Squirrels are members of the family Sciuridae, a family that includes small or medium-size rodents. The squirrel family includes tree squirrels, ground squirrels, marmots, flying squirrels, prairie dogs amongst other rodents. Squirrels are indigenous to the Americas and Africa, were introduced by humans to Australia; the earliest known squirrels date from the Eocene period and are most related to the mountain beaver and to the dormouse among other living rodent families. The word "squirrel", first attested in 1327, comes from the Anglo-Norman esquirel, from the Old French escurel, the reflex of a Latin word sciurus; this Latin word was borrowed from the Ancient Greek word σκίουρος, which means shadow-tailed, referring to the bushy appendage possessed by many of its members. The native Old English word for the squirrel, ācweorna, survived only into Middle English before being replaced; the Old English word is of Common Germanic origin, cognates of which are still used in other Germanic languages, including the German Eichhörnchen, the Norwegian ikorn/ekorn, the Dutch eekhoorn, the Swedish ekorre and the Danish egern.
Squirrels are small animals, ranging in size from the African pygmy squirrel at 7–10 cm in length and just 10 g in weight, to the Laotian giant flying squirrel at 1.08 m in length and the Alpine marmot, which weighs from 5 to 8 kg. Squirrels have slender bodies with bushy tails and large eyes. In general, their fur is silky, though much thicker in some species than others; the coat color of squirrels is variable between—and even within—species. In most squirrel species, the hind limbs are longer than the fore limbs, while all species have either four or five toes on each paw; the paws, which include an poorly developed thumb, have soft pads on the undersides and versatile, sturdy claws for grasping and climbing. Tree squirrels, unlike most mammals, can descend a tree head-first, they do so by rotating their ankles 180 degrees, enabling the hind paws to point backward and thus grip the tree bark from the opposite direction. Squirrels live in every habitat, from tropical rainforest to semiarid desert, avoiding only the high polar regions and the driest of deserts.
They are predominantly herbivorous, subsisting on seeds and nuts, but many will eat insects and small vertebrates. As their large eyes indicate, squirrels have an excellent sense of vision, important for the tree-dwelling species. Many have a good sense of touch, with vibrissae on their limbs as well as their heads; the teeth of sciurids follow the typical rodent pattern, with large incisors that grow throughout life, cheek teeth that are set back behind a wide gap, or diastema. The typical dental formula for sciurids is 220.127.116.11.0.1.3. Many juvenile squirrels die in the first year of life. Adult squirrels can have a lifespan of 5 to 10 years in the wild; some can survive 10 to 20 years in captivity. Premature death may be caused when a nest falls from the tree, in which case the mother may abandon her young if their body temperature is not correct. Many such baby squirrels have been rescued and fostered by a professional wildlife rehabilitator until they could be safely returned to the wild, although the density of squirrel populations in many places and the constant care required by premature squirrels means that few rehabilitators are willing to spend their time doing this and such animals are euthanized instead.
Squirrels mate either once or twice a year and, following a gestation period of three to six weeks, give birth to a number of offspring that varies by species. The young are altricial, being born naked and blind. In most species of squirrel, the female alone looks after the young, which are weaned at six to ten weeks and become sexually mature by the end of their first year. In general, the ground-dwelling squirrel species are social living in well-developed colonies, while the tree-dwelling species are more solitary. Ground squirrels and tree squirrels are either diurnal or crepuscular, while the flying squirrels tend to be nocturnal—except for lactating flying squirrels and their young, which have a period of diurnality during the summer; because squirrels cannot digest cellulose, they must rely on foods rich in protein and fats. In temperate regions, early spring is the hardest time of year for squirrels because the nuts they buried are beginning to sprout, while many of the usual food sources have not yet become available.
During these times, squirrels rely on the buds of trees. Squirrels, being herbivores, eat a wide variety of plants, as well as nuts, conifer cones, fruits and green vegetation; some squirrels, however consume meat when faced with hunger. Squirrels have been known to eat small birds, young snakes, smaller rodents, as well as bird eggs and insects. Indeed, some tropical squirrel species have shifted entirely to a diet of insects. Predatory behavior has been observed in various species of ground squirrels, in particular the thirteen-lined ground squirrel. For example, Bailey, a scientist in the 1920s, observed a thirteen-lined ground squirrel preying upon a young chicken. Wistrand reported seeing this same species eating a freshly killed snake. Whitaker examined the stomachs of 139 thirteen-lined ground squirrels and found bird flesh in four of the specimens and the remains of a short-tailed shrew in one.
Glacier National Park (U.S.)
Glacier National Park is an American national park located in northwestern Montana, on the Canada–United States border, adjacent to the Canadian provinces of Alberta and British Columbia. The park encompasses over 1 million acres and includes parts of two mountain ranges, over 130 named lakes, more than 1,000 different species of plants, hundreds of species of animals; this vast pristine ecosystem is the centerpiece of what has been referred to as the "Crown of the Continent Ecosystem," a region of protected land encompassing 16,000 square miles. The region that became Glacier National Park was first inhabited by Native Americans. Upon the arrival of European explorers, it was dominated by the Blackfeet in the east and the Flathead in the western regions. Under pressure, the Blackfeet ceded the mountainous parts of their treaty lands in 1895 to the federal government. Soon after the establishment of the park on May 11, 1910, a number of hotels and chalets were constructed by the Great Northern Railway.
These historic hotels and chalets are listed as National Historic Landmarks and a total of 350 locations are on the National Register of Historic Places. By 1932 work was completed on the Going-to-the-Sun Road designated a National Historic Civil Engineering Landmark, which provided greater accessibility for automobiles into the heart of the park; the mountains of Glacier National Park began forming 170 million years ago when ancient rocks were forced eastward up and over much younger rock strata. Known as the Lewis Overthrust, these sedimentary rocks are considered to have some of the finest examples of early life fossils on Earth; the current shapes of the Lewis and Livingston mountain ranges and positioning and size of the lakes show the telltale evidence of massive glacial action, which carved U-shaped valleys and left behind moraines which impounded water, creating lakes. Of the estimated 150 glaciers which existed in the park in the mid-19th century, only 25 active glaciers remained by 2010.
Scientists studying the glaciers in the park have estimated that all the active glaciers may disappear by 2030 if current climate patterns persist. Glacier National Park has all its original native plant and animal species. Large mammals such as grizzly bears and mountain goats, as well as rare or endangered species like wolverines and Canadian lynxes, inhabit the park. Hundreds of species of birds, more than a dozen fish species, a few reptile and amphibian species have been documented; the park has numerous ecosystems ranging from prairie to tundra. The easternmost forests of western redcedar and hemlock grow in the southwest portion of the park. Large forest fires are unusual in the park. Glacier National Park borders Waterton Lakes National Park in Canada—the two parks are known as the Waterton-Glacier International Peace Park and were designated as the world's first International Peace Park in 1932. Both parks were designated by the United Nations as Biosphere Reserves in 1976, in 1995 as World Heritage sites.
In April 2017, the joint park received a provisional Gold Tier designation as Waterton-Glacier International Dark Sky Park through the International Dark Sky Association, the first transboundary dark sky park. According to archeological evidence, Native Americans first arrived in the Glacier area some 10,000 years ago; the earliest occupants with lineage to current tribes were the Flathead and Kootenai and Cheyenne. The Blackfeet arrived around the beginning of the 18th century and soon dominated the eastern slopes of what became the park, as well as the Great Plains to the east; the park region provided the Blackfeet shelter from the harsh winter winds of the plains, allowing them to supplement their traditional bison hunts with other game meat. Today, the Blackfeet Indian Reservation borders the park in the east, while the Flathead Indian Reservation is located west and south of the park; when the Blackfeet Reservation was first established in 1855 by the Lame Bull Treaty, it included the eastern area of the current park up to the Continental Divide.
To the Blackfeet, the mountains of this area Chief Mountain and the region in the southeast at Two Medicine, were considered the "Backbone of the World" and were frequented during vision quests. In 1895 Chief White Calf of the Blackfeet authorized the sale of the mountain area, some 800,000 acres, to the U. S. government for $1.5 million, with the understanding that they would maintain usage rights to the land for hunting as long as the ceded stripe will be public land of the United States. This established the current boundary between the reservation. While exploring the Marias River in 1806, the Lewis and Clark Expedition came within 50 miles of the area, now the park. A series of explorations after 1850 helped to shape the understanding of the area that became the park. In 1885 George Bird Grinnell hired noted explorer James Willard Schultz to guide him on a hunting expedition into what would become the park. After several more trips to the region, Grinnell became so inspired by the scenery that he spent the next two decades working to establish a national park.
In 1901 Grinnell wrote a description of the region in which he referred to it as the "Crown of the Continent". His efforts to protect the land make him the premier contributor to this cause. A few years after Grinnell first visited, Henry L. Stimson and two companions, including a Blackfoot, climbed the steep east face of Chief Mountain in 1892. In 1891 the Great Northern Railway crossed the Continental Divide at Marias Pass 5,213 feet, along the sout
Pinus balfouriana, the foxtail pine, is a rare high-elevation pine, endemic to California, United States. It is related to the Great Basin and Rocky Mountain bristlecone pines, in the subsection Balfourianae; the two disjunct populations are found in the southern Klamath Mountains and the southern Sierra Nevada. A small outlying population was reported in southern Oregon, but was proven to have been misidentified. P. balfouriana is a tree to 10–20 m tall, exceptionally 35 m, with a trunk up to 2 m across. Its leaves are needle-like, in bundles of five with a semi-persistent basal sheath, 2–4 cm long, deep glossy green on the outer face, white on the inner faces; the cones are 6–11 cm long, dark purple ripening red-brown, with soft, flexible scales each with a 1-millimeter central prickle. P. balfouriana occurs in the subalpine forest at an elevation of 1,950–2,750 m in the Klamath Mountains, at 2,300–3,500 m in the Sierra Nevada. In the Sierra Nevada, Foxtail pines are limited to the area around Sequoia and Kings Canyon National Parks.
In both areas, it is a tree line species. It is thought that P. balfouriana can live up to 3000 years in the Sierra Nevada, although the highest proven age is 2110 years. In the Klamath Mountains, ages are only known to about 1000 years. P. balfouriana is related to the bristlecone pines, being classified in the same subsection Balfourianae. Chase, J. Smeaton. Cone-bearing Trees of the California Mountains. Chicago: A. C. McClurg & Co. p. 99. LCCN 11004975. OCLC 3477527. LCC QK495. C75 C4, with illustrations by Carl Eytel – Kurut, Gary F. "Carl Eytel: Southern California Desert Artist", California State Library Foundation, Bulletin No. 95, pp. 17-20 retrieved Nov. 13, 2011, Lanner, R. M. 2007 The Bristlecone Book, Ronald M Lanner, Mountain Press 2007 p. 14Conifer Specialist Group. "Pinus balfouriana". IUCN Red List of Threatened Species. Version 2006. International Union for Conservation of Nature. Retrieved 11 May 2006. Bailey, D. K. 1970. Phytogeography and taxonomy of Pinus subsection Balfourianae. Ann.
Missouri Bot. Gard. 57: 210–249. Mastrogiuseppe, R. J. & Mastrogiuseppe, J. D. 1980. A study of Pinus balfouriana Grev. & Balf.. Systematic Botany 5: 86–104. Richardson, D. M.. 1998. Ecology and Biogeography of Pinus. Cambridge University Press, Cambridge. 530 p. ISBN 0-521-55176-5. Fryer, Janet L.. "Pinus balfouriana". Fire Effects Information System. US Department of Agriculture, Forest Service, Rocky Mountain Research Station, Fire Sciences Laboratory – via https://www.feis-crs.org/feis/. Calflora: Pinus balfouriana CalFlora Database: Pinus balfouriana Gymnosperm Database — Pinus balfouriana USDA Plants Profile for Pinus balfouriana Arboretum de Villardebelle — photos of cones High Elevation White Pine Educational Website: Pinus balfouriana Conifercountry.com: Foxtail Pines in Northwest California Pinus balfouriana in the CalPhotos Photo Database, University of California, Berkeley
Neognaths are birds within the subclass Neornithes of the class Aves. The Neognathae include all living birds. There are nearly 10,000 species of neognaths; the earliest fossils are known from the end of the Cretaceous but molecular clocks suggest that neognaths originated sometime in the first half of the Late Cretaceous about 90 million year ago. Since they have undergone adaptive radiation producing the diversity of form and behavior that we see today, it includes the order Passeriformes, the largest clade of land vertebrates, containing some 60% of living birds and being more than twice as speciose as rodents and about five times as speciose as Chiroptera, which are the largest clades of mammals. There are some small orders birds of unclear relationships like the puzzling hoatzin; the neognaths have fused metacarpals, an elongate third finger, 13 or fewer vertebrae. They differ from the Palaeognathae in features like the structure of their jawbones. "Neognathae" means "new jaws", but it seems that the "more ancient" paleognath jaws are among the few apomorphic features of the Palaeognaths, meaning that the respective jaw structure of these groups is not informative in terms of comparative evolution.
The Neognathae were long ranked as a superorder subdivided into orders. Attempts to organise this group further, as in the Conspectus of Charles Lucien Bonaparte, were never accepted by a significant majority of ornithologists; until the 1980s, there was little subdivision of the Aves in general, less of phylogenetic merit. Since the availability of massive amounts of new data from fossils and molecular sequences allowed scientists to refine the classification. With new groups of neognath orders being verified, the taxonomic rank of the group needed to shift. Most researchers have now employed the unranked taxa of phylogenetic nomenclature; the Neognathae are now universally accepted to subdivide into two lineages, the "fowl" clade Galloanseres and the Neoaves. The subdivisions of the latter are still not well resolved, but several monophyletic lineages have been proposed, such as the Mirandornithes, Cypselomorphae and Coronaves. Although groups such as the former two are robustly supported, this cannot be said for the Metaves and Coronaves division for which there is no material evidence at present, while the Mesozoic record of Neognathae is at present utterly devoid of birds that should have been present if these proposed clades were real.
The orders are arranged in a sequence. It differs from the used Clements taxonomy as well as from the Sibley-Ahlquist taxonomy, combining those elements from each that more modern research agrees with while updating those that are refuted. Most of the changes affect those "higher landbirds". Feduccia defined the clade Neognathia as birds whose palatal mobility increased due to the following modifications: Loss of the Basipterygoid articulation with the cranium. Development of a pterygoid/palatine joint. Reduction of the vomer, such that it does not reach caudally to the pterygoid, or is lost entirely. Neognathae cladogram of modern bird relationships based on Prum, R. O. et al. with some clade names after Kimball et al.. 2013. Claramunt, S.. "A new time tree reveals Earth history's imprint on the evolution of modern birds". Sci Adv. 1: e1501005. Doi:10.1126/sciadv.1501005. PMC 4730849. PMID 26824065. Mindell, David P. & Brown, Joseph W.: The Tree of Life Web Project - Neornithes. Version of 2005-DEC-14.
Retrieved 2008-JAN-08. Mindell, David P.. Version of 2005-DEC-14. Retrieved 2008-JAN-08. Tree of Life: Neoaves Tree of Life: Galloanserae
A passerine is any bird of the order Passeriformes, which includes more than half of all bird species. Sometimes known as perching birds or – less – as songbirds, passerines are distinguished from other orders of birds by the arrangement of their toes, which facilitates perching. With more than 110 families and some 6,409 identified species, Passeriformes is the largest order of birds and among the most diverse orders of terrestrial vertebrates. Passerines are divided into three clades, Acanthisitti and Passeri; the passerines contain several groups of brood parasites such as the viduas, cuckoo-finches, the cowbirds. Most passerines are omnivorous; the terms "passerine" and "Passeriformes" are derived from the scientific name of the house sparrow, Passer domesticus, from the Latin term passer, which refers to sparrows and similar small birds. The order is divided into three suborders, Tyranni and the basal Acanthisitti. Oscines have the best control of their syrinx muscles among birds, producing a wide range of songs and other vocalizations.
The acanthisittids or New Zealand wrens are tiny birds restricted to New Zealand, at least in modern times. Most passerines are smaller than typical members of other avian orders; the heaviest and altogether largest passerines are the thick-billed raven and the larger races of common raven, each exceeding 1.5 kg and 70 cm. The superb lyrebird and some birds-of-paradise, due to long tails or tail coverts, are longer overall; the smallest passerine is the short-tailed pygmy tyrant, at 4.2 g. The foot of a passerine has three toes directed forward and one toe directed backward, called anisodactyl arrangement; this arrangement enables the passerine birds to perch upon vertical surfaces, such as trees and cliffs. The toes have no webbing or joining, but in some cotingas, the second and third toes are united at their basal third; the hind toe joins the leg at the same level as the front toes. The passeriformes have this toe arrangement in common with hunting birds like falcons; the leg arrangement of passerine birds contains a special adaptation for perching.
A tendon in the rear of the leg running from the underside of the toes to the muscle behind the tibiotarsus will automatically be pulled and tighten when the leg bends, causing the foot to curl and become stiff when the bird lands on a branch. This enables passerines to sleep. Most passerine birds develop 12 tail feathers, although the superb lyrebird has 16. Certain species of passerines have stiff tail feathers, which help the birds balance themselves when perching upon vertical surfaces; some passerines in the family Ploceidae, are well known for their elaborate sexual ornaments, including long tails. A well-known example is the long-tailed widowbird; the chicks of passerines are altricial: blind and helpless when hatched from their eggs. Hence, the chicks require extensive parental care. Most passerines lay coloured eggs, in contrast with nonpasserines, most of whose eggs are white except in some ground-nesting groups such as Charadriiformes and nightjars, where camouflage is necessary, in some parasitic cuckoos, which match the passerine host's egg.
Vinous-throated parrotbill has two egg colours and blue. This can prevent the brood parasitic Common cuckoo. Clutches vary in size: some larger passerines of Australia such as lyrebirds and scrub-robins lay only a single egg, most smaller passerines in warmer climates lay between two and five, while in the higher latitudes of the Northern Hemisphere, hole-nesting species like tits can lay up to a dozen and other species around five or six; the family Viduidae do not build their own nests, they lay eggs in other birds' nests. The evolutionary history of the passerine families and the relationships among them remained rather mysterious until the late 20th century. In many cases, passerine families were grouped together on the basis of morphological similarities that, it is now believed, are the result of convergent evolution, not a close genetic relationship. For example, the wrens of the Eurasia. Much research remains to be done, but advances in molecular biology and improved paleobiogeographical data are revealing a clearer picture of passerine origins and evolution that reconciles molecular affinities, the constraints of morphology and the specifics of the fossil record.
The first passerines are now thought to have evolved in the Southern Hemisphere in the late Paleocene or early Eocene, around 50 million years ago. The initial split was between the New Zealand wrens and all other passerines, the second split involved the Tyranni and the Passeri; the latter experienced a great radiation of forms out of the Australian continent. A major branch of the Passeri, parvorder Passerida, expanded deep into Eurasia and Africa, where a further explosive radiation of new lineages occurred; this led to three major Passerida lineages comprising about 4,000 species, which in addition to the Corvida and numerous minor linea
The nutcrackers are a genus of three species of passerine bird, in the family Corvidae, related to the jays and crows. The genus Nucifraga was introduced by the French zoologist Mathurin Jacques Brisson in 1760 with the spotted nutcracker as the type species; the genus name is a New Latin translation of German Nussbrecher, "nut-breaker". The genus contains three species: The most important food resources for these species are the seeds of various pines, principally the cold-climate species of white pine with large seeds: P. albicaulis, P. armandii, P. cembra, P. flexilis, P. koraiensis, P. parviflora, P. peuce, P. pumila, P. sibirica and P. wallichiana, the pinyon and lacebark pines. In some regions, where none of these pines occur, the seeds of spruce and hazelnuts form an important part of the diet too, their bills are specialized tools for extracting seeds from pine cones. Surplus seed is always stored for use, it is this genus, responsible for the re-establishment of their favoured pines over large areas either burnt in forest fires or cleared by man.
The nutcracker can store as many as 30,000 pine nuts in a single season, remembering the location of as many as 70% of their stash when buried in snow. Nutcrackers will cache seeds as far as 32 kilometres away from parent plants, about eight times farther than related dispersers like jays and crows, are thus important in re-establishing forests and responding to climate change. Various insects are taken, including bee and wasp larvae, birds' eggs and nestlings, carrion if it is found. Nesting is always early in this genus, so as to make the best use of pine nuts stored the previous autumn; the nest is built high in a conifer. There are 2–4 eggs laid and incubated for 18 days. Both sexes feed the young which are fledged by about 23 days and stay with their parents for many months, following them to learn food storage techniques. None of the species are migratory, but they will leave their usual ranges if a cone crop failure causes a food shortage. Nutcracker videos on the Internet Bird Collection