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Elephants
Elephants are the largest existing land animals. Three living species are currently recognised: the African bush elephant, the African forest elephant, and the Asian elephant. They are the only surviving members of the family Elephantidae and the order Proboscidea. The order was formerly much more diverse during the Pleistocene, but most species became extinct during the Late Pleistocene epoch. Distinctive features of elephants include a long proboscis called a trunk, tusks, large ear flaps, pillar-like legs, and tough but sensitive skin. The trunk is used for breathing, bringing food and water to the mouth, and grasping objects. Tusks, which are derived from the incisor teeth, serve both as weapons and as tools for moving objects and digging. The large ear flaps assist in maintaining a constant body temperature as well as in communication. African elephants have larger ears and concave backs, whereas Asian elephants have smaller ears, and convex or level backs. Elephants ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Asian Elephant
The Asian elephant (''Elephas maximus''), also known as the Asiatic elephant, is the only living species of the genus '' Elephas'' and is distributed throughout the Indian subcontinent and Southeast Asia, from India in the west, Nepal in the north, Sumatra in the south, and to Borneo in the east. Three subspecies are recognised—'' E. m. maximus'' from Sri Lanka, ''E. m. indicus'' from mainland Asia and '' E. m. sumatranus'' from the island of Sumatra. Formerly, there was also the Syrian elephant or Western Asiatic elephant (''Elephas maximus asurus'') which was the westernmost population of the Asian elephant (''Elephas maximus''). This subspecies became extinct in ancient times. Skeletal remains of ''E. m. asurus'' have been recorded from the Middle East: Iran, Iraq, Syria, and Turkey from periods dating between at least 1800 BC and likely 700 BC. It is one of only three living species of elephants or elephantids anywhere in the world, the others being the Afr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
African Bush Elephant
The African bush elephant (''Loxodonta africana'') is one of two extant African elephant species and one of three extant elephant species. It is the largest living terrestrial animal, with bulls reaching a shoulder height of up to and a body mass of up to . It is distributed across 37 African countries and inhabits forests, grasslands and woodlands, wetlands and agricultural land. Since 2021, it has been listed as Endangered on the IUCN Red List. It is threatened foremost by habitat destruction, and in parts of its range also by poaching for meat and ivory. It is a social mammal, travelling in herds composed of cows and their offspring. Adult bulls usually live alone or in small bachelor groups. It is a herbivore, feeding on grasses, creepers, herbs, leaves, and bark. The menstrual cycle lasts three to four months, and females are pregnant for 22 months, the longest gestation period of any mammal. Taxonomy ''Elephas africanus'' was the scientific name proposed by Johan ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
African Forest Elephant
The African forest elephant (''Loxodonta cyclotis'') is one of the two living African elephant species. It is native to humid forests in West Africa and the Congo Basin. It is the smallest of the three living elephant species, reaching a shoulder height of . Both sexes have straight, down-pointing tusks, which erupt when they are 1–3 years old. It lives in family groups of up to 20 individuals. Since it forages on leaves, seeds, fruit, and tree bark, it has been referred to as the 'megagardener of the forest'. It contributes significantly to maintain the composition and structure of the Guinean Forests of West Africa and the Congolese rainforests. The first scientific description of the species was published in 1900. During the 20th century, overhunting caused a sharp decline in population, and by 2013 it was estimated that less than 30,000 individuals remained. It is threatened by habitat loss, fragmentation, and poaching. The conservation status of populations varies across ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Musth
Musth or must (from Persian, )''The Oxford Dictionary and Thesaurus: American edition'', published 1996 by Oxford University Press; p. 984 is a periodic condition in bull (male) elephants characterized by aggressive behavior and accompanied by a large rise in reproductive hormones. Testosterone levels in an elephant in musth can be on average 60 times greater than in the same elephant at other times (in specific individuals these testosterone levels can even reach as much as 140 times the normal). However, whether this hormonal surge is the sole cause of musth or merely a contributing factor is unknown. Scientific investigation of musth is problematic because even the most placid elephants become violent toward humans and other elephants during musth. Musth differs from rut in that the female elephant's estrus cycle is not seasonally linked, whereas musth most often takes place in winter. Furthermore, bulls in musth have often been known to attack female elephants, regardle ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Elephantidae
Elephantidae is a family of large, herbivorous proboscidean mammals collectively called elephants and mammoths. These are terrestrial large mammals with a snout modified into a trunk and teeth modified into tusks. Most genera and species in the family are extinct. Only two genera, '' Loxodonta'' (African elephants) and ''Elephas'' (Asiatic elephants), are living. The family was first described by John Edward Gray in 1821, and later assigned to taxonomic ranks within the order Proboscidea. Elephantidae has been revised by various authors to include or exclude other extinct proboscidean genera. Classification Scientific classification of Elephantidae taxa embraces an extensive record of fossil specimens, over millions of years, some of which existed until the end of the last ice age. Some species were extirpated more recently. The discovery of new specimens and proposed cladistics have resulted in systematic revisions of the family and related proboscideans. Elephantids are ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Palaeoloxodon
''Palaeoloxodon'' is an extinct genus of elephant. The genus originated in Africa during the Pliocene era, and expanded into Eurasia during the Pleistocene era. The genus contains some of the largest known species of elephants, over four metres tall at the shoulders, including the European straight-tusked elephant (''Palaeoloxodon antiquus''), and the southern Asian '' Palaeoloxodon namadicus'', the latter of which was possibly the largest known land mammal based on fragmentary remains, but this requires proper reexamination. In contrast, the genus also contains many species of dwarf elephants that evolved via insular dwarfism on islands in the Mediterranean, some only a metre in height, making them the smallest elephants known. The genus has a long and complex taxonomic history, and at various times, it has been considered to belong to '' Loxodonta'' or '' Elephas'', but today is usually considered a valid and separate genus in its own right. Taxonomy In 1924, circumscribed ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mammuthus
A mammoth is any species of the extinct elephantid genus ''Mammuthus'', one of the many genera that make up the order of trunked mammals called proboscideans. The various species of mammoth were commonly equipped with long, curved tusks and, in northern species, a covering of long hair. They lived from the Pliocene epoch (from around 5 million years ago) into the Holocene at about 4,000 years ago, and various species existed in Africa, Europe, Asia, and North America. They were members of the family Elephantidae, which also contains the two genera of modern elephants and their ancestors. Mammoths are more closely related to living Asian elephants than African elephants. The oldest representative of ''Mammuthus'', the South African mammoth (''M. subplanifrons''), appeared around 5 million years ago during the early Pliocene in what is now southern and eastern Africa. Descendant species of these mammoths moved north and continued to propagate into numerous subsequent speci ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fission–fusion Society
In ethology, a fission–fusion society is one in which the size and composition of the social group change as time passes and animals move throughout the environment; animals merge into a group (fusion)—e.g. sleeping in one place—or split (fission)—e.g. foraging in small groups during the day. For species that live in fission–fusion societies, group composition is a dynamic property. The change in composition, subgroup size, and dispersion of different groups are 3 main elements of a fission-fusion society. This social organization is found in several primates, elephants, cetaceans, ungulates, social carnivores, some birds and some fish. Species Fission-fusion societies occur among many different species of primates (e.g. chimpanzees, orangutans, and humans), elephants (e.g. forest elephants, African elephants), and bats (e.g. northern long-eared bats). The change in composition, subgroup size, and dispersion of different groups are 3 main elements of a fission-fusion ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Largest And Heaviest Animals
The largest animal ever to have lived is thought to be the blue whale (''Balaenoptera musculus''). The maximum recorded weight was 190 tonnes for a specimen measuring , whereas longer ones, up to , have been recorded but not weighed.Wood, Gerald ''The Guinness Book of Animal Facts and Feats'' (1983) It is estimated however that this individual could have a mass of 250 tonnes. The title of the longest non-colonial animal is probably owned by the lion's mane jellyfish (36.6m / 120 ft). The African bush elephant (''Loxodonta africana'') is the largest living land animal. A native of various open habitats in sub-Saharan Africa, this elephant is commonly born weighing about . The largest elephant ever recorded was shot in Angola in 1974. It was a male measuring from trunk to tail and lying on its side in a projected line from the highest point of the shoulder to the base of the forefoot, indicating a standing shoulder height of . This male had a computed weight of 12.25 tonnes. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Matriarchy
Matriarchy is a social system in which women hold the primary power positions in roles of authority. In a broader sense it can also extend to moral authority, social privilege and control of property. While those definitions apply in general English, definitions specific to anthropology and feminism differ in some respects. Matriarchies may also be confused with matrilineal, matrilocal, and matrifocal societies. While there are those who may consider any non-patriarchal system to be matriarchal, most academics exclude those systems from matriarchies as strictly defined. Definitions, connotations, and etymology According to the ''Oxford English Dictionary'' (''OED''), matriarchy is a "form of social organization in which the mother or oldest female is the head of the family, and descent and relationship are reckoned through the female line; government or rule by a woman or women."''Oxford English Dictionary'' (online), entry ''matriarchy'', as accessed November 3, 2013. A ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Keystone Species
A keystone species is a species which has a disproportionately large effect on its natural environment relative to its abundance, a concept introduced in 1969 by the zoologist Robert T. Paine. Keystone species play a critical role in maintaining the structure of an ecological community, affecting many other organisms in an ecosystem and helping to determine the types and numbers of various other species in the community. Without keystone species, the ecosystem would be dramatically different or cease to exist altogether. Some keystone species, such as the wolf, are also apex predators. The role that a keystone species plays in its ecosystem is analogous to the role of a keystone in an arch. While the keystone is under the least pressure of any of the stones in an arch, the arch still collapses without it. Similarly, an ecosystem may experience a dramatic shift if a keystone species is removed, even though that species was a small part of the ecosystem by measures of biomas ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Proboscidea
The Proboscidea (; , ) are a taxonomic order of afrotherian mammals containing one living family ( Elephantidae) and several extinct families. First described by J. Illiger in 1811, it encompasses the elephants and their close relatives. From the mid-Miocene onwards, most proboscideans were very large. The largest land mammal of all time may have been a proboscidean; '' Palaeoloxodon namadicus'' was up to at the shoulder and may have weighed up to , almost double the weight of some sauropods like '' Diplodocus carnegii''. The largest extant proboscidean is the African bush elephant, with a record of size of at the shoulder and . In addition to their enormous size, later proboscideans are distinguished by tusks and long, muscular trunks, which were less developed or absent in early proboscideans. Three species of elephant are currently recognised: the African bush elephant, the African forest elephant, and the Asian elephant. Elephantidae is the only surviving family of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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