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Haul Out
Hauling-out is a behaviour associated with pinnipeds (true seals, sea lions, fur seals and walruses) temporarily leaving the water. Hauling-out typically occurs between periods of foraging activity. Rather than remain in the water, pinnipeds haul-out onto land or sea-ice for reasons such as reproduction and rest. Hauling-out is necessary in seals for mating (with the exception of the Baikal seal) and giving birth (although a distinction is generally made between reproductive aggregations, termed "rookeries", and non-reproductive aggregations, termed "haul-outs"). Other benefits of hauling-out may include predator avoidance, thermoregulation, social activity, parasite reduction and rest. There is much variation in haul-out patterns among different seal species.Hoelzel, A. Rus. (2002). ''Marine Mammal Biology: An Evolutionary Approach''. Blackwell Publishing. . p. 197. Haul-out sites may be segregated by age and sex within the same species. Many species of pinniped have only a fe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sea Lion Group At Haulout
The sea, connected as the world ocean or simply the ocean, is the body of salty water that covers approximately 71% of the Earth's surface. The word sea is also used to denote second-order sections of the sea, such as the Mediterranean Sea, as well as certain large, entirely landlocked, saltwater lakes, such as the Caspian Sea. The sea moderates Earth's climate and has important roles in the water, carbon, and nitrogen cycles. Humans harnessing and studying the sea have been recorded since ancient times, and evidenced well into prehistory, while its modern scientific study is called oceanography. The most abundant solid dissolved in seawater is sodium chloride. The water also contains salts of magnesium, calcium, potassium, and mercury, amongst many other elements, some in minute concentrations. Salinity varies widely, being lower near the surface and the mouths of large rivers and higher in the depths of the ocean; however, the relative proportions of dissolved salts vary li ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bass Strait
Bass Strait () is a strait separating the island state of Tasmania from the Australian mainland (more specifically the coast of Victoria, with the exception of the land border across Boundary Islet). The strait provides the most direct waterway between the Great Australian Bight and the Tasman Sea, and is also the only maritime route into the economically prominent Port Phillip Bay. Formed 8,000 years ago by rising sea levels at the end of the last glacial period, the strait was named after English explorer and physician George Bass (1771-1803) by European colonists. Extent The International Hydrographic Organization defines the limits of Bass Strait as follows: :''On the west.'' The eastern limit of the Great Australian Bight eing a line from Cape Otway, Australia, to King Island (Tasmania)">King Island and thence to Cape Grim, the northwest extreme of Tasmania]. :''On the east.'' The western limit of the Tasman Sea between Gabo Island and Eddystone Point eing a line fr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Maxima And Minima
In mathematical analysis, the maxima and minima (the respective plurals of maximum and minimum) of a function, known collectively as extrema (the plural of extremum), are the largest and smallest value of the function, either within a given range (the ''local'' or ''relative'' extrema), or on the entire domain (the ''global'' or ''absolute'' extrema). Pierre de Fermat was one of the first mathematicians to propose a general technique, adequality, for finding the maxima and minima of functions. As defined in set theory, the maximum and minimum of a set are the greatest and least elements in the set, respectively. Unbounded infinite sets, such as the set of real numbers, have no minimum or maximum. Definition A real-valued function ''f'' defined on a domain ''X'' has a global (or absolute) maximum point at ''x''∗, if for all ''x'' in ''X''. Similarly, the function has a global (or absolute) minimum point at ''x''∗, if for all ''x'' in ''X''. The value of the function at a m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Walrus
The walrus (''Odobenus rosmarus'') is a large pinniped, flippered marine mammal with a discontinuous distribution about the North Pole in the Arctic Ocean and subarctic seas of the Northern Hemisphere. The walrus is the only living species in the family (biology), family Odobenidae and genus ''Odobenus''. This species is subdivided into two subspecies: the Atlantic walrus (''O. r. rosmarus''), which lives in the Atlantic Ocean, and the Pacific walrus (''O. r. divergens''), which lives in the Pacific Ocean. Adult walrus are characterised by prominent tusks and whiskers, and their considerable bulk: adult males in the Pacific can weigh more than and, among pinnipeds, are exceeded in size only by the two species of elephant seals. Walruses live mostly in shallow waters above the continental shelves, spending significant amounts of their lives on the sea ice looking for benthic zone, benthic bivalvia, bivalve mollusks to eat. Walruses are relatively long-lived, social animals, an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wean
Weaning is the process of gradually introducing an infant human or another mammal to what will be its adult diet while withdrawing the supply of its mother's milk. The process takes place only in mammals, as only mammals produce milk. The infant is considered to be fully weaned once it is no longer fed by any breast milk (or bottled substitute). Humans In some cultures, weaning progresses with the introduction of feeding the child food that has been prechewed by the parent along with continued breastfeeding, a practice known as premastication. The practice was important throughout human history in that it naturally gave a child a greatly improved protein source in addition to preventing iron deficiency. However, premasticated food from caregivers of lower socioeconomic status in areas of endemic diseases can result in the passing of the disease to the child. How and when to wean a human infant is controversial. The American Academy of Pediatrics recommends feeding a baby onl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Parturition
Birth is the act or process of bearing or bringing forth offspring, also referred to in technical contexts as parturition. In mammals, the process is initiated by hormones which cause the muscular walls of the uterus to contract, expelling the fetus at a developmental stage when it is ready to feed and breathe. In some species the offspring is precocial and can move around almost immediately after birth but in others it is altricial and completely dependent on parenting. In marsupials, the fetus is born at a very immature stage after a short gestation and develops further in its mother's womb pouch. It is not only mammals that give birth. Some reptiles, amphibians, fish and invertebrates carry their developing young inside them. Some of these are ovoviviparous, with the eggs being hatched inside the mother's body, and others are viviparous, with the embryo developing inside her body, as in the case of mammals. Mammals Large mammals, such as primates, cattle, horses, some ant ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nocturnal
Nocturnality is an animal behavior characterized by being active during the night and sleeping during the day. The common adjective is "nocturnal", versus diurnal meaning the opposite. Nocturnal creatures generally have highly developed senses of hearing, smell, and specially adapted eyesight. Some animals, such as cats and ferrets, have eyes that can adapt to both low-level and bright day levels of illumination (see metaturnal). Others, such as bushbabies and (some) bats, can function only at night. Many nocturnal creatures including tarsiers and some owls have large eyes in comparison with their body size to compensate for the lower light levels at night. More specifically, they have been found to have a larger cornea relative to their eye size than diurnal creatures to increase their : in the low-light conditions. Nocturnality helps wasps, such as ''Apoica flavissima'', avoid hunting in intense sunlight. Diurnal animals, including squirrels and songbirds, are active du ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Diurnal Cycle
A diurnal cycle (or diel cycle) is any pattern that recurs every 24 hours as a result of one full rotation of the planet Earth around its axis. Earth's rotation causes surface temperature fluctuations throughout the day and night, as well as weather changes throughout the year. The diurnal cycle depends mainly on incoming solar radiation. Climate and atmosphere In climatology, the diurnal cycle is one of the most basic forms of climate patterns, including variations in diurnal temperature and rainfall. Diurnal cycles may be approximately sinusoidal or include components of a truncated sinusoid (due to the Sun's rising and setting) and thermal relaxation ( Newton cooling) at night. The diurnal cycle also has a great impact on carbon dioxide levels in the atmosphere, due to processes such as photosynthesis and cellular respiration. Biological effects Diurnal cycles of light and temperature can result in similar cycles in biological processes, such as photosynthesis i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Antarctic
The Antarctic ( or , American English also or ; commonly ) is a polar region around Earth's South Pole, opposite the Arctic region around the North Pole. The Antarctic comprises the continent of Antarctica, the Kerguelen Plateau and other island territories located on the Antarctic Plate or south of the Antarctic Convergence. The Antarctic region includes the ice shelves, waters, and all the island territories in the Southern Ocean situated south of the Antarctic Convergence, a zone approximately wide varying in latitude seasonally. The region covers some 20 percent of the Southern Hemisphere, of which 5.5 percent (14 million km2) is the surface area of the Antarctica continent itself. All of the land and ice shelves south of 60°S latitude are administered under the Antarctic Treaty System. Biogeographically, the Antarctic realm is one of eight biogeographic realms of Earth's land surface. Geography As defined by the Antarctic Treaty System, the Antarctic r ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Weddell Seal
The Weddell seal (''Leptonychotes weddellii'') is a relatively large and abundant true seal with a circumpolar distribution surrounding Antarctica. The Weddell seal was discovered and named in the 1820s during expeditions led by British sealing captain James Weddell to the area of the Southern Ocean now known as the Weddell Sea. The life history of this species is well documented since it occupies fast ice environments close to the Antarctic continent and often adjacent to Antarctic bases. This is the only species in the genus ''Leptonychotes''. Description Weddell seals measure about 2.5–3.5 m (8 ft 2 in–11 ft 6 in) long and weigh 400–600 kg (880–1,320 lb). They are amongst the largest seals, with a rather bulky body and short fore flippers relative to their body length. Males weigh less than females, usually about 500 kg (1,100 lb) or less. Male and female Weddell seals are generally about the same length, though females can be slightly l ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Weddell Seal (js)1
The Weddell seal (''Leptonychotes weddellii'') is a relatively large and abundant true seal with a circumpolar distribution surrounding Antarctica. The Weddell seal was discovered and named in the 1820s during expeditions led by British sealing captain James Weddell to the area of the Southern Ocean now known as the Weddell Sea. The life history of this species is well documented since it occupies fast ice environments close to the Antarctic continent and often adjacent to Antarctic bases. This is the only species in the genus ''Leptonychotes''. Description Weddell seals measure about 2.5–3.5 m (8 ft 2 in–11 ft 6 in) long and weigh 400–600 kg (880–1,320 lb). They are amongst the largest seals, with a rather bulky body and short fore flippers relative to their body length. Males weigh less than females, usually about 500 kg (1,100 lb) or less. Male and female Weddell seals are generally about the same length, though females can be slightly ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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