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Ruffed Lemur
The ruffed lemurs of the genus ''Varecia'' are strepsirrhine primates and the largest extant lemurs within the family Lemuridae. Like all living lemurs, they are found only on the island of Madagascar. Formerly considered to be a monotypic genus, two species are now recognized: the black-and-white ruffed lemur, with its three subspecies, and the red ruffed lemur. Ruffed lemurs are diurnal and arboreal quadrupeds, often observed leaping through the upper canopy of the seasonal tropical rainforests in eastern Madagascar. They are also the most frugivorous of the Malagasy lemurs, and they are very sensitive to habitat disturbance. Ruffed lemurs live in multi-male/multi-female groups and have a complex and flexible social structure, described as fission-fusion. They are highly vocal and have loud, raucous calls. Ruffed lemurs are seasonal breeders and highly unusual in their reproductive strategy. They are considered an "evolutionary enigma" in that they are the largest of the ext ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
John Edward Gray
John Edward Gray, FRS (12 February 1800 – 7 March 1875) was a British zoologist. He was the elder brother of zoologist George Robert Gray and son of the pharmacologist and botanist Samuel Frederick Gray (1766–1828). The same is used for a zoological name. Gray was keeper of zoology at the British Museum in London from 1840 until Christmas 1874, before the natural history holdings were split off to the Natural History Museum. He published several catalogues of the museum collections that included comprehensive discussions of animal groups and descriptions of new species. He improved the zoological collections to make them amongst the best in the world. Biography Gray was born in Walsall, but his family soon moved to London, where Gray studied medicine. He assisted his father in writing ''The Natural Arrangement of British Plants'' (1821). After being blackballed by the Linnean Society of London, Gray shifted his interest from botany to zoology. He began his zoologica ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Subspecies
In biological classification, subspecies is a rank below species, used for populations that live in different areas and vary in size, shape, or other physical characteristics (morphology), but that can successfully interbreed. Not all species have subspecies, but for those that do there must be at least two. Subspecies is abbreviated subsp. or ssp. and the singular and plural forms are the same ("the subspecies is" or "the subspecies are"). In zoology, under the International Code of Zoological Nomenclature, the subspecies is the only taxonomic rank below that of species that can receive a name. In botany and mycology, under the International Code of Nomenclature for algae, fungi, and plants, other infraspecific ranks, such as variety, may be named. In bacteriology and virology, under standard bacterial nomenclature and virus nomenclature, there are recommendations but not strict requirements for recognizing other important infraspecific ranks. A taxonomist decides whether ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Extinction
Extinction is the termination of a kind of organism or of a group of kinds (taxon), usually a species. The moment of extinction is generally considered to be the death of the last individual of the species, although the capacity to breed and recover may have been lost before this point. Because a species' potential range may be very large, determining this moment is difficult, and is usually done retrospectively. This difficulty leads to phenomena such as Lazarus taxa, where a species presumed extinct abruptly "reappears" (typically in the fossil record) after a period of apparent absence. More than 99% of all species that ever lived on Earth, amounting to over five billion species, are estimated to have died out. It is estimated that there are currently around 8.7 million species of eukaryote globally, and possibly many times more if microorganisms, like bacteria, are included. Notable extinct animal species include non-avian dinosaurs, saber-toothed cats, dodos, m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Altricial
In biology, altricial species are those in which the young are underdeveloped at the time of birth, but with the aid of their parents mature after birth. Precocial species are those in which the young are relatively mature and mobile from the moment of birth or hatching. Precocial species are normally nidifugous, meaning that they leave the nest shortly after birth or hatching. These categories form a continuum, without distinct gaps between them. Altriciality Etymology The word is derived from the Latin root ''alere'', meaning "to nurse, to rear, or to nourish" and indicates the need for young to be fed and taken care of for a long duration. By contrast, species whose young are immediately or quickly mobile are called ''precocial''. Precociality Etymology The word "precocial" is derived from the same root as ''precocious'', implying early maturity in both cases. Superprecociality Extremely precocial species are called "superprecocial". Examples are the megapode birds, which ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Litter (animal)
A litter is the live birth of multiple offspring at one time in animals from the same mother and usually from one set of parents, particularly from three to eight offspring. The word is most often used for the offspring of mammals, but can be used for any animal that gives birth to multiple young. In comparison, a group of eggs and the offspring that hatch from them are frequently called a clutch, while young birds are often called a brood. Animals from the same litter are referred to as litter-mates. Litter A species' average litter size is generally equal to one half of the number of teats and the maximum litter size generally matches the number of teats. Not all species abide by this rule, however. The naked mole rat, for example, averages roughly eleven young per birth and has eleven teats. Animals frequently display grouping behavior in herds, swarms, flocks, or colonies, and these multiple births derive similar advantages. A litter offers some protection from predation, not ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gestation
Gestation is the period of development during the carrying of an embryo, and later fetus, inside viviparous animals (the embryo develops within the parent). It is typical for mammals, but also occurs for some non-mammals. Mammals during pregnancy can have one or more gestations at the same time, for example in a multiple birth. The time interval of a gestation is called the '' gestation period''. In obstetrics, ''gestational age'' refers to the time since the onset of the last menses, which on average is fertilization age plus two weeks. Mammals In mammals, pregnancy begins when a zygote (fertilized ovum) implants in the female's uterus and ends once the fetus leaves the uterus during labor or an abortion (whether induced or spontaneous). Humans In humans, pregnancy can be defined clinically or biochemically. Clinically, pregnancy starts from first day of the mother's last period. Biochemically, pregnancy starts when a woman's human chorionic gonadotropin (hCG) levels ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Seasonal Breeder
Seasonal breeders are animal species that successfully mate only during certain times of the year. These times of year allow for the optimization of survival of young due to factors such as ambient temperature, food and water availability, and changes in the predation behaviors of other species. Related sexual interest and behaviors are expressed and accepted only during this period. Female seasonal breeders will have one or more estrus cycles only when she is "in season" or fertile and receptive to mating. At other times of the year, they will be anestrus, or have a dearth of their sexual cycle. Unlike reproductive cyclicity, seasonality is described in both males and females. Male seasonal breeders may exhibit changes in testosterone levels, testes weight, and fertility depending on the time of year. Seasonal breeders are distinct from opportunistic breeders, that mate whenever the conditions of their environment become favorable, and continuous breeders that mate year-round. T ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Frugivore
A frugivore is an animal that thrives mostly on raw fruits or succulent fruit-like produce of plants such as roots, shoots, nuts and seeds. Approximately 20% of mammalian herbivores eat fruit. Frugivores are highly dependent on the abundance and nutritional composition of fruits. Frugivores can benefit or hinder fruit-producing plants by either dispersing or destroying their seeds through digestion. When both the fruit-producing plant and the frugivore benefit by fruit-eating behavior the interaction is a form of mutualism. Frugivore seed dispersal Seed dispersal is important for plants because it allows their progeny to move away from their parents over time. The advantages of seed dispersal may have led to the evolution of fleshy fruits, which entice animals to consume them and move the plant's seeds from place to place. While many fruit-producing plant species would not disperse far without frugivores, their seeds can usually germinate even if they fall to the ground directl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tropical Rainforest
Tropical rainforests are rainforests that occur in areas of tropical rainforest climate in which there is no dry season – all months have an average precipitation of at least 60 mm – and may also be referred to as ''lowland equatorial evergreen rainforest''. True rainforests are typically found between 10 degrees north and south of the equator (see map); they are a sub-set of the tropical forest biome that occurs roughly within the 28-degree latitudes (in the equatorial zone between the Tropic of Cancer and Tropic of Capricorn). Within the World Wildlife Fund's biome classification, tropical rainforests are a type of tropical moist broadleaf forest (or tropical wet forest) that also includes the more extensive seasonal tropical forests. Overview Tropical rainforests are characterized by two words: hot and wet. Mean monthly temperatures exceed during all months of the year. Average annual rainfall is no less than and can exceed although it typically lies betwe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Canopy (biology)
In biology, the canopy is the aboveground portion of a plant cropping or crop, formed by the collection of individual plant crowns. In forest ecology, canopy also refers to the upper layer or habitat zone, formed by mature tree crowns and including other biological organisms ( epiphytes, lianas, arboreal animals, etc.). The communities that inhabit the canopy layer are thought to be involved in maintaining forest diversity, resilience, and functioning. Sometimes the term canopy is used to refer to the extent of the outer layer of leaves of an individual tree or group of trees. Shade trees normally have a dense canopy that blocks light from lower growing plants. Observation Early observations of canopies were made from the ground using binoculars or by examining fallen material. Researchers would sometimes erroneously rely on extrapolation by using more reachable samples taken from the understory. In some cases, they would use unconventional methods such as chairs susp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Quadruped
Quadrupedalism is a form of locomotion where four limbs are used to bear weight and move around. An animal or machine that usually maintains a four-legged posture and moves using all four limbs is said to be a quadruped (from Latin ''quattuor'' for "four", and ''pes'', ''pedis'' for "foot"). Quadruped animals are found among both vertebrates and invertebrates. Quadrupeds vs. tetrapods Although the words ‘quadruped’ and ‘tetrapod’ are both derived from terms meaning ‘four-footed’, they have distinct meanings. A tetrapod is any member of the taxonomic unit Tetrapoda (which is defined by descent from a specific four-limbed ancestor), whereas a quadruped actually uses four limbs for locomotion. Not all tetrapods are quadrupeds and not all entities that could be described as ‘quadrupedal’ are tetrapods. This last meaning includes certain artificial objects; almost all quadruped ''organisms'' are tetrapods (with the exception of some raptorial arthropods adapted fo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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