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Colombian Grebe
The Colombian grebe (''Podiceps andinus''), was a grebe found in the Bogotá wetlands on the Bogotá savanna in the Eastern Ranges of the Andes of Colombia. The species was still abundant in Lake Tota in 1945. The species has occasionally been considered a subspecies of black-necked grebe (''P. nigricollis''). It was flightless. The decline of the Colombian grebe is attributed to wetland drainage, siltation, pesticide pollution, disruption by reed harvesting, hunting, competition, and predation of chicks by rainbow trout (''Oncorhynchus mykiss''). The primary reason was loss of habitat: drainage of wetlands and siltation resulted in higher concentrations of pollutants, causing eutrophication across Lake Tota. This destroyed the open, submergent pondweed ('' Potamogeton'') vegetation and resulted in the formation of a dense monoculture of water weed (''Elodea ''Elodea'' is a genus of 6 species of aquatic plants often called the waterweeds described as a genus in 1803. Clas ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rodolphe Meyer De Schauensee
Rodolphe Meyer de Schauensee (January 4, 1901 – April 24, 1984) was an American ornithologist. He was born in Rome , established_title = Founded , established_date = 753 BC , founder = King Romulus ( legendary) , image_map = Map of comune of Rome (metropolitan city of Capital Rome, region Lazio, Italy).svg , map_caption ..., Italy to a Swiss aristocratic family. His family moved to the United States in 1913. He was the curator of ornithology at the Academy of Natural Sciences in Philadelphia for nearly fifty years. He was particularly noted for his study of South American birds. He expanded the academy's collection of bird skins, taking part in collecting trips to Brazil, Thailand, Burma, southern Africa, the East Indies, and Guatemala. He wrote about the birds of South America, including the groundbreaking ''A Guide to the Birds of South America'' in 1970, and published a book on the birds of China just two weeks before his death. De S ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eutrophication
Eutrophication is the process by which an entire body of water, or parts of it, becomes progressively enriched with minerals and nutrients, particularly nitrogen and phosphorus. It has also been defined as "nutrient-induced increase in phytoplankton productivity". Water bodies with very low nutrient levels are termed oligotrophic and those with moderate nutrient levels are termed mesotrophic. Advanced eutrophication may also be referred to as dystrophic and hypertrophic conditions. Eutrophication can affect freshwater or salt water systems. In freshwater ecosystems it is almost always caused by excess phosphorus. In coastal waters on the other hand, the main contributing nutrient is more likely to be nitrogen, or nitrogen and phosphorus together. This depends on the location and other factors. When occurring naturally, eutrophication is a very slow process in which nutrients, especially phosphorus compounds and organic matter, accumulate in water bodies. These nutrients deriv ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Extinct Birds Of South America
Extinction is the termination of a kind of organism or of a group of kinds (taxon), usually a species. The moment of extinction is generally considered to be the death of the last individual of the species, although the capacity to breed and recover may have been lost before this point. Because a species' potential range may be very large, determining this moment is difficult, and is usually done retrospectively. This difficulty leads to phenomena such as Lazarus taxa, where a species presumed extinct abruptly "reappears" (typically in the fossil record) after a period of apparent absence. More than 99% of all species that ever lived on Earth, amounting to over five billion species, are estimated to have died out. It is estimated that there are currently around 8.7 million species of eukaryote globally, and possibly many times more if microorganisms, like bacteria, are included. Notable extinct animal species include Dinosaur, non-avian dinosaurs, Machairodontinae, sab ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Taxa Named By Rodolphe Meyer De Schauensee
In biology, a taxon (back-formation from ''taxonomy''; plural taxa) is a group of one or more populations of an organism or organisms seen by taxonomists to form a unit. Although neither is required, a taxon is usually known by a particular name and given a particular ranking, especially if and when it is accepted or becomes established. It is very common, however, for taxonomists to remain at odds over what belongs to a taxon and the criteria used for inclusion. If a taxon is given a formal scientific name, its use is then governed by one of the nomenclature codes specifying which scientific name is correct for a particular grouping. Initial attempts at classifying and ordering organisms (plants and animals) were set forth in Carl Linnaeus's system in ''Systema Naturae'', 10th edition (1758), as well as an unpublished work by Bernard and Antoine Laurent de Jussieu. The idea of a unit-based system of biological classification was first made widely available in 1805 in the intro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Birds Described In 1959
Birds are a group of warm-blooded vertebrates constituting the class Aves (), characterised by feathers, toothless beaked jaws, the laying of hard-shelled eggs, a high metabolic rate, a four-chambered heart, and a strong yet lightweight skeleton. Birds live worldwide and range in size from the bee hummingbird to the ostrich. There are about ten thousand living species, more than half of which are passerine, or "perching" birds. Birds have whose development varies according to species; the only known groups without wings are the extinct moa and elephant birds. Wings, which are modified forelimbs, gave birds the ability to fly, although further evolution has led to the loss of flight in some birds, including ratites, penguins, and diverse endemic island species. The digestive and respiratory systems of birds are also uniquely adapted for flight. Some bird species of aquatic environments, particularly seabirds and some waterbirds, have further evolved for swimming. Birds ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bird Extinctions Since 1500
Birds are a group of warm-blooded vertebrates constituting the class Aves (), characterised by feathers, toothless beaked jaws, the laying of hard-shelled eggs, a high metabolic rate, a four-chambered heart, and a strong yet lightweight skeleton. Birds live worldwide and range in size from the bee hummingbird to the ostrich. There are about ten thousand living species, more than half of which are passerine, or "perching" birds. Birds have whose development varies according to species; the only known groups without wings are the extinct moa and elephant birds. Wings, which are modified forelimbs, gave birds the ability to fly, although further evolution has led to the loss of flight in some birds, including ratites, penguins, and diverse endemic island species. The digestive and respiratory systems of birds are also uniquely adapted for flight. Some bird species of aquatic environments, particularly seabirds and some waterbirds, have further evolved for swimming. Bird ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Podiceps
''Podiceps'' is a genus of birds in the grebe family. The genus name comes from Latin ''podicis'', "rear-end" and ''ped'', "foot", and is a reference to the placement of a grebe's legs towards the rear of its body. It has representatives breeding in Europe, Asia, North, and South America. Most northern hemisphere species migrate in winter to the coast or warmer climates. They breed in vegetated areas of freshwater lakes, nesting on the water's edge, since their legs are set too far back for easy walking. Usually two eggs are laid, and the striped young may be carried on the adult's back. All the genus are excellent swimmers and divers, and pursue their fish prey underwater. Adults have striking breeding plumage, with no difference between the sexes. In winter, the plumage is subdued whites and greys. Systematics The genus ''Podiceps'' was erected by the English naturalist John Latham in 1787. The type species was subsequently designated as the great crested grebe (''Podice ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Elodea
''Elodea'' is a genus of 6 species of aquatic plants often called the waterweeds described as a genus in 1803. Classified in the frog’s-bit family (Hydrocharitaceae), ''Elodea'' is native to the Americas and is also widely used as aquarium vegetation and laboratory demonstrations of cellular activities. It lives in fresh water. An older name for this genus is ''Anacharis'', which serves as a common name in North America. The introduction of some species of ''Elodea'' into waterways in parts of Europe, Australia, Africa, Asia, and New Zealand has created a significant problem and it is now considered a noxious weed in these areas. ''Elodea canadensis'', sometimes called American or Canadian water weed or pond weed, is widely known as the generic water weed. The use of these names causes it to be confused with similar-looking plants, like Brazilian elodea (''Egeria densa'') or hydrilla (''Hydrilla verticillata''). American water weed is an attractive aquarium plant and is a good ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Monoculture
In agriculture, monoculture is the practice of growing one crop species in a field at a time. Monoculture is widely used in intensive farming and in organic farming: both a 1,000-hectare/acre cornfield and a 10-ha/acre field of organic kale are monocultures. Monoculture of crops has allowed farmers to increase efficiency in planting, managing, and harvesting, mainly by facilitating the use of machinery in these operations, but monocultures can also increase the risk of diseases or pest outbreaks. Diversity can be added both in time, as with a crop rotation or sequence, or in space, with a polyculture or intercropping (see table below). Continuous monoculture, or monocropping, where farmers raise the same species year after year, can lead to the quicker buildup and spread of pests and diseases in a susceptible crop. The term "oligoculture" has been used to describe a crop rotation of just a few crops, as practiced in several regions of the world. The concept of monoculture c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Potamogeton
''Potamogeton'' is a genus of aquatic, mostly freshwater, plants of the family Potamogetonaceae. Most are known by the common name pondweed, although many unrelated plants may be called pondweed, such as Canadian pondweed (''Elodea canadensis''). The genus name means "river neighbor", originating from the Greek ''potamos'' (river) and ''geiton'' (neighbor). Morphology ''Potamogeton'' species range from large (stems of 6 m or more) to very small (less than 10 cm). Height is strongly influenced by environmental conditions, particularly water depth. All species are technically perennial, but some species disintegrate in autumn to a large number of asexually produced resting buds called turions, which serve both as a means of overwintering and dispersal. Turions may be borne on the rhizome, on the stem, or on stolons from the rhizome. Most species, however, persist by perennial creeping rhizomes. In some cases the turions are the only means to differentiate species. The leav ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pondweed , an order of green algae
{{Plant common name ...
Pondweed refers to many species and genera of aquatic plants and green algae: *''Potamogeton'', a diverse and worldwide genus *''Elodea'', found in North America *''Aponogeton'', in Africa, Asia and Australasia *''Groenlandia'', a genus of aquatic plants *'' Stuckenia'', a genus of aquatic plants *Charales Charales is an order of freshwater green algae in the division Charophyta, class Charophyceae, commonly known as stoneworts. Depending on the treatment of the genus '' Nitellopsis'', living (extant) species are placed into either one family (Ch ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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