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White-ankled Mouse
The white-ankled mouse (''Peromyscus pectoralis'') is a species of rodent in the family Cricetidae. It is found in Mexico and in New Mexico, Oklahoma and Texas in the United States. The white-ankled mouse is commonly found in coexistence with the brush mouse and Texas mouse (''P. boylii'' and ''P. attaweri'', respectively). Often, the sympatric overlap in characteristics between these species makes it difficult to identify a specific species. The most distinguishing feature of the white-ankled mouse, and the one most used to identify the species, is the baculum of males (Hooper 1958). The tip of the white-ankled mouse's baculum is long and cartilaginous, whereas the tips of brush and Texas mice are short and rounded (Clark 1952 and Hooper 1958). Description White-ankled mice have three distinct pelages in their life cycles: juvenile, subadult, and adult. Two molt phases (post-juvenile and post-subadult) are necessary for the distinct pelages in each phase of their lives (Hoffmei ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wilfred Hudson Osgood
Wilfred Hudson Osgood (December 8, 1875 – June 20, 1947) was an American zoologist. Biography Osgood was born in Rochester, New Hampshire, the oldest child of a family of watchmakers. The family moved to California in 1888 and he went to study in Santa Clara, California, Santa Clara and San Jose, California, San Jose. He joined in the activities of the Cooper Ornithological Club and found company in wikisource:Author:Chester Barlow, Chester Barlow and Rollo Beck, Rollo H. Beck. He taught at a school in Arizona for a year and then moved to the newly formed Stanford University, where he came to meet Charles Henry Gilbert, Charles H. Gilbert and David Starr Jordan. He joined the staff of the Bureau of Economic Ornithology and Mammalogy, of the United States Department of Agriculture at the age of 22. This group later became the Bureau of Biological Survey under Clinton Hart Merriam. In 1909 he moved to the Field Museum of Natural History in Chicago, where he was assistant curator o ... [...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] |
Rodents Of The United States
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 incisors al ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rodents Of Mexico
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 incisors al ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Peromyscus
''Peromyscus'' is a genus of rodents. They are commonly referred to as deer mice or deermice, not to be confused with the chevrotain or "mouse deer". They are New World mice only distantly related to the common house and laboratory mouse, ''Mus musculus''. From this relative, ''Peromyscus'' species are distinguished by relatively larger eyes, and also often two-tone coloring, with darker colors over the dorsum (back), and white abdominal and limb hair-coloring. In reference to the coloring, the word ''Peromyscus'' comes from Greek words meaning "booted mouse". They are also accomplished jumpers and runners by comparison to house mice, and their common name of "deer mouse" (coined in 1833) is in reference to this agility. The most common species of deer mice in the continental United States are two closely related species, '' P. maniculatus'' and '' P. leucopus''. In the United States, ''Peromyscus'' is the most populous mammalian genus overall, and has become notorious in the w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Interspecific Competition
Interspecific competition, in ecology, is a form of competition in which individuals of ''different'' species compete for the same resources in an ecosystem (e.g. food or living space). This can be contrasted with mutualism, a type of symbiosis. Competition between members of the same species is called intraspecific competition. If a tree species in a dense forest grows taller than surrounding tree species, it is able to absorb more of the incoming sunlight. However, less sunlight is then available for the trees that are shaded by the taller tree, thus interspecific competition. Leopards and lions can also be in interspecific competition, since both species feed on the same prey, and can be negatively impacted by the presence of the other because they will have less food. Competition is only one of many interacting biotic and abiotic factors that affect community structure. Moreover, competition is not always a straightforward, direct, interaction. Interspecific competition m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Microhabitats
In ecology, the term habitat summarises the array of resources, physical and biotic factors that are present in an area, such as to support the survival and reproduction of a particular species. A species habitat can be seen as the physical manifestation of its ecological niche. Thus "habitat" is a species-specific term, fundamentally different from concepts such as environment or vegetation assemblages, for which the term "habitat-type" is more appropriate. The physical factors may include (for example): soil, moisture, range of temperature, and light intensity. Biotic factors will include the availability of food and the presence or absence of predators. Every species has particular habitat requirements, with habitat generalist species able to thrive in a wide array of environmental conditions while habitat specialist species requiring a very limited set of factors to survive. The habitat of a species is not necessarily found in a geographical area, it can be the interior ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Molar Teeth
The molars or molar teeth are large, flat teeth at the back of the mouth. They are more developed in mammals. They are used primarily to grind food during chewing. The name ''molar'' derives from Latin, ''molaris dens'', meaning "millstone tooth", from ''mola'', millstone and ''dens'', tooth. Molars show a great deal of diversity in size and shape across mammal groups. The third molar of humans is sometimes vestigial. Human anatomy In humans, the molar teeth have either four or five cusps. Adult humans have 12 molars, in four groups of three at the back of the mouth. The third, rearmost molar in each group is called a wisdom tooth. It is the last tooth to appear, breaking through the front of the gum at about the age of 20, although this varies from individual to individual. Race can also affect the age at which this occurs, with statistical variations between groups. In some cases, it may not even erupt at all. The human mouth contains upper (maxillary) and lower (mandibul ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Biological Life Cycle
In biology, a biological life cycle (or just life cycle or lifecycle when the biological context is clear) is a series of changes in form that an organism undergoes, returning to the starting state. "The concept is closely related to those of the life history, development and ontogeny, but differs from them in stressing renewal." Transitions of form may involve growth, asexual reproduction, or sexual reproduction. In some organisms, different "generations" of the species succeed each other during the life cycle. For plants and many algae, there are two multicellular stages, and the life cycle is referred to as alternation of generations. The term life history is often used, particularly for organisms such as the red algae which have three multicellular stages (or more), rather than two.Dixon, P.S. 1973. ''Biology of the Rhodophyta.'' Oliver & Boyd. Life cycles that include sexual reproduction involve alternating haploid (''n'') and diploid (2''n'') stages, i.e., a change of pl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pelage
Fur is a thick growth of hair that covers the skin of mammals. It consists of a combination of oily #Guard hair, guard hair on top and thick #Down hair, underfur beneath. The guard hair keeps moisture from reaching the skin; the underfur acts as an thermal insulation, insulating blanket that keeps the animal warm. The fur of mammals has many uses: protection, sensory purposes, waterproofing, and camouflaging, with the primary usage being thermoregulation. The types of hair include * ''definitive'', which may be moulting, shed after reaching a certain length; * ''vibrissae'', which are sensory hairs and are most commonly whiskers; * ''pelage'', which consists of guard hairs, under-fur, and awn hair; * ''spine (zoology), spines'', which are a type of stiff guard hair used for defense in, for example, porcupines; * ''bristles'', which are long hairs usually used in visual signals, such as the mane (lion), mane of a lion; * ''velli'', often called "down fur", which insulates new ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Texas Mouse
The Texas mouse (''Peromyscus attwateri'') is a species of rodent in the family Cricetidae. It is found in Arkansas, Kansas, Missouri, Oklahoma, and Texas in the United States. This species is named in honor of Henry Philemon Attwater. Description The Texas mouse is considered medium-sized for its genus. Its long, bicolored tail has brownish fur, and the tail is brownish white and well haired, and slightly tufted at the end; it has large hind feet. It has usually dark or dusky ankles, and the ear is medium-sized. Color of the dorsum is dark mixed with brown and blackish hairs, and its side color is pinkish cinnamon, and the belly and feet have a pure white color. The mouse is morphological adapted to have a long tail, for balancing when climbing a vertical surface, and large eyes adapted to activity in darkness. Adult Peromyscus attwateri's total length is usually about 182 to 220 mm with weight 25-35 grams. The tail is about 83-104mm, ear length is about 18–20 mm ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Species
In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. Other ways of defining species include their karyotype, DNA sequence, morphology, behaviour or ecological niche. In addition, paleontologists use the concept of the chronospecies since fossil reproduction cannot be examined. The most recent rigorous estimate for the total number of species of eukaryotes is between 8 and 8.7 million. However, only about 14% of these had been described by 2011. All species (except viruses) are given a two-part name, a "binomial". The first part of a binomial is the genus to which the species belongs. The second part is called the specific name or the specific epithet (in botanical nomenclature, also sometimes i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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