Island Syndrome
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Island Syndrome
Island syndrome describes the differences in morphology, ecology, physiology and behaviour of insular species compared to their continental counterparts. These differences evolve due to the different ecological pressures affecting insular species, including a paucity of large predators and herbivores as well as a consistently mild climate. Ecological driving factors *Reduced predation. Island ecosystems cannot support a sufficient biomass of prey in order to accommodate large predators. This largely relieves prey species of the risk of predation, which mostly removes the selection pressure for morphologies, ecologies and behaviours that help to evade large predators. *Reduced biodiversity. Insular ecosystems tend to comprise large populations of a limited number of species (a state termed ''density compensation''), therefore, they exhibit low biodiversity. This results in reduced interspecific competition and increased intraspecific competition. *Reduced sexual selection. There i ...
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Hippopotamus
The hippopotamus ( ; : hippopotamuses or hippopotami; ''Hippopotamus amphibius''), also called the hippo, common hippopotamus, or river hippopotamus, is a large semiaquatic mammal native to sub-Saharan Africa. It is one of only two extant species in the family Hippopotamidae, the other being the pygmy hippopotamus (''Choeropsis liberiensis'' or ''Hexaprotodon liberiensis''). Its name comes from the ancient Greek for "river horse" (). Aside from elephants and rhinos, the hippopotamus is the largest land mammal. It is also the largest extant land artiodactyl. Despite their physical resemblance to pigs and other terrestrial even-toed ungulates, the closest living relatives of the hippopotamids are cetaceans (whales, dolphins, porpoises, etc.), from which they diverged about 55 million years ago. Hippos are recognisable for their barrel-shaped torsos, wide-opening mouths with large canine tusks, nearly hairless bodies, pillar-like legs, and large size: adults average ...
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Megalochelys
''Megalochelys'' ("great turtle") is an extinct genus of cryptodiran tortoises that lived from the Miocene to Pleistocene. They are noted for their giant size, which is among the largest of any known testudine, with a maximum carapace length over 2 m (6.5 ft) in ''M. atlas''. During the dry glacial periods it ranged from western India and Pakistan (possibly even as far west as southern and eastern Europe) to as far east as Sulawesi and Timor in Indonesia, though the island specimens likely represent distinct species. Description One species of ''Megalochelys,'' ''M. atlas'', is the largest known tortoise, with a shell length of and even , and an approximate total height of . Popular weight estimates for this taxon have varied greatly with the highest estimates reaching up to in some instances.Orenstein, R. 2001. Survivors in Armor: Turtles, Tortoises, and Terrapins. Key Porter Books Ltd. However, weights based on volumetric displacement of the skeleton,Brown, B. 19 ...
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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, linguistic, ...
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Meiolania
''Meiolania'' ("small roamer") is an extinct genus of meiolaniid stem-turtle native to Australasia from the Middle Miocene to Late Pleistocene and possibly Holocene. It is best known from fossils found on Lord Howe Island, though fossils are known from mainland Australia, New Caledonia, and possibly Vanuatu and Fiji. Taxonomy The genus was erected in 1886 based on remains found on Lord Howe Island, which Richard Owen assigned to the two species ''M. platyceps'' and ''M. minor'' (now a synonym of the former). These were the first good meiolaniid remains, and were used to show that the first known remains of a related animal, a species from Queensland now known as '' Ninjemys oweni'' (which was assigned to ''Meiolania'' until 1992), did not belong to lizards as initially thought, but to turtles. Woodward sank ''Niolamia argentina'' into ''Meiolania'', but this was not accepted by later authors. The species of the genus may be summarized as In New Caledonia, ''M. mackayi'' was ...
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Australia
Australia, officially the Commonwealth of Australia, is a Sovereign state, sovereign country comprising the mainland of the Australia (continent), Australian continent, the island of Tasmania, and numerous List of islands of Australia, smaller islands. With an area of , Australia is the largest country by area in Oceania and the world's List of countries and dependencies by area, sixth-largest country. Australia is the oldest, flattest, and driest inhabited continent, with the least fertile soils. It is a Megadiverse countries, megadiverse country, and its size gives it a wide variety of landscapes and climates, with Deserts of Australia, deserts in the centre, tropical Forests of Australia, rainforests in the north-east, and List of mountains in Australia, mountain ranges in the south-east. The ancestors of Aboriginal Australians began arriving from south east Asia approximately Early human migrations#Nearby Oceania, 65,000 years ago, during the Last Glacial Period, last i ...
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Aldabrachelys
''Aldabrachelys'' is the recognised genus for the Seychelles and Madagascan radiations of giant tortoises, including the Aldabra giant tortoise (''Aldabrachelys gigantea''). Naming This name is problematic in that the type specimen is actually represents '' Chelonoidis denticulata''; Bour R (2006). "Identity of ''Testudo gigantea'' Schweigger, 1812 and rediscovery of the type specimen". ''Emys'' 13 (4): 12–23. however, this was discussed and petitioned before the ICZNFrazer J (2009). "''Testudo gigantea'' Schweigger, 1812 (currently ''Geochelone (Aldabrachelys) gigantea''; Reptilia, Testudines): proposed conservation of usage of the specific name by maintenance of a designated neotype, and suppression of ''Testudo dussumieri'' Gray, 1831 (currently ''Dipsochelys dussumieri'')". ''Bulletin of Zoological Nomenclature'' 66 (1Case:3463/ref> and accepted: the name ''Aldabrachelys'' is therefore the correct name for this genus. Species * †'' A. abrupta'' - abrupt giant tortois ...
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Galápagos Tortoise
The Galápagos tortoise or Galápagos giant tortoise (''Chelonoidis niger'') is a species of very large tortoise in the genus ''Chelonoidis'' (which also contains three smaller species from mainland South America). It comprises 15 subspecies (13 Extant taxon, extant and 2 extinct). It is the largest living species of tortoise, with some modern Galápagos tortoises weighing up to . With lifespans in the wild of over 100 years, it is one of the longest-lived vertebrates. Captive Galapagos tortoises can live up to 177 years. For example, a captive individual, Harriet (tortoise), Harriet, lived for at least 175 years. Spanish explorers, who discovered the islands in the 16th century, named them after the Spanish ''wikt:en:galápago#Spanish, galápago'', meaning "tortoise". Galápagos tortoises are native to seven of the Galápagos Islands. Turtle shell, Shell size and shape vary between subspecies and populations. On islands with humid highlands, the tortoises are larger, with d ...
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Seychelles
Seychelles (, ; ), officially the Republic of Seychelles (french: link=no, République des Seychelles; Creole: ''La Repiblik Sesel''), is an archipelagic state consisting of 115 islands in the Indian Ocean. Its capital and largest city, Victoria, is east of mainland Africa. Nearby island countries and territories include the Comoros, Madagascar, Mauritius, and the French overseas departments of Mayotte and Réunion to the south; and Maldives and the Chagos Archipelago (administered by the United Kingdom as the British Indian Ocean Territory) to the east. It is the least populated sovereign African country, with an estimated 2020 population of 98,462. Seychelles was uninhabited prior to being encountered by Europeans in the 16th century. It faced competing French and British interests until coming under full British control in the late 18th century. Since proclaiming independence from the United Kingdom in 1976, it has developed from a largely agricultural society to ...
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Galápagos Islands
The Galápagos Islands (Spanish: , , ) are an archipelago of volcanic islands. They are distributed on each side of the equator in the Pacific Ocean, surrounding the centre of the Western Hemisphere, and are part of the Republic of Ecuador. Located west of continental Ecuador, the islands are known for their large number of endemic species that were studied by Charles Darwin during the second voyage of HMS ''Beagle''. His observations and collections contributed to the inception of Darwin's theory of evolution by means of natural selection. The Galápagos Islands and their surrounding waters form the Galápagos Province of Ecuador, the Galápagos National Park, and the Galápagos Marine Reserve. The principal language on the islands is Spanish. The islands have a population of slightly over 25,000. The first recorded visit to the islands happened by chance in 1535, when Fray Tomás de Berlanga, the Bishop of Panamá, was surprised to find this undiscovered land on a vo ...
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Komodo Dragon
The Komodo dragon (''Varanus komodoensis''), also known as the Komodo monitor, is a member of the monitor lizard family Varanidae that is endemic to the Indonesian islands of Komodo, Rinca, Flores, and Gili Motang. It is the largest extant species of lizard, growing to a maximum length of , and weighing up to . As a result of their size, Komodo dragons are apex predators, and dominate the ecosystems in which they live. Komodo dragons hunt and ambush prey including invertebrates, birds, and mammals. It has been claimed that they have a venomous bite; there are two glands in the lower jaw that secrete several toxic proteins. The biological significance of these proteins is disputed, but the glands have been shown to secrete an anticoagulant. Komodo dragons' group behavior in hunting is exceptional in the reptile world. The diet of Komodo dragons mainly consists of Javan rusa (''Rusa timorensis''), though they also eat considerable amounts of carrion. Komodo dragons also occ ...
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Cassowary
Cassowaries ( tpi, muruk, id, kasuari) are flightless birds of the genus ''Casuarius'' in the order Casuariiformes. They are classified as ratites (flightless birds without a keel on their sternum bones) and are native to the tropical forests of New Guinea (Papua New Guinea and East Indonesia), Aru Islands (Maluku), and northeastern Australia.. Three species are extant: The most common, the southern cassowary, is the third-tallest and second-heaviest living bird, smaller only than the ostrich and emu. The other two species are represented by the northern cassowary and the dwarf cassowary; the northern cassowary is the most recently discovered and the most threatened. A fourth but extinct species is represented by the pygmy cassowary. Cassowaries feed mainly on fruit, although all species are truly omnivorous and take a range of other plant foods, including shoots and grass seeds, in addition to fungi, invertebrates, and small vertebrates. Cassowaries are very wary of human ...
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