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Preen Gland
The uropygial gland, informally known as the preen gland or the oil gland, is a bilobed sebaceous gland possessed by the majority of birds used to distribute the gland's oil through the plumage by means of preening. It is located dorsally at the base of the tail (between the fourth caudal vertebra and the pygostyle) and is greatly variable in both shape and size. In some species, the opening of the gland has a small tuft of feathers to provide a wick for the preen oil (see below). It is a holocrine gland enclosed in a connective tissue capsule made up of glandular acini that deposit their oil secretion into a common collector tube ending in a variable number of pores (openings), most typically two. Each lobe has a central cavity that collects the secretion from tubules arranged radially around the cavity. The gland secretion is conveyed to the surface via ducts that, in most species, open at the top of a papilla (nipple-like structure). Etymology From : Medieval Latin, fro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cassowaries
Cassowaries ( tpi, muruk, id, kasuari) are flightless birds of the genus ''Casuarius'' in the order Casuariiformes. They are classified as ratites (flightless birds without a keel on their sternum bones) and are native to the tropical forests of New Guinea (Papua New Guinea and East Indonesia), Aru Islands (Maluku), and northeastern Australia.. Three species are extant: The most common, the southern cassowary, is the third-tallest and second-heaviest living bird, smaller only than the ostrich and emu. The other two species are represented by the northern cassowary and the dwarf cassowary; the northern cassowary is the most recently discovered and the most threatened. A fourth but extinct species is represented by the pygmy cassowary. Cassowaries feed mainly on fruit, although all species are truly omnivorous and take a range of other plant foods, including shoots and grass seeds, in addition to fungi, invertebrates, and small vertebrates. Cassowaries are very wary o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fatty Acid
In chemistry, particularly in biochemistry, a fatty acid is a carboxylic acid with an aliphatic chain, which is either saturated or unsaturated. Most naturally occurring fatty acids have an unbranched chain of an even number of carbon atoms, from 4 to 28. Fatty acids are a major component of the lipids (up to 70% by weight) in some species such as microalgae but in some other organisms are not found in their standalone form, but instead exist as three main classes of esters: triglycerides, phospholipids, and cholesteryl esters. In any of these forms, fatty acids are both important dietary sources of fuel for animals and important structural components for cells. History The concept of fatty acid (''acide gras'') was introduced in 1813 by Michel Eugène Chevreul, though he initially used some variant terms: ''graisse acide'' and ''acide huileux'' ("acid fat" and "oily acid"). Types of fatty acids Fatty acids are classified in many ways: by length, by saturation vs unsat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Monoester
In chemistry, an ester is a compound derived from an oxoacid (organic or inorganic) in which at least one hydroxyl group () is replaced by an alkoxy group (), as in the substitution reaction of a carboxylic acid and an alcohol. Glycerides are fatty acid esters of glycerol; they are important in biology, being one of the main classes of lipids and comprising the bulk of animal fats and vegetable oils. Esters typically have a pleasant smell; those of low molecular weight are commonly used as fragrances and are found in essential oils and pheromones. They perform as high-grade solvents for a broad array of plastics, plasticizers, resins, and lacquers, and are one of the largest classes of synthetic lubricants on the commercial market. Polyesters are important plastics, with monomers linked by ester moieties. Phosphoesters form the backbone of DNA molecules. Nitrate esters, such as nitroglycerin, are known for their explosive properties. '' Nomenclature Ety ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aliphatic Compound
In organic chemistry, hydrocarbons ( compounds composed solely of carbon and hydrogen) are divided into two classes: aromatic compounds and aliphatic compounds (; G. ''aleiphar'', fat, oil). Aliphatic compounds can be saturated, like hexane, or unsaturated, like hexene and hexyne. Open-chain compounds, whether straight or branched, and which contain no rings of any type, are always aliphatic. Cyclic compounds can be aliphatic if they are not aromatic. Structure Aliphatic compounds can be saturated, joined by single bonds (alkanes), or unsaturated, with double bonds ( alkenes) or triple bonds ( alkynes). If other elements ( heteroatoms) are bound to the carbon chain, the most common being oxygen, nitrogen, sulfur, and chlorine, it is no longer a hydrocarbon, and therefore no longer an aliphatic compound. The least complex aliphatic compound is methane (CH4). Properties Most aliphatic compounds are flammable, allowing the use of hydrocarbons as fuel, such as ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Grease Nipple
Grease fitting on a bearing A grease fitting, grease nipple, Zerk fitting, grease zerk, or Alemite fitting is a metal fitting used in mechanical systems to feed lubricants, usually lubricating grease, into a bearing under moderate to high pressure using a grease gun. Design Grease fittings are permanently installed by either a (taper) thread or straight push-fit ('hammer in') arrangement, leaving a nipple connection that a grease gun attaches to. The pressure supplied by the grease gun forces a small captive bearing ball in the fitting to move back against the force of its retaining spring. The arrangement is thus essentially a valve that opens under pressure to allow lubricant to pass through a channel and be forced into the voids of the bearing. When the pressure ceases, the ball returns to its closed position. The ball excludes dirt and functions as a check valve to prevent grease escaping back out of the fitting. The ball is almost flush with the surface of the fitt ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Glande Uropygienne
Glande (baptized as ''Richard'') was the leader of Sambians, one of the Prussian clans, during the Great Prussian Uprising (1260–1274) against the papal crusades undertaken by the Teutonic Knights. There is nothing known about his life or achievements, except that once the uprising started, Sambians elected him as their leader. The Prussian duke Glande was felled by a spear and his aid Swayno fell soon after. In the confusion and hopelessness, the Samlandians retreated to their villages. Hercus Monte came to their aid, but was also heavily wounded by a spear. Samlandians were the first tribe to give up the fight and surrendered in 1265.Urban, William. ''The Prussian Crusade'', p. 306. References Old Prussian people People from Prussia proper Pagans of the Prussian Crusade Military personnel killed in action {{Europe-mil-bio-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dust Bath
Dust bathing (also called sand bathing) is an animal behavior characterized by rolling or moving around in dust, dry earth or sand, with the likely purpose of removing parasites from fur, feathers or skin. Dust bathing is a maintenance behavior performed by a wide range of mammalian and avian species. For some animals, dust baths are necessary to maintain healthy feathers, skin, or fur, similar to bathing in water or wallowing in mud. In some mammals, dust bathing may be a way of transmitting chemical signals (or pheromones) to the ground which marks an individual's territory. Birds Birds cower close to the ground while taking a dust bath, vigorously wriggling their bodies and flapping their wings. This disperses loose substrate into the air. The birds spread one or both wings which allows the falling substrate to fall between the feathers and reach the skin. The dust bath is often followed by thorough shaking to further ruffle the feathers which may be accompanied w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Woodpeckers
Woodpeckers are part of the bird family Picidae, which also includes the piculets, wrynecks, and sapsuckers. Members of this family are found worldwide, except for Australia, New Guinea, New Zealand, Madagascar, and the extreme polar regions. Most species live in forests or woodland habitats, although a few species are known that live in treeless areas, such as rocky hillsides and deserts, and the Gila woodpecker specialises in exploiting cacti. Members of this family are chiefly known for their characteristic behaviour. They mostly forage for insect prey on the trunks and branches of trees, and often communicate by drumming with their beaks, producing a reverberatory sound that can be heard at some distance. Some species vary their diet with fruits, birds' eggs, small animals, tree sap, human scraps, and carrion. They usually nest and roost in holes that they excavate in tree trunks, and their abandoned holes are of importance to other cavity-nesting birds. They sometimes ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Frogmouths
The frogmouths are a group of nocturnal birds related to owlet-nightjars, swifts, and hummingbirds. Species in the group are distributed in the Indomalayan and Australasian realms. Biology They are named for their large flattened hooked bill and huge frog-like gape, which they use to capture insects. The three ''Podargus'' species are large frogmouths restricted to Australia and New Guinea, that have massive flat broad bills. They are known to take larger prey such as small vertebrates (frogs, mice, etc.), which are sometimes beaten against a stone before swallowing. The ten ''Batrachostomus'' frogmouths are found in tropical Asia. They have smaller, more rounded bills and are predominantly insectivorous. Both ''Podargus'' and ''Batrachostomus'' have bristles around the base of the bill, and ''Batrachostomus'' has other, longer bristles which may exist to protect the eyes from insect prey. In April 2007, a new species of frogmouth was described from the Solomon Islands and place ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Amazon Parrot
Amazon parrots are parrots in the genus ''Amazona''. They are medium-sized, short-tailed parrots native to the Americas, with their range extending from South America to Mexico and the Caribbean. ''Amazona'' is one of the 92 genera of parrots that make up the order Psittaciformes and is in the family Psittacidae, one of three families of true parrots. It contains about thirty species. Most amazons are predominantly green, with accenting colors that depend on the species, and they can be quite vivid. They feed primarily on seeds, nuts, and fruits, supplemented by leafy matter. Many amazons have the ability to mimic human speech and other sounds. Partly because of this, they are popular as pets or companion parrots, and a small industry has developed in breeding parrots in captivity for this market. This popularity has led to many parrots being taken from the wild to the extent that some species have become threatened. The United States and the European Union have made the cap ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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