The Cascade Range or Cascades is a major mountain range of western North America, extending from southern British Columbia through Washington and Oregon to Northern California. It includes both non-volcanic mountains, such as the North Cascades, and the notable volcanoes known as the High Cascades, the small part of the range in British Columbia is referred to as the Canadian Cascades or, locally, as the Cascade Mountains. The highest peak in the range is Mount Rainier in Washington at 14,411 feet, the Cascades are part of the Pacific Oceans Ring of Fire, the ring of volcanoes and associated mountains around the Pacific Ocean. All of the eruptions in the contiguous United States over the last 200 years have been from Cascade volcanoes, the two most recent were Lassen Peak from 1914 to 1921 and a major eruption of Mount St. Helens in 1980. Minor eruptions of Mount St. Helens have occurred since, the Cascade Range is a part of the American Cordillera, a nearly continuous chain of mountain ranges that form the western backbone of North America, Central America, and South America.
The Cascades extend northward from Lassen Peak in northern California to the confluence of the Nicola, the Fraser River separates the Cascades from the Coast Mountains. The highest volcanoes of the Cascades, known as the High Cascades, dominate their surroundings and they often have a visual height of one mile or more. The highest peaks, such as the 14, 411-foot Mount Rainier, Mount Baker in Washington recorded a world-record single-season snowfall in the winter of 1998–99 with 1,140 inches. Prior to that year, Mount Rainier held the record for snow accumulation at Paradise in 1978. It is not uncommon for some places in the Cascades to have over 500 inches of snow accumulation, such as at Lake Helen. Most of the High Cascades are therefore white with snow and ice year-round, annual rainfall is as low as 9 inches on the eastern foothills due to a rain shadow effect. Beyond the eastern foothills is a plateau that was largely created 17 to 14 million years ago by the many flows of the Columbia River Basalt Group.
Together, these sequences of fluid volcanic rock form the 200, 000-square-mile Columbia Plateau in eastern Washington, the Columbia River Gorge is the only major break of the range in the United States. When the Cascades began to rise 7 million years ago in the Pliocene, as the range grew, erosion from the Columbia River was able to keep pace, creating the gorge and major pass seen today. The gorge exposes uplifted and warped layers of basalt from the plateau, in early 1792, British navigator George Vancouver explored Puget Sound and gave English names to the high mountains he saw. Mount Baker was named for Vancouvers third lieutenant, Joseph Baker, although the first European to see it was Manuel Quimper, Mount Rainier was named after Admiral Peter Rainier. Later in 1792, Vancouver had his lieutenant William Robert Broughton explore the lower Columbia River and he named Mount Hood after Lord Samuel Hood, an admiral of the Royal Navy. Mount St. Helens was sighted by Vancouver in May 1792 and it was named for Alleyne FitzHerbert, 1st Baron St Helens, a British diplomat
Birdwatching, or birding, is a form of wildlife observation in which the observation of birds is a recreational activity. It can be done with the eye, through a visual enhancement device like binoculars and telescopes, by listening for bird sounds. Birdwatching often involves a significant auditory component, as bird species are more easily detected and identified by ear than by eye. Most birdwatchers pursue this activity for recreational or social reasons, unlike ornithologists, the first recorded use of the term birdwatcher was in 1891, bird was introduced as a verb in 1918. The term birding was used for the practice of fowling or hunting with firearms as in Shakespeares The Merry Wives of Windsor and her husband goes this morning a-birding. The terms birding and birdwatching are today used by some interchangeably, although some participants prefer birding, in North America, many birders differentiate themselves from birdwatchers, and the term birder is unfamiliar to most lay people. At the most basic level, the distinction is perceived as one of dedication or intensity, self-described birders perceive themselves to be more versed in minutiae like identification, distribution, migration timing, and habitat usage.
Indeed, in 1969 a Birding Glossary appeared in Birding magazine which gave the following definitions, the acceptable term used to describe the person who seriously pursues the hobby of birding. A hobby in which individuals enjoy the challenge of bird study, listing, a rather ambiguous term used to describe the person who watches birds for any reason at all, and should not be used to refer to the serious birder. Twitching is a British term used to mean the pursuit of a previously located rare bird, in North America it is more often called chasing, though the British usage is starting to catch on there, especially among younger birders. The term twitcher, sometimes misapplied as a synonym for birder, is reserved for those who travel long distances to see a bird that would be ticked. The term originated in the 1950s, when it was used for the behaviour of Howard Medhurst. Prior terms for those who chased rarities were pot-hunter, tally-hunter, the main goal of twitching is often to accumulate species on ones lists.
Some birders engage in competition to accumulate the longest species list, the act of the pursuit itself is referred to as a twitch or a chase. A rare bird that stays put long enough for people to see it is twitchable or chaseable, twitching is highly developed in the United Kingdom, the Netherlands, Ireland and Sweden. The size of these makes it possible to travel throughout them quickly. The most popular twitches in the UK have drawn large crowds, for example, approximately 2,500 people travelled to Kent, England, to view a golden-winged warbler, twitchers have developed their own vocabulary. For example, a twitcher who fails to see a bird has dipped out, if other twitchers do see the bird
Pinnacles National Park
Pinnacles is managed by the National Park Service and the majority of the park is protected as wilderness. The national park is divided by the formations into East and West Divisions, connected by foot trails. The east side has shade and water, the west has high walls, the rock formations provide for spectacular pinnacles that attract rock climbers. The park features unusual talus caves that house at least thirteen species of bat, Pinnacles is most often visited in spring or fall because of the intense heat during the summer months. Park lands are prime habitat for prairie falcons, and are a site for California condors that have been hatched in captivity. Pinnacles National Monument was established in 1908 by U. S. President Theodore Roosevelt, Pinnacles National Park was created from the former Pinnacles National Monument by legislation passed by Congress in late 2012 and signed into law by President Barack Obama on January 10,2013. Native Americans in the Pinnacles region comprised the Chalon and Mutsun groups of the Ohlone people and these native people declined with the arrival of the Spanish in the 18th century, who brought novel diseases and changes to the natives way of life.
The last Chalon had died or departed from the area by 1810, from 1810 to 1865, when the first Anglo-American settlers arrived, the Pinnacles region was a wilderness without human use or habitation. The establishment of a Spanish mission at Soledad hastened the areas native depopulation through disease, archaeological surveys have found thirteen sites inhabited by Native Americans, twelve of which post-date the establishment of the missions. One site is believed to be about 2000 years old, by the 1880s the Pinnacles, known as the Palisades, were visited by picnickers from the surrounding communities who would explore the caves and camp. The first account of the Pinnacles region appeared in print in 1881, between 1889 and 1891, newspaper articles shifted from describing excursions to the Palisades to calling them the Pinnacles. Interest in the rose to the point that the Hollister Free Lance sent a reporter to the Pinnacles. Investors came from San Francisco to consider placing a hotel there. In 1894 a post office was established in Bear Valley, since there was at least one other Bear Valley in California, the post office was named Cook after Mrs.
Hains maiden name. In 1924 the post office was renamed Pinnacles, Schuyler Hain was a homesteader who arrived in the Pinnacles area in 1891 from Michigan, following his parents and eight siblings to Bear Valley. White, was a student at Stanford University, and White brought one of his professors to see the Pinnacles in 1893, dr. Gilbert was impressed by the scenery, and his comments inspired Hain to publicize the region. Hain led tours to Bear Valley and through the caves, advocating the preservation of the Pinnacles, Hains efforts resulted in a 1904 visit by Stanford president David Starr Jordan, who contacted Fresno Congressman James C. Jordan and Needham in turn influenced Gifford Pinchot to advocate the establishment of the Pinnacles Forest Reserve to President Theodore Roosevelt, Roosevelt proclaimed the establishment on July 8,1906
National Park Service
It was created on August 25,1916, by Congress through the National Park Service Organic Act and is an agency of the United States Department of the Interior. As of 2014, the NPS employs 21,651 employees who oversee 417 units, the National Park Service celebrated its centennial in 2016. National parks and national monuments in the United States were originally individually managed under the auspices of the Department of the Interior, the movement for an independent agency to oversee these federal lands was spearheaded by business magnate and conservationist Stephen Mather, as well as J. Horace McFarland. With the help of journalist Robert Sterling Yard, Mather ran a publicity campaign for the Department of the Interior and they wrote numerous articles that praised the scenic and historic qualities of the parks and their possibilities for educational and recreational benefits. This campaign resulted in the creation of a National Park Service, Mather became the first director of the newly formed NPS.
On March 3,1933, President Herbert Hoover signed the Reorganization Act of 1933, the act would allow the President to reorganize the executive branch of the United States government. It wasnt until that summer when the new President, Franklin D. Roosevelt, President Roosevelt agreed and issued two Executive orders to make it happen. In 1951, Conrad Wirth became director of the National Park Service, the demand for parks after the end of the World War II had left the parks overburdened with demands that could not be met. In 1952, with the support of President Dwight D. Eisenhower, he began Mission 66, New parks were added to preserve unique resources and existing park facilities were upgraded and expanded. In 1966, as the Park Service turned 50 years old, emphasis began to turn from just saving great and wonderful scenery, Director George Hartzog began the process with the creation of the National Lakeshores and National Recreation Areas. Since its inception in 1916, the National Park Service has managed each of the United States national parks, Yellowstone National Park was the first national park in the United States.
In 1872, there was no government to manage it. Yosemite National Park began as a park, the land for the park was donated by the federal government to the state of California in 1864 for perpetual conservation. Yosemite was returned to federal ownership, at first, each national park was managed independently, with varying degrees of success. In Yellowstone, the staff was replaced by the U. S. Army in 1886. Due to the irregularities in managing these national treasures, Stephen Mather petitioned the government to improve the situation. In response, Secretary of the Interior Franklin K. Lane challenged him to lobby for creating a new agency, Mather was successful with the ratification of the National Park Service Organic Act in 1916. Later, the agency was given authority over other protected areas, the National Park System includes all properties managed by the National Park Service
The golden eagle is one of the best-known birds of prey in the Northern Hemisphere. It is the most widely distributed species of eagle, like all eagles, it belongs to the family Accipitridae. These birds are brown, with lighter golden-brown plumage on their napes. Immature eagles of this typically have white on the tail. Golden eagles use their agility and speed combined with powerful feet and massive, Golden eagles maintain home ranges or territories that may be as large as 200 km2. They build large nests in high places to which they may return for several breeding years, most breeding activities take place in the spring, they are monogamous and may remain together for several years or possibly for life. Females lay up to four eggs, and incubate them for six weeks, one or two young survive to fledge in about three months. These juvenile golden eagles usually attain full independence in the fall, once widespread across the Holarctic, it has disappeared from many areas which are now more heavily populated by humans.
It is the largest and least populous of the five species of true accipitrid to occur as a species in both the Palearctic and the Nearctic. Due to its prowess, the golden eagle is regarded with great mystic reverence in some ancient. The golden eagle is one of the most extensively studied species of raptor in the world in some parts of its range, such as the Western United States and the Western Palearctic. The golden eagle is a large, dark brown raptor with broad wings, ranging from 66 to 102 cm in length. This species wingspan is the fifth largest amongst extant eagle species, in the largest race males and females weigh typically 4.05 kg and 6.35 kg. In the smallest subspecies, A. c. japonica, males weigh 2.5 kg, in the species overall, males may average around 3.6 kg and females around 5.1 kg. The maximum size of species is a matter of some debate. Large races are the heaviest representatives of the Aquila genus and this species is on average the seventh-heaviest living eagle species, the golden eagle ranks as the second heaviest breeding eagle in North America and Africa but the fourth heaviest in Asia.
For some time, the largest known mass authenticated for a female was the specimen from the nominate race which weighed around 6.7 kg. No comprehensive range of weights are known for the largest subspecies, captive birds have been measured up to a wingspan of 2.81 m and a mass of 12.1 kg, respectively
Junipers are coniferous plants in the genus Juniperus /dʒuːˈnɪpərəs/ of the cypress family Cupressaceae. The highest-known Juniper forest occurs at an altitude of 16,000 feet in south-eastern Tibet, Junipers vary in size and shape from tall trees, 20–40 m tall, to columnar or low spreading shrubs with long trailing branches. They are evergreen with needle-like and/or scale-like leaves and they can be either monoecious or dioecious. The female seed cones are very distinctive, with fleshy, fruit-like coalescing scales which fuse together to form a structure, 4–27 mm long. In some species these berries are red-brown or orange but in most they are blue, they are often aromatic, the seed maturation time varies between species from 6–18 months after pollination. The male cones are similar to those of other Cupressaceae, with 6–20 scales, in zones 7 through 10, junipers can bloom and release pollen several times each year. A few species of juniper bloom in autumn, while most species pollinate from early winter until late spring.
Many junipers have two types of leaves and some twigs of trees have needle-like leaves 5–25 mm long. When juvenile foliage occurs on mature plants, it is most often found on shaded shoots, leaves on fast-growing whip shoots are often intermediate between juvenile and adult. In some species, all the foliage is of the juvenile needle-like type, in some of these, the needles are jointed at the base, in others, the needles merge smoothly with the stem, not jointed. The needle-leaves of junipers are hard and sharp, making the juvenile foliage very prickly to handle and this can be a valuable identification feature in seedlings, as the otherwise very similar juvenile foliage of cypresses and other related genera is soft and not prickly. Duplicana feed on the bark around injuries or canker, the number of juniper species is in dispute, with two recent studies giving very different totals, Farjon accepting 52 species, and Adams accepting 67 species. The junipers are divided into sections, though which species belong to which sections is still far from clear.
The section Juniperus is a monophyletic group though. The adult leaves are needle-like, in whorls of three, and jointed at the base, Cones with 3 separate seeds, needles with one stomatal band. Juniperus communis - Common Juniper Juniperus communis subsp, alpina - Alpine Juniper Juniperus conferta - Shore Juniper Juniperus rigida - Temple Juniper or Needle Juniper Juniperus sect. Oxycedrus, Cones with 3 separate seeds, needles with two stomatal bands, Cones with 3 seeds fused together, needles with two stomatal bands. Juniperus drupacea - Syrian Juniper Juniperus sect, the adult leaves are mostly scale-like, similar to those of Cupressus species, in opposite pairs or whorls of three, and the juvenile needle-like leaves are not jointed at the base
Sequoia National Park
Sequoia National Park is a national park in the southern Sierra Nevada east of Visalia, California, in the United States. It was established on September 25,1890, the park is south of and contiguous with Kings Canyon National Park, the two are administered by the National Park Service together as the Sequoia and Kings Canyon National Parks. They were designated the UNESCO Sequoia-Kings Canyon Biosphere Reserve in 1976, the park is famous for its giant sequoia trees, including the General Sherman tree, the largest tree on Earth. The General Sherman tree grows in the Giant Forest, which five out of the ten largest trees in the world. The Giant Forest is connected by the Generals Highway to Kings Canyon National Parks General Grant Grove, the parks giant sequoia forests are part of 202,430 acres of old-growth forests shared by Sequoia and Kings Canyon National Parks. Indeed, the preserve a landscape that still resembles the southern Sierra Nevada before Euro-American settlement. Many park visitors enter Sequoia National Park through its entrance near the town of Three Rivers at Ash Mountain at 1,700 ft elevation.
The last California grizzly was killed in this park in 1922, the California Black Oak is a key transition species between the chaparral and higher elevation conifer forest. At higher elevations in the front country, between 5,500 and 9,000 feet in elevation, the landscape becomes montane forest-dominated coniferous belt, found here are Ponderosa, Jeffrey and lodgepole pine trees, as well as abundant white and red fir. Found here too are the giant sequoia trees, the most massive living single-stem trees on earth, between the trees and summer snowmelts sometimes fan out to form lush, though delicate, meadows. In this region, visitors often see deer, Douglas squirrels, and American black bears. There are plans to reintroduce the bighorn sheep to this park, the vast majority of the park is roadless wilderness, no road crosses the Sierra Nevada within the parks boundaries. 84 percent of Sequoia and Kings Canyon National Parks is designated wilderness and is only by foot or by horseback. Sequoias backcountry offers a vast expanse of high-alpine wonders, covering the highest-elevation region of the High Sierra, the backcountry includes Mount Whitney on the eastern border of the park, accessible from the Giant Forest via the High Sierra Trail.
On the floor of canyon, at least two days hike from the nearest road, is the Kern Canyon hot spring, a popular resting point for weary backpackers. From the floor of Kern Canyon, the trail ascends again over 8,000 ft to the summit of Mount Whitney, in the summertime, Native Americans would travel over the high mountain passes to trade with tribes to the East. By the time the first European settlers arrived in the area, smallpox had spread to the region. The first European settler to homestead in the area was Hale Tharp, Tharp allowed his cattle to graze the meadow, but at the same time had a respect for the grandeur of the forest and led early battles against logging in the area
The horned lark, called the shore lark in Europe, is a species of lark in the Alaudidae family found across the northern hemisphere. The specific alpestris is Latin and means of the mountains, from Alpes. The horned lark was classified in the genus Alauda. Recent genetic analysis has suggested that the species consists of six clades that in the future may warrant recognition as separate species, Found from west-central to east-central Mexico E. a. oaxacae –, Found in southern Mexico Colombian horned lark –, Originally described as a separate species. Found in Colombia Shore lark –, Originally described as a species in the genus Alauda. Found in northern Europe and northern Asia Steppe horned lark –, Originally described as a separate species. Found from south-eastern European Russia to western Mongolia and northern China Moroccan horned lark –, Originally described as a separate species. Found in Morocco Balkan horned lark –, This subspecies is called shore lark, Found in southern Balkans and Greece E. a.
kumerloevei – Roselaar,1995, Found in western and central Asia Minor Southern horned lark –, This subspecies is called shore lark. Originally described as a species in the genus Alauda. Found from eastern Turkey and the Caucasus to Iran Lebanon horned lark –, Originally described as a separate species. Found from Lebanon to Israel/Syria border Pamir horned lark –, This subspecies is called shore lark, Originally described as a separate species. Found from north-eastern Iran and Turkmenistan to north-western Pakistan E. a. argalea –, Found in extreme western China Przewalskis lark –, This subspecies is called shore lark. Originally described as a separate species, Found in western and west-central China E. a. przewalskii –, This subspecies is called shore lark. Found in northern Qinghai E. a. nigrifrons –, This subspecies is called shore lark, Originally described as a separate species. Found in north-eastern Qinghai Long-billed horned lark –, This subspecies is called shore lark, Originally described as a separate species.
Found in north-eastern Pakistan and western Himalayas E. a. elwesi –, Originally described as a separate species. Found on southern and eastern Tibetan Plateau E. a. khamensis –, except for the central feathers, the tail is mostly black, contrasting with the paler body, this contrast is especially noticeable when the bird is in flight. The summer male has horns, which give this species its American name
Mount Shasta is a potentially active volcano at the southern end of the Cascade Range in Siskiyou County, California. At an elevation of 14,179 feet, it is the second highest peak in the Cascades, Mount Shasta has an estimated volume of 85 cubic miles, which makes it the most voluminous stratovolcano in the Cascade Volcanic Arc. The mountain and its area are managed by the U. S. Forest Service as part of the Shasta–Trinity National Forest. Mount Shasta is connected to nearby Shastina, and they dominate the northern California landscape and it rises abruptly and stands nearly 10,000 ft above the surrounding terrain. On a clear day, snowy Mount Shasta can be seen from the floor of the Central Valley 140 miles to the south. The mountain has attracted the attention of poets, authors, if Shastina were a separate mountain, it would rank as the fourth-highest peak of the Cascade Range. Mount Shastas surface is free of deep glacial erosion except, paradoxically. This is the largest glacial valley on the volcano, although it not now have a glacier in it.
There are seven named glaciers on Mount Shasta, with the four largest radiating down from high on the summit cone to below 10,000 ft primarily on the north. The Whitney Glacier is the longest, and the Hotlum is the most voluminous glacier in the state of California. Three of the smaller named glaciers occupy cirques near and above 11,000 ft on the south and southeast sides, including the Watkins and Mud Creek glaciers. The oldest known human habitation in the dates to about 7,000 years ago. The historic eruption of Mount Shasta in 1786 may have been observed by Lapérouse, although perhaps first seen by Spanish explorers, the first reliably reported land sighting of Mount Shasta by a European or American was by Peter Skene Ogden in 1826. In 1827, the name Sasty or Sastise was given to nearby Mount McLoughlin by Ogden, the name was transferred to present-day Mount Shasta in 1841, partly as a result of work by the United States Exploring Expedition. Beginning in the 1820s, Mount Shasta was a prominent landmark along what became known as the Siskiyou Trail, the Siskiyou Trail was on the track of an ancient trade and travel route of Native American footpaths between Californias Central Valley and the Pacific Northwest.
The California Gold Rush brought the first Euro-American settlements into the area in the early 1850s, including at Yreka, the first recorded ascent of Mount Shasta occurred in 1854, after several earlier failed attempts. In 1856, the first women reached the summit, by the 1860s and 1870s, Mount Shasta was the subject of scientific and literary interest. A book by California pioneer and entrepreneur James Hutchings, titled Scenes of Wonder and Curiosity in California, the summit was achieved by John Muir, Josiah Whitney, Clarence King, and John Wesley Powell
Located at the foot of the Sierra Nevada in Californias Owens Valley between the towns of Lone Pine to the south and Independence to the north, it is approximately 230 miles north of Los Angeles. Long before the first incarcerees arrived in March 1942, Manzanar was home to Native Americans and miners formally established the town of Manzanar in 1910, but abandoned the town by 1929 after the City of Los Angeles purchased the water rights to virtually the entire area. As different as these groups were, their histories displayed a common thread of forced relocation, the primary focus is the Japanese American incarceration era, as specified in the legislation that created the Manzanar National Historic Site. The site interprets the former town of Manzanar, the days, the settlement by the Owens Valley Paiute. Let us review the main points of the debate, over 120,000 residents of the U. S. A. two thirds of whom were American citizens, were incarcerated under armed guard. There were no crimes committed, no trials, and no convictions, to detain American citizens in a site under armed guard surely constitutes a concentration camp.
But what were the used by the government officials who were involved in the process. Raymond Okamura provides us with a detailed list of terms, lets consider three such euphemisms, evacuation and non-aliens. Earthquake and flood victims are evacuated and relocated, the words refer to moving people in order to rescue and protect them from danger. The official government policy makers consistently used evacuation to refer to the removal of the Japanese Americans. These are euphemisms as the terms do not imply forced removal nor incarceration in enclosures patrolled by armed guards. Hirabayashi went on to describe the harm done by the use of such euphemisms, the harm in continuing to use the governments euphemisms is that it disguises or softens the reality which subsequently has been legally recognized as a grave error. The actions abrogated some fundamental principles underlying the Constitution, the document under which we govern ourselves. This erosion of fundamental rights has consequences for all citizens of our society, some have argued that the Nazi Germany camps during the Holocaust were concentration camps and to refer to the Japanese American camps likewise would be an affront to the Jews.
It is certainly true that the Japanese Americans did not suffer the fate of the Jews in the terrible concentration camps or death camps where Nazi Germany practiced a policy of genocide. Although the loss of life was minimal in Americas concentration camps and Walter Weglyns research concerning Nazi Germanys euphemisms for their concentration camps revealed such phrases as protective custody camps, reception centers, and transit camps. Ironically, two Nazi euphemisms were identical to our governments usage, assembly centers and relocation centers and it might be well to point out, that the Nazis were not operating under the U. S. Constitution. Comparisons usually neglect to point out that Hitler was operating under the rules of the Third Reich
Rodents are mammals of the order Rodentia, which are characterized by a single pair of continuously growing incisors in each of the upper and lower jaws. About 40% of all species are rodents, they are found in vast numbers on all continents except Antarctica. They are the most diversified mammalian order and live in a variety of terrestrial habitats, Species can be arboreal, fossorial, or semiaquatic. Well-known rodents include mice, squirrels, prairie dogs, beavers, guinea pigs and capybaras. Other animals such as rabbits and pikas, whose incisors grow continually, were included with them, but are now considered to be in a separate order. Nonetheless and Lagomorpha are sister groups, sharing a most recent common ancestor, most rodents are small animals with robust bodies, short limbs, and long tails. They use their incisors to gnaw food, excavate burrows. Most eat seeds or other plant material, but some have more varied diets and they tend to be social animals and many species live in societies with complex ways of communicating with each other.
Mating among rodents can vary from monogamy, to polygyny, to promiscuity, many have litters of underdeveloped, altricial young, while others are precocial at birth. The rodent fossil record back to the Paleocene on the supercontinent of Laurasia. Rodents greatly diversified in the Eocene, as spread across continents. Rodents reached both South America and Madagascar from Africa, and were the only placental mammals to reach. Rodents have been used as food, for clothing, as pets, some species, in particular the brown rat, the black rat, and the house mouse, are serious pests and spoiling food stored by humans, and spreading diseases. The distinguishing feature of the rodents is their pairs of continuously growing and these incisors have thick layers of enamel on the front and little enamel on the back. Because they do not stop growing, the animal must continue to wear them down so that they do not reach and pierce the skull. As the incisors grind against each other, the softer dentine on the rear of the teeth wears away, most species have up to 22 teeth with no canines or anterior premolars. A gap, or diastema, occurs between the incisors and the teeth in most species.
This allows rodents to suck in their cheeks or lips to shield their mouth and throat from wood shavings and other inedible material and guinea pigs have a high-fiber diet, their molars have no roots and grow continuously like their incisors