The Holocene is the current geological epoch. It began 11,650 cal years before present, after the last glacial period, which concluded with the Holocene glacial retreat; the Holocene and the preceding Pleistocene together form the Quaternary period. The Holocene has been identified with the current warm period, known as MIS 1, it is considered by some to be an interglacial period within the Pleistocene Epoch. The Holocene has seen the growth and impacts of the human species worldwide, including all its written history, development of major civilizations, overall significant transition toward urban living in the present. Human impacts on modern-era Earth and its ecosystems may be considered of global significance for future evolution of living species, including synchronous lithospheric evidence, or more hydrospheric and atmospheric evidence of human impacts. In July 2018, the International Union of Geological Sciences split the Holocene epoch into three distinct subsections, Greenlandian and Meghalayan, as proposed by International Commission on Stratigraphy.
The boundary stratotype of Meghalayan is a speleothem in Mawmluh cave in India, the global auxiliary stratotype is an ice core from Mount Logan in Canada. The name Holocene comes from the Ancient Greek words ὅλος and καινός, meaning "entirely recent", it is accepted by the International Commission on Stratigraphy that the Holocene started 11,650 cal years BP. The Subcommission on Quaternary Stratigraphy quotes Gibbard and van Kolfschoten in Gradstein Ogg and Smith in stating the term'Recent' as an alternative to Holocene is invalid and should not be used and observe that the term Flandrian, derived from marine transgression sediments on the Flanders coast of Belgium has been used as a synonym for Holocene by authors who consider the last 10,000 years should have the same stage-status as previous interglacial events and thus be included in the Pleistocene; the International Commission on Stratigraphy, considers the Holocene an epoch following the Pleistocene and the last glacial period. Local names for the last glacial period include the Wisconsinan in North America, the Weichselian in Europe, the Devensian in Britain, the Llanquihue in Chile and the Otiran in New Zealand.
The Holocene can be subdivided into five time intervals, or chronozones, based on climatic fluctuations: Preboreal, Atlantic and Subatlantic. Note: "ka" means "kilo-annum" Before Present, i.e. 1,000 years before 1950 The Blytt–Sernander classification of climatic periods defined by plant remains in peat mosses, is being explored. Geologists working in different regions are studying sea levels, peat bogs and ice core samples by a variety of methods, with a view toward further verifying and refining the Blytt–Sernander sequence, they find a general correspondence across Eurasia and North America, though the method was once thought to be of no interest. The scheme was defined for Northern Europe, but the climate changes were claimed to occur more widely; the periods of the scheme include a few of the final pre-Holocene oscillations of the last glacial period and classify climates of more recent prehistory. Paleontologists have not defined any faunal stages for the Holocene. If subdivision is necessary, periods of human technological development, such as the Mesolithic and Bronze Age, are used.
However, the time periods referenced by these terms vary with the emergence of those technologies in different parts of the world. Climatically, the Holocene may be divided evenly into the Neoglacial periods. According to some scholars, a third division, the Anthropocene, has now begun; the International Commission on Stratigraphy Subcommission on Quaternary Stratigraphy’s working group on the'Anthropocene' note this term is used to denote the present time interval in which many geologically significant conditions and processes have been profoundly altered by human activities. The'Anthropocene' is not a formally defined geological unit. Continental motions due to plate tectonics are less than a kilometre over a span of only 10,000 years. However, ice melt caused world sea levels to rise about 35 m in the early part of the Holocene. In addition, many areas above about 40 degrees north latitude had been depressed by the weight of the Pleistocene glaciers and rose as much as 180 m due to post-glacial rebound over the late Pleistocene and Holocene, are still rising today.
The sea level rise and temporary land depression allowed temporary marine incursions into areas that are now far from the sea. Holocene marine fossils are known, from Vermont and Michigan. Other than higher-latitude temporary marine incursions associated with glacial depression, Holocene fossils are found in lakebed and cave deposits. Holocene marine deposits along low-latitude coastlines are rare because the rise in sea levels during the period exceeds any tectonic uplift of non-glacial origin. Post-glacial rebound in the Scandinavia region resulted in the formation of the Baltic Sea; the region continues to rise, still causing weak earthquakes across Northern Europe. The equivalent event in North America was the rebound of Hudson Bay, as it shrank from its larger, immediate post-glacial Tyrrell Sea phase, to near its present boundaries. Climate has been stable over the Holocene. Ice core
The biological family Canidae is a lineage of carnivorans that includes domestic dogs, coyotes, jackals and many other extant and extinct dog-like mammals. A member of this family is called a canid; the cat-like feliformia and dog-like caniforms emerged within the Carnivoramorpha 43 million years before present. The caniforms included the fox-like genus Leptocyon whose various species existed from 34 million years ago before branching 11.9 Mya into Vulpi and Canidae. Canids are found on all continents except Antarctica, having arrived independently or accompanied human beings over extended periods of time. Canids vary in size from the 2-m-long gray wolf to the 24-cm-long fennec fox; the body forms of canids are similar having long muzzles, upright ears, teeth adapted for cracking bones and slicing flesh, long legs, bushy tails. They are social animals, living together in family units or small groups and behaving co-operatively. Only the dominant pair in a group breeds, a litter of young is reared annually in an underground den.
Canids communicate by scent vocalizations. They are intelligent. One canid, the domestic dog, long ago entered into a partnership with humans and today remains one of the most kept domestic animals. In the history of the carnivores, the family Canidae is represented by the two extinct subfamilies designated as Hesperocyoninae and Borophaginae, the extant subfamily Caninae; this subfamily includes their most recent fossil relatives. All living canids as a group form a dental monophyletic relationship with the extinct borophagines, with both groups having a bicuspid on the lower carnassial talonid, which gives this tooth an additional ability in mastication. This, together with the development of a distinct entoconid cusp and the broadening of the talonid of the first lower molar, the corresponding enlargement of the talon of the upper first molar and reduction of its parastyle distinguish these late Cenozoic canids and are the essential differences that identify their clade. Within the Canidae, the results of allozyme and chromosome analyses have suggested several phylogenetic divisions: The wolf-like canids include the domestic dog, gray wolf, red wolf, eastern wolf, Eurasian golden jackal, African golden wolf, Ethiopian wolf, black-backed jackal, side-striped jackal and African wild dog.
The fox-like canids include the kit fox, red fox, Cape fox, Arctic fox, fennec fox. The South American canids include the bush dog, hoary fox, crab-eating fox, maned wolf. Various monotypic taxa include the bat-eared fox, gray fox, raccoon dog. DNA analysis shows; the wolf-like canids and the South American canids together form the tribe Canini. Molecular data imply a North American origin of living Canidae some 10 Mya and an African origin of wolf-like canines, with the jackals being the most basal of this group; the South American clade is rooted by the maned wolf and bush dog, the fox-like canids by the fennec fox and Blanford's fox. The gray fox and island fox are basal to the other clades; the cladogram below is based on the phylogeny of Lindblad-Toh et al. modified to incorporate recent findings on Canis, Vulpes and Dusicyon species. The Canidae today include a diverse group of some 34 species ranging in size from the maned wolf with its long limbs to the short-legged bush dog. Modern canids inhabit forests, tundra and deserts throughout tropical and temperate parts of the world.
The evolutionary relationships between the species have been studied in the past using morphological approaches, but more molecular studies have enabled the investigation of phylogenetic relationships. In some species, genetic divergence has been suppressed by the high level of gene flow between different populations and where the species have hybridized, large hybrid zones exist. Carnivorans evolved from miacoids about 55 Mya during the late Paleocene; some 5 million years the carnivorans split into two main divisions: caniforms and feliforms. By 40 Mya, the first member of the dog family proper had arisen. Called Prohesperocyon wilsoni, its fossilized remains have been found in what is now the southwestern part of Texas; the chief features which identify it as a canid include the loss of the upper third molar, the structure of the middle ear which has an enlarged bulla. Prohesperocyon had longer limbs than its predecessors, had parallel and touching toes which differ markedly from the splayed arrangements of the digits in bears.
The canid family soon subdivided into three subfamilies, each of which diverged during the Eocene: Hesperocyoninae and Caninae. The Caninae are the only surviving subfamily and all present-day canids, including wolves, coyotes and domestic dogs, belong to it. Members of each subfamily showed an increase in body mass with time and some ex
The Mackenzie River is the longest river system in Canada, has the second largest drainage basin of any North American river after the Mississippi River. The Mackenzie River flows through a vast, thinly populated region of forest and tundra within the Canadian Northwest Territories, although its many tributaries reach into four other Canadian provinces and territories; the river's main stem is 1,738 kilometres long, flowing north-northwest from Great Slave Lake into the Arctic Ocean, where it forms a large delta at its mouth. Its extensive watershed drains about 20 percent of Canada, it is the largest river flowing into the Arctic from North America, including its tributaries has a total length of 4,241 kilometres, making it the thirteenth longest river system in the world. Through its many tributaries, the Mackenzie River basin covers portions of five Canadian provinces and territories – British Columbia, Saskatchewan and Northwest Territories. Thutade Lake, in the Northern Interior of BC, is the ultimate source of the Mackenzie River via the Finlay–Peace River system, which stretches 1,923 kilometres through BC and Alberta.
The 1,231-kilometre Athabasca River originates further south, in Jasper National Park in southwest Alberta. Together, the Peace and Athabasca rivers drain a significant portion of the eastern slope of the Rocky Mountains and the central Alberta prairie; the Peace contributes the majority of the water, about 66 km3 per year, the Athabasca contributes 25 km3. The Peace and Athabasca meet at the Peace-Athabasca Delta, a vast inland delta at the western end of Lake Athabasca, which takes runoff from the northern third of Saskatchewan; the Slave River is formed by the confluence of the two rivers and flows 415 kilometres due north into Great Slave Lake, at Fort Resolution, Northwest Territories. The Slave is by far the largest river flowing into the lake, with an annual flow of 108 km3, it contributes about 77% of the overall inflow, forms a large delta where it enters the lake. Other rivers entering Great Slave Lake area the Taltson and Hay Rivers, the latter of which extends into Alberta and BC.
The Mackenzie River issues from the western end of Great Slave Lake about 150 km south-west of Yellowknife. The channel is several kilometres wide but narrows to about 800 m at Fort Providence, an important ferry crossing in the summer, used as an ice bridge in the winter for traffic along the Yellowknife Highway. In 2012 the Deh Cho Bridge was completed at a point about 10 km upstream, providing a safer permanent crossing, it is the only bridge across the main stem of the Mackenzie. West of Fort Providence the Mackenzie widens resembling a shallow, swampy lake more than a river. After heading west for about 100 km the Mackenzie narrows and turns northwest through a long stretch of fast water and rapids, past the village of Jean Marie River. At Fort Simpson it is joined by its biggest direct tributary, from the west; the Liard drains a large area in the southern Yukon and northern BC and carries a large amount of sediment during the summer melt – which does not mix with the clear water in the Mackenzie for 500 km downstream, with the resulting phenomenon of a clear current on the east bank and muddy water on the west bank.
The river continues west-northwest until its confluence with the North Nahanni River, where it turns north towards the Arctic. It flows through open taiga with its wide valley bounded, on the west, by the Mackenzie Mountains and to the east by low hills of the Canadian Shield; this uninhabited area is called the Mackenzie Lowlands. A number of major tributaries join from the west, including the Root River, Redstone River and Keele River. Below the Keele River, the Mackenzie River flows north along the western base of the Franklin Mountains before turning northwest, receives the Great Bear River, the outflow of Great Bear Lake at Tulita; the Mackenzie widens to about 6 to 7 km at Norman Wells, a major center of oil production. There is a narrows at the Mountain River confluence called the Sans Sault Rapids, where the Mackenzie falls about 6 metres. Below the Mountain River the Mackenzie flows due north until reaching The Ramparts, a limestone gorge 500 metres wide and up to 45 metres deep. Below The Ramparts is the village of Fort Good Hope, where the Mackenzie turns northwest again, soon crossing the Arctic Circle.
The Mackenzie here flows lower in elevation than the surrounding tundra, as a braided river between low bluffs about 3 to 5 km apart. It receives the Arctic Red River from the southwest at Tsiigehtchic, where traffic on the Dempster Highway crosses via ferry/ice bridge. About 30 kilometres northwest of Tsiigehtchic is Point Separation, the head of the vast Mackenzie River Delta, whose branching channels and wetlands spread across more than 12,000 square kilometres of the coastal plain; the delta is nearly 210 km from north to south, ranges in width from 50 to 80 km. It is the second biggest Arctic delta in the world, after the Lena River delta in Russia. Most land in the Mackenzie delta consists with great depths to bedrock. A characteristic feature of the delta is its numerous pingos, or hill
A chordate is an animal constituting the phylum Chordata. During some period of their life cycle, chordates possess a notochord, a dorsal nerve cord, pharyngeal slits, an endostyle, a post-anal tail: these five anatomical features define this phylum. Chordates are bilaterally symmetric; the Chordata and Ambulacraria together form the superphylum Deuterostomia. Chordates are divided into three subphyla: Vertebrata. There are extinct taxa such as the Vetulicolia. Hemichordata has been presented as a fourth chordate subphylum, but now is treated as a separate phylum: hemichordates and Echinodermata form the Ambulacraria, the sister phylum of the Chordates. Of the more than 65,000 living species of chordates, about half are bony fish that are members of the superclass Osteichthyes. Chordate fossils have been found from as early as the Cambrian explosion, 541 million years ago. Cladistically, vertebrates - chordates with the notochord replaced by a vertebral column during development - are considered to be a subgroup of the clade Craniata, which consists of chordates with a skull.
The Craniata and Tunicata compose the clade Olfactores. Chordates form a phylum of animals that are defined by having at some stage in their lives all of the following anatomical features: A notochord, a stiff rod of cartilage that extends along the inside of the body. Among the vertebrate sub-group of chordates the notochord develops into the spine, in wholly aquatic species this helps the animal to swim by flexing its tail. A dorsal neural tube. In fish and other vertebrates, this develops into the spinal cord, the main communications trunk of the nervous system. Pharyngeal slits; the pharynx is the part of the throat behind the mouth. In fish, the slits are modified to form gills, but in some other chordates they are part of a filter-feeding system that extracts particles of food from the water in which the animals live. Post-anal tail. A muscular tail that extends backwards behind the anus. An endostyle; this is a groove in the ventral wall of the pharynx. In filter-feeding species it produces mucus to gather food particles, which helps in transporting food to the esophagus.
It stores iodine, may be a precursor of the vertebrate thyroid gland. There are soft constraints that separate chordates from certain other biological lineages, but are not part of the formal definition: All chordates are deuterostomes; this means. All chordates are based on a bilateral body plan. All chordates are coelomates, have a fluid filled body cavity called a coelom with a complete lining called peritoneum derived from mesoderm; the following schema is from the third edition of Vertebrate Palaeontology. The invertebrate chordate classes are from Fishes of the World. While it is structured so as to reflect evolutionary relationships, it retains the traditional ranks used in Linnaean taxonomy. Phylum Chordata †Vetulicolia? Subphylum Cephalochordata – Class Leptocardii Clade Olfactores Subphylum Tunicata – Class Ascidiacea Class Thaliacea Class Appendicularia Class Sorberacea Subphylum Vertebrata Infraphylum incertae sedis Cyclostomata Superclass'Agnatha' paraphyletic Class Myxini Class Petromyzontida or Hyperoartia Class †Conodonta Class †Myllokunmingiida Class †Pteraspidomorphi Class †Thelodonti Class †Anaspida Class †Cephalaspidomorphi Infraphylum Gnathostomata Class †Placodermi Class Chondrichthyes Class †Acanthodii Superclass Osteichthyes Class Actinopterygii Class Sarcopterygii Superclass Tetrapoda Class Amphibia Class Sauropsida Class Synapsida Craniates, one of the three subdivisions of chordates, all have distinct skulls.
They include the hagfish. Michael J. Benton commented that "craniates are characterized by their heads, just as chordates, or all deuterostomes, are by their tails". Most craniates are vertebrates; these consist of a series of bony or cartilaginous cylindrical vertebrae with neural arches that protect the spinal cord, with projections that link the vertebrae. However hagfish have incomplete braincases and no vertebrae, are therefore not regarded as vertebrates, but as members of the craniates, the group from which vertebrates are thought to have evolved; however the cladistic exclusion of hagfish from the vertebrates is controversial, as they ma
The Plains bison is one of two subspecies/ecotypes of the American bison, the other being the wood bison. A natural population of Plains bison survives in Yellowstone National Park and multiple smaller reintroduced herds of bison in many places in Canada and the United States. At one time, at least 25 million American bison were spread across the United States and Canada. However, by the late 1880s, the total number of bison in the United States had been reduced to fewer than 600 individuals. Most of these were collected onto various private ranches, the last known free-roaming population of bison consisted of less than 30 in the area which became Yellowstone National Park. Though it was the official policy of the United States government to minimize or eliminate the bison, most farmers and ranchers considered bison to be a pest or nuisance, some people were concerned about the demise of this North American icon, so individual landowners took steps to protect a few; some people saved bison with the express purpose of ranching or hunting them, but some groups such as the American Bison Society were formed with the idea of saving the species and reintroducing them to at least part of their previous natural range.
Plains bison have since been reintroduced into a number of locations around North America. Five main foundation herds of American bison supplied; the northernmost introduction occurred in 1928 when the Alaska Game Commission brought bison to the area of present-day Delta Junction. Bison taken from this transplant were introduced to other Alaska locations, including Farewell and Chitina; the Delta Junction herd prospered the most, with a population of several hundred throughout the late 20th century. This herd is popular with hunters interested in hundreds of pounds of high-quality meat, but has been a problem for farming operations in the area. Though American bison prefer grasslands and plains habitats, they are quite adaptable and live in conditions ranging from desert, as in the case of the Henry Mountains bison herd, to forested areas, such as those of the Yellowstone Park bison herd. Over 500,000 bison are spread over the United States and Canada. However, most of these are on private ranches, some of them have small amounts of hybridized cattle genes.
Significant public bison herds that do not appear to have hybridized domestic cattle genes are the Yellowstone Park, the Henry Mountains, the Wind Cave, the Wood Buffalo National Park bison herds and subsidiary herds descended from it in Canada. Park officials transferred Plains bison from Fort Niobrara National Wildlife Refuge to Theodore Roosevelt National Park's South Unit in 1956 and its North Unit in 1962 for population increase. In 1969, Plains bison from Elk Island National Park were released into Prince Albert National Park in Saskatchewan, creating the Sturgeon River bison herd. At a population around 300 animals, they form a free herd able to wander; the bison are spread throughout Prince Albert National Park's southwestern corner, as well as some crown and private land in the area. In 2006, Plains bison from Elk Island National Park in Alberta were released into Saskatchewan's Grasslands National Park; this marks the first time Plains bison have wandered the shortgrass prairies of Canada since their near-extinction at the turn of the 20th century.
According to the national agency Parks Canada, the entire breeding population of these wild and "semiwild" bison are the descendants of just eight individuals that survived the period of near-extinction, due to overhunting and tuberculosis infecting the herd that the government belatedly attempted to conserve. A herd of about 650 of these animals lives in, can be seen at, the Wichita Mountains Wildlife Refuge near Lawton, Oklahoma; the herd was started in 1907 with stock from the New York Zoological Park, now known as the Bronx Zoo and located in the Bronx Park. Fifteen animals were shipped to Oklahoma, where bison had become extinct due to excessive hunting and overharvesting by non-native commercial buffalo hunters from 1874 to 1878; some of these specimens have been released in other areas of the United States, such as Paynes Prairie in Florida. Only one Southern Plains bison herd was established in Texas. A remnant of the last of this relict herd had been saved in 1876. "Molly" Goodnight had encouraged her rancher husband, Charles Goodnight, to save some of the last bison which were taking refuge in the Texas Panhandle.
By saving these few Plains bison, she was able to establish a buffalo herd near the Palo Duro Canyon. This herd peaked at 250 in 1933. Bison of this herd were introduced into the Yellowstone National Park in 1902 and into the larger zoos and ranches throughout the nation. A herd of around 80 of these animals lives in the Caprock Canyons State Park near Quitaque, located about 50 miles northeast of Plainview, Texas. In 2013, bison were reintroduced to Fort Belknap Indian Reservation from Yellowstone National Park. A herd of Plains bison were reintroduced to Banff National Park in Alberta in early 2017; the bison are to be kept under observation in an enclosed pasture of the park until the summer of 2018, according to Parks Canada. Besides using the meat and organs for food, Plains tribes have traditionally created a wide variety of tools and items from bison; these include arrow points, beads, berry pounders, hide scrapers, needles from bones, spoons from the horns, bow strings and thread from the sinew, waterproof containers from the bladder, paint brushes from the tail and bones with intact marro
Animals are multicellular eukaryotic organisms that form the biological kingdom Animalia. With few exceptions, animals consume organic material, breathe oxygen, are able to move, can reproduce sexually, grow from a hollow sphere of cells, the blastula, during embryonic development. Over 1.5 million living animal species have been described—of which around 1 million are insects—but it has been estimated there are over 7 million animal species in total. Animals range in length from 8.5 millionths of a metre to 33.6 metres and have complex interactions with each other and their environments, forming intricate food webs. The category includes humans, but in colloquial use the term animal refers only to non-human animals; the study of non-human animals is known as zoology. Most living animal species are in the Bilateria, a clade whose members have a bilaterally symmetric body plan; the Bilateria include the protostomes—in which many groups of invertebrates are found, such as nematodes and molluscs—and the deuterostomes, containing the echinoderms and chordates.
Life forms interpreted. Many modern animal phyla became established in the fossil record as marine species during the Cambrian explosion which began around 542 million years ago. 6,331 groups of genes common to all living animals have been identified. Aristotle divided animals into those with those without. Carl Linnaeus created the first hierarchical biological classification for animals in 1758 with his Systema Naturae, which Jean-Baptiste Lamarck expanded into 14 phyla by 1809. In 1874, Ernst Haeckel divided the animal kingdom into the multicellular Metazoa and the Protozoa, single-celled organisms no longer considered animals. In modern times, the biological classification of animals relies on advanced techniques, such as molecular phylogenetics, which are effective at demonstrating the evolutionary relationships between animal taxa. Humans make use of many other animal species for food, including meat and eggs. Dogs have been used in hunting, while many aquatic animals are hunted for sport.
Non-human animals have appeared in art from the earliest times and are featured in mythology and religion. The word "animal" comes from the Latin animalis, having soul or living being; the biological definition includes all members of the kingdom Animalia. In colloquial usage, as a consequence of anthropocentrism, the term animal is sometimes used nonscientifically to refer only to non-human animals. Animals have several characteristics. Animals are eukaryotic and multicellular, unlike bacteria, which are prokaryotic, unlike protists, which are eukaryotic but unicellular. Unlike plants and algae, which produce their own nutrients animals are heterotrophic, feeding on organic material and digesting it internally. With few exceptions, animals breathe oxygen and respire aerobically. All animals are motile during at least part of their life cycle, but some animals, such as sponges, corals and barnacles become sessile; the blastula is a stage in embryonic development, unique to most animals, allowing cells to be differentiated into specialised tissues and organs.
All animals are composed of cells, surrounded by a characteristic extracellular matrix composed of collagen and elastic glycoproteins. During development, the animal extracellular matrix forms a flexible framework upon which cells can move about and be reorganised, making the formation of complex structures possible; this may be calcified, forming structures such as shells and spicules. In contrast, the cells of other multicellular organisms are held in place by cell walls, so develop by progressive growth. Animal cells uniquely possess the cell junctions called tight junctions, gap junctions, desmosomes. With few exceptions—in particular, the sponges and placozoans—animal bodies are differentiated into tissues; these include muscles, which enable locomotion, nerve tissues, which transmit signals and coordinate the body. There is an internal digestive chamber with either one opening or two openings. Nearly all animals make use of some form of sexual reproduction, they produce haploid gametes by meiosis.
These fuse to form zygotes, which develop via mitosis into a hollow sphere, called a blastula. In sponges, blastula larvae swim to a new location, attach to the seabed, develop into a new sponge. In most other groups, the blastula undergoes more complicated rearrangement, it first invaginates to form a gastrula with a digestive chamber and two separate germ layers, an external ectoderm and an internal endoderm. In most cases, a third germ layer, the mesoderm develops between them; these germ layers differentiate to form tissues and organs. Repeated instances of mating with a close relative during sexual reproduction leads to inbreeding depression within a population due to the increased prevalence of harmful recessive traits. Animals have evolved numerous mechanisms for avoiding close inbreeding. In some species, such as the splendid fairywren, females benefit by mating with multiple males, thus producing more offspring of higher genetic quality; some animals are capable of asexual reproduction, which results
The coyote, Canis latrans, is a canine native to North America. It is smaller than its close relative, the gray wolf, smaller than the related eastern wolf and red wolf, it fills much of the same ecological niche as the golden jackal does in Eurasia, though it is larger and more predatory, is sometimes called the American jackal by zoologists. The coyote is listed as least concern by the International Union for Conservation of Nature due to its wide distribution and abundance throughout North America, southwards through Mexico, into Central America; the species is able to adapt to and expand into environments modified by humans. It is enlarging its range, with coyotes moving into urban areas in the Eastern U. S. and was sighted in eastern Panama for the first time in 2013. As of 2005, 19 coyote subspecies are recognized; the average male weighs the average female 7 to 18 kg. Their fur color is predominantly light gray and red or fulvous interspersed with black and white, though it varies somewhat with geography.
It is flexible in social organization, living either in a family unit or in loosely knit packs of unrelated individuals. It has a varied diet consisting of animal meat, including deer, hares, birds, amphibians and invertebrates, though it may eat fruits and vegetables on occasion, its characteristic vocalization is a howl made by solitary individuals. Humans are the coyote's greatest threat, followed by gray wolves. In spite of this, coyotes sometimes mate with gray, eastern, or red wolves, producing "coywolf" hybrids. In the northeastern United States and eastern Canada, the eastern coyote is the result of various historical and recent matings with various types of wolves. Genetic studies show that most North American wolves contain some level of coyote DNA; the coyote is a prominent character in Native American folklore in the Southwestern United States and Mexico depicted as a trickster that alternately assumes the form of an actual coyote or a man. As with other trickster figures, the coyote uses deception and humor to rebel against social conventions.
The animal was respected in Mesoamerican cosmology as a symbol of military might. After the European colonization of the Americas, it was reviled in Anglo-American culture as a cowardly and untrustworthy animal. Unlike wolves, which have undergone an improvement of their public image, attitudes towards the coyote remain negative. Coyote males average 8 to 20 kg in weight, while females average 7 to 18 kg, though size varies geographically. Northern subspecies, which average 18 kg, tend to grow larger than the southern subspecies of Mexico, which average 11.5 kg. Body length ranges on average from 1.0 to 1.35 m, tail length 40 cm, with females being shorter in both body length and height. The largest coyote on record was a male killed near Afton, Wyoming, on November 19, 1937, which measured 1.5 m from nose to tail, weighed 34 kg. Scent glands are a bluish-black color; the color and texture of the coyote's fur varies somewhat geographically. The hair's predominant color is light gray and red or fulvous, interspersed around the body with black and white.
Coyotes living at high elevations tend to have more black and gray shades than their desert-dwelling counterparts, which are more fulvous or whitish-gray. The coyote's fur consists of soft underfur and long, coarse guard hairs; the fur of northern subspecies is longer and denser than in southern forms, with the fur of some Mexican and Central American forms being hispid. Adult coyotes have a sable coat color, dark neonatal coat color, bushy tail with an active supracaudal gland, a white facial mask. Albinism is rare in coyotes; the coyote is smaller than the gray wolf, but has longer ears and a larger braincase, as well as a thinner frame and muzzle. The scent glands are the same color, its fur color variation is much less varied than that of a wolf. The coyote carries its tail downwards when running or walking, rather than horizontally as the wolf does. Coyote tracks can be distinguished from those of dogs by less rounded shape. Unlike dogs, the upper canines of coyotes extend past the mental foramina.
At the time of the European colonization of the Americas, coyotes were confined to open plains and arid regions of the western half of the continent. In early post-Columbian historical records, distinguishing between coyotes and wolves is difficult. One record from 1750 in Kaskaskia, written by a local priest, noted that the "wolves" encountered there were smaller and less daring than European wolves. Another account from the early 1800s in Edwards County mentioned wolves howling at night, though these were coyotes; this species was encountered several times during the Lewis and Clark Expedition, though it was well known to European traders on the upper Missouri. Lewis, writing on 5 May 1805, in northeastern Montana, described the coyote in these terms: The small woolf or burrowing dog of the prairies are the inhabitants invariably of the open plains.