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Yellow-pine Chipmunk
The yellow-pine chipmunk (''Neotamias amoenus'') is a species of order Rodentia in the family Sciuridae. It is found in western North America: parts of Canada and the United States. These chipmunks are normally found in brush-covered areas, and in California, they inhabit an elevation range of around 975 to 2,900 meters. Description Their body color is dark and reddish, mixed with cinnamon, with five longitudinal dark (black or mixed black) stripes that are separated by four lighter stripes. The outer pair of pale stripes is creamy white and narrower, and the more median pair is a gray or smoke gray. The sides of the head each have three dark stripes, with two lighter in between, and the crown is black or smoke gray. Males and females have similar brain size and roughly the same tail length, ear length from notch, and length of lower tooth row, but females are larger in other body measurements; average body mass varies, with large males weighing an average of 49.7 g and large ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rodent
Rodents (from Latin , 'to gnaw') are mammals of the order Rodentia (), which are characterized by a single pair of continuously growing incisors in each of the upper and lower jaws. About 40% of all mammal species are rodents. They are native to all major land masses except for New Zealand, Antarctica, and several oceanic islands, though they have subsequently been introduced to most of these land masses by human activity. Rodents are extremely diverse in their ecology and lifestyles and can be found in almost every terrestrial habitat, including human-made environments. Species can be arboreal, fossorial (burrowing), saltatorial/richochetal (leaping on their hind legs), or semiaquatic. However, all rodents share several morphological features, including having only a single upper and lower pair of ever-growing incisors. Well-known rodents include mice, rats, squirrels, prairie dogs, porcupines, beavers, guinea pigs, and hamsters. Rabbits, hares, and pikas, whose i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sciuridae
Squirrels are members of the family Sciuridae, a family that includes small or medium-size rodents. The squirrel family includes tree squirrels, ground squirrels (including chipmunks and prairie dogs, among others), and flying squirrels. Squirrels are indigenous to the Americas, Eurasia, and Africa, and were introduced by humans to Australia. The earliest known fossilized squirrels date from the Eocene epoch, and among other living rodent families, the squirrels are most closely related to the mountain beaver and to the dormice. Etymology The word ''squirrel'', first attested in 1327, comes from the Anglo-Norman which is from the Old French , the reflex of a Latin word , which was taken from the Ancient Greek word (; from ) 'shadow-tailed', referring to the long bushy tail which many of its members have. The native Old English word for the squirrel, , survived only into Middle English (as ) before being replaced. The Old English word is of Common Germanic origin, cognat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sexual Dimorphism
Sexual dimorphism is the condition where the sexes of the same animal and/or plant species exhibit different morphological characteristics, particularly characteristics not directly involved in reproduction. The condition occurs in most animals and some plants. Differences may include secondary sex characteristics, size, weight, colour, markings, or behavioural or cognitive traits. These differences may be subtle or exaggerated and may be subjected to sexual selection and natural selection. The opposite of dimorphism is ''monomorphism'', which is when both biological sexes are phenotypically indistinguishable from each other. Overview Ornamentation and coloration Common and easily identified types of dimorphism consist of ornamentation and coloration, though not always apparent. A difference in coloration of sexes within a given species is called sexual dichromatism, which is commonly seen in many species of birds and reptiles. Sexual selection leads to the exaggerated dim ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Least Chipmunk
The least chipmunk (''Neotamias minimus'') is the smallest species of chipmunk and the most widespread in North America. Description It is the smallest species of chipmunk, measuring about in total length with a weight of . The body is gray to reddish-brown on the sides, and grayish white on the underparts. The back is marked with five dark brown to black stripes separated by four white or cream-colored stripes, all of which run from the nape of the neck to the base of the tail. Two light and two dark stripes mark the face, running from the tip of the nose to the ears. The bushy tail is orange-brown in color, and measures long. In some areas, where range overlap with the yellow-pine chipmunk occurs, it may be difficult or impossible to distinguish the two species in the field; laboratory examination of skeletal structures may be required. As in other chipmunks, there are four toes on each of the forefeet and five on the hindfeet. Females have eight teats. The brain to body mass ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Red-tailed Chipmunk
The red-tailed chipmunk (''Neotamias ruficaudus'') is a species of rodent in the family Sciuridae. It is found in Alberta and British Columbia in Canada and Montana, Idaho and Washington in the United States. Description The red-tailed chipmunk is a large species with a total length of about including a bushy tail of . The mass varies from about in the spring to in the fall. Females are marginally larger than males. The head is mottled grayish-brown with dark stripes above, through and below the eye. The body is basically orange-brown with five blackish stripes separated by four pale gray, tawny or cream-colored ones. The shoulders, sides, rump and flanks are tawny or buff. The underparts are creamy-white suffused with pinkish-buff. The upper side of the tail is black suffused with pinkish-buff and the underside is tawny tipped with pinkish-buff. In winter the animal's color is greyer and less tawny. In some areas, where range overlap with the yellow-pine chipmunk occurs, it ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hibernation
Hibernation is a state of minimal activity and metabolic depression undergone by some animal species. Hibernation is a seasonal heterothermy characterized by low body-temperature, slow breathing and heart-rate, and low metabolic rate. It most commonly occurs during winter months. Although traditionally reserved for "deep" hibernators such as rodents, the term has been redefined to include animals such as bears and is now applied based on active metabolic suppression rather than any absolute decline in body temperature. Many experts believe that the processes of daily torpor and hibernation form a continuum and utilise similar mechanisms. The equivalent during the summer months is aestivation. Hibernation functions to conserve energy when sufficient food is not available. To achieve this energy saving, an endothermic animal decreases its metabolic rate and thereby its body temperature. Hibernation may last days, weeks, or months—depending on the species, ambient temperature ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Baculum
The baculum (also penis bone, penile bone, or ''os penis'', ''os genitale'' or ''os priapi'') is a bone found in the penis of many placental mammals. It is absent from the human penis, but present in the penises of some primates, such as the gorilla and chimpanzee. The os penis arises from primordial cells within soft tissues of the penis, and its formation is largely under the influence of androgens. The bone is located above the male urethra, and it aids sexual reproduction by maintaining sufficient stiffness during sexual penetration. The homologue to the baculum in female mammals is known as the baubellum or ''os clitoridis'' (also ''os clitoris''), a bone in the clitoris. Etymology The word ''baculum'' meant "stick" or "staff" in Latin and originated from el, βάκλον, ''baklon'' "stick". Function The baculum is used for copulation and varies in size and shape by species. Its evolution may be influenced by sexual selection, and its characteristics are sometimes ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Baculum
The baculum (also penis bone, penile bone, or ''os penis'', ''os genitale'' or ''os priapi'') is a bone found in the penis of many placental mammals. It is absent from the human penis, but present in the penises of some primates, such as the gorilla and chimpanzee. The os penis arises from primordial cells within soft tissues of the penis, and its formation is largely under the influence of androgens. The bone is located above the male urethra, and it aids sexual reproduction by maintaining sufficient stiffness during sexual penetration. The homologue to the baculum in female mammals is known as the baubellum or ''os clitoridis'' (also ''os clitoris''), a bone in the clitoris. Etymology The word ''baculum'' meant "stick" or "staff" in Latin and originated from el, βάκλον, ''baklon'' "stick". Function The baculum is used for copulation and varies in size and shape by species. Its evolution may be influenced by sexual selection, and its characteristics are sometimes ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Estrous Cycle
The estrous cycle (, originally ) is the set of recurring physiological changes that are induced by reproductive hormones in most mammalian therian females. Estrous cycles start after sexual maturity in females and are interrupted by anestrous phases, otherwise known as "rest" phases, or by pregnancies. Typically, estrous cycles repeat until death. These cycles are widely variable in duration and frequency depending on the species.Bronson, F. H., 1989. Mammalian Reproductive Biology. University of Chicago Press, Chicago, IL, USA. Some animals may display bloody vaginal discharge, often mistaken for menstruation. Many mammals used in commercial agriculture, such as cattle and sheep, may have their estrous cycles artificially controlled with hormonal medications for optimum productivity. The male equivalent, seen primarily in ruminants, is called rut. Differences from the menstrual cycle Mammals share the same reproductive system, including the regulatory hypothalamic system t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Neotamias
''Neotamias'' is a genus of chipmunks within the tribe Marmotini of the squirrel family. It contains 23 species, which mostly occur in western North America. Along with ''Eutamias'', this genus is often considered a subgenus of ''Tamias''. Species *Alpine chipmunk, ''Neotamias alpinus'' *Yellow-pine chipmunk ''Neotamias amoenus'' *Buller's chipmunk, ''Neotamias bulleri'' *Gray-footed chipmunk, ''Neotamias canipes'' * Gray-collared chipmunk, ''Neotamias cinereicollis'' *Cliff chipmunk, ''Neotamias dorsalis'' * Durango chipmunk, ''Neotamias durangae'' *Merriam's chipmunk, ''Neotamias merriami'' *Least chipmunk, ''Neotamias minimus'' *California chipmunk, ''Neotamias obscurus'' *Yellow-cheeked chipmunk, ''Neotamias ochrogenys'' *Palmer's chipmunk, ''Neotamias palmeri'' * Panamint chipmunk, ''Neotamias panamintinus'' *Long-eared chipmunk, ''Neotamias quadrimaculatus'' *Colorado chipmunk, ''Neotamias quadrivittatus'' *Red-tailed chipmunk, ''Neotamias ruficaudus'' * Hopi chipmunk, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mammals Described In 1890
Mammals () are a group of vertebrate animals constituting the class Mammalia (), characterized by the presence of mammary glands which in females produce milk for feeding (nursing) their young, a neocortex (a region of the brain), fur or hair, and three middle ear bones. These characteristics distinguish them from reptiles (including birds) from which they diverged in the Carboniferous, over 300 million years ago. Around 6,400 extant species of mammals have been described divided into 29 orders. The largest orders, in terms of number of species, are the rodents, bats, and Eulipotyphla (hedgehogs, moles, shrews, and others). The next three are the Primates (including humans, apes, monkeys, and others), the Artiodactyla ( cetaceans and even-toed ungulates), and the Carnivora (cats, dogs, seals, and others). In terms of cladistics, which reflects evolutionary history, mammals are the only living members of the Synapsida (synapsids); this clade, together wi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Taxonomy Articles Created By Polbot
Taxonomy is the practice and science of categorization or classification (general theory), classification. A taxonomy (or taxonomical classification) is a scheme of classification, especially a hierarchical classification, in which things are organized into groups or types. Among other things, a taxonomy can be used to organize and index knowledge (stored as documents, articles, videos, etc.), such as in the form of a library classification system, or a Taxonomy for search engines, search engine taxonomy, so that users can more easily find the information they are searching for. Many taxonomies are hierarchy, hierarchies (and thus, have an intrinsic tree structure), but not all are. Originally, taxonomy referred only to the categorisation of organisms or a particular categorisation of organisms. In a wider, more general sense, it may refer to a categorisation of things or concepts, as well as to the principles underlying such a categorisation. Taxonomy organizes taxonomic uni ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
