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Toucanet
Toucans (, ) are members of the Neotropical near passerine bird family Ramphastidae. The Ramphastidae are most closely related to the American barbets. They are brightly marked and have large, often colorful bills. The family includes five genera and over forty different species. Toucans are arboreal and typically lay 2–4 white eggs in their nests. They make their nests in tree hollows and holes excavated by other animals such as woodpeckers—the toucan bill has very limited use as an excavation tool. When the eggs hatch, the young emerge completely naked, without any down. Toucans are resident breeders and do not migrate. Toucans are usually found in pairs or small flocks. They sometimes fence with their bills and wrestle, which scientists hypothesize they do to establish dominance hierarchies. In Africa and Asia, hornbills occupy the toucans' ecological niche, an example of convergent evolution. Taxonomy and systematics The name of this bird group is derived from the Tup ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aulacorhynchus
Green toucanets are near-passerine birds from the genus ''Aulacorhynchus'' in the toucan family. They are native to Mexico, and Central and South America. All are found in humid forests and woodlands in highlands, but a few also occur in adjacent lowlands.Short, L. L., & Horne, J. F. M. (2002). Toucans (Ramphastidae). pp. 220-272 in del Hoyo, J., Elliott, A., & Sargatal, J. eds. (2002). ''Handbook of the Birds of the World.'' Vol. 7 Jacamars to Woodpecker. Lynx Edicions, Barcelona. They are relatively small toucans, long, with colorful, mainly green, plumage. They are typically seen in pairs or small groups, and sometimes follow mixed species flocks.Restall, R. L., Rodner, C., & Lentino, M. (2006). ''Birds of Northern South America.'' Christopher Helm, London. (vol. 1). (vol. 2). Taxonomy and systematics A major taxonomy review in 1974 resulted in 6 species in the genus ''Aulacorhynchus'', and this was adopted by virtually all later authorities.Remsen, J. V., Jr., C. D. Cade ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Selenidera
''Selenidera'' is a bird genus containing six species of dichromatic toucanets in the toucan family Ramphastidae. They are found in lowland rainforest (below ) in tropical South America with one species in Central America. All the species have green upper-parts, red undertail-coverts and a patch of bare blue or blue-green skin around the eye. Unlike most other toucans, the sexes are different in colour ( sexually dichromatic; hence the name dichromatic toucanets). The males all have a black crown, nape, throat and breast and an orange/yellow auricular streak. The females of most species have the black sections in the male replaced by rich brown and a reduced/absent auricular streak, while the female of one species, the Guianan toucanet, has grey underparts and a rufous nuchal collar, and the female of another, the yellow-eared toucanet, resemble the male except for its brown crown and lack of an auricular streak. The calls are low-pitched and croaking. Most species are relatively ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
White-throated Toucanet
The white-throated toucanet or greyish-throated toucanet (''Aulacorhynchus albivitta'') is a near-passerine bird in the toucan family Ramphastidae. It is found in Colombia, Ecuador, and Venezuela. Taxonomy and systematics The white-throated toucanet was originally described in the genus '' Pteroglossus''. What is now the white-throated toucanet was four of many subspecies of the then emerald toucanet (''Aulacorhynchus prasinus'' ''sensu lato''). In 2008 the International Ornithological Committee (IOC) split 10 of those subspecies to create seven new species, one of which is the white-throated toucanet, and retained four of them as subspecies of their current emerald toucanet ''sensu stricto''. BirdLife International's Handbook of the Birds of the World (HBW) concurred. In 2016 the IOC merged two of the seven, the Santa Marta toucanet (''A. lautus'') and gray-throated toucanet (''A. griseigularis''), into the white-throated and again HBW concurred. However, the North and Sout ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bird Migration
Bird migration is the regular seasonal movement, often north and south along a flyway, between breeding and wintering grounds. Many species of bird migrate. Migration carries high costs in predation and mortality, including from hunting by humans, and is driven primarily by the availability of food. It occurs mainly in the northern hemisphere, where birds are funneled onto specific routes by natural barriers such as the Mediterranean Sea or the Caribbean Sea. Migration of species such as storks, turtle doves, and swallows was recorded as many as 3,000 years ago by Ancient Greek authors, including Homer and Aristotle, and in the Book of Job. More recently, Johannes Leche began recording dates of arrivals of spring migrants in Finland in 1749, and modern scientific studies have used techniques including bird ringing and satellite tracking to trace migrants. Threats to migratory birds have grown with habitat destruction, especially of stopover and wintering sites, a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Arboreal
Arboreal locomotion is the locomotion of animals in trees. In habitats in which trees are present, animals have evolved to move in them. Some animals may scale trees only occasionally, but others are exclusively arboreal. The habitats pose numerous mechanical challenges to animals moving through them and lead to a variety of anatomical, behavioral and ecological consequences as well as variations throughout different species.Cartmill, M. (1985). Climbing. In ''Functional Vertebrate Morphology'', eds. M. Hildebrand D. M. Bramble K. F. Liem and D. B. Wake, pp. 73–88. Cambridge: Belknap Press. Furthermore, many of these same principles may be applied to climbing without trees, such as on rock piles or mountains. Some animals are exclusively arboreal in habitat, such as the tree snail. Biomechanics Arboreal habitats pose numerous mechanical challenges to animals moving in them, which have been solved in diverse ways. These challenges include moving on narrow branches, mov ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tree Hollow
A tree hollow or tree hole is a semi-enclosed cavity which has naturally formed in the trunk or branch of a tree. They are found mainly in old trees, whether living or not. Hollows form in many species of trees, and are a prominent feature of natural forests and woodlands, and act as a resource or habitat for a number of vertebrate and invertebrate animals. Hollows may form as the result of physiological stress from natural forces causing the excavating and exposure of the heartwood. Forces may include wind, fire, heat, lightning, rain, attack from insects (such as ants or beetles), bacteria, or fungi. Also, trees may self-prune, dropping lower branches as they reach maturity, exposing the area where the branch was attached. Many animals further develop the hollows using instruments such as their beak, teeth or claws. The size of hollows may depend on the age of the tree. For example, eucalypts develop hollows at all ages, but only from when the trees are 120 years old do they f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Woodpecker
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] |
Down Feathers
The down of birds is a layer of fine feathers found under the tougher exterior feathers. Very young birds are clad only in down. Powder down is a specialized type of down found only in a few groups of birds. Down is a fine thermal insulator and padding, used in goods such as jackets, bedding ( duvets and featherbeds), pillows and sleeping bags. The discovery of feathers trapped in ancient amber suggests that some species of dinosaur may have possessed down-like feathers. Description and etymology The word ''down'' comes from the Old Norse word ''dúnn'', which had the same meaning as its modern equivalent. The down feather is considered to be the most "straightforward" of all feather types. It has a short or vestigial rachis (shaft), few barbs, and barbules that lack hooks. There are three types of down: natal down, body down and powder down. Natal down is the layer of down feathers that cover most birds at some point in their early development. Precocial nestlings ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pleistocene
The Pleistocene ( , often referred to as the '' Ice age'') is the geological epoch that lasted from about 2,580,000 to 11,700 years ago, spanning the Earth's most recent period of repeated glaciations. Before a change was finally confirmed in 2009 by the International Union of Geological Sciences, the cutoff of the Pleistocene and the preceding Pliocene was regarded as being 1.806 million years Before Present (BP). Publications from earlier years may use either definition of the period. The end of the Pleistocene corresponds with the end of the last glacial period and also with the end of the Paleolithic age used in archaeology. The name is a combination of Ancient Greek grc, label=none, πλεῖστος, pleīstos, most and grc, label=none, καινός, kainós (latinized as ), 'new'. At the end of the preceding Pliocene, the previously isolated North and South American continents were joined by the Isthmus of Panama, causing a faunal interchange between the t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Africa
Africa is the world's second-largest and second-most populous continent, after Asia in both cases. At about 30.3 million km2 (11.7 million square miles) including adjacent islands, it covers 6% of Earth's total surface area and 20% of its land area.Sayre, April Pulley (1999), ''Africa'', Twenty-First Century Books. . With billion people as of , it accounts for about of the world's human population. Africa's population is the youngest amongst all the continents; the median age in 2012 was 19.7, when the worldwide median age was 30.4. Despite a wide range of natural resources, Africa is the least wealthy continent per capita and second-least wealthy by total wealth, behind Oceania. Scholars have attributed this to different factors including geography, climate, tribalism, Scramble for Africa, colonialism, the Cold War, neocolonialism, lack of democracy, and corruption. Despite this low concentration of wealth, recent economic expansion and the large and young ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Genus
Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial nomenclature, the genus name forms the first part of the binomial species name for each species within the genus. :E.g. '' Panthera leo'' (lion) and '' Panthera onca'' (jaguar) are two species within the genus ''Panthera''. ''Panthera'' is a genus within the family Felidae. The composition of a genus is determined by taxonomists. The standards for genus classification are not strictly codified, so different authorities often produce different classifications for genera. There are some general practices used, however, including the idea that a newly defined genus should fulfill these three criteria to be descriptively useful: # monophyly – all descendants of an ancestral taxon are grouped together (i.e. phylogenetic analysis should c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Asia
Asia (, ) is one of the world's most notable geographical regions, which is either considered a continent in its own right or a subcontinent of Eurasia, which shares the continental landmass of Afro-Eurasia with Africa. Asia covers an area of , about 30% of Earth's total land area and 8.7% of Earth's total surface area. The continent, which has long been home to the majority of the human population, was the site of many of the first civilizations. Its 4.7 billion people constitute roughly 60% of the world's population. In general terms, Asia is bounded on the east by the Pacific Ocean, on the south by the Indian Ocean, and on the north by the Arctic Ocean. The border of Asia with Europe is a historical and cultural construct, as there is no clear physical and geographical separation between them. It is somewhat arbitrary and has moved since its first conception in classical antiquity. The division of Eurasia into two continents reflects East–West cultural, ling ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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