|
Lesser Dwarf Lemur
The fat-tailed dwarf lemur (''Cheirogaleus medius''), also known as the lesser dwarf lemur, western fat-tailed dwarf lemur, or spiny forest dwarf lemur, is endemic to Madagascar. Hibernation Recent research has shown that ''C. medius'' hibernates (or aestivates), even though in the tropical winter of Madagascar, temperatures remain high. It is the first tropical mammal and only primate in which hibernation has been demonstrated. However, the Malagasy winter is dry, and it appears that the lemur is avoiding the drought. It can hibernate for seven months. Unlike animals that hibernate in temperate regions, the lemur does not control its body temperature while hibernating, and if the tree hole in which it is sleeping is not well insulated, its body temperature fluctuates in accordance with the outside temperature. During torpor, this lemur has been found to periodically enter REM sleep; non-REM sleep has not been observed, a pattern opposite that found in hibernating ground squir ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Étienne Geoffroy Saint-Hilaire
Étienne Geoffroy Saint-Hilaire (15 April 177219 June 1844) was a French naturalist who established the principle of "unity of composition". He was a colleague of Jean-Baptiste Lamarck and expanded and defended Lamarck's evolutionary theories. Geoffroy's scientific views had a transcendental flavor (unlike Lamarck's materialistic views) and were similar to those of German morphologists like Lorenz Oken. He believed in the underlying unity of organismal design, and the possibility of the transmutation of species in time, amassing evidence for his claims through research in comparative anatomy, paleontology, and embryology. He is considered as a predecessor of the evo-devo evolutionary concept. Life and early career Geoffroy was born at Étampes (in present-day Essonne), and studied at the Collège de Navarre, in Paris, where he studied natural philosophy under M. J. Brisson. He then attended the lectures of Daubenton at the College de France and Fourcroy at the Jardin des Pl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
International Union For Conservation Of Nature
The International Union for Conservation of Nature (IUCN; officially International Union for Conservation of Nature and Natural Resources) is an international organization working in the field of nature conservation and sustainable use of natural resources. It is involved in data gathering and analysis, research, field projects, advocacy, and education. IUCN's mission is to "influence, encourage and assist societies throughout the world to conserve nature and to ensure that any use of natural resources is equitable and ecologically sustainable". Over the past decades, IUCN has widened its focus beyond conservation ecology and now incorporates issues related to sustainable development in its projects. IUCN does not itself aim to mobilize the public in support of nature conservation. It tries to influence the actions of governments, business and other stakeholders by providing information and advice and through building partnerships. The organization is best known to the wider pu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Madagascar
Madagascar (; mg, Madagasikara, ), officially the Republic of Madagascar ( mg, Repoblikan'i Madagasikara, links=no, ; french: République de Madagascar), is an island country in the Indian Ocean, approximately off the coast of East Africa across the Mozambique Channel. At Madagascar is the world's List of island countries, second-largest island country, after Indonesia. The nation is home to around 30 million inhabitants and consists of the island of Geography of Madagascar, Madagascar (the List of islands by area, fourth-largest island in the world), along with numerous smaller peripheral islands. Following the prehistoric breakup of the supercontinent Gondwana, Madagascar split from the Indian subcontinent around 90 million years ago, allowing native plants and animals to evolve in relative isolation. Consequently, Madagascar is a biodiversity hotspot; over 90% of wildlife of Madagascar, its wildlife is endemic. Human settlement of Madagascar occurred during or befo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hibernation
Hibernation is a state of minimal activity and metabolic depression undergone by some animal species. Hibernation is a seasonal heterothermy characterized by low body-temperature, slow breathing and heart-rate, and low metabolic rate. It most commonly occurs during winter months. Although traditionally reserved for "deep" hibernators such as rodents, the term has been redefined to include animals such as bears and is now applied based on active metabolic suppression rather than any absolute decline in body temperature. Many experts believe that the processes of daily torpor and hibernation form a continuum and utilise similar mechanisms. The equivalent during the summer months is aestivation. Hibernation functions to conserve energy when sufficient food is not available. To achieve this energy saving, an endothermic animal decreases its metabolic rate and thereby its body temperature. Hibernation may last days, weeks, or months—depending on the species, ambient temperature ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aestivation
Aestivation ( la, aestas (summer); also spelled estivation in American English) is a state of animal dormancy, similar to hibernation, although taking place in the summer rather than the winter. Aestivation is characterized by inactivity and a lowered metabolic rate, that is entered in response to high temperatures and arid conditions. It takes place during times of heat and dryness, the hot dry season, which are often the summer months. Invertebrate and vertebrate animals are known to enter this state to avoid damage from high temperatures and the risk of desiccation. Both terrestrial and aquatic animals undergo aestivation. Fossil records suggest that aestivation may have evolved several hundred million years ago. Physiology Organisms that aestivate appear to be in a fairly "light" state of dormancy, as their physiological state can be rapidly reversed, and the organism can quickly return to a normal state. A study done on '' Otala lactea'', a snail native to parts of Eu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lemur
Lemurs ( ) (from Latin ''lemures'' – ghosts or spirits) are Strepsirrhini, wet-nosed primates of the Superfamily (biology), superfamily Lemuroidea (), divided into 8 Family (biology), families and consisting of 15 genera and around 100 existing species. They are endemic to the island of Madagascar. Most existing lemurs are small, have a pointed snout, large eyes, and a long tail. They arboreal, chiefly live in trees and nocturnal, are active at night. Lemurs share resemblance with other primates, but evolved independently from monkeys and apes. Due to Madagascar's highly seasonal climate, Evolution of lemurs, lemur evolution has produced a level of species diversity rivaling that of any other primate group. Until shortly after humans arrived on the island around 2,000 years ago, there were lemurs as large as a male gorilla. Most species have been discovered or promoted to full species status since the 1990s; however, lemur Taxonomy (biology), taxonomic classification is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
REM Sleep
Rapid eye movement sleep (REM sleep or REMS) is a unique phase of sleep in mammals and birds, characterized by random rapid movement of the eyes, accompanied by low muscle tone throughout the body, and the propensity of the sleeper to dream vividly. The REM phase is also known as paradoxical sleep (PS) and sometimes desynchronized sleep or dreamy sleep, because of physiological similarities to waking states including rapid, low-voltage desynchronized brain waves. Electrical and chemical activity regulating this phase seems to originate in the brain stem, and is characterized most notably by an abundance of the neurotransmitter acetylcholine, combined with a nearly complete absence of monoamine neurotransmitters histamine, serotonin and norepinephrine. Experiences of REM sleep are not transferred to permanent memory due to absence of norepinephrine. REM sleep is physiologically different from the other phases of sleep, which are collectively referred to as non-REM sleep (NREM s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Non-REM Sleep
Non-rapid eye movement sleep (NREM), also known as quiescent sleep, is, collectively, sleep stages 1–3, previously known as stages 1–4. Rapid eye movement sleep (REM) is not included. There are distinct electroencephalographic and other characteristics seen in each stage. Unlike REM sleep, there is usually little or no eye movement during these stages. Dreaming occurs during both sleep states, and muscles are not paralyzed as in REM sleep. People who do not go through the sleeping stages properly get stuck in NREM sleep, and because muscles are not paralyzed a person may be able to sleepwalk. According to studies, the mental activity that takes place during NREM sleep is believed to be thought-like, whereas REM sleep includes hallucinatory and bizarre content. NREM sleep is characteristic of dreamer-initiated friendliness, compared to REM sleep where it's more aggressive, implying that NREM is in charge of simulating friendly interactions. The mental activity that occurs in NR ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ground Squirrel
Ground squirrels are members of the squirrel family of rodents (Sciuridae), which generally live on or in the ground, rather than trees. The term is most often used for the medium-sized ground squirrels, as the larger ones are more commonly known as marmots (genus ''Marmota'') or prairie dogs, while the smaller and less bushy-tailed ground squirrels tend to be known as chipmunks (genus ''Tamias''). Together, they make up the "marmot tribe" of squirrels, Marmotini, a division within the large and mainly ground squirrel subfamily Xerinae, and containing six living genera. Well-known members of this largely Holarctic group are the marmots (''Marmota''), including the American groundhog, the chipmunks, the susliks (''Spermophilus''), and the prairie dogs (''Cynomys''). They are highly variable in size and habitus, but most are remarkably able to rise up on their hind legs and stand fully erect comfortably for prolonged periods. They also tend to be far more gregarious than other sq ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cheirogaleus Adipicaudatus 1894
The dwarf lemurs are the lemurs of the genus ''Cheirogaleus''. All of the species in this genus, like all other lemurs, are native to Madagascar. Description Measuring 19–27 cm in body length with a tail about 16–17 cm, they are larger than the mouse lemur but smaller than the gentle lemur. Their heads are globular compared to the fox-like heads of the lemurs, but their muzzles are more pointed than those of the hapalemurs. Their hind limbs are slightly longer than their forelimbs, but not as elongated as in lepilemurs or indriids. Dwarf lemurs have an intermembral index of 71 on average. In contrast to most other primates, their grip is similar to that of South American monkeys with objects picked up and branches grasped between the second and third fingers, rather than between the thumb and index finger. Their nails are somewhat keeled and pointed. Dwarf lemurs roam the lower strata of the foliage in the coastal forests of eastern Madagascar. They a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Colin Groves
Colin Peter Groves (24 June 1942 – 30 November 2017) was a British-Australian biologist and anthropologist. Groves was Professor of Biological Anthropology at the Australian National University in Canberra, Australia. Education Born in England, Groves completed a Bachelor of Science at University College London in 1963, and a Doctor of Philosophy at the Royal Free Hospital School of Medicine in 1966. From 1966 to 1973, he was a Postdoctoral Researcher and Teaching Fellow at the University of California, Berkeley, Queen Elizabeth College and the University of Cambridge. Career Groves emigrated to Australia in 1973 and joined the Australian National University, where he was promoted to full Professor in 2000 and remained Emeritus Professor until his death. Along with the Czech biologist Professor Vratislav Mazák, Groves was the describer of ''Homo ergaster''. Groves also wrote ''Primate Taxonomy'' published by the Smithsonian Institution Press in 2001, and Ungulate Taxonomy, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pelage
Fur is a thick growth of hair that covers the skin of mammals. It consists of a combination of oily #Guard hair, guard hair on top and thick #Down hair, underfur beneath. The guard hair keeps moisture from reaching the skin; the underfur acts as an thermal insulation, insulating blanket that keeps the animal warm. The fur of mammals has many uses: protection, sensory purposes, waterproofing, and camouflaging, with the primary usage being thermoregulation. The types of hair include * ''definitive'', which may be moulting, shed after reaching a certain length; * ''vibrissae'', which are sensory hairs and are most commonly whiskers; * ''pelage'', which consists of guard hairs, under-fur, and awn hair; * ''spine (zoology), spines'', which are a type of stiff guard hair used for defense in, for example, porcupines; * ''bristles'', which are long hairs usually used in visual signals, such as the mane (lion), mane of a lion; * ''velli'', often called "down fur", which insulates new ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
