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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] |
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