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Fat-tailed Dunnart
The fat-tailed dunnart (''Sminthopsis crassicaudata'') is a species of mouse-like marsupial of the Dasyuridae, the family that includes the little red kaluta, quolls, and the Tasmanian devil. It has an average body length of with a tail of . Ear length is . One of the smallest carnivorous marsupials, its weight varies between . The tail becomes fat a few mm from the proximal end and remains so right up to the tip. The dunnart has trichromat vision, similar to some other marsupials as well as primates but unlike most mammals which have dichromat vision. The dunnart is often eaten by other carnivores, including invasive foxes and cats, as well as other feral animals that live among its environment. Distribution and habitat The range of ''S. crassicaudata'' in Australia is in diverse habitats except for the Kimberley region of Western Australia and northern Northern Territory like Arnhem Land and Kakadu National Park, but avoids the Wannon and Mallee scrub habitats in Victoria. In ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
John Gould
John Gould (; 14 September 1804 – 3 February 1881) was an English ornithologist. He published a number of monographs on birds, illustrated by plates produced by his wife, Elizabeth Gould, and several other artists, including Edward Lear, Henry Constantine Richter, Joseph Wolf and William Matthew Hart. He has been considered the father of bird study in Australia and the Gould League in Australia is named after him. His identification of the birds now nicknamed "Darwin's finches" played a role in the inception of Darwin's theory of evolution by natural selection. Gould's work is referenced in Charles Darwin's book, ''On the Origin of Species''. Early life Gould was born in Lyme Regis, the first son of a gardener. Both father and son probably had little education. After working on Dowager Lady Poulett's glass house, his father obtained a position on an estate near Guildford, Surrey, and then in 1818, Gould Snr became foreman in the Royal Gardens of Windsor. Gould then be ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Woodland
A woodland () is, in the broad sense, land covered with trees, or in a narrow sense, synonymous with wood (or in the U.S., the ''plurale tantum'' woods), a low-density forest forming open habitats with plenty of sunlight and limited shade (see differences between British, American, and Australian English explained below). Woodlands may support an understory of shrubs and herbaceous plants including grasses. Woodland may form a transition to shrubland under drier conditions or during early stages of primary or secondary succession. Higher-density areas of trees with a largely closed canopy that provides extensive and nearly continuous shade are often referred to as forests. Extensive efforts by conservationist groups have been made to preserve woodlands from urbanization and agriculture. For example, the woodlands of Northwest Indiana have been preserved as part of the Indiana Dunes. Definitions United Kingdom ''Woodland'' is used in British woodland management to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dasyuromorphs
Dasyuromorphia (, meaning "hairy tail" in Greek) is an order comprising most of the Australian carnivorous marsupials, including quolls, dunnarts, the numbat, the Tasmanian devil, and the thylacine. In Australia, the exceptions include the omnivorous bandicoots (order Peramelemorphia) and the marsupial moles (which eat meat but are very different and are now accorded an order of their own, Notoryctemorphia). Numerous South American species of marsupials (orders Didelphimorphia, Paucituberculata, and Microbiotheria) are also carnivorous, as were some extinct members of the order Diprotodontia, including extinct kangaroos (such as '' Ekaltadeta'' and '' Propleopus)'' and thylacoleonids, and some members of the partially extinct clade Metatheria and all members of the extinct superorder Sparassodonta. The order contains four families: one with just a single living species (the numbat), two with only extinct species (including the thylacine and ''Malleodectes''), and one, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
House Mouse
The house mouse (''Mus musculus'') is a small mammal of the order Rodentia, characteristically having a pointed snout, large rounded ears, and a long and almost hairless tail. It is one of the most abundant species of the genus ''Mus''. Although a wild animal, the house mouse has benefited significantly from associating with human habitation to the point that truly wild populations are significantly less common than the semi-tame populations near human activity. The house mouse has been domesticated as the pet or fancy mouse, and as the laboratory mouse, which is one of the most important model organisms in biology and medicine. The complete mouse reference genome was sequenced in 2002. Characteristics House mice have an adult body length (nose to base of tail) of and a tail length of . The weight is typically . In the wild they vary in color from grey and light brown to black (individual hairs are actually agouti coloured), but domesticated fancy mice and laboratory mice ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lactation
Lactation describes the secretion of milk from the mammary glands and the period of time that a mother lactates to feed her young. The process naturally occurs with all sexually mature female mammals, although it may predate mammals. The process of feeding milk in all animals (including humans) is called ''nursing'', and in humans it is also called ''breastfeeding''. Newborn infants often produce some milk from their own breast tissue, known colloquially as witch's milk. In most species, lactation is a sign that the female has been pregnant at some point in her life, although it can happen without pregnancy. Nearly every species of mammal has nipples; except for monotremes, egg-laying mammals, which instead release milk through ducts in the abdomen. In only one species of mammal, the Dayak fruit bat from Southeast Asia, is milk production a normal male function. ''Galactopoiesis'' is the maintenance of milk production. This stage requires prolactin. Oxytocin is critical fo ... [...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 temperatu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Steady State
In systems theory, a system or a process is in a steady state if the variables (called state variables) which define the behavior of the system or the process are unchanging in time. In continuous time, this means that for those properties ''p'' of the system, the partial derivative with respect to time is zero and remains so: : \frac = 0 \quad \text t. In discrete time, it means that the first difference of each property is zero and remains so: :p_t-p_=0 \quad \text t. The concept of a steady state has relevance in many fields, in particular thermodynamics, economics, and engineering. If a system is in a steady state, then the recently observed behavior of the system will continue into the future. In stochastic systems, the probabilities that various states will be repeated will remain constant. See for example Linear difference equation#Conversion to homogeneous form for the derivation of the steady state. In many systems, a steady state is not achieved until some time afte ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Photoperiodism
Photoperiodism is the physiological reaction of organisms to the length of night or a dark period. It occurs in plants and animals. Plant photoperiodism can also be defined as the developmental responses of plants to the relative lengths of light and dark periods. They are classified under three groups according to the photoperiods: short-day plants, long-day plants, and day-neutral plants. Plants Many flowering plants (angiosperms) use a photoreceptor protein, such as phytochrome or cryptochrome, to sense seasonal changes in night length, or photoperiod, which they take as signals to flower. In a further subdivision, ''obligate'' photoperiodic plants absolutely require a long or short enough night before flowering, whereas ''facultative'' photoperiodic plants are more likely to flower under one condition. Phytochrome comes in two forms: Pr and Pfr. Red light (which is present during the day) converts phytochrome to its active form (pfr). This then triggers the plant to grow. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Basal Metabolic Rate
Basal metabolic rate (BMR) is the rate of energy expenditure per unit time by endothermic animals at rest. It is reported in energy units per unit time ranging from watt (joule/second) to ml O2/min or joule per hour per kg body mass J/(h·kg). Proper measurement requires a strict set of criteria to be met. These criteria include being in a physically and psychologically undisturbed state and being in a thermally neutral environment while in the post- absorptive state (i.e., not actively digesting food). In bradymetabolic animals, such as fish and reptiles, the equivalent term standard metabolic rate (SMR) applies. It follows the same criteria as BMR, but requires the documentation of the temperature at which the metabolic rate was measured. This makes BMR a variant of standard metabolic rate measurement that excludes the temperature data, a practice that has led to problems in defining "standard" rates of metabolism for many mammals. Metabolism comprises the processes that the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Heterothermy
Heterothermy or heterothermia (from Greek ἕτερος ''heteros'' "other" and θέρμη ''thermē'' "heat") is a physiological term for animals that vary between self-regulating their body temperature, and allowing the surrounding environment to affect it. In other words, they exhibit characteristics of both poikilothermy and homeothermy. Definition Heterothermic animals are those that can switch between poikilothermic and homeothermic strategies. These changes in strategies typically occur on a daily basis or on an annual basis. More often than not, it is used as a way to dissociate the fluctuating metabolic rates seen in some small mammals and birds (e.g. bats and hummingbirds), from those of traditional cold blooded animals. In many bat species, body temperature and metabolic rate are elevated only during activity. When at rest, these animals reduce their metabolisms drastically, which results in their body temperature dropping to that of the surrounding environment. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Circadian Rhythm
A circadian rhythm (), or circadian cycle, is a natural, internal process that regulates the sleep–wake cycle and repeats roughly every 24 hours. It can refer to any process that originates within an organism (i.e., endogenous) and responds to the environment ( entrained by the environment). These 24-hour rhythms are driven by a circadian clock, and they have been widely observed in animals, plants, fungi and cyanobacteria. The term ''circadian'' comes from the Latin ''circa'', meaning "approximately", and ''dies'', meaning "day". Processes with 24-hour cycles are more generally called diurnal rhythms; diurnal rhythms should not be called circadian rhythms unless they can be confirmed as endogenous, and not environmental. Although circadian rhythms are endogenous, they are adjusted to the local environment by external cues called zeitgebers (German for "time givers"), which include light, temperature and redox cycles. In clinical settings, an abnormal circadian rhythm in h ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dunnart
Dunnart is a common name for species of the genus ''Sminthopsis'', narrow-footed marsupials the size of a European mouse. They have a largely insectivorous diet. Taxonomy The genus name ''Sminthopsis'' was published by Oldfield Thomas in 1887, the author noting that the name '' Podabrus'' that had previously been used to describe the species was preoccupied as a genus of beetles. The type species is '' Phascogale crassicaudata'', published by John Gould in 1844. There are 23 species, all of which occur in Australia and New Guinea New Guinea (; Hiri Motu: ''Niu Gini''; id, Papua, or , historically ) is the world's second-largest island with an area of . Located in Oceania in the southwestern Pacific Ocean, the island is separated from Australia by the wide Torres ...: * Genus ''Sminthopsis'' ** ''S. crassicaudata'' species-group *** Fat-tailed dunnart, ''Sminthopsis crassicaudata'' ** ''S. macroura'' species-group *** Kakadu dunnart, ''Sminthopsis bindi'' *** C ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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