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Population Cycle
A population cycle in zoology is a phenomenon where populations rise and fall over a predictable period of time. There are some species where population numbers have reasonably predictable patterns of change although the full reasons for population cycles is one of the major unsolved ecological problems. There are a number of factors which influence population change such as availability of food, predators, diseases and climate. Occurrence in mammal populations Olaus Magnus, the Archbishop of Uppsala in central Sweden, identified that species of northern rodents had periodic peaks in population and published two reports on the subject in the middle of the 16th century. In North America, the phenomenon was identified in populations of the snowshoe hare. In 1865, trappers with the Hudson's Bay Company were catching plenty of animals. By 1870, they were catching very few. It was finally identified that the cycle of high and low catches ran over approximately a ten-year period. The mos ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Charles Sutherland Elton
Charles Sutherland Elton (29 March 1900 – 1 May 1991) was an English zoologist and animal ecologist. He is associated with the development of population and community ecology, including studies of invasive organisms. Personal life Charles Sutherland Elton was born in Manchester, a son of the literary scholar Oliver Elton and the children's writer Letitia Maynard Elton (''née'' MacColl). He had an older brother, Geoffrey Elton, who died at 33, and to whom Charles Elton in many of his writings attributes his interest in scientific natural history. Charles Elton married the English poet Edith Joy Scovell in 1937, a first five-year marriage to Rose Montague having ended in amicable divorce. Charles and Joy had two children, Catherine Ingrid Buffonge MBE and Robert Elton. Professional life Charles Elton was educated at Liverpool College and Oxford University, from which he graduated in zoology in 1922, with a first in his field research project and a third in the exams, and wh ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Population
Population typically refers to the number of people in a single area, whether it be a city or town, region, country, continent, or the world. Governments typically quantify the size of the resident population within their jurisdiction using a census, a process of collecting, analysing, compiling, and publishing data regarding a population. Perspectives of various disciplines Social sciences In sociology and population geography, population refers to a group of human beings with some predefined criterion in common, such as location, Race (human categorization), race, ethnicity, nationality, or religion. Demography is a social science which entails the statistical study of populations. Ecology In ecology, a population is a group of organisms of the same species who inhabit the same particular geographical area and are capable of Sexual reproduction, interbreeding. The area of a sexual population is the area where interbreeding, inter-breeding is possible between any pai ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Olaus Magnus
Olaus Magnus (October 1490 – 1 August 1557) was a Swedish writer, cartographer, and Catholic ecclesiastic. Biography Olaus Magnus (a Latin translation of his birth name Olof Månsson) was born in Linköping in October 1490. Like his elder brother, Sweden's last Catholic archbishop Johannes Magnus, he obtained several ecclesiastical preferments, among them a canonry at Uppsala and Linköping, and the archdeaconry of Strängnäs. He was furthermore employed on various diplomatic services after his mission to Rome in 1524, on behalf of Gustav I of Sweden (Vasa), to procure the appointment of Olaus Magnus' brother Johannes Magnus as archbishop of Uppsala. He remained abroad dealing with foreign affairs and is known to have sent home a document that contained agreed trade-relations with the Netherlands. With the success of the reformation in Sweden, his attachment to the Catholic church led him to stay abroad for good where he accompanied his brother in Poland. They were both exi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Uppsala
Uppsala (, or all ending in , ; archaically spelled ''Upsala'') is the county seat of Uppsala County and the fourth-largest city in Sweden, after Stockholm, Gothenburg, and Malmö. It had 177,074 inhabitants in 2019. Located north of the capital Stockholm it is also the seat of Uppsala Municipality. Since 1164, Uppsala has been the ecclesiastical centre of Sweden, being the seat of the Archbishop of the Church of Sweden. Uppsala is home to Scandinavia's largest cathedral – Uppsala Cathedral, which was the frequent site of the coronation of the Swedish monarch until the late 19th century. Uppsala Castle, built by King Gustav Vasa, served as one of the royal residences of the Swedish monarchs, and was expanded several times over its history, making Uppsala the secondary capital of Sweden during its greatest extent. Today it serves as the residence of the Governor of Uppsala County. Founded in 1477, Uppsala University is the oldest centre of higher education in Sca ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rodent
Rodents (from Latin , 'to gnaw') are mammals of the order Rodentia (), which are characterized by a single pair of continuously growing incisors in each of the upper and lower jaws. About 40% of all mammal species are rodents. They are native to all major land masses except for New Zealand, Antarctica, and several oceanic islands, though they have subsequently been introduced to most of these land masses by human activity. Rodents are extremely diverse in their ecology and lifestyles and can be found in almost every terrestrial habitat, including human-made environments. Species can be arboreal, fossorial (burrowing), saltatorial/richochetal (leaping on their hind legs), or semiaquatic. However, all rodents share several morphological features, including having only a single upper and lower pair of ever-growing incisors. Well-known rodents include mice, rats, squirrels, prairie dogs, porcupines, beavers, guinea pigs, and hamsters. Rabbits, hares, and pikas, wh ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Snowshoe Hare
The snowshoe hare (''Lepus americanus''), also called the varying hare or snowshoe rabbit, is a species of hare found in North America. It has the name "snowshoe" because of the large size of its hind feet. The animal's feet prevent it from sinking into the snow when it hops and walks. Its feet also have fur on the soles to protect it from freezing temperatures. For camouflage, its fur turns white during the winter and rusty brown during the summer. Its flanks are white year-round. The snowshoe hare is also distinguishable by the black tufts of fur on the edge of its ears. Its ears are shorter than those of most other hares. In summer, it feeds on plants such as grass, ferns, and leaves; in winter, it eats twigs, the bark from trees, and plants and, similar to the Arctic hare, has been known to occasionally eat dead animals. It can sometimes be seen feeding in small groups. This animal is mainly active at night and does not hibernate. The snowshoe hare may have up to four li ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hudson's Bay Company
The Hudson's Bay Company (HBC; french: Compagnie de la Baie d'Hudson) is a Canadian retail business group. A fur trading business for much of its existence, HBC now owns and operates retail stores in Canada. The company's namesake business division is Hudson's Bay, commonly referred to as The Bay ( in French). After incorporation by English royal charter in 1670, the company functioned as the ''de facto'' government in parts of North America for nearly 200 years until the HBC sold the land it owned (the entire Hudson Bay drainage basin, known as Rupert's Land) to Canada in 1869 as part of the Deed of Surrender, authorized by the Rupert's Land Act 1868. At its peak, the company controlled the fur trade throughout much of the English- and later British-controlled North America. By the mid-19th century, the company evolved into a mercantile business selling a wide variety of products from furs to fine homeware in a small number of sales shops (as opposed to trading posts) ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lemming
A lemming is a small rodent, usually found in or near the Arctic in tundra biomes. Lemmings form the subfamily Arvicolinae (also known as Microtinae) together with voles and muskrats, which form part of the superfamily Muroidea, which also includes rats, mice, hamsters, and gerbils. In popular culture, a longstanding myth holds that they exhibit herd mentality and jump off cliffs, committing mass suicide. Description and habitat Lemmings measure around in length and weigh around . Lemmings are quite rounded in shape, with brown and black, long, soft fur. They have a very short tail, a stubby, hairy snout, short legs, and small ears. They have a flattened claw on the first digit of their front feet, which helps them to dig in the snow. They are herbivorous, feeding mostly on mosses and grasses. They also forage through the snow surface to find berries, leaves, shoots, roots, bulbs, and lichens. Lemmings choose their preferred dietary vegetation disproportionately to its occurren ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mouse Plagues In Australia
Mouse plagues have occurred several times throughout parts of Australia since wild house mice (''Mus musculus'') were introduced by European colonists along with the First Fleet in 1788. Australia and China are the two countries in the world where plagues of mice are known to occur. Mouse plagues occur in southern and eastern Australia, usually in the grain-growing regions, around every four years. Aggregating around food sources during plagues, mice can reach a density of up to . History Early mice plagues Mice probably arrived in Australia as stowaways on board the First Fleet of British colonists in 1788. An early localised plague of mice occurred around Walgett in New South Wales in 1871. In 1872 another plague was recorded near Saddleworth in South Australia with farmers ploughing the soil to destroy mice nests. 1880s and 1890s In 1880 a plague of mice was noted along an area of the Goulburn River. South Australia experienced another plague in 1890 in the Mid Nor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ruffed Grouse
The ruffed grouse (''Bonasa umbellus'') is a medium-sized grouse occurring in forests from the Appalachian Mountains across Canada to Alaska. It is the most widely distributed game bird in North America. It is non-migratory. It is the only species in the genus ''Bonasa''. The ruffed grouse is sometimes incorrectly referred to as a "partridge", an unrelated phasianid, and occasionally confused with the grey partridge, a bird of open areas rather than woodlands. The ruffed grouse is the state game bird of Pennsylvania, United States. Taxonomy ''Bonasa umbellus'' was first described by Carl Linnaeus in his 1766 12th edition of ''Systema Naturae''. He classified it as ''Tetrao umbellus'', placing it in a subfamily with Eurasian grouse. The genus ''Bonasa'' was applied by British naturalist John Francis Stephens in 1819. Ruffed grouse is the preferred common name because it applies only to this species. Misleading vernacular names abound, however, and it is often called partridg ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Caelifera
The Caelifera are a suborder of orthopteran insects. They include the grasshoppers and grasshopper-like insects, as well as other superfamilies classified with them: the ground-hoppers (Tetrigoidea) and pygmy mole crickets ( Tridactyloidea). The latter should not be confused with the mole crickets ( Gryllotalpidae), which belong to the other Orthopteran sub-order Ensifera. The name of this suborder comes from Latin meaning ''chisel-bearing'' ("chisel" in Latin: ''caelum''), referring to the "stout" shape of its species' ovipositors. Subdivisions and their distribution The Caelifera include some 2,400 valid genera and about 12,000 known species. Many undescribed species probably exist, especially in tropical forests. The Caelifera have a predominantly tropical distribution (as with most Orthoptera) with fewer species known from temperate climate zones. Caelifera are divided into two infraorders: the more basal Tridactylidea and the Acrididea or grasshopper-like species. Th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Locust
Locusts (derived from the Vulgar Latin ''locusta'', meaning grasshopper) are various species of short-horned grasshoppers in the family Acrididae that have a swarming phase. These insects are usually solitary, but under certain circumstances they become more abundant and change their behaviour and habits, becoming gregarious. No taxonomic distinction is made between locust and grasshopper species; the basis for the definition is whether a species forms swarms under intermittently suitable conditions; this has evolved independently in multiple lineages, comprising at least 18 genera in 5 different acridid subfamilies. Normally, these grasshoppers are innocuous, their numbers are low, and they do not pose a major economic threat to agriculture. However, under suitable conditions of drought followed by rapid vegetation growth, serotonin in their brains triggers dramatic changes: they start to breed abundantly, becoming gregarious and nomadic (loosely described as migratory) ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
