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Grey Teal
The grey teal (''Anas gracilis'') is a dabbling duck found in open wetlands in Australia and New Zealand. Description It can be identified due to the presence of a crimson coloured iris in its eyes.Winter, M. (2018). Grey Teal. Wilderness Magazine, (September 2018). Retrieved from https://www.wildernessmag.co.nz/grey-teal/ This crimson colour is relatively more prominent in adult males.[Marchant, S., & Higgins, P. (1990). Handbook of Australian, New Zealand & Antarctic Birds. Volume 1, Ratites to ducks; Part B Australian pelican to ducks. (pp. 1252-1281). Melbourne: Oxford University Press.] It is a mottled brown duck with white and green flashes on its wings. Males and females share the same colouration, in contrast to the related chestnut teal, whose male and female are strikingly different. The grey teal has almost identical colouration to the female chestnut teal and the grey can only be distinguished by its lighter coloured neck and paler face. Juveniles are paler than ad ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Walter Buller
Sir Walter Lawry Buller (9 October 1838 – 19 July 1906) was a New Zealand lawyer and naturalist who was a dominant figure in New Zealand ornithology. His book, ''A History of the Birds of New Zealand'', first published in 1873, was published as an enlarged version in 1888 and became a New Zealand classic. Biography Buller was born at Newark, the Wesleyan mission at Pakanae in the Hokianga, the son of Rev. James Buller, a Cornish missionary who had helped convert the people of Tonga to Methodism. He was educated at Wesley College in Auckland. In 1854, he moved to Wellington with his parents, where he was befriended by the naturalist William John Swainson. In 1859 he was made Native Commissioner for the Southern Provinces. In 1871 he travelled to England and was called to the bar at the Inner Temple. Three years later he returned to Wellington and practised law. In 1862, he married Charlotte Mair at Whangārei. They were to have four children. Buller was the author of '' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vegetation
Vegetation is an assemblage of plant species and the ground cover they provide. It is a general term, without specific reference to particular taxa, life forms, structure, spatial extent, or any other specific botanical or geographic characteristics. It is broader than the term ''flora'' which refers to species composition. Perhaps the closest synonym is plant community, but ''vegetation'' can, and often does, refer to a wider range of spatial scales than that term does, including scales as large as the global. Primeval redwood forests, coastal mangrove stands, sphagnum bogs, desert soil crusts, roadside weed patches, wheat fields, cultivated gardens and lawns; all are encompassed by the term ''vegetation''. The vegetation type is defined by characteristic dominant species, or a common aspect of the assemblage, such as an elevation range or environmental commonality. The contemporary use of ''vegetation'' approximates that of ecologist Frederic Clements' term earth cover ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stochastic
Stochastic (, ) refers to the property of being well described by a random probability distribution. Although stochasticity and randomness are distinct in that the former refers to a modeling approach and the latter refers to phenomena themselves, these two terms are often used synonymously. Furthermore, in probability theory, the formal concept of a '' stochastic process'' is also referred to as a ''random process''. Stochasticity is used in many different fields, including the natural sciences such as biology, chemistry, ecology, neuroscience, and physics, as well as technology and engineering fields such as image processing, signal processing, information theory, computer science, cryptography, and telecommunications. It is also used in finance, due to seemingly random changes in financial markets as well as in medicine, linguistics, music, media, colour theory, botany, manufacturing, and geomorphology. Etymology The word ''stochastic'' in English was originally used as ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Migration (ecology)
Migration, in ecology, is the large-scale movement of members of a species to a different environment. Migration is a natural behavior and component of the life cycle of many species of mobile organisms, not limited to animals, though animal migration is the best known type. Migration is often cyclical, frequently occurring on a seasonal basis, and in some cases on a daily basis. Species migrate to take advantage of more favorable conditions with respect to food availability, safety from predation, mating opportunity, or other environmental factors. While members of some species learn a migratory route on their first journey with older members of their group, other species genetically pass on information regarding their migratory paths. Despite many differences in organisms’ migratory cues and behaviors, “considerable similarities appear to exist in the cues involved in the different phases of migration.” Migratory organisms use environmental cues like photoperiod and we ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fledging
Fledging is the stage in a flying animal's life between hatching or birth and becoming capable of flight. This term is most frequently applied to birds, but is also used for bats. For altricial birds, those that spend more time in vulnerable condition in the nest, the nestling and fledging stage can be the same. For precocial birds, those that develop and leave the nest quickly, a short nestling stage precedes a longer fledging stage. All birds are considered to have fledged when the feathers and wing muscles are sufficiently developed for flight. A young bird that has recently fledged but is still dependent upon parental care and feeding is called a fledgling. People often want to help fledglings, as they appear vulnerable, but it is best to leave them alone. The USA National Phenology Network defines the phenophase (or life cycle stage) of fledged young for birds as "One or more young are seen recently departed from the nest. This includes young incapable of sustained fli ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Brooding
Egg incubation is the process by which an egg, of oviparous (egg-laying) animals, develops an embryo within the egg, after the egg's formation and ovipositional release. Egg incubation is done under favorable environmental conditions, possibly by brooding and hatching the egg. Multiple and various factors are vital to the incubation of various species of animal. In many species of reptile for example, no fixed temperature is necessary, but the actual temperature determines the sex ratio of the offspring. In birds in contrast, the sex of offspring is genetically determined, but in many species a constant and particular temperature is necessary for successful incubation. Especially in poultry, the act of sitting on eggs to incubate them is called brooding. The action or behavioral tendency to sit on a clutch of eggs is also called broodiness, and most egg-laying breeds of poultry have had this behavior selectively bred out of them to increase production. Avian incubation A w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Offspring
In biology, offspring are the young creation of living organisms, produced either by a single organism or, in the case of sexual reproduction, two organisms. Collective offspring may be known as a brood or progeny in a more general way. This can refer to a set of simultaneous offspring, such as the chicks hatched from one clutch of eggs, or to all the offspring, as with the honeybee. Human offspring ( descendants) are referred to as children (without reference to age, thus one can refer to a parent's " minor children" or " adult children" or " infant children" or " teenage children" depending on their age); male children are sons and female children are daughters (see kinship). Offspring can occur after mating or after artificial insemination. Offspring contains many parts and properties that are precise and accurate in what they consist of, and what they define. As the offspring of a new species, also known as a child or f1 generation, consist of genes of the father and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Incubation Period
Incubation period (also known as the latent period or latency period) is the time elapsed between exposure to a pathogenic organism, a chemical, or radiation, and when symptoms and signs are first apparent. In a typical infectious disease, the incubation period signifies the period taken by the multiplying organism to reach a threshold necessary to produce symptoms in the host. While ''latent'' or ''latency period'' may be synonymous, a distinction is sometimes made whereby the latent period is defined as the time from infection to infectiousness. Which period is shorter depends on the disease. A person may carry disease, such as '' Streptococcus'' in the throat, without exhibiting any symptoms. Depending on the disease, the person may or may not be contagious during the incubation period. During latency, an infection is subclinical. With respect to viral infections, in incubation the virus is replicating. This is in contrast to viral latency, a form of dormancy in which the v ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
North Australia
North Australia can refer to a short-lived former British colony, a former federal territory of the Commonwealth of Australia, or a proposed state which would replace the current Northern Territory. Colony (1846–1847) A colony of North Australia existed briefly after it was authorised by letters patent of 17 February 1846. The colony comprised all land in the Northern Territory and the present state of Queensland lying north of the 26th parallel. The capital was at Port Curtis, now called Gladstone, under Colonel George Barney as Lieutenant-Governor and Superintendent. Charles Augustus FitzRoy, the Governor of New South Wales, was Governor. The colony was proclaimed at a ceremony at Settlement Point on 30 January 1847. The establishment of the new colony, and its status as a penal colony, attracted much criticism in the New South Wales Legislative Council. The Letters Patent establishing the colony were revoked in December the same year, after a change of government in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
South Australia
South Australia (commonly abbreviated as SA) is a state in the southern central part of Australia. It covers some of the most arid parts of the country. With a total land area of , it is the fourth-largest of Australia's states and territories by area, and second smallest state by population. It has a total of 1.8 million people. Its population is the second most highly centralised in Australia, after Western Australia, with more than 77 percent of South Australians living in the capital Adelaide, or its environs. Other population centres in the state are relatively small; Mount Gambier, the second-largest centre, has a population of 33,233. South Australia shares borders with all of the other mainland states, as well as the Northern Territory; it is bordered to the west by Western Australia, to the north by the Northern Territory, to the north-east by Queensland, to the east by New South Wales, to the south-east by Victoria, and to the south by the Great Australian Bight.M ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Down Feather
The down of birds is a layer of fine feathers found under the tougher exterior feathers. Very young birds are clad only in down. Powder down is a specialized type of down found only in a few groups of birds. Down is a fine thermal insulator and padding, used in goods such as jackets, bedding ( duvets and featherbeds), pillows and sleeping bags. The discovery of feathers trapped in ancient amber suggests that some species of dinosaur may have possessed down-like feathers. Description and etymology The word ''down'' comes from the Old Norse word ''dúnn'', which had the same meaning as its modern equivalent. The down feather is considered to be the most "straightforward" of all feather types. It has a short or vestigial rachis (shaft), few barbs, and barbules that lack hooks. There are three types of down: natal down, body down and powder down. Natal down is the layer of down feathers that cover most birds at some point in their early development. Precocial nestlings a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Estuaries
An estuary is a partially enclosed coastal body of brackish water with one or more rivers or streams flowing into it, and with a free connection to the open sea. Estuaries form a transition zone between river environments and maritime environments and are an example of an ecotone. Estuaries are subject both to marine influences such as tides, waves, and the influx of saline water, and to fluvial influences such as flows of freshwater and sediment. The mixing of seawater and freshwater provides high levels of nutrients both in the water column and in sediment, making estuaries among the most productive natural habitats in the world. Most existing estuaries formed during the Holocene epoch with the flooding of river-eroded or glacially scoured valleys when the sea level began to rise about 10,000–12,000 years ago. Estuaries are typically classified according to their geomorphological features or to water-circulation patterns. They can have many different names, such as bay ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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