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Volcán Alcedo Giant Tortoise
''Chelonoidis niger vandenburghi'', also known as the Volcán Alcedo giant tortoise, the Alcedo Volcano giant tortoise or the Alcedo giant tortoise, is a subspecies of Galápagos tortoise endemic to the Galápagos archipelago in the equatorial eastern Pacific Ocean. The specific epithet ''vandenburghi'' honours American herpetologist John Van Denburgh. Taxonomy This tortoise is a subspecies of ''Chelonoidis niger'', and is sometimes considered to be a distinct species itself. Description Male tortoises grow to about and females to about in length, with domed carapaces. Behaviour The tortoises spend most of the day feeding, resting, or congregating in muddy pools. They sleep in the open at night. Adults migrate seasonally, travelling along the rim of the volcano's caldera and descending to the lower slopes to graze on new vegetation after wet season rains. Feeding The tortoises feed on grass, leaves, forbs, sedges, fruit and lichens, obtaining water from their diet and p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Turtle Taxonomy Working Group
The Turtle Taxonomy Working Group (TTWG) is an informal working group of the IUCN/SSC Tortoise and Freshwater Turtle Specialist Group (TFTSG). It is composed of a number of leading turtle taxonomists, with varying participation by individual participants over the years, some dropping out and others joining. Works The TTWG has produced an annual checklist of living and recently extinct turtles since 2007, deliberates on proposed changes to turtle taxonomy, and describes its consideration whether to accept, reject, or suspend adoption of proposed changes in a series of annotations to the checklist. Recent versions of the checklist have included full primary synonymies and citations to all original descriptions of recent turtle taxa, as well as CITES CITES (shorter acronym for the Convention on International Trade in Endangered Species of Wild Fauna and Flora, also known as the Washington Convention) is a multilateral treaty to protect endangered plants and animals from the thre ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lichen
A lichen ( , ) is a hybrid colony (biology), colony of algae or cyanobacteria living symbiotically among hypha, filaments of multiple fungus species, along with yeasts and bacteria embedded in the cortex or "skin", in a mutualism (biology), mutualistic relationship.Introduction to Lichens – An Alliance between Kingdoms . University of California Museum of Paleontology. . Lichens are the lifeform that first brought the term symbiosis (as ''Symbiotismus'') into biological context. Lichens have since been recognized as important actors in nutrient cycling and producers which many higher trophic feeders feed on, such as reindeer, gastropods, nematodes, mites, and springtails. Lichens have properties different from those of their component organisms. They come in man ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Endemic Reptiles Of The Galápagos Islands
Endemism is the state of a species being found only in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also found elsewhere. For example, the Cape sugarbird is found exclusively in southwestern South Africa and is therefore said to be ''endemic'' to that particular part of the world. An endemic species can also be referred to as an ''endemism'' or, in scientific literature, as an ''endemite''. Similarly, many species found in the Western ghats of India are examples of endemism. Endemism is an important concept in conservation biology Conservation biology is the study of the conservation of nature and of Earth's biodiversity with the aim of protecting species, their habitats, and ecosystems from excessive rates of extinction and the erosion of biotic interactions. It is an i ... for measuring biodiversity in a particular place and evaluating th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Turtles Of South America
Turtles are reptiles of the order Testudines, characterized by a special shell developed mainly from their ribs. Modern turtles are divided into two major groups, the Pleurodira (side necked turtles) and Cryptodira (hidden necked turtles), which differ in the way the head retracts. There are 360 living and recently extinct species of turtles, including land-dwelling tortoises and freshwater terrapins. They are found on most continents, some islands and, in the case of sea turtles, much of the ocean. Like other amniotes (reptiles, birds, and mammals) they breathe air and do not lay eggs underwater, although many species live in or around water. Turtle shells are made mostly of bone; the upper part is the domed carapace, while the underside is the flatter plastron or belly-plate. Its outer surface is covered in scales made of keratin, the material of hair, horns, and claws. The carapace bones develop from ribs that grow sideways and develop into broad flat plates that joi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Subspecies
In Taxonomy (biology), biological classification, subspecies (: subspecies) is a rank below species, used for populations that live in different areas and vary in size, shape, or other physical characteristics (Morphology (biology), morphology), but that can successfully interbreed. Not all species have subspecies, but for those that do there must be at least two. Subspecies is abbreviated as subsp. or ssp. and the singular and plural forms are the same ("the subspecies is" or "the subspecies are"). In zoology, under the International Code of Zoological Nomenclature, the subspecies is the only taxonomic rank below that of species that can receive a name. In botany and mycology, under the International Code of Nomenclature for algae, fungi, and plants, other infraspecific name, infraspecific ranks, such as variety (botany), variety, may be named. In bacteriology and virology, under standard International Code of Nomenclature of Prokaryotes, bacterial nomenclature and virus clas ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chelonoidis
''Chelonoidis'' is a genus of turtles in the tortoise family erected by Leopold Fitzinger in 1835. They are found in South America and the Galápagos Islands, and formerly had a wide distribution in the West Indies. The multiple subspecies of the Galápagos tortoise (''C. niger'') are among the largest extant terrestrial chelonians. Giant members of the genus, such as Lutz's giant tortoise (''C. lutzae'') were also present in mainland South America and the West Indies during the Pleistocene, and the latter into the Holocene. Taxonomy They were formerly assigned to '' Geochelone'', but a 2006 genetic analysis indicated that they were actually most closely related to hingeback tortoises. However, a more recent genetic analysis of mtDNA has found that they are actually most closely related to the lineage containing '' Centrochelys'' and '' Geochelone''. Their ancestors apparently floated across the Atlantic from Africa to South America in the Oligocene. This crossing was made ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Genetic Diversity
Genetic diversity is the total number of genetic characteristics in the genetic makeup of a species. It ranges widely, from the number of species to differences within species, and can be correlated to the span of survival for a species. It is distinguished from '' genetic variability'', which describes the tendency of genetic characteristics to vary. Genetic diversity serves as a way for populations to adapt to changing environments. With more variation, it is more likely that some individuals in a population will possess variations of alleles that are suited for the environment. Those individuals are more likely to survive to produce offspring bearing that allele. The population will continue for more generations because of the success of these individuals. The academic field of population genetics includes several hypotheses and theories regarding genetic diversity. The neutral theory of evolution proposes that diversity is the result of the accumulation of neutral substitu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vulnerable Species
A vulnerable species is a species which has been Conservation status, categorized by the International Union for Conservation of Nature as being threatened species, threatened with extinction unless the circumstances that are threatened species, threatening its survival and reproduction improve. Vulnerability is mainly caused by habitat loss or destruction of the species' home. Vulnerable habitat or species are monitored and can become increasingly threatened. Some species listed as "vulnerable" may be common in captivity (animal), captivity, an example being the military macaw. In 2012 there were 5,196 animals and 6,789 plants classified as vulnerable, compared with 2,815 and 3,222, respectively, in 1998. Practices such as cryoconservation of animal genetic resources have been enforced in efforts to conserve vulnerable breeds of livestock specifically. Criteria The International Union for Conservation of Nature uses several criteria to enter species in this category. A taxon ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Grassland
A grassland is an area where the vegetation is dominance (ecology), dominated by grasses (Poaceae). However, sedge (Cyperaceae) and rush (Juncaceae) can also be found along with variable proportions of legumes such as clover, and other Herbaceous plant, herbs. Grasslands occur naturally on all continents except Antarctica and are found in most ecoregions of the Earth. Furthermore, grasslands are one of the largest biomes on Earth and dominate the landscape worldwide. There are different types of grasslands: natural grasslands, semi-natural grasslands, and agricultural grasslands. They cover 31–69% of the Earth's land area. Definitions Included among the variety of definitions for grasslands are: * "...any plant community, including harvested forages, in which grasses and/or legumes make up the dominant vegetation." * "...terrestrial ecosystems dominated by herbaceous and shrub vegetation, and maintained by fire, grazing, drought and/or freezing temperatures." (Pilot Assessm ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Isabela Island (Galápagos)
Isabela Island () is the largest of the Galápagos Islands, with an area of and a length of . By itself, it is larger than all the other islands in the chain combined, and it has a little under 2,000 permanent inhabitants. The island straddles the equator. Names The original Spanish name of Isabela () was Santa Isabela Island ( or ) in honor of the Aragonese Queen Elizabeth of Portugal, who was canonized by Pope Urban VIII on 24 June 1626. When the name was formally changed to Isabela Island in 1892 as part of Ecuador's quadricentennial celebration of Columbus's first voyage, its eponym changed to Columbus's patron Queen IsabellaI of Castile. Isabela and nearby Fernandina Islandhonoring Isabella's husband FerdinandII of Aragonalso preserve the names bestowed on the third and fourth islands encountered by Columbus during his voyage. The former English name Duke of Albemarl's Island or Albemarle Island was bestowed by English buccaneer Ambrose Cowley in 1684 in honor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alcedo Volcano
Alcedo Volcano is one of the six coalescing shield volcanoes that make up Isabela Island in the Galapagos. The remote location of the volcano has meant that even the most recent eruption in 1993 was not recorded until two years later. It is also the only volcano in the Galapagos to have erupted rhyolite and basaltic lava. The volcano has the largest number of wild tortoises of any of the volcanoes in the Galapagos, though their genetic diversity is amongst the lowest of any of the breeds in the archipelago. The habitat of the tortoises was threatened when feral goats crossed from southern Isabela Island in the 1970s and then reproduced rapidly. Geology It is believed that Alcedo volcano emerged from the sea approximately 313,000 years ago, based on its sub -aerial volume of 234 km3 and average eruption rate of 1 million m3 per year. This has produced a volcano that is 1130m high with a caldera that measures 6.1 x 7.4 km. Alcedo volcano is similar to its neighbours ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Caldera
A caldera ( ) is a large cauldron-like hollow that forms shortly after the emptying of a magma chamber in a volcanic eruption. An eruption that ejects large volumes of magma over a short period of time can cause significant detriment to the structural integrity of such a chamber, greatly diminishing its capacity to support its own roof and any substrate or rock resting above. The ground surface then collapses into the emptied or partially emptied magma chamber, leaving a large depression at the surface (from one to dozens of kilometers in diameter). Although sometimes described as a Volcanic crater, crater, the feature is actually a type of sinkhole, as it is formed through subsidence and collapse rather than an explosion or impact. Compared to the thousands of volcanic eruptions that occur over the course of a century, the formation of a caldera is a rare event, occurring only a few times within a given window of 100 years. Only eight caldera-forming collapses are known to have ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
