wide, deep and over long. It has been hypothesized that beavers' canals are not only transportation routes but an extension of their "central place" around the lodge and/or food cache. As they drag wood across the land, beavers leave behind trails or "slides", which they reuse when moving new material.


title: Beaver

text: The beaver works as an ecosystem engineer and keystone species as its activities can have a great impact on the landscape and biodiversity of an area. The beaver is known to facilitate the diversity of many taxa, including mammals, waterbirds, and aquatic invertebrates. Aside from humans, few other extant animals appear to do more to shape their environment. When building dams, beavers alter the paths of streams and rivers allowing for the creation of extensive wetland habitats. In one study, beavers were associated with large increases in open-water areas. When beavers returned to an area, 160% more open-water was available during droughts than in previous years when they were absent. Beaver dams also lead to higher water tables, both in mineral soil environments and in wetlands such as peatlands. In peatlands particularly, their dams stabilize the constantly changing water levels, leading to greater carbon storage.


title: Beaver

text: Beaver ponds, and the wetlands that succeed them, remove sediments and pollutants from waterways, and can stop the loss of important soils. These ponds can increase the productivity of freshwater ecosystems by accumulating nitrogen in sediments. Beaver activity can affect the temperature of the water. In northern latitudes, ice thaws earlier in the warmer beaver-dammed waters. Beavers may contribute to climate change. In Arctic areas, the floods they create can cause permafrost to thaw, releasing methane into the atmosphere.


title: Beaver

text: As wetlands are formed and riparian habitats enlarged, aquatic plants colonize the newly available watery habitat. One study in the Adirondacks found that beaver engineering leads an over 33 percent increase in herbaceous plant diversity along the water edge. Another study in semiarid eastern Oregon found that the width of riparian vegetation on stream banks increased several-fold as beaver dams watered previously dry terraces adjacent to the stream. Riparian ecosystems in arid areas appear to sustain more plant life when beaver dams are present. Beaver ponds act as a refuge for water bank plants during wildfires and provide them with enough moisture to resist such fires. Introduced beavers at Tierra del Fuego have been responsible for destroying the indigenous forest. Unlike trees in North America, many trees in South America cannot grow back after being cut down.


title: Beaver

text: Beaver activity impacts communities of aquatic invertebrates. Damming typically leads to an increase of slow or motionless water species, like dragonflies, oligochaetes, snails and mussels, to the detriment of rapid water species like black flies, stoneflies and net-spinning caddisflies. Beaver floodings create more dead trees, providing more habitat for terrestrial invertebrates like "Drosophila" flies and bark beetles, which live and breed in dead wood. The presence of beavers can increase wild salmon and trout populations, and the average size of these fish. These species use beaver habitats for spawning, overwintering, feeding and as havens from changes in water flow. The positive effects of beaver dams on fish appear to outweigh the negative effects, such as blocking of migration. Beaver ponds have been shown to be beneficial to frog populations by protecting areas for larvae to mature in warm water. The stable waters of beaver ponds also provide ideal habitat for freshwater turtles.


title: Beaver

text: Beavers help waterfowl by creating increased areas of water. The widening of the riparian zone associated with beaver dams has been shown to increase the abundance and diversity of birds favoring the water edge, an impact that may be especially important in semi-arid climates. Fish-eating birds use beaver ponds for foraging, and in some areas certain species appear more frequently where beavers were active than at sites with no beaver activity. In a study of Wyoming streams and rivers, watercourses with beavers had 75 times as many ducks as those without. As trees are drowned by rising beaver impoundments, they become ideal habitat for woodpeckers, which carve cavities that may be later used by other bird species. Beaver-caused ice thawing in northern latitudes allows Canada geese to nest earlier.


title: Beaver

text: Other semi-aquatic mammals, such as water voles, muskrats, minks and otters will shelter in beaver lodges. Beaver modifications to streams in Poland create habitats favorable to bat species that hunt at the water surface and use moderate vegetation litter. Large herbivores such as some deer species benefit from beaver activity as they can access vegetation from fallen trees and ponds.


title: Beaver

text: Beavers are mainly nocturnal and crepuscular and spend the daytime in their shelters. In northern latitudes, beaver activity is decoupled from the 24-hour cycle during the winter and may last as much as 29 hours. They do not hibernate during winter, and spend much of their time in their lodges.


title: Beaver

text: The core of beaver social organization is the family, which is composed of an adult male and an adult female in a monogamous pair and their offspring. Beaver families can have as many as ten members; groups about this size require multiple lodges. Mutual grooming and play fighting maintains bonds between family members, and aggression between them is uncommon.


title: Beaver

text: Adult beavers mate with their partners, though partner replacement appears to be common. A beaver that loses its partner will wait for another one to come by. Estrus cycles began in late December and peak in mid-January. Females may have two to four estrus cycles per season; each lasting 12–24 hours. The pair typically mate in the water and to a lesser extent in the lodge, for half a minute to three minutes. Up to four young or kits are born in spring and summer, after a three or four-month gestation. Newborn beavers are precocial with a full fur coat and can open their eyes within days. Their mother is the primary caretaker, while their father maintains the territory. Older siblings from a previous litter also play a role.


title: Beaver

text: After they are born, the kits spend the next first month or two in the lodge. Kits suckle for as long as three months but can eat solid food within their second week and rely on their parents and older siblings to bring it to them. Eventually, beaver kits explore outside the lodge and forage on their own but may follow an older relative and hold on to their backs. After their first year, young beavers help their families with construction. Beavers sexually mature around 1.5–3 years. They become independent at two years old, but remain with their parents for an extra year or more during times of food shortage, high population density, or drought.


title: Beaver

text: Beavers typically disperse from their parental colonies during the spring or when the winter snow melts. They often travel less than , but long-distance dispersals are not uncommon when previous colonizers have already exploited local resources. Beavers are able to travel greater distances when free-flowing water is available. Individuals may meet their mates during the dispersal stage and the pair travel together. It may take them weeks or months to reach their final destination; longer distances may require several years. Beavers establish and defend territories along the banks of their ponds, which may be in length.


title: Beaver

text: Beavers mark their territories by constructing scent mounds made of mud and litter and scented with castoreum. Those with many territorial neighbors create more scent mounds. Scent marking increases in spring during the dispersal of yearlings to deter interlopers. Beavers are generally intolerant of intruders and fights may result in deep bites to the sides, rump and tail. They exhibit a behavior known as the "dear enemy effect". A territory-holder will investigate and become familiar with the scents of its neighbors and react more aggressively to the scents of strangers passing by. Beavers are also more tolerant of individuals that are their kin. They recognize them by using their keen sense of smell to detect differences in the composition of anal gland secretions. Anal gland secretion profiles are more similar among relatives than unrelated individuals.


title: Beaver

text: Beavers within a family greet each other with whines. Kits will attract the attention of adults with mews, squeaks and cries. Defensive beavers produce a hissing growl and gnash their teeth. Tail slaps, which involve an animal hitting the water surface with its tail, serve as alarm signals warning other beavers of a potential threat. An adult's tail slap is more successful in alerting others, which then escape into the lodge or deeper water. Juveniles have not yet learned the proper use of a tail slap, and hence are normally ignored. Eurasian beavers have been recorded using a territorial "stick display". This involves individuals holding up a stick and bouncing in shallow water.


title: Beaver

text: Beavers sometimes come into conflict with humans over land use; the individual beavers being labeled a "nuisance beaver". Beavers can damage crops, timber stocks, roads, ditches, gardens and pastures via gnawing, eating, digging or flooding. They occasionally attack humans and domestic pets, particularly when infected with rabies, in defense of their territory, or when they feel threatened. Some of these attacks have been fatal, including at least one human death. Beavers can spread giardiasis by infecting surface waters, though outbreaks are more commonly caused by human activity.


title: Beaver

text: Flow devices, like beaver pipes, are used to manage beaver flooding, while fencing and hardwire cloth protects trees and shrubs from beaver damage. If necessary, hand tools, heavy equipment or explosives are used to remove dams. Hunting, trapping and relocation may be permitted as forms of population control and for removal of individuals. The governments of Argentina and Chile have authorized the trapping of invasive beavers in hopes of their elimination. The ecological importance of beavers has led to cities like Seattle designing their parks and green spaces to accommodate the animals. The Martinez beavers became famous in the mid-2000s for their role in improving the ecosystem of Alhambra Creek in Martinez, California.


title: Beaver

text: Zoos have displayed beavers since at least the 19th century, though not commonly. In captivity, beavers have been used for entertainment, fur harvesting and for reintroduction into the wild. Captive beavers require access to water, substrate for digging, and artificial shelters. Archibald Stansfeld "Grey Owl" Belaney pioneered beaver conservation in the early 20th century. Belaney wrote several books and was first to professionally film them in their environment. In 1931 he moved to a log cabin in Prince Albert National Park, where he was the "caretaker of park animals", and raised a beaver pair and their four offspring.


title: Beaver

text: Beavers have been hunted, trapped and exploited for their fur, meat and castoreum. Since they typically stayed in one place, trappers could easily find the animals and would kill entire families in a lodge. Pre-modern people appear to have thought that the castor sacs of the beaver were its testicles. Aesop's Fables describes beavers chewing off their testicles to preserve themselves from hunters, which is impossible because a beaver's testicles are internal; this myth has persisted for centuries. Beavers have historically been hunted and captured using deadfalls, snares, nets, bows and arrows, spears, clubs, firearms and leg-hold traps. Castoreum was used to lure the animals.


title: Beaver

text: Castoreum was used for a variety of medical purposes; Pliny the Elder promoted it as a treatment for stomach problems, flatulence, seizures, sciatica, vertigo and epilepsy. He stated it could stop hiccups when mixed with vinegar, toothaches if mixed with oil and administered into the ear opening on the same side as the tooth, and could be used as an antivenom. The substance has traditionally been prescribed to treat hysteria in women, which was believed to have been caused by a "toxic" womb. Castoreum's properties have been credited to the accumulation of salicylic acid from willow and aspen trees in the beaver's diet, and has a physiological effect very similar to aspirin. Today, the medical use of castoreum has declined and is limited mainly to homeopathy. The substance has also lent itself as an ingredient in perfumes and tinctures.


title: Beaver

text: Various Native American cultures have historically hunted beavers for food. Beaver meat was advantageous, being more calorie-rich and fattened than other red meats, and the animals remained plump in winter, when they were most hunted. The bones were used to make tools. In medieval Europe, the Catholic Church considered the beaver to be part mammal and part fish and allowed followers to eat the scaly, fishlike tail on meatless Fridays during Lent. Beaver tails were thus highly prized in Europe and were described by French naturalist Pierre Belon as tasting like a "nicely dressed eel".


title: Beaver

text: Beaver pelts were used to make hats; felters would remove the guard hairs. The number of pelts needed depended on the type of hat with Cavalier and Puritan hats requiring more fur than top hats. In the late 16th century, Europeans began to deal in North American furs due to the lack of taxes or tariffs on the continent and the decline of fur-bearers at home. Beaver pelts were valuable enough to cause or contribute to the Beaver Wars, King William's War and the French and Indian War. Fur traders were the main driver of the westward expansion of Europeans into the continent and make contact with the native peoples, who traded with the Europeans. The fur trade peaked between 1860 and 1870, when over 150,000 beaver pelts were purchased annually by the Hudson's Bay Company and fur companies in the US. The contemporary global fur trade is not as profitable due to conservation, anti-fur and animal rights campaigns.


title: Beaver

text: The beaver has been used to represent productivity, trade, tradition, masculinity and respectability. References to the beaver's skills are reflected in everyday language. The English verb "to beaver" means working with great effort and being "as busy as a beaver", and a "beaver intellect" refers to a way of thinking that is both slow and honest. The name "beaver" also refers to the human vulva.


title: Beaver

text: Native American myths emphasize the beaver's skill and industriousness. In the mythology of the Haida, beavers are descended from the Beaver-Woman, who built a dam on a stream next to their cabin while her husband was out hunting and gave birth to the first beavers. In a Cree story, the Great Beaver and its dam caused a world flood. Other tales involve beavers using their tree chewing skills against an enemy. Beavers have been featured as companions in some stories, including a Lakota tale where a young woman flees from her evil husband with the aid of her pet beaver.


title: Beaver

text: Europeans have traditionally thought of beavers as fantastical animals due to their amphibious nature. They depicted them as with exaggerated tusk-like teeth, dog- or pig-like bodies, fish tails and visible testicles. French cartographer Nicolas de Fer illustrated beavers building a dam at Niagara Falls; fantastically depicting them like human builders. Beavers have also appeared in literature such as in Dante Alighieri's "Divine Comedy" and in the writings of Athanasius Kircher, who wrote that on Noah's Ark the beavers were housed near a water-filled tub that was also used by mermaids and otters.


title: Beaver

text: The beaver has long been associated with Canada, appearing on the first pictorial postage stamp issued in the Canadian colonies in 1851—the so-called "Three-Penny Beaver". It was declared the national animal in 1975. The five-cent coin, the coat of arms of the Hudson's Bay Company and the logos for Parks Canada and Roots Canada use its image. Frank and Gordon are two fictional beavers that appeared in Bell Canada's advertisements between 2005 and 2008. However, the beaver's status as a rodent has made it controversial, and it was not chosen to be on the Arms of Canada in 1921. The beaver has commonly been used to represent Canada in political cartoons, typically to signify it as a friendly but relatively weak nation. In the United States, the beaver is the state animal of New York and Oregon. It is also featured on the coat of arms of the London School of Economics.


title: Montreal Canadiens

text: The Montreal Canadiens (), officially ( The Canadian Hockey Club) and colloquially known as the Habs, are a professional ice hockey team based in Montreal. They compete in the National Hockey League (NHL) as a member of the Atlantic Division of the Eastern Conference. Since 1996, the Canadiens have played their home games at Bell Centre, originally known as Molson Centre. The team previously played at the Montreal Forum, which housed the team for seven decades and all but their first two Stanley Cup championships.


title: Montreal Canadiens

text: Founded in 1909, the Canadiens are the longest continuously operating professional ice hockey team worldwide, and the only existing NHL club to predate the founding of the NHL. One of the oldest North American professional sports franchises, the Canadiens' history predates that of every other Canadian franchise outside football, as well as every American franchise outside baseball and the National Football League's Arizona Cardinals. The franchise is one of the "Original Six", the teams that made up the NHL from 1942 until the 1967 expansion. The team's championship season in 1992–93 marked the last time a Canadian team won the Stanley Cup.


title: Montreal Canadiens

text: The Canadiens have won the Stanley Cup more times than any other franchise, having earned 24 championships, with 23 victories since the founding of the NHL, and 22 since 1927, when NHL teams became the only ones to compete for the Stanley Cup. The Canadiens also had the most championships by a team of any of the four major North American sports until the New York Yankees won their 25th World Series title in 1999.


title: Montreal Canadiens

text: The Canadiens were founded by J. Ambrose O'Brien on December 4, 1909, as a charter member of the National Hockey Association,


title: Montreal Canadiens

text: the forerunner to the National Hockey League. It was to be the team of the francophone community in Montreal, composed of francophone players, and under francophone ownership as soon as possible. The founders named the team "Les Canadiens," a term identified at the time with French speakers. The team's first season was not a success, as they placed last in the league. After the first year, ownership was transferred to George Kennedy of Montreal and the team's record improved over the next seasons. The team won its first Stanley Cup championship in the 1915–16 season. In 1917, with four other NHA teams, the Canadiens formed the NHL, and they won their first NHL Stanley Cup during the 1923–24 season, led by Howie Morenz. The team moved from the Mount Royal Arena to the Montreal Forum for the 1926–27 season.