Rattlesnakes are a group of venomous snakes of the genera Crotalus and Sistrurus of the subfamily Crotalinae. The scientific name Crotalus is derived from the Greek κρόταλον, meaning "castanet"; the name Sistrurus is the Latinized form of the Greek word for "tail rattler" and shares its root with the ancient Egyptian musical instrument the sistrum, a type of rattle. The 36 known species of rattlesnakes have between 65 and 70 subspecies, all native to the Americas, ranging from southern Alberta and Saskatchewan and southern British Columbia in Canada to central Argentina. Rattlesnakes are predators that live in a wide array of habitats, hunting small animals such as birds and rodents. Rattlesnakes receive their name from the rattle located at the end of their tails, which makes a loud rattling noise when vibrated that deters predators or serves as a warning to passers-by. However, rattlesnakes fall prey to hawks, king snakes, a variety of other species. Rattlesnakes are preyed upon as neonates, while they are still weak and immature.
Large numbers of rattlesnakes are killed by humans. Rattlesnake populations in many areas are threatened by habitat destruction and extermination campaigns. Rattlesnakes are the leading contributor to snakebite injuries in North America. However, rattlesnakes bite unless provoked or threatened. Rattlesnakes are native to the Americas, living in diverse habitats from southwestern Canada to central Argentina; the large majority of species lives in Mexico. Four species may be found east of the Mississippi River, two in South America. In the United States, the states with the most types of rattlesnakes are Arizona. Rattlesnakes are found in every type of habitat capable of supporting terrestrial ectothermic vertebrates, but individual species can have specific habitat requirements, only able to live within certain plant associations in a narrow range of altitudes. Most species live near rocky areas. Rocks offer them cover from predators, plentiful prey, open basking areas. However, rattlesnakes can be found in a wide variety of other habitats including prairies, marshes and forests.
Rattlesnakes prefer a temperature range between 80 and 90°F, but can survive temperatures below freezing, recovering from brief exposure to temperatures as low as 4°F, surviving for several days in temperatures as low as 37°F. The most probable ancestral area of rattlesnakes is the Sierra Madre Occidental region in Mexico; the most probable vegetation or habitat of the ancestral area appears to be pine-oak forests. Feeding habits play an important ecological role by limiting the size of rodent populations, which prevents crop damage and stabilizes ecosystems. Rattlesnakes consume mice, small birds, other small animals, they lie in hunt for it in holes. The prey is killed with a venomous bite as opposed to constriction. If the bitten prey moves away before dying, the rattlesnake can follow it by its scent; when it locates the fallen prey, it checks for signs of life by prodding with its snout, flicking its tongue, using its sense of smell. Once the prey has become incapacitated, the rattlesnake locates its head by odors emitted from the mouth.
The prey is ingested head-first, which allows wings and limbs to fold at the joints in a manner which minimizes the girth of the meal. The gastric fluids of rattlesnakes are powerful, allowing for the digestion of flesh, as well as bone. Optimal digestion occurs when the snake maintains a body temperature between 80 and 85 °F. If the prey is small, the rattlesnake continues hunting. If it was an adequate meal, the snake finds a warm, safe location in which to coil up and rest until the prey is digested. Rattlesnakes are believed to require at least their own body weight in water annually to remain hydrated; the method in which they drink depends on the water source. In larger bodies of water, they submerge their heads and ingest water by opening and closing their jaws, which sucks in water. If drinking dew, or drinking from small puddles, they sip the liquid either by capillary action or by flattening and flooding their lower jaws. Newborn rattlesnakes are preyed upon by a variety of species, including ravens, roadrunners, opossums, coyotes, whipsnakes and racers.
Neonates of the smaller crotaline species are killed and eaten by small predatory birds such as jays and shrikes. Some species of ants in the genus Formica are known to prey upon neonates, Solenopsis invicta do, as well. On occasion, hungry adult rattlesnakes cannibalize neonates; the small proportion of rattlesnakes that make it to their second year are preyed upon by a variety of larger predators including coyotes, hawks, falcons, feral pigs, indigo snakes, kingsnakes. The common kingsnake, a constrictor, is immune to the venom of rattlesnakes and other vipers, rattlesnakes form part of its natural diet. Rattlesnakes sense kingsnakes' presence by their odor; when they realize a kingsnake is nearby, they begin enacting a set of defensive postures known as "body bridging". Unlike its normal erect and coiled defensive-striking posture, the rattlesnake keeps its head low to the ground in an attempt to prevent the kingsnake from gaining a hold on it; the rattlesnake jerks its body about, while bridging its back upwards, fo
Lizards are a widespread group of squamate reptiles, with over 6,000 species, ranging across all continents except Antarctica, as well as most oceanic island chains. The group is paraphyletic as it excludes Amphisbaenia. Lizards range in size from chameleons and geckos a few centimeters long to the 3 meter long Komodo dragon. Most lizards are quadrupedal. Others are legless, have long snake-like bodies; some such as the forest-dwelling Draco lizards are able to glide. They are territorial, the males fighting off other males and signalling with brightly colours, to attract mates and to intimidate rivals. Lizards are carnivorous being sit-and-wait predators. Lizards make use of a variety of antipredator adaptations, including venom, reflex bleeding, the ability to sacrifice and regrow their tails; the adult length of species within the suborder ranges from a few centimeters for chameleons such as Brookesia micra and geckos such as Sphaerodactylus ariasae to nearly 3 m in the case of the largest living varanid lizard, the Komodo dragon.
Most lizards are small animals. Lizards have four legs and external ears, though some are legless, while snakes lack these characteristics. Lizards and snakes share a movable quadrate bone, distinguishing them from the rhynchocephalians, which have more rigid diapsid skulls; some lizards such as chameleons have prehensile tails. As in other reptiles, the skin of lizards is covered in overlapping scales made of keratin; this reduces water loss through evaporation. This adaptation enables lizards to thrive in some of the driest deserts on earth; the skin is tough and leathery, is shed as the animal grows. Unlike snakes which shed the skin in a single piece, lizards slough their skin in several pieces; the scales may be modified into spines for display or protection, some species have bone osteoderms underneath the scales. The dentitions of lizards reflect their wide range of diets, including carnivorous, omnivorous, herbivorous and molluscivorous. Species have uniform teeth suited to their diet, but several species have variable teeth, such as cutting teeth in the front of the jaws and crushing teeth in the rear.
Most species are pleurodont, though chameleons are acrodont. The tongue can be extended outside the mouth, is long. In the beaded lizards and monitor lizards, the tongue is forked and used or to sense the environment, continually flicking out to sample the environment, back to transfer molecules to the vomeronasal organ responsible for chemosensation, analogous to but different from smell or taste. In geckos, the tongue is used to lick the eyes clean: they have no eyelids. Chameleons have long sticky tongues which can be extended to catch their insect prey. Three lineages, the geckos and chameleons, have modified the scales under their toes to form adhesive pads prominent in the first two groups; the pads are composed of millions of tiny setae which fit to the substrate to adhere using van der Waals forces. In addition, the toes of chameleons are divided into two opposed groups on each foot, enabling them to perch on branches as birds do. Aside from legless lizards, most lizards are quadrupedal and move using gaits with alternating movement of the right and left limbs with substantial body bending.
This body bending prevents significant respiration during movement, limiting their endurance, in a mechanism called Carrier's constraint. Several species can run bipedally, a few can prop themselves up on their hindlimbs and tail while stationary. Several small species such as those in the genus Draco can glide: some can attain a distance of 60 metres, losing 10 metres in height; some species, like chameleons, adhere to vertical surfaces including glass and ceilings. Some species, like the common basilisk, can run across water. Lizards make use of their senses of sight, touch and hearing like other vertebrates; the balance of these varies with the habitat of different species. Monitor lizards have acute vision and olfactory senses; some lizards make unusual use of their sense organs: chameleons can steer their eyes in different directions, sometimes providing non-overlapping fields of view, such as forwards and backwards at once. Lizards lack external ears, having instead a circular opening in which the tympanic membrane can be seen.
Many species rely on hearing for early warning of predators, flee at the slightest sound. As in snakes and many mammals, all lizards have a specialised olfactory system, the vomeronasal organ, used to detect pheromones. Monitor lizards transfer scent from the tip of their tongue to the organ; some lizards iguanas, have retained a photosensory organ on the top of their heads called the parietal eye, a basal feature present in the tuatara. This "eye" has only a rudimentary retina and lens and cannot form images, but is sensitive to changes in light and dark and can detect movemen
Junipers are coniferous plants in the genus Juniperus of the cypress family Cupressaceae. Depending on taxonomic viewpoint, between 50 and 67 species of junipers are distributed throughout the Northern Hemisphere, from the Arctic, south to tropical Africa, from Ziarat, east to eastern Tibet in the Old World, in the mountains of Central America; the highest-known juniper forest occurs at an altitude of 16,000 ft in southeastern Tibet and the northern Himalayas, creating one of the highest tree-lines on earth. 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. They can be either dioecious; the female seed cones are distinctive, with fleshy, fruit-like coalescing scales which fuse together to form a "berry"-like structure, 4–27 mm long, with one to 12 unwinged, hard-shelled seeds. In some species, these "berries" are red-brown or orange; the seed maturation time varies between species from 6 to 18 months after pollination.
The male cones are similar to those of other Cupressaceae, with six to 20 scales. In zones 7 through 10, junipers can release pollen several times each year. A few species of junipers bloom in autumn, while most species pollinate from early winter until late spring. Many junipers have two types of leaves; when juvenile foliage occurs on mature plants, it is most found on shaded shoots, with adult foliage in full sunlight. Leaves on fast-growing'whip' shoots are intermediate between juvenile and adult. In some species, all the foliage is with no scale leaves. 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 prickly to handle. This can be a valuable identification feature in seedlings, as the otherwise similar juvenile foliage of cypresses and other related genera is soft and not prickly. Juniper is the exclusive food plant of the larvae of some Lepidoptera species, including Bucculatrix inusitata and juniper carpet, is eaten by the larvae of other Lepidoptera species such as Chionodes electella, Chionodes viduella, juniper pug, pine beauty.
Junipers are gymnosperms, which means they have no flowers or fruits. Depending on the species, the seeds they produce take 1 -- 3 years; the impermeable coat of the seed keeps water from getting in and protects the embryo when being dispersed. It can result in a long dormancy, broken by physically damaging the seed coat. Dispersal can occur from being swallowed whole by mammals; the resistance of the seed coat allows it to be passed down through the digestive system and out without being destroyed along the way. These seeds last a long time, as they can be dispersed long distances over the course of a few years; the number of juniper species is in dispute, with two recent studies giving different totals, Farjon accepting 52 species, Adams accepting 67 species. The junipers are divided into several sections, though which species belong to which sections is still far from clear, with research still on-going; the section Juniperus is an obvious monophyletic group though. Juniperus sect. Juniperus: Needle-leaf junipers.
The adult leaves are needle-like, in whorls of three, jointed at the base. Juniperus sect. Juniperus subsect. Juniperus: Cones with 3 separate seeds. Juniperus communis – Common juniper Juniperus communis subsp. Alpina – Alpine juniper Juniperus conferta – Shore juniper Juniperus rigida – Temple juniper or needle juniper Juniperus sect. Juniperus subsect. Oxycedrus: Cones with 3 separate seeds. Juniperus brevifolia – Azores juniper Juniperus cedrus – Canary Islands juniper Juniperus deltoides – Eastern prickly juniper Juniperus formosana – Chinese prickly juniper Juniperus lutchuensis – Ryukyu juniper Juniperus navicularis – Portuguese prickly juniper Juniperus oxycedrus – Western prickly juniper or cade juniper Juniperus macrocarpa – Large-berry juniper Juniperus sect. Juniperus subsect. Caryocedrus: Cones with 3 seeds fused together. Juniperus drupacea – Syrian juniperJuniperus sect. Sabina: Scale-leaf junipers; the adult leaves are scale-like, similar to those of Cupressus species, in opposite pairs or whorls of three, the juvenile needle-like leaves are not jointed at the base.
Provisionally, all the other junipers are included here. Old World species Juniperus chinensis – Chinese juniper Juniperus convallium – Mekong juniper Juniperus excelsa – Greek juniper Juniperus excelsa polycarpos – Persian juniper Juniperus foetidissima – Stinking juniper Juniperus indica – Black juniper Juniperus komarovii – Komarov's juniper Juniperus phoenicea – Phoenicean juniper Juniperus pingii – Ping juniper Juniperus procera – East African juniper Juniperus procumbens – Ibuki juniper Juniperu
Continental climates have a significant annual variation in temperature. They tend to occur in the middle latitudes, where prevailing winds blow overland, temperatures are not moderated by bodies of water such as oceans or seas. Continental climates occur in the Northern Hemisphere, which has the kind of large landmasses on temperate latitudes required for this type of climate to develop. Most of northern and northeastern China and southeastern Europe and southeastern Canada, the central and upper eastern United States have this type of climate. In continental climates, precipitation tends to be moderate in amount, concentrated in the warmer months. Only a few areas—in the mountains of the Pacific Northwest of North America and in Iran, northern Iraq, adjacent Turkey, Afghanistan and Central Asia—show a winter maximum in precipitation. A portion of the annual precipitation falls as snowfall, snow remains on the ground for more than a month. Summers in continental climates can feature frequent hot temperatures.
The timing of intermediate spring-like or autumn-like temperatures in this zone vary depending on latitude and/or elevation. For example, spring may arrive as soon as early March in the southern parts of this zone or as late as May in the north. Annual precipitation in this zone is between 600 millimetres and 1,200 millimetres, most of it in the form of snow during winter, it has cold winters and warm summers. Most such areas fit Dwb. Dry summer continental climates exist in high altitude areas near Mediterranean climates. In some cases, the semi-arid climate classification of BSk can be considered to be continental as long as it has cold winters; the definition of this climate regarding temperature is as follows: the mean temperature of the coldest month must be below −3 °C and there must be at least four months whose mean temperatures are at or above 10 °C. Continental climates exist where cold air masses infiltrate during the winter and warm air masses form in summer under conditions of high sun and long days.
Places with continental climates are as a rule are either far from any moderating effect of oceans or are so situated that prevailing winds tend to head offshore. Such regions get quite warm in the summer, achieving temperatures characteristic of tropical climates but are colder than any other climates of similar latitude in the winter. In the Koppen climate system, these climates grade off toward temperate climates equator-ward where winters are less severe and semi-arid climates where precipitation becomes inadequate for tall-grass prairies. In Europe these climates may grade off into oceanic climates in which the influence of cool oceanic air masses is more marked toward the west; the subarctic climate, with cold and dry winters, but with at least one month above 10 °C, might be considered a sub-type of the continental climate. Canada: throughout much of Southern Canada from the Rocky Mountains to Atlantic Canada. Major cities: Whistler. Marie. While there are no major cities in South America that fall in to the classification of a continental climate, there are some remote places that have this climate.
Due to the influence of the Ocean, including cities such as Punta Arenas and Ushuaia, have an average winter temperature above 0°C, so are classified as an oceanic climate. Argentina: Moderately high elevations in the central Andes west of Mendoza, Argentina towards the Argentine Patagonia's internal areas (e.g.
The American robin is a migratory songbird of the true thrush genus and Turdidae, the wider thrush family. It is named after the European robin because of its reddish-orange breast, though the two species are not related, with the European robin belonging to the Old World flycatcher family; the American robin is distributed throughout North America, wintering from southern Canada to central Mexico and along the Pacific Coast. It is the state bird of Connecticut and Wisconsin. According to some sources, the American robin ranks behind only the red-winged blackbird as the most abundant extant land bird in North America, it has seven subspecies, but only T. m. confinis of Baja California Sur is distinctive, with pale gray-brown underparts. The American robin is active during the day and assembles in large flocks at night, its diet consists of invertebrates and berries. It is one of the earliest bird species to lay eggs, beginning to breed shortly after returning to its summer range from its winter range.
Its nest consists of long coarse grass, twigs and feathers, is smeared with mud and cushioned with grass or other soft materials. It is one of the first birds to sing at dawn, its song consists of several discrete units that are repeated; the adult robin is preyed upon by hawks and snakes. When feeding in flocks, it can be vigilant. Brown-headed cowbirds lay eggs in robin nests, but the robins reject the eggs; this species was first described in 1766 by Carl Linnaeus in the twelfth edition of his Systema Naturae as Turdus migratorius. The binomial name derives from two Latin words: turdus, "thrush", migratorius from migrare "to go"; the term robin for this species has been recorded since at least 1703. There are about 65 species of medium to large thrushes in the genus Turdus, characterized by rounded heads, longish pointed wings, melodious songs. A study of the mitochondrial cytochrome b gene indicates that the American robin is not part of the Central/South American clade of Turdus thrushes; this conflicts with a 2007 DNA study of 60 of 65 Turdus species which places the American robin's closest relative as the rufous-collared thrush of Central America.
Though having distinct plumage, the two species are similar in behavior. Beyond this, it lies in a small group of four species of otherwise Central American distribution, suggesting it spread northwards into North America. Seven subspecies of American robin are recognized; these subspecies are only weakly defined. T. m. migratorius, the nominate subspecies, breeds in the US and Canada, other than down the west coast, to the edge of the tundra from Alaska and northern Canada east to New England and south to Maryland, northwest Virginia, North Carolina. It winters in southern coastal Alaska, southern Canada, most of the US, the Bahamas and eastern Mexico. T. m. nigrideus breeds from coastal northern Quebec to Labrador and Newfoundland and winters from southern Newfoundland south through most of the eastern US states to southern Louisiana, southern Mississippi and northern Georgia. It is uniformly darker or blackish with a dark gray back; the underparts are more red than those of the nominate subspecies.
T. m. achrusterus breeds from southern Oklahoma east to Maryland and western Virginia and south to northern Florida and the Gulf states. It winters through much of the southern part of the breeding range, it is smaller than the nominate subspecies. The black feathers of the forehead and crown have pale gray tips; the underparts are paler than those of the nominate subspecies. T. m. caurinus breeds in southeast Alaska through coastal British Columbia to Washington and northwest Oregon. It winters from southwest British Columbia south to central and southern California and east to northern Idaho, it is slightly smaller than the nominate subspecies and dark-headed. The white on the tips of the outer two tail feathers is restricted. T. m. propinquus breeds from southeast British Columbia, southern Alberta, southwest Saskatchewan south to southern California and northern Baja California. It winters throughout much of south to Baja California, it is the same size as or larger than nominate T. m. migratorius, but paler and tinged more brownish-gray.
It has little white on the tip of the outermost tail feather. Some birds females, lack any red below. Males are darker and may show pale or whitish sides to the head. T. m. confinis breeds above 1,000 m in the highlands of southern Baja California. This form is distinctive, with pale gray-brown underparts, it is small, the palest subspecies, with uniform pale gray-brown on the head and upperparts. It lacks any white spots to the tips of the outer tail feathers, which have white edges, it is sometimes classed as a separate species, the San Lucas robin, but the American Ornithologists' Union regards it as only a subspecies, albeit in a different group from the other races. T. m. phillipsi is resident in Mexico south to central Oaxaca. It is smaller than propinquus but has a larger bill; the nominate subspecies of the American robin is 23 to 28 cm long
The wild turkey is an upland ground bird native to North America and is the heaviest member of the diverse Galliformes. It is the same species as the domestic turkey, derived from a southern Mexican subspecies of wild turkey. Although native to North America, the turkey got its name from the domesticated variety being imported to Britain in ships coming from the Levant via Spain; the British at the time therefore associated the wild turkey with the country Turkey and the name prevails. Adult wild turkeys have long reddish-yellow to grayish-green legs; the body feathers are blackish and dark, sometimes grey brown overall with a coppery sheen that becomes more complex in adult males. Adult males, called toms or gobblers, have a large, reddish head, red throat, red wattles on the throat and neck; the head has fleshy growths called caruncles. Juvenile males are called jakes; the adult male's tail fan feathers will be all the same length. When males are excited, a fleshy flap on the bill expands, this, the wattles and the bare skin of the head and neck all become engorged with blood concealing the eyes and bill.
The long fleshy object over a male's beak is called a snood. Each foot has three toes in front, with a shorter, rear-facing toe in back. Male turkeys have a long, fan-shaped tail and glossy bronze wings; as with many other species of the Galliformes, turkeys exhibit strong sexual dimorphism. The male is larger than the female, his feathers have areas of red, green, copper and gold iridescence; the preen gland is larger in male turkeys compared to female ones. In contrast to the majority of other birds, they are colonized by bacteria of unknown function. Females, called hens, have feathers that are duller overall, in shades of gray. Parasites can dull coloration of both sexes; the primary wing feathers have white bars. Turkeys have 5000 to 6000 feathers. Tail feathers are of the same length in different lengths in juveniles. Males have a "beard", a tuft of coarse hair growing from the center of the breast. Beards average 230 mm in length. In some populations, 10 to 20% of females have a beard shorter and thinner than that of the male.
The adult male weighs from 5 to 11 kg and measures 100–125 cm in length. The adult female is much smaller at 2.5–5.4 kg and is 76 to 95 cm long. Per two large studies, the average weight of adult males is 7.6 kg and the average weight of adult females is 4.26 kg. The wings are small, as is typical of the galliform order, the wingspan ranges from 1.25 to 1.44 m. The wing chord is only 20 to 21.4 cm. The bill is relatively small, as adults measure 2 to 3.2 cm in culmen length. The tarsus of the wild turkey sturdy, measuring from 9.7 to 19.1 cm. The tail is relatively long, ranging from 24.5 to 50.5 cm. The record-sized adult male wild turkey, according to the National Wild Turkey Federation, weighed 16.85 kg, with records of tom turkeys weighing over 13.8 kg uncommon but not rare. While it is rather lighter than the waterfowl, after the trumpeter swan, the turkey has the second heaviest maximum weight of any North American bird. Going on average mass, several other birds on the continent, including the American white pelican, the tundra swan and the rare California condor and whooping crane surpass the mean weight of turkeys.
On one hand, none of these other species are as sexually dimorphic in size as the wild turkey, but on the other, they are far less numerous and are not hunted unlike the turkey, thousands of which are weighed every year during hunting season. Wild turkeys prefer hardwood and mixed conifer-hardwood forests with scattered openings such as pastures, fields and seasonal marshes, they can adapt to any dense native plant community as long as coverage and openings are available. Open, mature forest with a variety of interspersion of tree species appear to be preferred. In the Northeast of North America, turkeys are most profuse in hardwood timber of oak-hickory and forests of red oak, beech and white ash. Best ranges for turkeys in the Coastal Plain and Piedmont sections have an interspersion of clearings and plantations with preferred habitat along principal rivers and in cypress and tupelo swamps. In Appalachian and Cumberland plateaus, birds occupy mixed forest of oaks and pines on southern and western slopes hickory with diverse understories.
Bald cypress and sweet gum swamps of s. Florida. Lykes Fisheating Creek area of s. Florida has up to 51% cypress, 12% hardwood hammocks, 17% glades of short grasses with isolated live oak. Original habitat here was longleaf pine with turkey oak and slash pine "flatwoods," now main
The Kaibab Plateau is located in northern Arizona in the United States. The plateau, part of the larger Colorado Plateau, is bordered on the south by the Grand Canyon and reaches an elevation of 9200 feet above sea level; the plateau is divided between Kaibab National Forest and the "North Rim" portion of Grand Canyon National Park. Tributary canyons of the Colorado River form the plateau's eastern and western boundaries, tiers of uplifted cliffs define the northern edges of the land form. Winter snowfall is heavy, this creates opportunities for backcountry Nordic skiing and snow camping; this broad feature is forested with aspen, spruce-fir, ponderosa pine, pinyon-juniper woodland, stands in sharp contrast to the arid lowlands encircling it. The cool forests of the plateau are home to the Kaibab squirrel, endemic to the region. Other fauna includes deer, turkey and bobcat; the Kaibab deer are important because of the changes in their population during the early 1900s. This particular fluctuation is a great example of population engineering and the effects humans can have on nature.
The Kaibab Plateau consists of 1,152 square miles which are above 6,000 feet. The highest point has an elevation of 9,200 feet; the plateau is bounded on the south by the Grand Canyon of the Colorado River, the elevation in this southern area of the plateau varies from 8,800 feet to less than 6,000 feet. The most extensive platform of the plateau is the Esplanade, called "Sand Rocks" by local cowboys; this area was formed as a result from weathering of the Hermit shale, which left a hard layer of Permian sandstone exposed. This red sandstone is one of the outstanding features of the plateau; the plateau's western boundary is the Kanab Creek Canyon which high perpendicular walls form a natural barrier to the movement of most animals. The northwestern boundary of the plateau is marked by a fault line north of the Snake Gulch, sixteen miles to the east of the Kanab Creek; the eastern boundary is marked by the so-called Houserock Valley, a marble platform caused by a monoclinical fold, which strata dips down 2,000 to 3,000 feet.
The climate of the Kaibab Plateau consists of rain and thunderstorms in late summer, heavy at times, in winter, drier weather in early summer. There was an average annual precipitation of 26.57 inches for the period 1925 to 1936. During winter, snow is heavy and accumulates at a depth of eight to ten feet. June is the driest month of the year, early July. Storms occur several times each week until early September; the highest portions of the plateau are touched by snow, snowstorms occur in May and September. At the beginning of the 20th century, the Kaibab Plateau was witness to an interesting experiment in what some might call population engineering; the plateau's pre-1905 population of mule deer was estimated to be around 4,000. This number was never confirmed by any kind of count or survey, has become an accepted number because no other estimate is available; the average carrying capacity of the land was unknown, in part because this concept was not used by naturalists at the time. Years Aldo Leopold famously estimated that the capacity had been about 30,000 deer.
The idea in 1906 was to protect and expand the herd, so on November 28, President Theodore Roosevelt created the Grand Canyon National Game Preserve. Overgrazing by herds of sheep and horses had taken place on the plateau since the 1880s. During that time, many predators were killed by ranchers and bounty hunters. By the time Roosevelt established the game preserve, ranchers had moved most domestic livestock elsewhere; the primary change brought by the creation of the game preserve was to ban deer hunting. Government efforts, led by the United States Forest Service, began to protect the deer's numbers by killing off their natural predators once again; the deer population experienced a great increase in numbers during the early decades of the 20th century. One estimate put the population as high as 100,000 deer inhabiting the range in 1924. Again, there was no systematic survey to support this estimate, which may have been exaggerated to twice the actual number. Shortly after that time, the deer population did begin to decline from over-browsing.
By the mid-1920s, many deer were starving to death. After a heated legal dispute between the federal government and the state of Arizona, hunting was once more permitted, to reduce the deer's numbers. Hunters were able to kill only a small fraction of the starving deer; the range itself was damaged, its carrying capacity was reduced. Once ecologists began to study the area and reflect on the changes that had occurred there, they began to use the Kaibab deer as a simple lesson about how the removal of the deer's natural predators, done in the interest of preserving the deer population, had allowed the deer to over-reproduce, overwhelm the plateau's resources; some ecologists suggested that the situation highlighted the importance of keeping a population in balance with its environment's carrying capacity. The more meaningful lesson of the Kaibab suggests that human efforts to protect wildlife and preserve wild areas must be balanced with ecological complexity and social priorities that are difficult to predict.
Changes take place, sometimes but their effects linger for decades. Today, the Arizona Game Commission manages the area, controlling the numbers of deer as well as predators, issues hunting permits to keep the deer in balan