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Spermophilus Vorontsovi
''Spermophilus'' is a genus of ground squirrels in the squirrel family. As traditionally defined the genus was very species-rich, ranging through Europe, Asia and North America, but this arrangement was found to be paraphyletic to the certainly distinct prairie dogs, marmots, and antelope squirrels. As a consequence, all the former ''Spermophilus'' species of North America have been moved to other genera, leaving the European and Asian species as true ''Spermophilus'' (the only exceptions are two Asian ''Urocitellus''). Some species are sometimes called susliks (or sousliks). This name comes from Russian суслик, ''suslik''. In some languages, a derivative of the name is in common usage, for example ''suseł'' in Polish. The scientific name of this genus means "seed-lovers" (gr. σπέρμα ''sperma'', genitive σπέρματος ''spermatos'' – seed; φίλος ''philos'' – friend, lover). Habitat and behavior As typical ground squirrels, ''Spermophilus'' live in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Miocene
The Miocene ( ) is the first epoch (geology), geological epoch of the Neogene Period and extends from about (Ma). The Miocene was named by Scottish geologist Charles Lyell; the name comes from the Greek words (', "less") and (', "new") and means "less recent" because it has 18% fewer modern marine invertebrates than the Pliocene has. The Miocene followed the Oligocene and preceded the Pliocene. As Earth went from the Oligocene through the Miocene and into the Pliocene, the climate slowly cooled towards a series of ice ages. The Miocene boundaries are not marked by distinct global events but by regionally defined transitions from the warmer Oligocene to the cooler Pliocene Epoch. During the Early Miocene, Afro-Arabia collided with Eurasia, severing the connection between the Mediterranean and Indian Oceans, and allowing the interchange of fauna between Eurasia and Africa, including the dispersal of proboscideans and Ape, hominoids into Eurasia. During the late Miocene, the conn ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Poliocitellus
Franklin's ground squirrel (''Poliocitellus franklinii'') is a species of squirrel native to North America, and the only member of the genus ''Poliocitellus''. Due to the destruction of prairie, the populations of Franklin's ground squirrel have dwindled, approaching levels of concern. Its decline in the eastern portion of its range is mostly attributed to habitat fragmentation. Taxonomy Franklin's ground squirrel was first described by Joseph Sabine in 1822, who named it in honor of the British Arctic explorer Sir John Franklin. It was formerly placed in the large ground squirrel genus ''Spermophilus'', in its own subgenus, ''Poliocitellus'', but since DNA sequencing of the cytochrome ''b'' gene has shown ''Spermophilus'' to be paraphyletic it is now placed in its own genus. Franklin's ground squirrel is suggested to be sister to a clade containing not only the Mohave, round-tailed, spotted, and Perote ground squirrels (genus '' Xerospermophilus''), but the prairie dogs as ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hibernate
Hibernation is a state of minimal activity and metabolic reduction entered by some animal species. Hibernation is a seasonal heterothermy characterized by low body-temperature, slow breathing and heart-rate, and low metabolic rate. It is most commonly used to pass through winter months – called overwintering. 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 use 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 s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Diurnality
Diurnality is a form of plant and ethology, animal behavior characterized by activity during daytime, with a period of sleeping or other inactivity at night. The common adjective used for daytime activity is "diurnal". The timing of activity by an animal depends on a variety of environmental factors such as the temperature, the ability to gather food by sight, the risk of predation, and the time of year. Diurnality is a cycle of activity within a 24-hour period; cyclic activities called circadian rhythms are endogenous cycles not dependent on external cues or environmental factors except for a zeitgeber. Animals active during twilight are crepuscular, those active during the night are nocturnal and animals active at sporadic times during both night and day are cathemerality, cathemeral. Plants that open their flowers during the daytime are described as diurnal, while those that bloom during nighttime are nocturnal. The timing of flower opening is often related to the time at whic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Steppe
In physical geography, a steppe () is an ecoregion characterized by grassland plains without closed forests except near rivers and lakes. Steppe biomes may include: * the montane grasslands and shrublands biome * the tropical and subtropical grasslands, savannas, and shrublands biome * the temperate grasslands, savannas, and shrublands biome A steppe is usually covered with grass and shrubs, depending on the season and latitude. The term ''steppe climate'' denotes a semi-arid climate, which is encountered in regions too dry to support a forest, but not dry enough to be a desert. Steppes are usually characterized by a semi-arid or continental climate. Temperature extremes can be recorded in the summer of up to and in winter of down to . Besides this major seasonal difference, fluctuations between day and night are also significant: in both the highlands of Mongolia and northern Nevada, can be reached during the day with sub-freezing readings at night. Steppes ave ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Antelope Squirrel
Antelope squirrels or antelope ground squirrels of the genus ''Ammospermophilus'' are sciurids found in the desert and dry scrub areas of the southwestern United States and northern Mexico. They are a type of ground squirrel and are able to resist hyperthermia and can survive body temperatures over . Common characteristics All the antelope squirrels share a common white stripe along the lateral sides from the shoulder to the hip similar to chipmunks. However, unlike chipmunks, these characteristic white stripes do not extend onto the head of the animals. The tails of antelope squirrels are often arched forward over their back. In the United States, these ground squirrels are found in the dry, desert like regions of the southwest. The different members of the genus ''Ammospermophilus'' have unique adaptations that allow them to overcome the extreme heat of the day and the low temperatures of the night. All antelope squirrels burrow into the ground for shelter, however not a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Marmot
Marmots are large ground squirrels in the genus ''Marmota'', with 15 species living in Asia, Europe, and North America. These herbivores are active during the summer, when they can often be found in groups, but are not seen during the winter, when they hibernate underground. They are the heaviest members of the squirrel family. Description Marmots are large rodents with characteristically short but robust legs, enlarged claws which are well adapted to digging, stout bodies, and large heads and incisors to quickly process a variety of vegetation. While most species are various forms of earthen-hued brown, marmots vary in fur coloration based roughly on their surroundings. Species in more open habitat are more likely to have a paler color, while those sometimes found in well-forested regions tend to be darker. Total length varies typically from about and body mass averages about in spring in the smaller species and in autumn, at times exceeding , in the larger species. The lar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Prairie Dog
Prairie dogs (genus ''Cynomys'') are herbivorous burrowing Marmotini, ground squirrels native to the grasslands of North America. There are five recognized species of prairie dog: black-tailed prairie dog, black-tailed, white-tailed prairie dog, white-tailed, Gunnison's prairie dog, Gunnison's, Utah prairie dog, Utah, and Mexican prairie dogs. In Mexico, prairie dogs are found primarily in the northern states, which lie at the southern end of the Great Plains: northeastern Sonora, north and northeastern Chihuahua (state), Chihuahua, northern Coahuila, northern Nuevo León, and northern Tamaulipas. In the United States, they range primarily to the west of the Mississippi River, though they have also been introduced in a few eastern locales. They are also found in the Canadian Prairies. Despite the name, they are not actually Canidae, canines; prairie dogs, along with the marmots, chipmunks, and several other Basal (phylogenetics), basal genera belong to the ground squirrels (Tribe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Paraphyletic
Paraphyly is a taxonomic term describing a grouping that consists of the grouping's last common ancestor and some but not all of its descendant lineages. The grouping is said to be paraphyletic ''with respect to'' the excluded subgroups. In contrast, a monophyletic grouping (a clade) includes a common ancestor and ''all'' of its descendants. The terms are commonly used in phylogenetics (a subfield of biology) and in the tree model of historical linguistics. Paraphyletic groups are identified by a combination of synapomorphies and symplesiomorphies. If many subgroups are missing from the named group, it is said to be polyparaphyletic. The term received currency during the debates of the 1960s and 1970s accompanying the rise of cladistics, having been coined by zoologist Willi Hennig to apply to well-known taxa like Reptilia (reptiles), which is paraphyletic with respect to birds. Reptilia contains the last common ancestor of reptiles and all descendants of that ancestor exc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sciuridae
Squirrels are members of the family Sciuridae (), a family that includes small or medium-sized 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 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 language">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. ''Sciurus'' is also the name of one of its genuses. The native Old English language, Old English word for the squirrel, , only survived into Middle Eng ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ground Squirrel
Ground squirrels are rodents of the squirrel family (Sciuridae) that generally live on the ground or in burrows, rather than in trees like the tree squirrels. The term is most often used for the medium-sized ground squirrels, as the larger ones are more commonly known as marmots (genus ''Marmota'') or prairie dogs, while the smaller and less bushy-tailed ground squirrels tend to be known as chipmunks (genus ''Tamias''). Together, they make up the "marmot Tribe (biology), tribe" of squirrels, Marmotini, a clade within the large and mainly ground squirrel subfamily Xerinae, and containing six living genera. Well-known members of this largely Holarctic group are the marmots (''Marmota''), including the American groundhog, the chipmunks, the susliks (''Spermophilus''), and the prairie dogs (''Cynomys''). They are highly variable in size and Morphology (biology), habitus, but most are remarkably able to rise up on their hind legs and upright posture, stand fully erect comfortably for pr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
