Amazon basin

The Amazon Basin is the part of South America drained by the Amazon River and its tributaries. The Amazon drainage basin covers an area of about 6,300,000 km2 (2,400,000 sq mi), or about 35.5 percent that of the South American continent. It is located in the countries of Bolivia, Brazil, Colombia, Ecuador, Guyana, Peru, Suriname and Venezuela.[1]

Most of the basin is covered by the Amazon Rainforest, also known as Amazonia. With a 5,500,000 km2 (2,100,000 sq mi) area of dense tropical forest, this is the largest rainforest in the world.

Amazonriverbasin basemap
Amazon River Basin (the southern Guianas, not marked on this map, are part of the basin)
Mouths of amazon geocover 1990
The mouth of the Amazon River

Geography

The Amazon River begins in the Andes Mountains at the west of the basin with its main tributary the Marañón River in Peru. The highest point in the watershed of the Amazon is the peak of Yerupajá at 6,635 metres (21,768 ft).

With a length of about 6,400 km (4,000 mi) before it drains into the Atlantic Ocean, it is one of the two longest rivers in the world; a team of Brazilian scientists has claimed that the Amazon is longer than the Nile [2] but debate about its exact length continues. [3]

The Amazon system transports the largest volume of water of any river system, accounting for about 20% of the total water carried to the oceans by rivers.

Some of the Amazon rainforests are deforested because of the increasing of cattle ranches and soy beans field.

The Amazon basin formerly flowed west to Pacific Ocean until the Andes formed, causing the basin to flow eastward towards the Atlantic Ocean.[4]

Politically the basin is divided into the Brazilian Amazônia Legal, the Peruvian Amazon, the Amazon region of Colombia and parts of Bolivia, Ecuador and the Venezuelan state of Amazonas.

Plant life

Campo12Foto 2
Aerial view of part of the Amazon rainforest.

Plant growth is dense and its variety of animal inhabitants is comparatively high due to the heavy rainfall and the dense and extensive evergreen and coniferous forests. Little sunlight reaches the ground due to the dense roof canopy by plants. The ground remains dark and damp and only shade tolerant vegetation will grow here. Orchids and bromeliads exploit trees and other plants to get closer to the sunlight. They grow hanging onto the branches or tree trunks with aerial roots, not as parasites but as epiphytes. Species of tropical trees native to the Amazon include Brazil nut, rubber tree and Assai palm.[5][6]

Animal life

Mammals

More than 1,400 species of mammals are found in the Amazon, the majority of which are species of bats and rodents. Its larger mammals include the jaguar, ocelot, capybara and South American tapir.

Birds

About 1500 bird species inhabit the Amazon Basin.[7] The biodiversity of the Amazon and the sheer number of diverse bird species is given by the number of different bird families that reside in these humid forests. An example of such would be the cotinga family, to which the Guianan cock-of-the-rock belong. Birds such as toucans, and hummingbirds are also found here. Macaws are famous for gathering by the hundreds along the clay cliffs of the Amazon River. In the western Amazon hundreds of macaws and other parrots descend to exposed river banks to consume clay on an almost daily basis,[8] the exception being rainy days.[9]

Reptiles

The green anaconda inhabits the shallow waters of the Amazon and the emerald tree boa and boa constrictor live in the Amazonian tree tops.

Many reptiles species are illegally collected and exported for the international pet trade. Live animals are the fourth largest commodity in the smuggling industry after drugs, diamonds, and weapons.[10]

Amphibians

More than 1,500 species of amphibians swim and are found in the Amazon. Unlike temperate frogs which are mostly limited to habitats near the water, tropical frogs are most abundant in the trees and relatively few are found near bodies of water on the forest floor. The reason for this occurrence is quite simple: frogs must always keep their skin moist since almost half of their respiration is carried out through their skin. The high humidity of the rainforest and frequent rainstorms gives tropical frogs infinitely more freedom to move into the trees and escape the many predators of rainforest waters. The differences between temperate and tropical frogs extend beyond their habitat.

Gregory Moine - Red bellied Piranha (by)
Red-bellied piranha (Pygocentrus nattereri) is a species of piranha. This species lives in the Amazon River basin, coastal rivers of northeastern Brazil, and the basins of the Paraguay, Paraná and Essequibo Rivers.

Fish

About 2,500 fish species are known from the Amazon basin and it is estimated that more than 1,000 additional undescribed species exist.[11] This is more than any other river basin on Earth, and Amazonia is the center of diversity for Neotropical fishes.[12] About 45% (more than 1,000 species) of the known Amazonian fish species are endemic to the basin.[13] The remarkable species richness can in part be explained by the large differences between the various parts of the Amazon basin, resulting in many fish species that are endemic to small regions. For example, fauna in clearwater rivers differs from fauna in white and blackwater rivers, fauna in slow moving sections show distinct differences compared to that in rapids, fauna in small streams differ from that in major rivers, and fauna in shallow sections show distinct differences compared to that in deep parts.[14][15][16] By far the most diverse orders in the Amazon are Characiformes (43% of total fish species in the Amazon) and Siluriformes (39%), but other groups with many species include Cichlidae (6%) and Gymnotiformes (3%).[11]

In addition to major differences in behavior and ecology, Amazonian fish vary extensively in form and size. The largest, the arapaima and piraiba can reach 3 m (9.8 ft) or more in length and up to 200 kg (440 lb) in weight, making them some of the largest strict freshwater fish in the world.[17][18] The bull shark and common sawfish, which have been recorded far up the Amazon, may reach even greater sizes, but they are euryhaline and often seen in marine waters.[19][20] In contrast to the giants, there are Amazonian fish from several families that are less than 2 cm (0.8 in) long. The smallest are likely the Leptophilypnion sleeper gobies, which do not surpass 1 cm (0.4 in) and are among the smallest fish in the world.[21]

The Amazon supports very large fisheries, including well-known species of large catfish (such as Brachyplatystoma, which perform long breeding migrations up the Amazon), arapaima and tambaqui, and is also home to many species that are important in the aquarium trade, such as the oscar, discus, angelfish, Corydoras catfish and neon tetra.[11] Although the true danger they represent often is greatly exaggerated, the Amazon basin is home to several feared fish species such as piranhas (including the famous red-bellied), electric eel, river stingrays and candiru. Several cavefish species in the genus Phreatobius are found in the Amazon, as is the cave-dwelling Astroblepus pholeter in the far western part of the basin (Andean region).[22] The Tocantins basin, arguably not part of the Amazon basin, has several other cavefish species.[22] The deeper part of the major Amazonian rivers are always dark and a few species have adaptions similar to cavefish (reduced pigment and eyes). Among these are the knifefish Compsaraia and Orthosternarchus, some Cetopsis whale catfish (especially C. oliveirai), some Xyliphius and Micromyzon banjo catfish,[23] and the loricariid catfish Loricaria spinulifera, L. pumila, Peckoltia pankimpuju, Panaque bathyphilus and Panaqolus nix (these five also occur in "normal" forms of shallower waters).[24][25][26] The perhaps most unusual habitat used by Amazonian fish is land. The splash tetra is famous for laying its eggs on plants above water, keeping them moist by continuously splashing on them,[27] the South American lungfish can survive underground in a mucous cocoon during the dry season,[28] some small rivulid killifish can jump over land between water sources (sometimes moving relatively long distances, even uphill) and may deliberately jump onto land to escape aquatic predators,[29][30] and an undescribed species of worm-like Phreatobius catfish lives in waterlogged leaf litter near (not in) streams.[31][32]

Some of the major fish groups of the Amazon basin include:

Insects

More than 90% of the animal species in the Amazon are insects,[33] of which about 40% are beetles (Coleoptera constituting almost 25% of all known types of animal life-forms[34][35][36]).

Whereas all of Europe has some 321 butterfly species, the Manú National Park in Peru (4000 hectare-survey) has 1300 species, while Tambopata National Reserve (5500 hectare-survey) has at least 1231 species.

Climate and seasons

The Amazon River basin has a low-water season, and a wet season during which, the rivers flood the adjacent, low-lying forests. The climate of the basin is generally hot and humid. In some areas, however, the winter months (June–September) can bring cold snaps, fueled by Antarctic winds travelling along the adjacent mountain range. The average annual temperature is around 25 degree and 30 degree Celsius with no distinction between summer and winter seasons.

Human lifestyle

Amazonas floating village, Iquitos, Photo by Sascha Grabow
A floating village in Iquitos, Peru

Amazonia is sparsely populated. There are scattered settlements inland, but most of the population lives in a few larger cities on the banks of the Amazon and other major rivers, such as in Iquitos, Peru, and Manaus and Belém (Brazil). In many regions, the forest has been cleared for soya bean plantations and ranching (the most extensive non-forest use of the land); some of the inhabitants harvest wild rubber latex, and Brazil nuts. This is a form of extractive farms, where the trees are not cut down. These are relatively sustainable operations in contrast to lumbering or agriculture dependent on clearing the rainforest. The people live in thatched houses shaped liked beehives. They also build apartment-like houses called "Maloca", with a steeply slanting roof.

The largest organization fighting for the indigenous peoples in this area is COICA. It is a supra organization encompassing all indigenous rights organizations working in the Amazon basin area, and covers the people living in several countries.

River commerce

The river is the principal path of transportation for people and produce in the regions, with transport ranging from balsa rafts and dugout canoes to hand built wooden river craft and modern steel hulled craft.

Agriculture

Seasonal floods excavate and redistribute nutrient-rich silt onto beaches and islands, enabling dry-season riverside agriculture of rice, beans, and corn on the river's shoreline without the addition of fertilizer, with additional slash and burn agriculture on higher floodplains. Fishing provides additional food year round, and free-range chickens need little or no food beyond what they can forage locally. Charcoal made largely from forest and shoreline deadfall is produced for use in urban areas. Exploitation of bush meat, particularly deer and turtles is common.

Amazonie deforestation
Deforestationand increased road-building bring human encroachment upon wild areas, increased resource extraction and threats to biodiversity.

Extensive deforestation, particularly in Brazil, is leading to the extinction of known and unknown species, reducing biological diversity and adversely impacting soil, water, and air quality. A final part of the deforestation process is the large-scale production of charcoal for industrial processes such as steel manufacturing. Soils within the region are generally shallow and cannot be used for more than a few seasons without the addition of imported fertilizers and chemicals.

Languages

The most widely spoken language in the Amazon is Portuguese, followed closely by Spanish. On the Brazilian side Portuguese is spoken by at least 98% of the population, whilst in the Spanish-speaking countries a large number of speakers of indigenous languages are present, though Spanish is predominant.

There are hundreds of native languages still spoken in the Amazon, most of which are spoken by only a handful of people, and thus are critically endangered. One of the more widely spoken indigenous languages in the Amazon is Nheengatu, which descends from the ancient Tupi language, originally spoken in the coastal and central regions of Brazil. It was brought to its present location along the Rio Negro by Brazilian colonizers who, until the mid-17th century, primarily used Tupi rather than the official Portuguese to communicate. Besides modern Nheengatu, other languages of the Tupi family are spoken there, along with other language families like , Arawak, Karib, Arawá, Yanomamo, Matsés and others.

See also

References

  1. ^ Goulding, M., Barthem, R. B. and Duenas, R. (2003). The Smithsonian Atlas of the Amazon, Smithsonian Books ISBN 1-58834-135-6
  2. ^ Roach, John (18 June 2007). "Amazon Longer Than Nile River, Scientists Say". National Geographic.
  3. ^ Raymond E. Crist, Alarich R. Schultz, James J. Parsons (16 March 2018). "Amazon River". Encyclopædia Britannica. Retrieved 21 August 2018.CS1 maint: Uses authors parameter (link)
  4. ^ "Amazon river flowed into the Pacific millions of years ago". Mongabay. 24 October 2006. Archived from the original on 3 January 2013. Retrieved 8 June 2014.
  5. ^ Amazon, Plants. "Amazon plants and trees".
  6. ^ "The Coolest Plants in the Amazon Rainforest". Rainforest Cruises.
  7. ^ Butler, Rhett (31 July 2012). "Diversities of Image". Mongabay.com. Retrieved 20 December 2014.
  8. ^ Munn, C. A. 1994. Macaws: winged rainbows. National Geographic, 185, 118–140.
  9. ^ Brightsmith D. J. (2004). "Effects of weather on parrot geophagy in Tambopata, Peru". Wilson Bulletin. 116 (2): 134–145. doi:10.1676/03-087b.
  10. ^ "Amazon Reptiles". Mongabay.com.
  11. ^ a b c Junk, W.J.; M.G.M. Soares; P.B. Bayley (2007), "Freshwater fishes of the Amazon River Basin: their biodiversity, fisheries, and habitats", Aquatic Ecosystem Health and Management, 10 (2): 153–173, doi:10.1080/14634980701351023
  12. ^ James S. Albert; Roberto E. Reis (8 March 2011). Historical Biogeography of Neotropical Freshwater Fishes. p. 308. ISBN 978-0-520-26868-5. Retrieved 28 June 2011.
  13. ^ Reis R.E., Albert J.S., Di Dario F., Mincarone M.M., Petry P., Rocha L.A. (2016). "Fish biodiversity and conservation in South America". Journal of Fish Biology. 89 (1): 12–47. doi:10.1111/jfb.13016. PMID 27312713.CS1 maint: Multiple names: authors list (link)
  14. ^ Stewart D. J., Ibarra M. (2002). "Comparison of Deep-River and Adjacent Sandy-Beach Fish Assemblages in the Napo River basin, Eastern Ecuador". Copeia. 2002 (2): 333–343. doi:10.1643/0045-8511(2002)002[0333:codraa]2.0.co;2.
  15. ^ Mendonça, F. P., W. E. Magnusson, J. Zuanon and C. M. Taylor. (2005) Relationships between habitat characteristics and fish assemblages in small streams of Central Amazonia. Copeia 2005(4): 751–764
  16. ^ Duncan, W.P.; and Fernandes, M.N. (2010). Physicochemical characterization of the white, black, and clearwater rivers of the Amazon Basin and its implications on the distribution of freshwater stingrays (Chondrichthyes, Potamotrygonidae). PanamJAS 5(3): 454–464.
  17. ^ Froese, Rainer and Pauly, Daniel, eds. (2017). "Arapaima gigas" in FishBase. September 2017 version.
  18. ^ Froese, Rainer and Pauly, Daniel, eds. (2017). "Brachyplatystoma filamentosum" in FishBase. September 2017 version.
  19. ^ Froese, Rainer and Pauly, Daniel, eds. (2017). "Carcharhinus leucas" in FishBase. September 2017 version.
  20. ^ Froese, Rainer and Pauly, Daniel, eds. (2017). "Pristis pristis" in FishBase. September 2017 version.
  21. ^ Roberts, T.R. (2013). "Leptophilypnion, a new genus with two new species of tiny central Amazonian gobioid fishes (Teleostei, Eleotridae)". Aqua, International Journal of Ichthyology. 19 (2): 85–98.
  22. ^ a b Romero, Aldemaro, ed. (2001). The Biology of Hypogean Fishes. Developments in environmental biology of fishes. 21. ISBN 978-1402000768.
  23. ^ Fenolio, Danté (2016). Life in the Dark: Illuminating Biodiversity in the Shadowy Haunts of Planet Earth. Johns Hopkins University Press. ISBN 978-1421418636.
  24. ^ Lujan, Nathan. K.; Chamon, Carine. C. (2008). "Two new species of Loricariidae (Teleostei: Silurifomes) from main channels of the upper and middle Amazon Basin, with discussion of deep water specialization in loricariids". Ichthyological Exploration of Freshwaters. 19: 271–282.
  25. ^ Thomas, M.R.; L.H.R. Py-Daniel (2008). "Three new species of the armored catfish genus Loricaria (Siluriformes: Loricariidae) from river channels of the Amazon basin". Neotrop. Ichthyol. 6 (3): 379–394. doi:10.1590/S1679-62252008000300011.
  26. ^ Cramer, C.A.; L.H.R. Py-Daniel (2015). "A new species of Panaqolus (Siluriformes: Loricariidae) from the rio Madeira basin with remarkable intraspecific color variation". Neotrop. Ichthyol. 13 (3): 461–470. doi:10.1590/1982-0224-20140099.
  27. ^ Howard, B.C. (27 September 2013). Fish That Lay Eggs Out of the Water: Freshwater Species of the Week. National Geographic. Retrieved 30 April 2017.
  28. ^ SeriouslyFish. "Lepidosiren paradoxa". Retrieved 30 April 2017.
  29. ^ Vermeulen, F. "The genus Rivulus". itrainsfishes.net. Retrieved 6 May 2017.
  30. ^ Turko, A.J.; P.A. Wright (2015). "Evolution, ecology and physiology of amphibious killifishes (Cyprinodontiformes)". Journal of Fish Biology. 87 (4): 815–835. doi:10.1111/jfb.12758. PMID 26299792.
  31. ^ Planet Catfish. "Cat-eLog: Heptapteridae: Phreatobius: Phreatobius sp. (1)". Planet Catfish. Retrieved 30 April 2017.
  32. ^ Henderson, P.A.; I. Walker (1990). "Spatial organization and population density of the fish community of the litter banks within a central Amazonian blackwater stream". Journal of Fish Biology. 37 (3): 401–411. doi:10.1111/j.1095-8649.1990.tb05871.x.
  33. ^ "Amazon Insects". Mongabay.com.
  34. ^ Powell (2009)
  35. ^ Rosenzweig, Michael L. (1995). Species Diversity in Space and Time. Cambridge University Press. ISBN 978-0-521-49952-1.
  36. ^ Hunt, T.; Bergsten, J.; Levkanicova, Z.; Papadopoulou, A.; John, O. St.; Wild, R.; Hammond, P. M.; Ahrens, D.; Balke, M.; Caterino, M. S.; Gomez-Zurita, J.; Ribera, I.; Barraclough, T. G.; Bocakova, M.; Bocak, L.; Vogler, A. P.; et al. (2007). "A Comprehensive Phylogeny of Beetles Reveals the Evolutionary Origins of a Superradiation". Science. 318 (5858): 1913–1916. Bibcode:2007Sci...318.1913H. doi:10.1126/science.1146954. PMID 18096805.

Further reading

External links

Coordinates: 2°18′35″S 54°53′17″W / 2.3096°S 54.8881°W

Amazon Basin (sedimentary basin)

The Amazon Basin is a major 620,000 square kilometres (240,000 sq mi) large sedimentary basin located roughly at the middle and lower course of the Amazon River, south the Guiana Shield and north of the Central Brazilian Shield. It is bound to the west by the Púrus Arch, separating the Amazon Basin from the Solimões Basin and in the east by the Gurupá Arch, separating the basin from the Marajó Basin. The basin developed on a rift that originated possibly about 550 million years ago during the Cambrian. Parts of the rift were reactivated during the opening of the South Atlantic.The basin has an elongated shape with a WSW-ENE orientation. It long axis runs from the vicinity of Manaus to the area near the confluence of Xingu River with the Amazon River.

Amazon River

The Amazon River (UK: , US: ; Spanish and Portuguese: Amazonas) in South America is the largest river by discharge volume of water in the world, and by some definitions it is the longest.The headwaters of the Apurímac River on Nevado Mismi had been considered for nearly a century as the Amazon's most distant source, until a 2014 study found it to be the headwaters of the Mantaro River on the Cordillera Rumi Cruz in Peru. The Mantaro and Apurímac join, and with other tributaries form the Ucayali River, which in turn meets the Marañón River upstream of Iquitos, Peru, to form what countries other than Brazil consider to be the main stem of the Amazon. Brazilians call this section the Solimões River above its confluence with the Rio Negro to form what Brazilians call the Amazon at the Meeting of Waters (Portuguese: Encontro das Águas) at Manaus, the river's largest city.

At an average discharge of about 209,000 cubic metres per second (7,400,000 cu ft/s; 209,000,000 L/s; 55,000,000 USgal/s)—approximately 6,591 cubic kilometres per annum (1,581 cu mi/a), greater than the next seven largest independent rivers combined—the Amazon represents 20% of the global riverine discharge to the ocean. The Amazon basin is the largest drainage basin in the world, with an area of approximately 7,050,000 square kilometres (2,720,000 sq mi). The portion of the river's drainage basin in Brazil alone is larger than any other river's basin. The Amazon enters Brazil with only one-fifth of the flow it finally discharges into the Atlantic Ocean, yet already has a greater flow at this point than the discharge of any other river.

Amazon natural region

Amazonía region in southern Colombia comprises the departments of Amazonas, Caquetá, Guainía, Guaviare, Putumayo and Vaupés, and covers an area of 403,000 km², 35% of Colombia's total territory. The region is mostly covered by tropical rainforest, or jungle, which is a part of the massive Amazon rainforest.

Amazon rainforest

The Amazon rainforest (Portuguese: Floresta Amazônica or Amazônia; Spanish: Selva Amazónica, Amazonía or usually Amazonia; French: Forêt amazonienne; Dutch: Amazoneregenwoud), also known in English as Amazonia or the Amazon Jungle, is a moist broadleaf forest in the Amazon biome that covers most of the Amazon basin of South America. This basin encompasses 7,000,000 km2 (2,700,000 sq mi), of which 5,500,000 km2 (2,100,000 sq mi) are covered by the rainforest. This region includes territory belonging to nine nations.

The majority of the forest is contained within Brazil, with 60% of the rainforest, followed by Peru with 13%, Colombia with 10%, and with minor amounts in Venezuela, Ecuador, Bolivia, Guyana, Suriname and France (French Guiana). States or departments in four nations contain "Amazonas" in their names. The Amazon represents over half of the planet's remaining rainforests, and comprises the largest and most biodiverse tract of tropical rainforest in the world, with an estimated 390 billion individual trees divided into 16,000 species.

Amazonas before the Inca Empire

The present-day Department of Amazonas in Peru, occupying part of the western Amazon basin, carries evidence of human cultures predating the Inca Empire.

Amazônia Legal

Amazônia Legal (Portuguese pronunciation: [amaˈzonjɐ leˈɡaw], Legal Amazon) is the largest socio-geographic division in Brazil, containing all nine states in the Amazon basin. The region was created in 1948 based on studies of the Brazilian government on how to plan the economic and social development of the Amazon region.

Black-tailed trogon

The black-tailed trogon (Trogon melanurus) is a species of bird in the family Trogonidae. It is found in humid forest in the Amazon basin, north-western South America and adjacent Panama. The taxon mesurus from western Ecuador and far north-western Peru was formerly considered a subspecies of the black-tailed trogon, but is now considered a separate species, the Ecuadorian trogon.

Blue-crowned trogon

The blue-crowned trogon (Trogon curucui) is a species of bird in the family Trogonidae.

It is found in Argentina, Bolivia, Brazil, Colombia, Ecuador, Paraguay, and Peru.

Its natural habitats are subtropical or tropical moist lowland forests and heavily degraded former forest.

Coordinator of Indigenous Organizations of the Amazon River Basin

Coordinator of Indigenous Organizations of the Amazon River Basin (COICA) (Spanish: Coordinadora de las Organizaciones Indígenas de la Cuenca Amazónica) was founded in 1984 in Lima, Peru. This organization coordinates the following nine national Amazonian indigenous organizations:

Asociación Interétnica de Desarrollo de la Selva Peruana (AIDESEP)

Amerindian People's Association of Guyana (APA)

Confederación de Pueblos Indígenas de Bolivia (CIDOB)

Coordenação das Organizações Indígenas da Amazônia Brasileira (COIAB)

Confederation of Indigenous Nationalities of the Ecuadorian Amazonia (CONFENIAE)

Regional Organization of Indigenous Towns of the Amazon (ORPIA)

Federation des Organisations Amerindiennes de Guyane (FOAG)

Organization Van Inheemsen in Suriname (OIS)

Organization of the Indigenous Towns of the Colombian AmazoniaThe objectives of the COICA organization are to promote and develop mechanisms that encourage the interaction of Indigenous peoples with the member organizations of COICA, to defend the self-determination of Indigenous peoples, to respect the human rights of its members, to coordinate the actions of its members on an international level, to fortify and cultivate mutual collaboration between all Indigenous peoples of the region, and to promote the cultural vindication of its members. Some of the initiatives that COICA has been able to accomplish include allowing indigenous peoples to be educated in their native languages and the foundation of an Amazon Indigenous University. Accomplishments such as these have encouraged the revitalization of traditional cultures. In 1993, COICA's headquarters was permanently relocated to Quito, Ecuador. Here the organization has received legal recognition by the Ecuadorian state.

Dry season

The dry season is a yearly period of low rainfall, especially in the tropics. The weather in the tropics is dominated by the tropical rain belt, which moves from the northern to the southern tropics and back over the course of the year. The tropical rain belt lies in the southern hemisphere roughly from October to March; during that time the northern tropics have a dry season with sparser precipitation, and days are typically sunny throughout. From April to September, the rain belt lies in the northern hemisphere, and the southern tropics have their dry season. Under the Köppen climate classification, for tropical climates, a dry season month is defined as a month when average precipitation is below 60 millimetres (2.4 in).During the dry season, humidity is very low, causing some watering holes and rivers to dry up. This lack of water (and hence of food) may force many grazing animals to migrate to more fertile spots. Examples of such animals are zebras, elephants, and wildebeest. Because of the lack of water in the plants, bushfires are common.Data shows that in Africa the start of the dry season coincides with a rise in the cases of measles—which researchers believe might be attributed to the higher concentration of people in the dry season, as agricultural operations are all but impossible without irrigation. During this time, some farmers move into cities, creating hubs of higher population density, and allowing the disease to spread more easily.The rain belt reaches roughly as far north as the Tropic of Cancer and as far south as the Tropic of Capricorn. Near these latitudes, there is one wet season and one dry season annually. At the equator there are two wet and two dry seasons, as the rain belt passes over twice a year, once moving north and once moving south. Between the tropics and the equator, locations may experience a short wet and a long wet season; and a short dry and a long dry season. Local geography may substantially modify these climate patterns, however.

New data shows that in the seasonal parts of the South American Amazon rainforest, foliage growth and coverage varies between the dry and wet seasons—with about 25% more leaves and faster growth in the dry season. Researchers believe that the Amazon itself has an effect in bringing the onset of the wet season: by growing more foliage, it evaporates more water. However, this growth appears only in the undisturbed parts of the Amazon basin, where researchers believe roots can reach deeper and gather more rainwater. It has also been shown that ozone levels are much higher in the dry than in the wet season in the Amazon basin.

Horned screamer

The horned screamer (Anhima cornuta) is a member of a small family of birds, the Anhimidae, which occurs in wetlands of tropical South America. There are three screamer species, the other two being the southern screamer and the northern screamer in the genus Chauna. They are related to the ducks, geese and swans, which are in the family Anatidae, but have bills looking more like those of game birds.

List of snakes of Colombia

The nearly 300 species of snake found in Colombia represent nine of the eighteen families. Six families (Aniliidae, Boidae, Colubridae, Elapidae, Tropidophiidae, Viperidae) are within the infraorder Alethinophidia (advanced snakes) and three families (Anomalepididae, Leptotyphlopidae, Typhlopidae) are within the infraorder Scolecophidia (blind snakes).

The largest snake ever known, Titanoboa, was discovered as a fossil in northeastern Colombia.

Peruvian Amazonia

Peruvian Amazonia (Spanish: Amazonía del Perú) is the area of the Amazon rainforest included within the country of Peru, from east of the Andes to the borders with Ecuador, Colombia, Brazil and Bolivia. This region comprises 60% of the country and is marked by a large degree of biodiversity. Peru has the second-largest portion of the Amazon rainforest after the Brazilian Amazon.

Plush-crested jay

The plush-crested jay (Cyanocorax chrysops) is a jay of the family Corvidae (which includes the crows and their many allies). It is found in central-southern South America: in southwestern Brazil, Bolivia, Paraguay, Uruguay, and northeastern Argentina, including southern regions of the Amazon Basin river systems bordering the Pantanal.

This is an elegant medium-sized bird, dark plumaged with a cream-yellow breast; the bulky tail is also cream colored, top and underneath, for the lower half.

Reddish hermit

The reddish hermit (Phaethornis ruber) is a species of bird in the family Trochilidae, the hummingbirds. It is found in Bolivia, Brazil, Colombia, Ecuador, Peru, Venezuela, and in the Guianas. At 7.5 cm (3 in) and a weight under 3 grams, it is among the smallest of the hermits and smallest birds overall. Its natural habitats are forest and woodland, primarily humid.

Rio Negro (Amazon)

The Rio Negro (Portuguese: Rio Negro [ˈʁi.u neɡɾu]; Spanish: Río Negro [ˈri.o ˈneɣɾo] "Black River") is the largest left tributary of the Amazon River, the largest blackwater river in the world (accounting for about 14% of the water in the Amazon basin), and one of the world's ten largest rivers by average discharge.

Slate-colored hawk

The slate-colored hawk (Buteogallus schistaceus) is a species of bird of prey in the Accipitridae family: the hawks, eagles, and allies.

It is found in northern South America: Brazil, Bolivia, Peru, Ecuador, Colombia, Venezuela, and French Guiana. Its natural habitat is subtropical or tropical swamps.

White-browed hawk

The white-browed hawk (Leucopternis kuhli) is a species of bird of prey in the family Accipitridae. It is found in northern South America's southern Amazon Basin in eastern Peru, Bolivia and northern Brazil.

Its natural habitat is tropical moist lowland forests.

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