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Vagrant Shrew
The vagrant shrew (''Sorex vagrans''), also known as the wandering shrew, is a medium-sized North American shrew. At one time, the montane shrew and the Orizaba long-tailed shrew were considered to belong to the same species. Range and habitat This animal inhabits open and wooded areas in western Canada and the United States west of the Continental Divide. In Canada, it is found in southern British Columbia, including Vancouver Island, and as far east as extreme south-western Alberta. In the United States, it is found throughout most of Washington, Oregon, and Idaho, as far south as central California, in northern and central Nevada, northern Utah, and western Montana and Wyoming. Their preferred habitat appears to be wet grassland and meadows, ranging from alpine tundra to swampland, and they are often found close to rivers or other sources of water. They are also found in open coniferous forest, but only rarely in dense woodlands. Because they often use fallen logs as cover, th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spencer Fullerton Baird
Spencer Fullerton Baird (; February 3, 1823 – August 19, 1887) was an American naturalist, ornithologist, ichthyologist, herpetologist, and museum curator. Baird was the first curator to be named at the Smithsonian Institution. He eventually served as assistant Secretary of the Smithsonian from 1850 to 1878, and as Secretary from 1878 until 1887. He was dedicated to expanding the natural history collections of the Smithsonian which he increased from 6,000 specimens in 1850 to over 2 million by the time of his death. He published over 1,000 works during his lifetime. Early life and education Spencer Fullerton Baird was born in Reading, Pennsylvania in 1823. His mother was a member of the prominent Philadelphia Biddle family; he was a nephew of Speaker of the Pennsylvania Senate Charles B. Penrose and a first cousin, once removed, of U.S. Senator Boies Penrose and his distinguished brothers, Richard, Spencer, and Charles. He became a self-trained naturalist as a young man, le ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Swamp
A swamp is a forested wetland.Keddy, P.A. 2010. Wetland Ecology: Principles and Conservation (2nd edition). Cambridge University Press, Cambridge, UK. 497 p. Swamps are considered to be transition zones because both land and water play a role in creating this environment. Swamps vary in size and are located all around the world. The water of a swamp may be fresh water, brackish water, or seawater. Freshwater swamps form along large rivers or lakes where they are critically dependent upon rainwater and seasonal flooding to maintain natural water level fluctuations.Hughes, F.M.R. (ed.). 2003. The Flooded Forest: Guidance for policy makers and river managers in Europe on the restoration of floodplain forests. FLOBAR2, Department of Geography, University of Cambridge, Cambridge, UK. 96 p. Saltwater swamps are found along tropical and subtropical coastlines. Some swamps have hammocks, or dry-land protrusions, covered by aquatic vegetation, or vegetation that tolerates periodic inundatio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Animals That Use Echolocation
Animals are multicellular, eukaryotic organisms in the biological kingdom Animalia. With few exceptions, animals consume organic material, breathe oxygen, are able to move, can reproduce sexually, and go through an ontogenetic stage in which their body consists of 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 to . They have complex interactions with each other and their environments, forming intricate food webs. The scientific study of animals is known as zoology. Most living animal species are in Bilateria, a clade whose members have a bilaterally symmetric body plan. The Bilateria include the protostomes, containing animals such as nematodes, arthropods, flatworms, annelids and molluscs, and the deuterostomes, containing the echinoder ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sorex
The genus ''Sorex'' includes many of the common shrews of Eurasia and North America, and contains at least 142 known species and subspecies. Members of this genus, known as long-tailed shrews, are the only members of the tribe Soricini of the subfamily ''Soricinae'' ( red-toothed shrews). They have 32 teeth. These animals have long, pointed snouts, small ears, which are often not visible, and scent glands located on the sides of their bodies. As their eyesight is generally poor, they rely on hearing and smell to locate their prey, mainly insects. Some species also use echolocation. Distinguishing between species without examining the dental pattern is often difficult. In some species, a female shrew and her dependent young form "caravans", in which each shrew grasps the rear of the shrew in front, when changing location. Species * Genus ''Sorex'' – most basal of the genera ** Kashmir pygmy shrew (''S. planiceps'') – India and Pakistan ** Tibetan shrew (''S. thibetanus'') ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Weaning
Weaning is the process of gradually introducing an infant human or another mammal to what will be its adult diet while withdrawing the supply of its mother's milk. The process takes place only in mammals, as only mammals produce milk. The infant is considered to be fully weaned once it is no longer fed by any breast milk (or bottled substitute). Humans In some cultures, weaning progresses with the introduction of feeding the child food that has been prechewed by the parent along with continued breastfeeding, a practice known as premastication. The practice was important throughout human history in that it naturally gave a child a greatly improved protein source in addition to preventing iron deficiency. However, premasticated food from caregivers of lower socioeconomic status in areas of endemic diseases can result in the passing of the disease to the child. How and when to wean a human infant is controversial. The American Academy of Pediatrics recommends feeding a baby on ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vole
Voles are small rodents that are relatives of lemmings and hamsters, but with a stouter body; a longer, hairy tail; a slightly rounder head; smaller eyes and ears; and differently formed molars (high-crowned with angular cusps instead of low-crowned with rounded cusps). They are sometimes known as meadow mice or field mice in North America. Vole species form the subfamily Arvicolinae with the lemmings and the muskrats. There are approximately 155 different vole species. Description Voles are small rodents that grow to , depending on the species. Females can have five to ten litters per year, though with an average lifespan of three months and requiring one month to adulthood, two litters is the norm. Gestation lasts for three weeks and the young voles reach sexual maturity in a month. As a result of this biological exponential growth, vole populations can grow very large within a short time. A mating pair can produce a hundred more voles in a year. Voles outwardly res ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Animal Echolocation
Echolocation, also called bio sonar, is a biological sonar used by several animal species. Echolocating animals emit calls out to the environment and listen to the echoes of those calls that return from various objects near them. They use these echoes to locate and identify the objects. Echolocation is used for navigation, foraging, and hunting in various environments. Echolocating animals include some mammals (most notably Laurasiatheria) and a few birds, especially some bat species and odontocetes (toothed whales and dolphins), but also in simpler forms in other groups such as shrews, and two cave-dwelling bird groups, the so-called cave swiftlets in the genus '' Aerodramus'' (formerly ''Collocalia'') and the unrelated oilbird ''Steatornis caripensis''. Early research The term ''echolocation'' was coined in 1938 by the American zoologist Donald Griffin, who, with Robert Galambos, first demonstrated the phenomenon in bats. As Griffin described in his book, the 18t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Home Range
A home range is the area in which an animal lives and moves on a periodic basis. It is related to the concept of an animal's territory which is the area that is actively defended. The concept of a home range was introduced by W. H. Burt in 1943. He drew maps showing where the animal had been observed at different times. An associated concept is the utilization distribution which examines where the animal is likely to be at any given time. Data for mapping a home range used to be gathered by careful observation, but nowadays, the animal is fitted with a transmission collar or similar GPS device. The simplest way of measuring the home range is to construct the smallest possible convex polygon around the data but this tends to overestimate the range. The best known methods for constructing utilization distributions are the so-called bivariate Gaussian or normal distribution kernel density methods. More recently, nonparametric methods such as the Burgman and Fox's alpha-hull and Get ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Torpor
Torpor is a state of decreased physiological activity in an animal, usually marked by a reduced body temperature and metabolic rate. Torpor enables animals to survive periods of reduced food availability. The term "torpor" can refer to the time a hibernator spends at low body temperature, lasting days to weeks, or it can refer to a period of low body temperature and metabolism lasting less than 24 hours, as in "daily torpor". Animals that undergo daily torpor include birds (even tiny hummingbirds, notably Cypselomorphae) and some mammals, including many marsupial species, rodent species (such as mice), and bats. During the active part of their day, such animals maintain normal body temperature and activity levels, but their metabolic rate and body temperature drop during a portion of the day (usually night) to conserve energy. Some animals seasonally go into long periods of inactivity, with reduced body temperature and metabolism, made up of multiple bouts of torpor. This ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Basal Metabolic Rate
Basal metabolic rate (BMR) is the rate of energy expenditure per unit time by endothermic animals at rest. It is reported in energy units per unit time ranging from watt (joule/second) to ml O2/min or joule per hour per kg body mass J/(h·kg). Proper measurement requires a strict set of criteria to be met. These criteria include being in a physically and psychologically undisturbed state and being in a thermally neutral environment while in the post-absorptive state (i.e., not actively digesting food). In bradymetabolic animals, such as fish and reptiles, the equivalent term standard metabolic rate (SMR) applies. It follows the same criteria as BMR, but requires the documentation of the temperature at which the metabolic rate was measured. This makes BMR a variant of standard metabolic rate measurement that excludes the temperature data, a practice that has led to problems in defining "standard" rates of metabolism for many mammals. Metabolism comprises the processes that the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Trowbridge's Shrew
Trowbridge's shrew (''Sorex trowbridgii'') is a species of mammal in the family Soricidae. It is found in southern British Columbia in Canada and in Washington, Oregon, and California in the United States. Taxonomy Trowbridge's shrew was first described in the scientific literature in 1857 by Spencer Fullerton Baird, in a report of surveys and explorations conducted to find a suitable route for a railroad from the Mississippi to the Pacific Ocean. The scientific name given was ''Sorex trowbridgii''. The generic name ''Sorex'' is Latin, meaning "shrew-mouse." The species name "trowbridgii" is a patronym to honor William Petit Trowbridge. The type locality for the species is Astoria, Oregon. Baird's initial record describes four specimens made available to him. The first two were provided by Trowbridge. They were skins that had been collected by "Jas. Wayne" in June 1855. The other two specimens were collected by George Suckley at Fort Steilacoom in 1856. Those two spe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Friction Pad
Friction is the force resisting the relative motion of solid surfaces, fluid layers, and material elements sliding against each other. There are several types of friction: *Dry friction is a force that opposes the relative lateral motion of two solid surfaces in contact. Dry friction is subdivided into ''static friction'' (" stiction") between non-moving surfaces, and ''kinetic friction'' between moving surfaces. With the exception of atomic or molecular friction, dry friction generally arises from the interaction of surface features, known as asperities (see Figure 1). *Fluid friction describes the friction between layers of a viscous fluid that are moving relative to each other. *Lubricated friction is a case of fluid friction where a lubricant fluid separates two solid surfaces. *Skin friction is a component of drag, the force resisting the motion of a fluid across the surface of a body. *Internal friction is the force resisting motion between the elements making up a so ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
