美洲野牛
维基百科，自由的百科全书
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| Bison bison (Linnaeus, 1758) |
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B. b. athabasacae Rhoads, 1898 |
犎牛（Bison bison），又名美洲水牛或美洲野牛，是牛亞科哺乳動物，也是北美洲體型最大的哺乳類動物，和世界上最大野牛之一。儘管體型龐大，仍可維持60公里的奔跑速度。主要群體由雌牛和幼牛組成；雄性會另外組成單身漢群，只有交配時才會聚集在一起。平時以嫩莖晘草為食，無領域性。美洲森林野牛一般被認為是其亞種，但分類地位仍有爭議。最近根據最新DNA研究顯示，牠和歐洲野牛親源關係比所知還要接近。
體型龐大的美洲森林野牛是北美洲最大的亞種，牠的體型大過亞洲野牛和野生水牛，後兩者主要出現在印度。野牛大量集體居住在美國和加拿大的大平原，由加拿大遠北的大奴湖至南面的墨西哥，再由奧勒崗州東部至大西洋一帶。其兩個亞種分別是美洲草原野牛(Bison bison bison)，體型較小和有較圓滑的背部隆肉，和美洲森林野牛(Bison bison athabascae)，體型較大和較高和方形的背部隆肉。
雖然美洲野牛也稱美洲水牛，但實際牠和水牛和非洲水牛只有微略相似。
目录 |
[编辑] 生理
美洲野牛冬天的毛長且深啡色；夏季則較輕薄和淺色。野牛高2米，長3米，重450至900公斤。而據紀錄最大的物種重約1140kg。其頭部和前半部巨大，雌雄野牛均有短而彎的角，可作為戰鬥和防禦之用。野牛一般於8月至9月交配，然後紅啡色的小牛就會於接著的春天出生，小牛會由其母親照顧約一年時間。野牛一般3歲為成熟，野生野牛的壽命由18至22年，飼養的則有35至40年。
在罕有情況下，部分野牛出生時全身是白色的。但某些並非白化症，因為其身體，如皮膚，毛髮和眼睛仍然會整正常生產色素，並在漸漸長大後變回啡色。但有些則是白化症，即使長大了也是白色。此外，白野牛更被美洲原住民認為是神聖物。
由於其體型關係，並受到同住野牛群的保護，美洲野牛除了人類外，牠們很少有令其受威脅的敵人。即使灰熊和狼群會攻擊剛出生的或年幼的小牛，但也只是在嚴冬，因為那時候野牛無法消耗能量去保護那些離群的野牛。雖然狼群也能擊敗一頭野牛，但一般都要有7隻狼以上才能做到，不過狼很多時候都會敗給野牛。除了人類的獵殺外，野牛消失的另一原因就是與家畜牛的品種雜交。實際上，現時在北美的野牛裡，很少是純種野牛。
[编辑] 交配與繁殖
美洲野牛的交配習性是一夫多妻制的，也就是說一頭雄性野牛會和幾頭雌性野牛交配。開始時，單身的雄性野牛會一直"看管"著雌性野牛，直至交配到為止，這期間雄性會跟著雌性，並趕走附近的競爭雄性。
年幼的野牛（約三個月大的野牛）的顏色比會成年野牛的淺色。交配季節在夏季的中後部分，北方可以至每年的九月。懷孕期為285天（約九個半月），所以小牛通常在春季出生[1]。
[编辑] 捕獵
[编辑] 自然捕獵
美洲野牛是北美洲的新移民，牠們源自歐亞大陸，後來遷移至白令海峽。大概於10,000年前，牠取代了當時數量龐大的移居者——長角野牛(Bison priscus)。長角野牛的絕種被認為是因為生態系統的改變，克洛維斯石器文物的發展和相關技術而引致的獵殺，和不斷進步的捕獵技能所致。在同一時期，其他巨型土壤動物消失和被適應力較好的移居的歐亞動物所取代。美洲野牛, 學術上來說是這些動物的其中一類。此外還有啡熊, 牠們取代了短面熊。
野牛是基石物種，其牧草能力對大草原的生態學有一定影響，如週期性的草原火，並是大草原文化生活形式的中心。但現在也有部份對於牠門干擾的爭議 。"Hernando De Soto's expedition staggered through the Southeast for four years in the early 16th century and saw hordes of people but apparently did not see a single bison," Charles C. Mann writes in 1491: New Revelations of the Americas Before Columbus. Mann discusses the evidence that Native Americans not only created (by selective use of fire) the large grasslands that provided the bison's ideal habitat but also kept the bison population regulated. In this theory, it was only when the aboriginal population was decimated by wave after wave of epidemic (from diseases of Europeans) after the 16th century that the bison herds propagated wildly. In such a view, the seas of bison herds that stretched to the horizon were a symptom of an ecology out of balance, only rendered possible by decades of heavier-than-average rainfall. Bison were the most numerous single species of large wild mammal on Earth.
What is not disputed is that before the introduction of horses, bison were herded into large chutes made of rocks and willow branches and then stampeded over cliffs. These bison jumps are found in several places in the U.S. and Canada, such as Head-Smashed-In Buffalo Jump. Large groups of people would herd the bison for several miles, forcing them into a stampede that would ultimately drive many animals over a cliff. The large quantities of meat obtained in this way provided the hunters with surplus which they could trade with other cultures. A similar method of hunting was to drive the bison into natural corrals, such as Ruby site.
To get full use out of the bison, the Native Americans had a specific method of butchery, first identified at the Olsen-Chubbock archaeological site in Colorado. The method involves skinning down the back in order to get at the tender meat just beneath the surface, the area known as the "hatched area." After the removal of the hatched area, the front legs are cut off as well as the shoulder blades. Doing so exposes the hump meat (in the Wood Bison), as well as the meat of the ribs and the Bison's inner organs. After everything was exposed, the spine was then severed and the pelvis and hind legs removed. Finally, the neck and head were removed as one. This allowed for the tough meat to be dried and made into pemmican.
Later when Plains Indians obtained horses, it was found that a good horseman could easily lance or shoot enough bison to keep his tribe and family fed, as long as a herd was nearby. The bison provided meat, leather, sinew for bows, grease, dried dung for fires, and even the hooves could be boiled for glue. When times were bad, bison were consumed down to the last bit of marrow.
[编辑] 十九世紀的野牛捕獵
野牛在19世紀被獵殺至近乎絕種，1880年代中更只減至幾百頭。其中主要的一個原因是，鐵路的興建逼使獵人去捕殺剩下的所有群族:
- The herds formed the basis of the economies of local Plains tribes of Native Americans for whom the bison were a primary food source; without bison, the Native Americans would be forced to leave or starve.
- Herds of these large animals on tracks could damage locomotives when the trains failed to stop in time.
- Herds often took shelter in the artificial cuts formed by the grade of the track winding though hills and mountains in harsh winter conditions. As a result, the herds could delay a train for days.
Bison skins were used for industrial machine belts, clothing such as robes, and rugs. There was a huge export trade to Europe of bison hides. Old West bison hunting was very often a big commercial enterprise, involving organized teams of one or two professional hunters, backed by a team of skinners, gun cleaners, cartridge reloaders, cooks, wranglers, blacksmiths, security guards, teamsters, and numerous horses and wagons. Men were even employed to recover and re-cast lead bullets taken from the carcasses. Many of these professional hunters such as Buffalo Bill Cody killed over a hundred animals at a single stand and many thousands in their career. One professional hunter killed over 20,000 by his own count. A good hide could bring $3.00 in Dodge City, Kansas, and a very good one (the heavy winter coat) could sell for $50.00 in an era when a laborer would be lucky to make a dollar a day.
The hunter would customarily locate the herd in the early morning, and station himself about 100 meters from it, shooting the animals broadside through the lungs. Head shots were not preferred as the soft lead bullets would often flatten and fail to penetrate the skull, especially if mud was matted on the head of the animal. The bison would drop until either the herd sensed danger and stampeded or perhaps a wounded animal attacked another, causing the herd to disperse. If done properly a large number of bison would be felled at one time. Following up were the skinners, who would drive a spike through the nose of each dead animal with a sledgehammer, hook up a horse team, and pull the hide from the carcass. The hides were dressed, prepared, and stacked on the wagons by other members of the organization.
For a decade from 1873 on there were several hundred, perhaps over a thousand, such commercial hide hunting outfits harvesting bison at any one time, vastly exceeding the take by American Indians or individual meat hunters. The commercial take arguably was anywhere from 2000 to 100,000 animals per day depending on the season, though there are no statistics available. It was said that the Big .50s were fired so much that hunters needed at least two rifles to let the barrels cool off; The Fireside Book of Guns reports they were sometimes quenched in the winter snow. Dodge City saw railroad cars sent East filled with stacked hides.
As the great herds began to wane, proposals to protect the bison were discussed. Cody, among others, spoke in favor of protecting the bison because he saw that the pressure on the species was too great. But these were discouraged since it was recognized that the Plains Indians, often at war with the United States, depended on bison for their way of life. General Phillip Sheridan spoke to the Texas Legislature against a proposal to outlaw commercial bison hunting for that reason, and President Grant also "pocket vetoed" a similar Federal bill to protect the dwindling bison herds. By 1884, the American Bison was close to extinction.
[编辑] 保護
The Famous Buffalo Herd of James "Scotty" Philip in South Dakota was the beginning of the reintroduction of Bison to North America. In 1899, he purchased a small herd (5 of them, including the female) from Dug Carlin, Pete Dupree's brother-in-law, whose son Fred had roped 5 calves in the Last Big Buffalo Hunt on the Grand River in 1881 and taken them back home to the ranch on the Cheyenne River. At the time of purchase there were approximately 7 pure buffalo and it was believed to be one of the largest known herds left in North America. Scotty's goal was to preserve the animal from extinction. At the time of his death in 1911 at 53, Scotty had grown the herd to an estimated 1,000 to 1,200 head of Bison.
A variety of privately owned herds have also been established, starting from this population. The current American Bison population has been growing rapidly and is estimated at 350,000, but this is compared to an estimated 60–100 million in the mid-19th century. Most current herds, however, are partly crossbred with cattle (see "beefalo"); today there are only four genetically unmixed herds and only one that is also free of brucellosis: it roams Wind Cave National Park. A founder population from the Wind Cave herd was recently established in Montana by the World Wildlife Fund.
The only continuously wild bison herd in the United States resides within Yellowstone National Park. Numbering between 3000 and 3500, this herd is descended from a remnant population of 23 individual mountain bison that survived the mass slaughter of the 1800s by hiding out in the Pelican Valley of Yellowstone Park. In 1902, a captive herd of 21 plains bison were introduced to the Lamar Valley and managed as livestock until the 1960s, when a policy of natural regulation was adopted by the park.
The end of the ranching era and the onset of the natural regulation era set into motion a chain of events that have led to the bison of Yellowstone Park migrating to lower elevations outside the park in search of winter forage. The presence of wild bison in Montana is perceived as a threat to many cattle ranchers, who fear that the small percentage of bison that carry brucellosis will infect livestock and cause cows to abort their first calves. However, there has never been a documented case of brucellosis being transmitted to cattle from wild bison. The management controversy that began in the early 1980s continues to this day, with advocacy groups arguing that the Yellowstone herd should be protected as a distinct population segment under the Endangered Species Act.
[编辑] 現時野牛捕獵的情況
在某些地地方或省份捕獵野牛是合法的，因為那裡需要用這方法去要把野牛的數量保持在一定的數目裡。在亞伯特，那裡只有一個野生野牛群生活在美北州的美國森林野牛國家公園，他們用捕獵野牛來保護不健全的公共的自由野牛群和私人群的野牛。在蒙大拿州，2005年公共狩獵再次成立，並有50份許可證被發布。蒙大拿魚類及野生動物公園委員會於2006至2007年度頒發的狩獵許可證增至140個。野牛 擁護團體則認為這是太早去重建狩獵，因為野牛在蒙大拿的棲息地和野生動物地位仍然很少。
野牛少有的自然掠奪者是狼，狼主要獵食雌性和年幼的野牛，健康的雄性野牛則很少捕獵。此外熊也會獵食年幼的野牛。
[编辑] 水牛開拓的道路
北美洲首條道路，是由以前的乳齒象和麝香牛的路徑，並是築墩人的路線，路徑是由野牛和鹿於季節遷徙不斷走過而行成的，於攝食場和（野獸愛舔食的）鹽漬地之間。 很多這些路徑，被無數到分水嶺和山脊頂部的有蹄動物不斷本能地走過，那裡牠們可以避開低地夏天的髒亂和冬天的雪堆，接著印地安人把這些路線作為狩獵場地和戰士路徑；它們對於探險者是無價的，並由拓荒者所採用。野牛的路線一般為北面和南面；但一些主要東西面路線後來被建為火車軌道。這些包括了坎伯蘭山口 ；沿紐約分水嶺；由波多馬克河到阿利根尼河，並分支到俄亥俄河上游；並穿過藍嶺山脈再到肯塔基州。參議員托馬斯·哈特·本頓（Thomas Hart Benton）曾稱讚這些聰慧的開路者，水牛開拓了至太平洋的鐵路。
[编辑] 現今的野牛
Bison are now raised for meat and hides. Over 250,000 of the 350,000 remaining bison are being raised for human consumption. Bison meat is lower in fat and cholesterol than beef which has led to the development of beefalo, a fertile cross-breed of bison and domestic cattle. In 2005, about 35,000 bison were processed for meat in the U.S., with the National Bison Association and USDA providing a "Certified American Buffalo" program with birth-to-consumer tracking of bison via RFID ear tags.
Recent genetic studies of privately owned herds of bison show that many of them include animals with genes from domestic cattle; there are as few as 12,000 to 15,000 pure bison in the world. The numbers are uncertain because the tests so far used mitochondrial DNA analysis, and thus would miss cattle genes inherited in the male line; most of the hybrids look exactly like purebred bison.
The American Bison was depicted on the reverse side of the U.S. "buffalo nickel" from 1913 to 1938. In 2005, the United States Mint coined a nickel with a new depiction of the bison as part of its "Westward Journey" series; the Kansas and North Dakota quarters have a depiction of the bison on its reverse as part of its "50 State Quarter" series. The Kansas State Quarter only has the bison and does not feature any writing. The North Dakota State Quarter has two bison.
The bison is a symbol of Manitoba, University of Manitoba, the Royal Canadian Mounted Police, Bucknell University, the University of Colorado, Howard University, Lipscomb University, Harding University, Marshall University, the Independence Party of Minnesota, North Dakota State University, and West Texas A&M University. It is also commonly used as a symbol of the city of Buffalo, New York and its professional sports teams, the Buffalo Bills and Buffalo Sabres, although the city was not named for the animal. The bison is also the state mammal of Wyoming. It is the state animal of Kansas (see Governor of Kansas Quick Facts).
Custer State Park in South Dakota is home to 1,500 bison, one of the largest publicly held herds in the world.
A proposal known as Buffalo Commons has been suggested by a handful of academics and policymakers to restore large parts of the drier portion of the Great Plains to native prairie grazed by bison. Proponents argue that current agricultural use of the shortgrass prairie is not sustainable, pointing to periodic disasters such as the Dust Bowl and continuing significant population loss over the last 60 years. However, this plan is opposed by most who live in the sparsely-populated area, though it might benefit participating states economically.
[编辑] 危險
野牛是美國國家公園裡最危險的動物之一，尤其是黃石國家公園。雖然牠們是不食肉的，但當牠們被激怒時也會襲擊人類的。牠們平時的行動顯得緩慢，但當牠們跑起來卻能輕易超越人類，奔跑速度可達每小時35英里（約56公里）。在1978年至1992年間，在黃石國家公園被野牛殺死或傷害的人數是同公園被熊傷害的四倍有多（熊為12個，野牛為56）。野牛也有不能預計的能力，而牠的身形和結構，也能輕盈地跳越標準的鐵絲網籬笆。
[编辑] 野牛的美國本地名稱
雖然在英語一般稱水牛或野牛，但在美國本地語言裡，也有很多其他別名，包括
[编辑] 參考
- ↑ The Gale Group, Inc. Grzimek's Animal Life Encyclopedia article on American bison. Accessed Aug 13th 2006
- Bison Specialist Group (1996). Bison bison. 2006 IUCN Red List of Threatened Species. IUCN 2006. 擷取於2007年3月14日.（英文）
- 參考：ITIS 分類資訊. Bison bison (TSN 180706). 擷取於2007年3月14日 （英文）
- Fagan, Brian. Ancient North America. 2005. Thames and Hudson
- Koller, Larry. Fireside Book of Guns. 1959 Simon and Schuster
- James Truslow Adams, 1940. Dictionary of American History (New York: Charles Scribner's Sons)
[编辑] 參見
[编辑] 外部連結
- 全美野牛協會的網頁 （英文）
- 水牛場地運動 （英文）
- 加拿大野牛 （英文）
- 黃石公園給遊客的野生動物資料，包括野牛 （英文）
- Videos of animal attacks, including bison incidents （英文）
- 美洲野牛的滅種 節錄自William T. Hornaday的古登堡計劃 （英文）
- 野生野牛參考計畫 保護，管理和提倡野生野牛的共同參考書目 （英文）
- 遊美國／印地安人在底下撿肉醬～野牛跳崖看野牛 （中文）
