1.
Lion
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The lion is one of the big cats in the genus Panthera and a member of the family Felidae. The commonly used term African lion collectively denotes the several subspecies in Africa, with some males exceeding 250 kg in weight, it is the second-largest living cat after the tiger. Wild lions currently exist in sub-Saharan Africa and in India, in ancient historic times, their range was in most of Africa, including North Africa, and across Eurasia from Greece and southeastern Europe to India. Lion populations are untenable outside designated reserves and national parks, although the cause of the decline is not fully understood, habitat loss and conflicts with humans are the greatest causes of concern. Within Africa, the West African lion population is particularly endangered, in the wild, males seldom live longer than 10 to 14 years, as injuries sustained from continual fighting with rival males greatly reduce their longevity. In captivity they can more than 20 years. They typically inhabit savanna and grassland, although they may take to bush, Lions are unusually social compared to other cats. A pride of lions consists of related females and offspring and a number of adult males. Groups of female lions typically hunt together, preying mostly on large ungulates, Lions are apex and keystone predators, although they are also expert scavengers obtaining over 50 percent of their food by scavenging as opportunity allows. While lions do not typically hunt humans, some have, sleeping mainly during the day, lions are active primarily at night, although sometimes at twilight. Highly distinctive, the lion is easily recognised by its mane. It has been depicted in sculptures, in paintings, on national flags. Lions have been kept in menageries since the time of the Roman Empire, Zoos are cooperating worldwide in breeding programs for the endangered Asiatic subspecies. The lions name, similar in many Romance languages, is derived from the Latin leo, the Hebrew word לָבִיא may also be related. It was one of the originally described by Linnaeus, who gave it the name Felis leo, in his eighteenth-century work. The lions closest relatives are the species of the genus Panthera, the tiger, the snow leopard, the jaguar. P. leo evolved in Africa between 1 million and 800,000 years ago, before spreading throughout the Holarctic region and it appeared in the fossil record in Europe for the first time 700,000 years ago with the subspecies Panthera leo fossilis at Isernia in Italy. From this lion derived the later cave lion, which appeared about 300,000 years ago, Lions died out in northern Eurasia at the end of the last glaciation, about 10,000 years ago, this may have been secondary to the extinction of Pleistocene megafauna
2.
Saltwater crocodile
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Males of this species can reach sizes up to at least 6.30 m and possibly up to 7.0 m in length. However, an adult male saltwater crocodile rarely reaches or exceeds a size of 6 m weighing 1,000 to 1,200 kg, females are much smaller and often do not surpass 3 m. As its name implies, this species of crocodile can live in environments, but usually resides in saline and brackish mangrove swamps, estuaries, deltas, lagoons. They have the broadest distribution of any modern crocodile, ranging from the eastern coast of India throughout most of Southeast Asia, the saltwater crocodile is a formidable and opportunistic hypercarnivorous apex predator. Most prey are ambushed and then drowned or swallowed whole, due to their size, aggression and distribution, saltwater crocodiles are regarded as the most dangerous extant crocodilian to humans. Incomplete fossil records make it difficult to trace the emergence of the species. The genome was sequenced in 2007. The earliest fossil evidence of the dates to around 4. 0–4.5 million years ago. Scientists estimate that C. porosus is an ancient species that could have diverged from 12 to 6 million years ago, other relatively broad-snouted species such as Mugger and Siamese crocodiles seem to be the most likely candidates to bear the closest relation among living species. Currently, most sources state that the saltwater crocodile does not have a subspecies, however, based largely on morphological variability, some have claimed that not only are there subspecies but that C. porosus actually houses a species complex. According to Ross, specimens of C, another attempt to derive a species came from Australia, Wells & Wellington, and was based upon large-bodied, relatively large-headed and short-tailed crocodiles from Australia. The type specimen reported for this species was a crocodile nicknamed Sweetheart that was inadvertently killed in 1979. However, this species, C. pethericki, has later been considered as a misinterpretation of the physiological changes undergone by very large male crocodiles. The saltwater crocodile has a wide snout compared to most crocodiles, however, it has a longer muzzle than the mugger crocodile, its length is twice its width at the base. The saltwater crocodile has fewer armour plates on its neck than other crocodilians, on this species, a pair of ridges runs from the eyes along the centre of the snout. The scales are oval in shape and the scutes are either small compared to species or commonly are entirely absent. The adult saltwater crocodiles broad body contrasts with that of most other lean crocodiles, the head is very large.3 cm and a maximum width across the skull of 48 cm. The length of the specimen came from is not known
3.
Predation
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In an ecosystem, predation is a biological interaction where a predator feeds on its prey. Predators may or may not kill their prey prior to feeding on it, but the act of predation often results in the death of the prey, thus predation is often, though not always, carnivory. Other categories of consumption are herbivory, fungivory, and detritivory, all of these are consumer-resource systems. It can often be difficult to separate various types of feeding behaviors. For example, some parasites prey on their host and then lay their eggs on it, for their offspring to feed on it while it continues to live, the key characteristic of predation is the predators direct impact on the prey population. Selective pressures imposed on one another leads to an evolutionary arms race between prey and predator, resulting in various antipredator adaptations. Ways of classifying predation include grouping by trophic level or diet, by specialization, Predators can be classified by their interactions with their prey. Two factors are considered here, how close the predator and prey are, and whether the prey is killed by the predator. A true predator is one that kills and eats another living thing, Predators may hunt actively for prey in pursuit predation, or sit and wait for prey to approach within striking distance, as in ambush predators. Some predation entails venom that subdues a prey before the predator ingests it, as in the box jellyfish, or disables it, in some cases, the venom contributes to the digestion of the prey, as in rattlesnakes and some spiders. In contrast, baleen whales eat millions of microscopic plankton at once, seed and egg predation are true predation, as seeds and eggs are potential organisms. Predators need not eat prey entirely, for example, some predators cannot digest bones, some may eat only part of an organism, but still consistently cause its death. Grazing organisms do not often kill their prey, while some herbivores like zooplankton live on unicellular phytoplankton and therefore, by the individualized nature of the organism, kill their prey, many others only eat a small part of the plant. Grazing livestock may pull some grass out at the roots, but most is simply grazed upon, kelp is frequently grazed in subtidal kelp forests, but regrows at the base of the blade continuously to cope with browsing pressure. Animals may also be grazed upon, female mosquitos land on hosts briefly to gain sufficient proteins for the development of their offspring, starfish may be grazed on, being capable of regenerating lost arms. Parasites can at times be difficult to distinguish from grazers and their feeding behavior is similar in many ways, however they are noted for their close association with their host species. This close living arrangement may be described by the symbiosis, living together. Parasitic organisms range from the mistletoe, a parasitic plant
4.
Food chain
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A food chain is a linear network of links in a food web starting from producer organisms and ending at apex predator species, detritivores, or decomposer species. A food chain also shows how the organisms are related with each other by the food they eat, each level of a food chain represents a different trophic level. A food chain differs from a web, because the complex network of different animals feeding relations are aggregated. Natural interconnections between food chains make it a food web, a common metric used to quantify food web trophic structure is food chain length. Food chains are used in ecological modeling. They are simplified abstractions of real food webs, but complex in their dynamics, food chain studies have an important role in ecotoxicology studies tracing the pathways and biomagnification of environmental contaminants. Producers, such as plants, are organisms that utilize solar or chemical energy to synthesize starch, all food chains must start with a producer. In the deep sea, food chains centered on hydrothermal vents, chemosynthetic bacteria and archaea use hydrogen sulfide and methane from hydrothermal vents and cold seeps as an energy source to produce carbohydrates, they form the base of the food chain. Consumers are organisms that eat other organisms, all organisms in a food chain, except the first organism, are consumers. Autotroph Heterotroph Lithotroph Trophic pyramid Predator-prey interaction
5.
Food web
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A food web is the natural interconnection of food chains and a graphical representation of what-eats-what in an ecological community. Another name for food web is a consumer-resource system, ecologists can broadly lump all life forms into one of two categories called trophic levels, 1) the autotrophs, and 2) the heterotrophs. To maintain their bodies, grow, develop, and to reproduce, autotrophs produce organic matter from inorganic substances and these chemical reactions require energy, which mainly comes from the sun and largely by photosynthesis, although a very small amount comes from hydrothermal vents and hot springs. The linkages in a food web illustrate the feeding pathways, such as where heterotrophs obtain organic matter by feeding on autotrophs, the food web is a simplified illustration of the various methods of feeding that links an ecosystem into a unified system of exchange. There are different kinds of feeding relations that can be divided into herbivory, carnivory, scavenging. Some of the organic matter eaten by heterotrophs, such as sugars, autotrophs and heterotrophs come in all sizes, from microscopic to many tonnes - from cyanobacteria to giant redwoods, and from viruses and bdellovibrio to blue whales. Charles Elton pioneered the concept of cycles, food chains. Elton organized species into groups, which was the basis for Raymond Lindemans classic. Lindeman emphasized the important role of organisms in a trophic system of classification. Even earlier, in 1768 John Bruckner described nature as one continued web of life, ecologists use these simplifications in quantitative models of trophic or consumer-resource systems dynamics. Using these models they can measure and test for generalized patterns in the structure of food web networks. Ecologists have identified non-random properties in the structure of food webs. Published examples that are used in analysis are of variable quality with omissions. However, the number of studies on community webs is on the rise. Scaling laws, for example, predict a relationship between the topology of food web predator-prey linkages and levels of species richness, links in food webs map the feeding connections in an ecological community. Food cycle is a term that is synonymous with food web. Ecologists can broadly group all life forms into one of two layers, the autotrophs and the heterotrophs. Autotrophs produce more energy, either chemically without the suns energy or by capturing the suns energy in photosynthesis
6.
Trophic level
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The trophic level of an organism is the position it occupies in a food chain. The word trophic derives from the Greek τροφή referring to food or feeding, a food chain represents a succession of organisms that eat another organism and are, in turn, eaten themselves. The number of steps an organism is from the start of the chain is a measure of its trophic level. Food chains start at trophic level 1 with primary producers such as plants, move to herbivores at level 2, predators at level 3, the path along the chain can form either a one-way flow or a food web. Ecological communities with higher biodiversity form more complex trophic paths, the three basic ways in which organisms get food are as producers, consumers and decomposers. Producers are typically plants or algae, Plants and algae do not usually eat other organisms, but pull nutrients from the soil or the ocean and manufacture their own food using photosynthesis. For this reason, they are called primary producers, in this way, it is energy from the sun that usually powers the base of the food chain. An exception occurs in deep-sea hydrothermal ecosystems, where there is no sunlight, here primary producers manufacture food through a process called chemosynthesis. Consumers are species that cannot manufacture their own food and need to other organisms. Animals that eat primary producers are called herbivores, animals that eat other animals are called carnivores, and animals that eat both plant and other animals are called omnivores. Decomposers break down plant and animal material and wastes and release it again as energy. Decomposers, such as bacteria and fungi, feed on waste and dead matter, Trophic levels can be represented by numbers, starting at level 1 with plants. Further trophic levels are numbered according to how far the organism is along the food chain. Level 1, Plants and algae make their own food and are called primary producers, level 2, Herbivores eat plants and are called primary consumers. Level 3, Carnivores that eat herbivores are called secondary consumers, level 4, Carnivores that eat other carnivores are called tertiary consumers. Level 5, Apex predators that have no predators are at the top of the food chain. In real world ecosystems, there is more than one chain for most organisms. A diagram that sets out the network of intersecting and overlapping food chains for an ecosystem is called its food web
7.
Gray wolf
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The gray wolf or grey wolf, also known as the timber wolf or western wolf, is a canine native to the wilderness and remote areas of Eurasia and North America. It is the largest extant member of its family, with males averaging 43–45 kg, like the red wolf, it is distinguished from other Canis species by its larger size and less pointed features, particularly on the ears and muzzle. Its winter fur is long and bushy, and predominantly a mottled gray in color, although pure white, red. As of 2005,37 subspecies of C. lupus are recognised by MSW3 and it is nonetheless closely related enough to smaller Canis species, such as the eastern wolf, coyote, and golden jackal to produce fertile hybrids. It is an animal, travelling in nuclear families consisting of a mated pair. The gray wolf is typically an apex predator throughout its range, with only humans and it feeds primarily on large ungulates, though it also eats smaller animals, livestock, carrion, and garbage. The gray wolf is one of the worlds best known and well researched animals, although the fear of wolves is pervasive in many human societies, the majority of recorded attacks on people have been attributed to animals suffering from rabies. The English wolf stems from the Old English wulf, which is thought to be derived from the Proto-Germanic *wulfaz. The Latin lupus is a Sabine loanword, both derive from the Proto-Indo-European root *wlqwos/*lukwos. The species Canis lupus was first recorded by Carl Linnaeus in his publication Systema Naturae in 1758, the thirty-seven subspecies of Canis lupus are listed under the designated common name of wolf in Mammal Species of the World third edition that was published in 2005. The nominate subspecies is the Eurasian wolf, also known as the common wolf, the subspecies includes the domestic dog, dingo, eastern wolf and red wolf, but lists C. l. italicus and C. l. communis as synonyms of C. l. lupus. However, the classification of several as either species or subspecies has recently been challenged, ecological factors including habitat type, climate, prey specialization and predatory competition will greatly influence the wolfs genetic population structure and cranio-dental plasticity. The domestic dog is the most widely abundant large carnivore and a descendant from one of those now-extinct wolf populations, in 2013, a genetic study found that the wolf population in Europe was divided along a north-south axis and formed five major clusters. Three clusters were identified occupying southern and central Europe in Italy, the Carpathians, another two clusters were identified occupying north-central Europe and the Ukrainian steppe. The Italian wolf consisted of a population with low genetic diversity. Wolves from Croatia, Bulgaria, and Greece formed the Dinaric-Balkans cluster, the wolves from the Carpathians were more similar to the wolves from the Pontic-Caspian Steppe than they were to wolves from north-central Europe. These clusters may have been the result of expansion from glacial refugia, an adaptation to environments, and landscape fragmentation. These six wolf ecotypes were named West Forest, Boreal Forest, Arctic, High Arctic, Baffin, the studies found that precipitation and mean diurnal temperature range were the most influential variables
8.
Herbivore
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A herbivore is an animal anatomically and physiologically adapted to eating plant material, for example foliage, for the main component of its diet. As a result of their plant diet, herbivorous animals typically have mouthparts adapted to rasping or grinding, horses and other herbivores have wide flat teeth that are adapted to grinding grass, tree bark, and other tough plant material. A large percentage of herbivores have mutualistic gut flora that help them digest plant matter and this gut flora is made up of cellulose-digesting protozoans or bacteria living in the herbivores intestines. Herbivore is the form of a modern Latin coinage, herbivora. Richard Owen employed the term in an 1854 work on fossil teeth. Herbivora is derived from the Latin herba meaning a small plant or herb, Herbivory is a form of consumption in which an organism principally eats autotrophs such as plants, algae and photosynthesizing bacteria. More generally, organisms feed on autotrophs in general are known as primary consumers. Herbivory usually refers to eating plants, fungi, bacteria and protists that feed on living plants are usually termed plant pathogens. Flowering plants that obtain nutrition from other living plants are usually termed parasitic plants, there is however no single exclusive and definitive ecological classification of consumption patterns, each textbook has its own variations on the theme. Insects fed on the spores of early Devonian plants, and the Rhynie chert also provides evidence that organisms fed on plants using a pierce, during the next 75 million years, plants evolved a range of more complex organs, such as roots and seeds. There is no evidence of any organism being fed upon until the middle-late Mississippian,330.9 million years ago, further than their arthropod status, the identity of these early herbivores is uncertain. Hole feeding and skeletonisation are recorded in the early Permian, with surface fluid feeding evolving by the end of that period, Herbivory among four-limbed terrestrial vertebrates, the tetrapods developed in the Late Carboniferous. Early tetrapods were large amphibious piscivores, while amphibians continued to feed on fish and insects, some reptiles began exploring two new food types, tetrapods and plants. The entire dinosaur order ornithischia was composed with herbivores dinosaurs, carnivory was a natural transition from insectivory for medium and large tetrapods, requiring minimal adaptation. In contrast, a set of adaptations was necessary for feeding on highly fibrous plant materials. Arthropods evolved herbivory in four phases, changing their approach to it in response to changing plant communities, tetrapod herbivores made their first appearance in the fossil record of their jaws near the Permio-Carboniferous boundary, approximately 300 million years ago. The earliest evidence of their herbivory has been attributed to dental occlusion, the evolution of dental occlusion led to a drastic increase in plant food processing and provides evidence about feeding strategies based on tooth wear patterns. Examination of phylogenetic frameworks of tooth and jaw morphologes has revealed that dental occlusion developed independently in several lineages tetrapod herbivores and this suggests that evolution and spread occurred simultaneously within various lineages
9.
Wildlife management
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Wildlife management attempts to balance the needs of wildlife with the needs of people using the best available science. Wildlife management can include game keeping, wildlife conservation and pest control, Wildlife management draws on disciplines such as mathematics, chemistry, biology, ecology, climatology and geography to gain the best results. Most wildlife biologists are concerned with the preservation and improvement of habitats although rewilding is increasingly being used, techniques can include reforestation, pest control, nitrification and denitrification, irrigation, coppicing and hedge laying. Pest control is the control of real or perceived pests and can be used for the benefit of wildlife, farmers, in the United States, wildlife management practices are often implemented by a governmental agency to uphold a law, such as the Endangered Species Act. Legislation has also passed to protect wildlife such as the Wildlife. The UK government also give farmers subsidies through the Countryside Stewardship Scheme to improve the value of their farms. The history of wildlife management begins with the laws, which regulated the right to kill certain kinds of fish. In Britain game laws developed out of the forest laws, which in the time of the Norman kings were very oppressive, under William the Conqueror, it was as great a crime to kill one of the kings deer as to kill one of his subjects. The Game Act of 1831 protected game birds by establishing close seasons when they could not be legally taken, the act made it lawful to take game only with the provision of a game licence and provided for the appointment of gamekeepers around the country. The purposes of the law was to balance the needs for preservation and harvest, early game laws were also enacted in the US, - in 1839 Rhode Island closed the hunting season for white-tailed deer from May to November. Other regulations during this time focused primarily on restricting hunting, at this time, lawmakers did not consider population sizes or the need for preservation or restoration of wildlife habitats. The late 19th century saw the passage of the first pieces of wildlife conservation legislation, the Sea Birds Preservation Act of 1869 was passed in Britain as the first nature protection law in the world after extensive lobbying from the Association for the Protection of Seabirds. The group gained popularity and eventually amalgamated with the Fur and Feather League in Croydon to form the RSPB, the Society attracted growing support from the suburban middle-classes as well as support from many other influential figures, such as the ornithologist Professor Alfred Newton. The National Trust formed in 1895 with the manifesto to. promote the permanent preservation, for the benefit of the nation, of lands. to preserve their natural aspect. On 1 May 1899, the Trust purchased two acres of Wicken Fen with a donation from the amateur naturalist Charles Rothschild, establishing the first nature reserve in Britain. Rothschild was a pioneer of conservation in Britain, and went on to establish many other nature reserves, such as one at Woodwalton Fen, near Huntingdon. During his lifetime he built and managed his estate at Ashton Wold in Northamptonshire to maximise its suitability for wildlife, concerned about the loss of wildlife habitats, in 1912 he set up the Society for the Promotion of Nature Reserves, the forerunner of The Wildlife Trusts partnership. During the societys early years, membership tended to be made up of specialist naturalists and its growth was comparatively slow and these early Trusts tended to focus on purchasing land to establish nature reserves in the geographical areas they served
10.
Conservation biology
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It is an interdisciplinary subject drawing on natural and social sciences, and the practice of natural resource management. The conservation ethic is based on the findings of conservation biology, wilcox and Michael E. Soulé with a group of leading university and zoo researchers and conservationists including Kurt Benirschke, Sir Otto Frankel, Thomas E. Lovejoy, and Jared M. Diamond. The meeting was prompted by the concern over deforestation, disappearing species. Conservation biology and the concept of biological diversity emerged together, helping crystallize the modern era of conservation science, the inherent multidisciplinary basis for conservation biology has led to new subdisciplines including conservation social science, conservation behavior and conservation physiology. It stimulated further development of genetics which Otto Frankel had originated first but is now often considered a subdiscipline as well. The rapid decline of established biological systems around the means that conservation biology is often referred to as a Discipline with a deadline. Conservation biology is tied closely to ecology in researching the ecology of rare or endangered species. Conservation biologists work in the field and office, in government, universities, non-profit organizations, the topics of their research are diverse, because this is an interdisciplinary network with professional alliances in the biological as well as social sciences. Those dedicated to the cause and profession advocate for a response to the current biodiversity crisis based on morals, ethics. Conscious efforts to conserve and protect global biodiversity are a recent phenomenon, natural resource conservation, however, has a history that extends prior to the age of conservation. Resource ethics grew out of necessity through direct relations with nature and this social dilemma with respect to natural resource management is often called the Tragedy of the Commons. From this principle, conservation biologists can trace communal resource based ethics throughout cultures as a solution to communal resource conflict. For example, the Alaskan Tlingit peoples and the Haida of the Pacific Northwest had resource boundaries, rules and these rules were guided by clan elders who knew lifelong details of each river and stream they managed. There are numerous examples in history where cultures have followed rules, rituals, Conservation ethics are also found in early religious and philosophical writings. There are examples in the Tao, Shinto, Hindu, Islamic, in the bible, through Moses, God commanded to let the land rest from cultivation every seventh year. Before the 18th century, however, much of European culture considered it a view to admire nature. Wilderness was denigrated while agricultural development was praised, however, as early as AD680 a wildlife sanctuary was founded on the Farne Islands by St Cuthbert in response to his religious beliefs. Natural history was a preoccupation in the 18th century, with grand expeditions
11.
Ecotourism
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It means responsible travel to natural areas conserving the environment and improving the well being of the local people. Since the 1980s, ecotourism has been considered a critical endeavor by environmentalists, several university programs use this description as the working definition of ecotourism. Generally, ecotourism deals with interaction with components of the natural environments. Ecotourism focuses on responsible travel, personal growth, and environmental sustainability. Ecotourism typically involves travel to destinations where flora, fauna, Ecotourism is intended to offer tourists insight into the impact of human beings on the environment, and to foster a greater appreciation of our natural habitats. Responsible ecotourism programs include those that minimize the negative aspects of tourism on the environment. For these reasons, ecotourism often appeals to advocates of environmental and social responsibility, the term ecotourism, like sustainable tourism, is considered by many to be an oxymoron. Like most forms of tourism, ecotourism generally depends on air transportation, additionally, the overall effect of sustainable tourism is negative, where, like ecotourism, philanthropic aspirations mask hard-nosed immediate self-interest. An ecotourist is different from a tourist in the sense that, he or she is mindful of his environment, Ecotourism is a responsible tourism which conserves the environment and sustains the well being of local people. For many countries, ecotourism is not simply a marginal activity to finance protection of the environment, for example, in Costa Rica, Ecuador, Nepal, Kenya, Madagascar and territories such as Antarctica, ecotourism represents a significant portion of the gross domestic product and economic activity. Ecotourism is often misinterpreted as any form of tourism that involves nature, self-proclaimed practitioners and hosts of ecotourism experiences assume it is achieved by simply creating destinations in natural areas. According to critics of this commonplace and assumptive practice, true ecotourism must, above all, sensitize people to the beauty and these critics condemn some operators as greenwashing their operations, using the labels of green and eco-friendly”, while behaving in environmentally irresponsible ways. Currently, there are moves to create national and international ecotourism accreditation programs. National ecotourism certification programs have been put in place in such as Costa Rica, Australia, Kenya, Estonia. Ecotourism is a late 20th-century neologism compounded from eco- and tourism, according to the Oxford English Dictionary, ecotour was first recorded in 1973 and ecotourism, probably after ecotour, in 1982. One source claims the terms were used earlier, claus-Dieter Hetzer, an academic and adventurer from Forum International in Berkeley, CA, supposedly coined ecotourism in 1965 and ran the first ecotours in the Yucatán during the early 1970s. The failure to acknowledge responsible, low-impact ecotourism puts legitimate ecotourism companies at a competitive disadvantage, many environmentalists have argued for a global standard of accreditation, differentiating ecotourism companies based on their level of environmental commitment, creating a standard to follow. The decisions of the board would be sanctioned by governments, so that non-compliant companies would be required to disassociate themselves from the use of the ecotourism brand
12.
Mesopredator release hypothesis
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This hypothesis describes the phenomenon of trophic cascade in specific terrestrial communities. A mesopredator is a medium-sized, middle trophic level predator, which predates and is predated upon. Examples are raccoons, skunks, snakes, cownose rays, and this, in turn, resulted in decreased populations of still smaller prey species, such as birds. This may lead to dramatic prey population decline, or even extinction and this process arises when mammalian top predators are considered to be the most influential factor on trophic structure and biodiversity in terrestrial ecosystems. Top predators may feed on herbivores and kill predators in lower levels as well. Thus, reduction in the abundance of top predators may cause the predator population to increase. The mesopredator release hypothesis offers an explanation for the high numbers of mesopredators. The hypothesis supports the argument for conservation of top predators because they protect smaller prey species that are in danger of extinction and this argument has been a subject of interest within conservation biology for years, but few studies have adequately documented the phenomenon. Further too, populations of smaller predators do not always increase after the removal of top predators, in fact, another problem is that the hypothesis is offered as an explanation after large predators have already become rare or extinct in an ecosystem. Consequently, there is no data on the past ecosystem structure, as a result, information on the past conditions has been inferred from studies of the present conditions. However, contemporary examples of mesopredator release exist, such as the culling of cats on Macquarie Island, the hypothesis is sometimes also applied to humans as apex predators that produce top-down effects on lower trophic levels. However, it fails to recognize bottom-up effects that anthropogenic land transformations can have on landscapes on which primary producers, prey species, possible bottom-up effects on an ecosystem can be from bioclimatic impacts on ecosystem productivity and from anthropogenic habitat alterations. Examples of anthropogenic habitat change include agriculture, grazing land, more importantly, the hypothesis does not take into account that higher trophic levels are affected by primary productivity. It also does not mention that trophic interactions operate at different strengths according to the ecosystem, therefore, the roles of predation and food/nutrient processes in influencing ecosystem structures remain open to controversy and further testing
13.
Ecological niche
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In ecology, a niche is a term with a variety of meanings related to the behavior of a species living under specific environmental conditions. The ecological niche describes how an organism or population responds to the distribution of resources and competitors, the notion of ecological niche is central to ecological biogeography, which focuses on spatial patterns of ecological communities. Species distributions and their dynamics over time result from properties of the species, and interactions between the two — in particular the abilities of some species, especially our own, to modify their environments and alter the range dynamics of many other species. Alteration of a niche by its inhabitants is the topic of niche construction. Island biogeography can help explain island species and associated unfilled niches, the ecological meaning of niche comes from the meaning of niche as a recess in a wall for a statue, which itself is probably derived from the Middle French word nicher, meaning to nest. The Grinnellian niche concept embodies the idea that the niche of a species is determined by the habitat in which it lives, in other words, the niche is the sum of the habitat requirements and behaviors that allow a species to persist and produce offspring. Its niche is defined by the felicitous complementing of the thrashers behavior and this perspective of niche allows for the existence of both ecological equivalents and empty niches. In 1927 Charles Sutherland Elton, a British ecologist, defined a niche as follows, The niche of an animal means its place in the environment, its relations to food. Elton classified niches according to foraging activities, For instance there is the niche that is filled by birds of prey which eat small animals such as shrews, in an oak wood this niche is filled by tawny owls, while in the open grassland it is occupied by kestrels. Conceptually, the Eltonian niche introduces the idea of a response to. In an extreme example, beavers require certain resources in order to survive and reproduce, thus, the beaver affects the biotic and abiotic conditions of other species that live in and near the watershed. In a more subtle case, competitors that consume resources at different rates can lead to cycles in resource density that differ between species, not only do species grow differently with respect to resource density, their own population growth can lead to different effects on resource density over time. The hypervolume defines the space of resources available to organisms. The niche concept was popularized by the zoologist G. Evelyn Hutchinson in 1957, Hutchinson inquired into the question of why there are so many types of organisms in any one habitat. For such a distribution, the position, width and form of the niche correspond to the mean, standard deviation. This postulate, however, can be misguided, as it ignores the impacts that the resources of each category have on the organism, for instance, the resource in the overlap region can be non-limiting, in which case there is no competition for this resource despite niche overlap. An organism free of interference from other species could use the range of conditions and resources in which it could survive. Hutchinson used the idea of competition for resources as the mechanism driving ecology
14.
Population dynamics
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Population dynamics is the branch of life sciences that studies the size and age composition of populations as dynamical systems, and the biological and environmental processes driving them. Example scenarios are ageing populations, population growth, or population decline, the first principle of population dynamics is widely regarded as the exponential law of Malthus, as modeled by the Malthusian growth model. The Lotka–Volterra predator-prey equations are another example, as well as the alternative Arditi-Ginzburg equations. The computer game SimCity and the MMORPG Ultima Online, among others, in the past 30 years, population dynamics has been complemented by evolutionary game theory, developed first by John Maynard Smith. Under these dynamics, evolutionary biology concepts may take a deterministic mathematical form, Population dynamics overlap with another active area of research in mathematical biology, mathematical epidemiology, the study of infectious disease affecting populations. Various models of viral spread have been proposed and analyzed, the rate at which a population increases in size if there are no density-dependent forces regulating the population is known as the intrinsic rate of increase. D N d t 1 N = r Where d N / d t is the rate of increase of the population, N is the population size and this is therefore the theoretical maximum rate of increase of a population per individual. The concept is used in insect population biology to determine how environmental factors affect the rate at which pest populations increase. See also exponential population growth and logistic population growth and it is very unusual to see this in nature. In the last 100 years, human population growth has appeared to be exponential, in the long run, however, it is not likely. Paul Ehrlich and Thomas Malthus believed that population growth would lead to overpopulation and starvation due to scarcity of resources. They believed that population would grow at rate in which they exceed the ability at which humans can find food. In the future, humans would be unable to feed large populations, the biological assumptions of exponential growth is that the per capita growth rate is constant. Growth is not limited by resource scarcity or predation, N t +1 = λ N t where λ is the discrete-time per capita growth rate. At λ =1, we get a line and a discrete-time per capita growth rate of zero. At λ <1, we get a decrease in per capita growth rate, at λ >1, we get an increase in per capita growth rate. At λ =0, we get extinction of the species, D N d T = r N where d N d T is the rate of population growth per unit time, r is the maximum per capita growth rate, and N is the population size. At r >0, there is an increase in per capita growth rate, at r =0, the per capita growth rate is zero
15.
Smallmouth bass
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The smallmouth bass is a species of freshwater fish in the sunfish family of the order Perciformes. It is the species of its genus. The maximum recorded size is approximately 27 inches and 12 pounds, the smallmouth bass is native to the upper and middle Mississippi River basin, the Saint Lawrence River–Great Lakes system, and up into the Hudson Bay basin. Its common names include smallmouth, bronzeback, brown bass, brownie, smallie, bronze bass, the smallmouth bass is generally brown, appearing sometimes as black or green with red eyes, and dark brown vertical bands, rather than a horizontal band along the side. There are 13–15 soft rays in the dorsal fin, the upper jaw of smallmouth bass extends to the middle of the eye. The smallmouths coloration and hue may vary according to variables such as water clarity or diet. Males are generally smaller than felmales, the males tend to range around two pounds, while females can range from three to six pounds. Their habitat plays a significant role in their color, weight, River water smallmouth that live in dark water tend to be rather torpedo-shaped and very dark brown to be more efficient for feeding. Lakeside smallmouth bass, however, that live in sandy areas and they have been seen eating tadpoles, fish, aquatic insects, crayfish, frogs, small mice and birds, and even French fries. There are two recognized subspecies, the Northern smallmouth bass and the Neosho smallmouth bass, the smallmouth bass is found in clearer water than the largemouth, especially streams, rivers, and the rocky areas and stumps and also sandy bottoms of lakes and reservoirs. The smallmouth prefers cooler temperatures than its cousin the largemouth bass. Because it is intolerant of pollution, the bass is a good natural indicator of a healthy environment. Carnivorous, its diet comprises crayfish, insects, and smaller fish, the female can lay up to 21,100 eggs, which are guarded by the male in his nest. The migration patterns of smallmouth have been tracked and it is not unusual for a smallmouth to travel 12 miles in a day in a stream. The overall migration can exceed 60 miles, in the United States, smallmouth bass were first introduced outside of their native range with the construction of the Erie Canal in 1825, extending the fishs range into central New York state. During the mid-to-late 19th century, smallmouth were transplanted via the rail system to lakes and rivers throughout the northern and western United States. Shippers found that smallmouth bass were a species that could be transported in buckets or barrels by rail. They were introduced east of the Appalachians just before the Civil War, with increased industrialization and land use changes, many of the nations eastern trout rivers were polluted or experienced elevated water temperatures, reducing the range of native brook trout
16.
Lake trout
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Lake trout is a freshwater char living mainly in lakes in northern North America. Other names for it include mackinaw, lake char, touladi, togue, in Lake Superior, it can also be variously known as siscowet, paperbelly and lean. The lake trout is prized both as a fish and as a food fish. From a zoogeographical perspective, lake trout have a narrow distribution. They are native only to the parts of North America, principally Canada, but also Alaska and, to some extent. Lake trout have been introduced into non-native waters in North America and into many other parts of the world, mainly Europe. Lake trout are the largest of the chars, the record weighed almost 46.3 kilograms with a length of 50 inches, the average length is 24–36 inches. The largest caught on a rod and reel according to the IGFA was 72 pounds, when hooked, especially the big ones will make a short run and just thump and twist and turn. Lake trout inhabit cold, oxygen-rich waters and they are pelagic during the period of summer stratification in dimictic lakes, often living at depths of 20–60 m. The lake trout is a fish, typical of oligotrophic waters. It is also late to mature. Populations are extremely susceptible to overfishing, many native lake trout populations have been severely damaged through the combined effects of hatchery stocking and over harvest. Three subspecies of trout are accepted. There is the lake trout, the siscowet lake trout. Some lakes do not have pelagic forage fish during the period of summer stratification, in these lakes, lake trout take on a life history known as planktivory. Lake trout in planktivorous populations are abundant, grow very slowly. In those lakes that do contain deep-water forage, lake trout become piscivorous, piscivorous lake trout grow much more quickly, mature at a larger size and are less abundant. In Lake Superior, common lake trout and siscowet lake trout live together, Common lake trout tend to stay in shallower waters, while siscowet lake trout stay in deeper water
17.
Badger
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Badgers are short-legged omnivores in the family Mustelidae, which also includes the otters, polecats, weasels, and wolverines. They belong to the suborder of carnivoran mammals. The 11 species of badgers are grouped in three subfamilies, Melinae, Mellivorinae, and Taxideinae and they include the species in the genera Arctonyx, Meles, Mellivora, Melogale and Taxidea. Their lower jaws are articulated to the upper by means of transverse condyles firmly locked into long cavities of the skull, so complete dislocation of the jaw is all, Badgers have rather short, wide bodies, with short legs for digging. They have elongated, weasel-like heads with small ears and their tails vary in length depending on species, the stink badger has a very short tail, while the ferret badgers tail can be 46–51 cm long, depending on age. They have black faces with white markings, grey bodies with a light-coloured stripe from head to tail. They grow to around 90 cm in length including tail, the European badger is one of the largest, the American badger, the hog badger, and the honey badger are generally a little smaller and lighter. The stink badgers are smaller still, and the badgers are the smallest of all. They weigh around 9–11 kg, with some Eurasian badgers weighing around 18 kg, the word badger, originally applied to the European badger, comes from earlier bageard, presumably referring to the white mark borne like a badge on its forehead. Similarly, a now archaic synonym was bauson ‘badger’, a variant of bausond ‘striped, piebald’, the less common name brock, is a Celtic loanword meaning grey. A male badger is a boar, a female is a sow, a collective name suggested for a group of badgers is a cete, but badger colonies are more often called clans. A badgers home is called a sett, the following list shows where the various species with the common name of badger are placed in the Mustelidae classification. The list is polyphyletic and the commonly called badgers do not, if the stink badgers are included. They live as far east as Japan and China, the Javan ferret-badger lives in Indonesia, and the Bornean ferret-badger lives in Malaysia. The honey badger is found in most of sub-Saharan Africa, the Arabian Desert, southern Levant, Turkmenistan, the behavior of badgers differs by family, but all shelter underground, living in burrows called setts, which may be very extensive. Some are solitary, moving from home to home, while others are known to form clans called cetes, cete size is variable from two to 15. Badgers can run or gallop at 25–30 km/h for short periods of time, in North America, coyotes sometimes eat badgers and vice versa, but the majority of their interactions seem to be mutual or neutral. American badgers and coyotes have been seen hunting together in a cooperative fashion, the diet of the Eurasian badger consists largely of earthworms, insects, grubs, and the eggs and young of ground-nesting birds
18.
Hedgehog
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A hedgehog is any of the spiny mammals of the subfamily Erinaceinae, in the Eulipotyphlan family Erinaceidae. There are seventeen species of hedgehog in five genera, found through parts of Europe, Asia, and Africa, there are no hedgehogs native to Australia, and no living species native to the Americas. Hedgehogs share distant ancestry with shrews, with gymnures possibly being the intermediate link, like many of the first mammals, they have adapted to a nocturnal way of life. Hedgehogs spiny protection resembles that of the porcupines, which are rodents, and echidnas. The name hedgehog came into use around the year 1450, derived from the Middle English heyghoge, from heyg, hegge, because it frequents hedgerows, other names include urchin, hedgepig and furze-pig. The collective noun for a group of hedgehogs is array, hedgehogs are easily recognized by their spines, which are hollow hairs made stiff with keratin. Their spines are not poisonous or barbed and unlike the quills of a porcupine, however, the immature animals spines normally fall out as they are replaced with adult spines. Spines can also shed when the animal is diseased or under extreme stress, a defense that all species of hedgehogs possess is the ability to roll into a tight ball, causing all of the spines to point outwards. The hedgehogs back contains two large muscles that control the position of the quills, when the creature is rolled into a ball, the quills on the back protect the tucked head, feet, and belly, which are not quilled. Hedgehogs are primarily nocturnal, though some species can also be active during the day, hedgehogs sleep for a large portion of the day under bushes, grasses, rocks, or most commonly in dens dug in the ground, with varying habits among the species. All wild hedgehogs can hibernate, though not all do, depending on temperature, species, hedgehogs are fairly vocal and communicate through a combination of grunts, snuffles and/or squeals, depending on species. Hedgehogs occasionally perform a ritual called anointing, when the animal encounters a new scent, it will lick and bite the source, then form a scented froth in its mouth and paste it on its spines with its tongue. Anointing is sometimes also called anting because of a behavior in birds. In addition, hedgehogs are one of four known mammalian groups with mutations that protect against another snake venom, the olfactory regions have not been thoroughly studied in the hedgehog. In mammals, the part of the brain is covered by neopallium. This difficulty is not impossible, as it varies from one species to another, tests have suggested that hedgehogs share the same electrical activity as cats. Although traditionally classified in the now abandoned order Insectivora, hedgehogs are omnivorous and they feed on insects, snails, frogs and toads, snakes, bird eggs, carrion, mushrooms, grass roots, berries, melons and watermelons. Berries constitute a part of an Afghan hedgehogs diet in early spring after hibernation
19.
Keystone species
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A keystone species is a species that has a disproportionately large effect on its environment relative to its abundance. A keystone species is a plant or animal that plays a unique, without keystone species, the ecosystem would be dramatically different or cease to exist altogether. The role that a species plays in its ecosystem is analogous to the role of a keystone in an arch. While the keystone is under the least pressure of any of the stones in an arch, similarly, an ecosystem may experience a dramatic shift if a keystone species is removed, even though that species was a small part of the ecosystem by measures of biomass or productivity. It became a concept in conservation biology. The concept of the species was introduced in 1969 by Robert T. Paine. Paine developed the concept to explain his observations and experiments on the relationship between intertidal invertebrates, in his 1966 paper, Food Web Complexity and Species Diversity, Paine described such a system in Makah Bay in Washington. In his follow-up 1969 paper, Paine proposed the species concept, using Pisaster ochraceus, a species of starfish, and Mytilus californianus. The concept became popular in conservation, and was deployed in a range of contexts, given that there are many historical definitions of the keystone species concept, and without a consensus on its exact definition, a list of examples best illustrates the concept of keystone species. A classic keystone species is a predator that prevents a particular herbivorous species from eliminating dominant plant species. Since the prey numbers are low, the keystone predator numbers can be even lower, yet without the predators, the herbivorous prey would explode in numbers, wipe out the dominant plants, and dramatically alter the character of the ecosystem. The exact scenario changes in each example, but the idea remains that through a chain of interactions. One example is the herbivorous weevil Euhrychiopsis lecontei and its suggested keystone effects on plant species diversity by foraging on nuisance Eurasian watermilfoil. Similarly, the wasp species Agelaia vicina has been labeled a keystone species due to their unparalleled nest size, colony size, the diversity of their prey and the quantity necessary to sustain their high rate of growth have a direct impact on local neighboring species. As was described by Dr. Robert Paine in his classic 1966 paper, some sea stars may prey on sea urchins, mussels, if the sea star is removed from the ecosystem, the mussel population explodes uncontrollably, driving out most other species. Similarly, sea otters protect kelp forests from damage by consuming sea urchins, kelp roots, called holdfasts, are merely anchors, and do not perform similar roles to the roots of terrestrial plants, which form large networks that acquire nutrients from the soil. In the absence of sea otters, sea urchins are released from predation pressure, sea urchins rapidly consume nearshore kelp, severing the structures at the base. Where sea otters are present, sea urchins tend to be small, large nearshore kelp forests proliferate and serve as important habitat for a number of other species
20.
Trophic cascade
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Trophic cascades occur when predators in a food web suppress the abundance or alter the behavior of their prey, thereby releasing the next lower trophic level from predation. For example, if the abundance of large fish is increased in a lake. The resulting increase in zooplankton should, in turn, cause the biomass of its prey, phytoplankton, the trophic cascade is an ecological concept which has stimulated new research in many areas of ecology. For example, it can be important for understanding the effects of removing top predators from food webs. A top-down cascade is a cascade where the food chain or food web is disrupted by the removal of a top predator, or a third or fourth level consumer. On the other hand, a cascade occurs when a primary producer, or primary consumer is removed. Nelson Hairston, Frederick E. Smith and Lawrence B, Slobodkin are generally credited with introducing the concept into scientific discourse, although they did not use the term either. Hairston, Smith and Slobodkin argued that predators reduce the abundance of herbivores and this is often referred to as the green world hypothesis. The green world hypothesis is credited with bringing attention to the role of top-down forces, the prevailing view of communities prior to Hairston, Smith and Slobodkin was trophodynamics, which attempted to explain the structure of communities using only bottom-up forces. Smith may have inspired by the experiments of a Czech ecologist, Hrbáček. Hrbáček had shown that fish in artificial ponds reduced the abundance of zooplankton, Hairston, Smith and Slobodkin feuded that the ecological communities acted as food chains with three trophic levels. Subsequent models expanded the argument to food chains with more than or fewer than three trophic levels, additionally, he argued that the number of trophic levels in a food chain increases as the productivity of the ecosystem increases. Although the existence of trophic cascades is not controversial, ecologists have long debated how ubiquitous they are, Hairston, Smith and Slobodkin argued that terrestrial ecosystems, as a rule, behave as a three trophic level trophic cascade, which provoked immediate controversy. Herbivore populations may be limited by other than food or predation. For trophic cascades to be ubiquitous, communities must generally act as food chains, most communities, however, have complex food webs. Antagonistically, this principle is called the trophic trickle. Removal of piscivorous fish can change water from clear to green by allowing phytoplankton to flourish. In the Eel River, in Northern California, fish consume fish larvae and these smaller predators prey on midge larvae, which feed on algae
21.
Subarctic
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The subarctic is a region in the Northern Hemisphere immediately south of the true Arctic and covering much of Alaska, Canada, Iceland, the north of Scandinavia, Siberia, and the Shetland Islands. Generally, subarctic regions fall between 50°N and 70°N latitude, depending on local climates, monthly temperatures are above 10 °C for at least one and at most three months of the year. Precipitation tends to be low due to the low content of the cold air. Precipitation is typically greater in warmer months, with a summer maximum ranging from moderate in North America to extreme in the Russian Far East, the dominant soil orders are podsols and further north gelisols. Typically, there are only a few species of terrestrial mammals in the subarctic regions, the most important being elk, moose, bears, reindeer. Agriculture is mainly limited to animal husbandry, though in some areas barley can be grown, except for those areas adjacent to warm ocean currents, there is almost always continuous permafrost due to the very cold winters. This means that building in most subarctic regions is difficult and expensive, cities are very few and generally small. Subarctic rail transport exists in Europe and the Norilsk–Dudinka line in northern Siberia. An important consequence is that transportation tends to be restricted to bush planes, helicopters and, in summer, riverboats. Except for a few parts of Europe where the winters are mild due to prevailing wind and ocean current patterns. Even then, the difficulty of transportation ensured that few settlements lasted long—the abandoned, once-thriving cities of the Yukon, Northwest Territories, today, many towns in subarctic Russia are declining precipitously as mines close. In Canada, after the early minerals ran out, development stalled until hydroelectric development occurred in the 1950s and 1960s. Tourism in recent years has become a source of revenue for most countries of the subarctic due to the beautiful, generally glacial. Most areas in the subarctic are among the most expensive places in the world to visit, nonetheless, the great opportunities for outdoor recreation lure an ever-increasing number of travelers. At the same time, the industries of the subarctic are being threatened by both environmental opposition and overfishing leading to depleted stocks of commercially important species. Indigenous peoples of Subarctic America Muskeg Nordicity Northern Canada Subarctic climate Subarctic climate in, Ritter, the Physical Environment, an Introduction to Physical Geography
22.
Arctic fox
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The Arctic fox, also known as the white fox, polar fox, or snow fox, is a small fox native to the Arctic regions of the Northern Hemisphere and common throughout the Arctic tundra biome. It is well adapted to living in cold environments and it has a deep thick fur which is brown in summer and white in winter. Its body length ranges from 46 to 68 cm, with a rounded body shape to minimize the escape of body heat. The Arctic fox preys on any small creatures such as, lemmings, voles, ringed seal pups, fish, waterfowl and it also eats carrion, berries, seaweed, insects, and other small invertebrates. Arctic foxes form monogamous pairs during the season and they stay together to raise their young in complex underground dens. Occasionally, other members may assist in raising their young. The Arctic fox lives in some of the most frigid extremes on the planet, the fox has a low surface area to volume ratio, as evidenced by its generally compact body shape, short muzzle and legs, and short, thick ears. Since less of its area is exposed to the Arctic cold. Its paws have fur on the soles for additional insulation and to help it walk on ice and its fur changes color with the seasons, in most populations it is white in the winter to blend in with snow, while in the summer it is greyish-brown or darker brown. In some populations, however, it is a steely bluish-gray in the winter, the fur of the Arctic fox provides the best insulation of any mammal. The Arctic fox has such keen hearing, it can determine exactly where an animal is moving under the snow. When it has located its prey, it pounces and punches through the snow to catch its victim, Arctic foxes do not hibernate and are active all year round. They build up their fat reserves in the autumn, sometimes increasing their weight by more than 50%. This provides greater insulation during the winter and a source of energy when food is scarce and they live in large dens in frost-free, slightly raised ground. These are complex systems of tunnels covering as much as 1,000 m2 and are often in eskers and they have multiple entrances and may have been in existence for many decades and used by many generations of foxes. Arctic foxes tend to form pairs in the breeding season. Breeding usually takes place in April and May, and the period is about 52 days. Litters tend to average five to eight kits, but exceptionally contain as many as 25, both the mother and father help to raise the young which emerge from the den when 3 to 4 weeks old and are weaned by 9 weeks of age
23.
Seabird
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Seabirds are birds that are adapted to life within the marine environment. The first seabirds evolved in the Cretaceous period, and modern seabird families emerged in the Paleogene, in general, seabirds live longer, breed later and have fewer young than other birds do, but they invest a great deal of time in their young. Most species nest in colonies, which can vary in size from a few birds to millions. Many species are famous for undertaking long annual migrations, crossing the equator or circumnavigating the Earth in some cases and they feed both at the oceans surface and below it, and even feed on each other. Seabirds can be highly pelagic, coastal, or in some cases spend a part of the year away from the sea entirely, Seabirds and humans have a long history together, they have provided food to hunters, guided fishermen to fishing stocks and led sailors to land. Many species are threatened by human activities, and conservation efforts are under way. There exists no single definition of which groups, families and species are seabirds, and most definitions are in some way arbitrary. In the words of two scientists, The one common characteristic that all seabirds share is that they feed in saltwater. However, by all of the Sphenisciformes and Procellariiformes, all of the Pelecaniformes except the darters. The phalaropes are usually included as well, since although they are waders, loons and grebes, which nest on lakes but winter at sea, are usually categorized as water birds, not seabirds. Although there are a number of sea ducks in the family Anatidae that are truly marine in the winter, many waders and herons are also highly marine, living on the seas edge, but are also not treated as seabirds. Seabirds, by virtue of living in a depositional environment, are well represented in the fossil record. In the Paleogene the seas were dominated by early Procellariidae, giant penguins, modern genera began their wide radiation in the Miocene, although the genus Puffinus might date back to the Oligocene. The highest diversity of seabirds apparently existed during the Late Miocene, Seabirds have made numerous adaptations to living on and feeding in the sea. Wing morphology has been shaped by the niche an individual species or family has evolved, so that looking at a wings shape, longer wings and low wing loading are typical of more pelagic species, while diving species have shorter wings. Seabirds also almost always have webbed feet, to aid movement on the surface as well as assisting diving in some species. The Procellariiformes are unusual among birds in having a sense of smell, which is used to find widely distributed food in a vast ocean. Salt glands are used by seabirds to deal with the salt they ingest by drinking and feeding, the excretions from these glands are almost pure sodium chloride
24.
Grassland
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Grasslands are areas where the vegetation is dominated by grasses, however sedge and rush families can also be found. Grasslands occur naturally on all continents except Antarctica, grasslands are found in most ecoregions of the Earth. For example, there are five terrestrial ecoregion classifications of the grasslands, savannas, and shrublands biome. Grassland vegetation can vary in height from short, as in chalk grassland, to quite tall, as in the case of North American tallgrass prairie, South American grasslands. Woody plants, shrubs or trees, may occur on some grasslands – forming savannas, scrubby grassland or semi-wooded grassland, as flowering plants and trees, grasses grow in great concentrations in climates where annual rainfall ranges between 500 and 900 mm. The root systems of perennial grasses and forbs form complex mats that hold the soil in place, graminoids are among the most versatile life forms. Existing forest biomes declined, and grasslands became much more widespread, following the Pleistocene ice ages, grasslands expanded in range in the hotter, drier climates, and began to become the dominant land feature worldwide. Grasslands often occur in areas with annual precipitation between 600 mm and 1,500 mm and average annual temperatures ranges from −5 and 20 °C. However, some occur in colder and hotter climatic conditions. Grassland can exist in habitats that are disturbed by grazing or fire. Grasslands dominated by unsown wild-plant communities can be called natural or semi-natural habitats. The majority of grasslands in temperate climates are semi-natural and these grasslands contain many species of wild plants – grasses, sedges, rushes and herbs –25 or more species per square metre is not unusual. Chalk downlands in England can support over 40 species per square metre, in many parts of the world, few examples have escaped agricultural improvement. For example, original North American prairie grasslands or lowland wildflower meadows in the UK are now rare and their associated wild flora equally threatened. Some of the worlds largest expanses of grassland are found in African savanna, grasslands may occur naturally or as the result of human activity. Grasslands created and maintained by human activity are called anthropogenic grasslands, hunting peoples around the world often set regular fires to maintain and extend grasslands, and prevent fire-intolerant trees and shrubs from taking hold. The tallgrass prairies in the U. S. Midwest may have been extended eastward into Illinois, Indiana, much grassland in northwest Europe developed after the Neolithic Period, when people gradually cleared the forest to create areas for raising their livestock. Grassland types by Schimper, meadow steppe savannah Grassland types by Ellenberg & Mueller-Dombois, terrestrial herbaceous communities A. Savannas and related grasslands B
25.
Tundra
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In physical geography, tundra is a type of biome where the tree growth is hindered by low temperatures and short growing seasons. The term tundra comes through Russian тундра from the Kildin Sami word tūndâr uplands, there are three types of tundra, Arctic tundra, alpine tundra, and Antarctic tundra. In tundra, the vegetation is composed of shrubs, sedges and grasses, mosses. Scattered trees grow in tundra regions. The ecotone between the tundra and the forest is known as the line or timberline. Arctic tundra occurs in the far Northern Hemisphere, north of the taiga belt, the word tundra usually refers only to the areas where the subsoil is permafrost, or permanently frozen soil. Permafrost tundra includes vast areas of northern Russia and Canada, the polar tundra is home to several peoples who are mostly nomadic reindeer herders, such as the Nganasan and Nenets in the permafrost area. Arctic tundra contains areas of landscape and is frozen for much of the year. The soil there is frozen from 25–90 cm down, and it is impossible for trees to grow, instead, bare and sometimes rocky land can only support low growing plants such as moss, heath, and lichen. There are two seasons, winter and summer, in the polar tundra areas. During the winter it is cold and dark, with the average temperature around −28 °C. However, extreme temperatures on the tundra do not drop as low as those experienced in taiga areas further south. During the summer, temperatures rise somewhat, and the top layer of seasonally-frozen soil melts, the tundra is covered in marshes, lakes, bogs and streams during the warm months. Generally daytime temperatures during the rise to about 12 °C. Arctic tundras are sometimes the subject of conservation programs. In Canada and Russia, many of areas are protected through a national Biodiversity Action Plan. Tundra tends to be windy, with winds often blowing upwards of 50–100 km/h, however, in terms of precipitation, it is desert-like, with only about 15–25 cm falling per year. Although precipitation is light, evaporation is also relatively minimal, there is a natural pattern of accumulation of fuel and wildfire which varies depending on the nature of vegetation and terrain
26.
Sperm whale
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The sperm whale, or cachalot, is the largest of the toothed whales and the largest toothed predator. It is the only living member of genus Physeter, and one of three extant species in the whale family, along with the pygmy sperm whale and dwarf sperm whale of the genus Kogia. Mature males average 16 metres in length but some may reach 20.5 metres, plunging to 2,250 metres, it is the second deepest diving mammal, following only the Cuviers beaked whale. The sperm whales clicking vocalization, a form of echolocation and communication and it has the largest brain of any animal on Earth, more than five times heavier than a humans. Sperm whales can live for more than 60 years, the sperm whale can be found anywhere in the open ocean. Females and young males live together in groups while males live solitary lives outside of the mating season. The females cooperate to protect and nurse their young, females give birth every four to twenty years, and care for the calves for more than a decade. A mature sperm whale has few predators, although calves. From the early eighteenth century through the late 20th, the species was a target of whalers. The head of the whale contains a liquid wax called spermaceti, spermaceti was used in lubricants, oil lamps, and candles. Ambergris, a product from its digestive system, is still used as a fixative in perfumes. Occasionally the sperm whales great size allowed it to defend effectively against whalers. The species is now protected by a moratorium, and is currently listed as vulnerable by the International Union for the Conservation of Nature. The name sperm whale is a clip of spermaceti whale, spermaceti, originally mistakenly identified as the whales semen, is the semi-liquid, waxy substance found within the whales head. The sperm whale is known as the cachalot, which is thought to derive from the archaic French for tooth or big teeth. The etymological dictionary of Corominas says the origin is uncertain, but it suggests that it comes from the Vulgar Latin cappula, plural of cappulum, the word cachalot came to English via French from Spanish or Portuguese cachalote, perhaps from Galician/Portuguese cachola, big head. The term is retained in the Russian word for the animal, кашалот, the scientific genus name Physeter comes from Greek physētēr, meaning blowpipe, blowhole, or – as a pars pro toto – whale. The specific name macrocephalus is Latinized from the Greek makrokephalos, from makros + kefalos and its synonymous specific name catodon means down-tooth, from the Greek elements cat- and odṓn, so named because it has visible teeth only in its lower jaw
27.
Greater Yellowstone Ecosystem
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The Greater Yellowstone Ecosystem is one of the last remaining large, nearly intact ecosystems in the northern temperate zone of the Earth. It is located within the northern Rocky Mountains, in areas of northwestern Wyoming, southwestern Montana, Yellowstone National Park and the Yellowstone Caldera hotspot are within it. Conflict over ecological and resource management has been controversial, and the area is a flagship site among conservation groups that promote ecosystem management, the Greater Yellowstone Ecosystem is one of the worlds foremost natural laboratories in landscape ecology and Holocene geology, and is a world-renowned recreational destination. It is also home to the native plants and animals of Yellowstone. Yellowstone National Park boundaries were drawn in 1872 to include all the known geothermal basins in the region, no other landscape ecology considerations were incorporated into boundary decisions. Since then, definitions of the greater ecosystems size have grown larger. A1994 study listed the size as 76,890 square kilometres, federally managed areas within the GYE include, United States National Park Service — Yellowstone National Park, Grand Teton National Park, and John D. Rockefeller, Jr. Memorial Parkway. The GYE also encompasses some privately held and state lands surrounding those managed by the U. S. Government, the great ecosystem concept has been most often advanced through concerns over individual species rather than over broader ecological principles. The Yellowstone hot springs are important for their diversity of thermophilic bacteria and these bacteria have been useful in studies of the evolution of photosynthesis and as sources of thermostable enzymes for molecular biology. Although the smell of sulfur is common and there are some sulfur fixing cyanobacteria, in this case, researchers do not have a good long-term data set on the species, but they understand its ecology well enough to project declining future conservation status. A more immediate and serious threat to whitebark pines is an introduced fungal rust disease, White Pine Blister Rust, occasional resistant individuals occur, but in the short to medium term, a severe population decline is expected. Estimates of the decline of quaking aspen on the northern range since 1872 range from 50% to 95%. Perhaps no conservation controversy underway in Greater Yellowstone more clearly reveals the need for comprehensive interdisciplinary research, European influences on wildfire frequency since 1886, regional climate warming. Human harvests of beaver and ungulates in the first 15 years of the parks history, anecdotal information on grizzly bear abundance dates to the mid-19th century, and administrators have made informal population estimates for more than 70 years. From these sources, ecologists know the species was common in Greater Yellowstone when Europeans arrived and that the population was not isolated before the 1930s, researchers do not know if bears were more or less common than now. A 1959-1970 bear study suggested a grizzly bear population size of about 176, later revised to about 229. Later estimates have ranged as low as 136 and as high as 540, the most recent is an estimate of 236. Although the Greater Yellowstone population is close to recovery goals
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Yellowstone National Park
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Yellowstone National Park is a national park located in the U. S. states of Wyoming, Montana and Idaho. It was established by the U. S. Congress and signed into law by President Ulysses S. Grant on March 1,1872. Yellowstone was the first National Park in the U. S. and is widely held to be the first national park in the world. The park is known for its wildlife and its many features, especially Old Faithful Geyser. It has many types of ecosystems, but the subalpine forest is the most abundant and it is part of the South Central Rockies forests ecoregion. Native Americans have lived in the Yellowstone region for at least 11,000 years, aside from visits by mountain men during the early-to-mid-19th century, organized exploration did not begin until the late 1860s. Management and control of the park fell under the jurisdiction of the Secretary of the Interior. However, the U. S. Army was subsequently commissioned to oversee management of Yellowstone for a 30-year period between 1886 and 1916, in 1917, administration of the park was transferred to the National Park Service, which had been created the previous year. Hundreds of structures have been built and are protected for their architectural and historical significance, Yellowstone National Park spans an area of 3,468.4 square miles, comprising lakes, canyons, rivers and mountain ranges. Yellowstone Lake is one of the largest high-elevation lakes in North America and is centered over the Yellowstone Caldera, the caldera is considered an active volcano. It has erupted with tremendous force several times in the last two million years, half of the worlds geothermal features are in Yellowstone, fueled by this ongoing volcanism. Lava flows and rocks from volcanic eruptions cover most of the area of Yellowstone. The park is the centerpiece of the Greater Yellowstone Ecosystem, the largest remaining nearly-intact ecosystem in the Earths northern temperate zone, hundreds of species of mammals, birds, fish, and reptiles have been documented, including several that are either endangered or threatened. The vast forests and grasslands also include species of plants. Yellowstone Park is the largest and most famous location in the Continental United States. Grizzly bears, wolves, and free-ranging herds of bison and elk live in the park, the Yellowstone Park bison herd is the oldest and largest public bison herd in the United States. Forest fires occur in the each year, in the large forest fires of 1988. Yellowstone has numerous opportunities, including hiking, camping, boating, fishing and sightseeing
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Elk
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The elk, or wapiti, is one of the largest species within the deer family, Cervidae, in the world, and one of the largest land mammals in North America and Eastern Asia. This animal should not be confused with the still larger moose to which the name elk applies in British English, apart from the moose, the only other member of the deer family to rival the elk in size is the south Asian sambar. Elk range in forest and forest-edge habitat, feeding on grasses, plants, leaves, male elk have large antlers which are shed each year. Although they are native to North America and eastern Asia, they have adapted well to countries in which they have introduced, including Argentina. Their great adaptability may threaten endemic species and ecosystems into which they have been introduced, Elk are susceptible to a number of infectious diseases, some of which can be transmitted to livestock. Efforts to eliminate infectious diseases from elk populations, largely by vaccination, have had mixed success, some cultures revere the elk as a spiritual force. In parts of Asia, antlers and their velvet are used in traditional medicines, Elk are hunted as a game species. The meat is leaner and higher in protein than beef or chicken and it was long believed to be a subspecies of the European red deer, but evidence from a number of mitochondrial DNA genetic studies beginning in 1998 show that the two are distinct species. Key morphological differences that distinguish C. canadensis from C. elaphus are the formers wider rump patch and paler-hued antlers. The word elk is related to the Latin alces, Old Norse elgr, Scandinavian elg/älg and German Elch, the name wapiti is from the Shawnee and Cree word waapiti, meaning white rump. This name is used in particular for the Asian subspecies, because in Eurasia the name elk continues to be used for the moose, Asian subspecies are sometimes referred to as the maral, but this name applies primarily to the Caspian red deer, a subspecies of red deer. There is a subspecies of elk in Mongolia called the Altai wapiti, members of the genus Cervus first appear in the fossil record 25 million years ago, during the Oligocene in Eurasia, but do not appear in the North American fossil record until the early Miocene. The extinct Irish elk was not a member of the genus Cervus, until recently, red deer and elk were considered to be one species, Cervus elaphus. However, the two species have freely inter-bred in New Zealands Fiordland National Park, where the animals have all. There are numerous subspecies of elk described, with six from North America and four from Asia, populations vary as to antler shape and size, body size, coloration and mating behavior. DNA investigations of the Eurasian subspecies revealed that phenotypic variation in antlers, mane, of the six subspecies of elk known to have inhabited North America in historical times, four remain, including the Roosevelt, tule, Manitoban and Rocky Mountain. The eastern elk and Merriams elk subspecies have been extinct for at least a century, four subspecies described in Asia include the Altai wapiti and the Tianshan wapiti. Two distinct subspecies found in China and Korea are the Manchurian wapiti, the Manchurian wapiti is darker and more reddish in coloration than the other populations
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Riparian zone
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A riparian zone or riparian area is the interface between land and a river or stream. Riparian is also the proper nomenclature for one of the fifteen terrestrial biomes of the earth, Plant habitats and communities along the river margins and banks are called riparian vegetation, characterized by hydrophilic plants. In some regions the terms riparian woodland, riparian forest, riparian buffer zone, the word riparian is derived from Latin ripa, meaning river bank. Riparian zones may be natural or engineered for soil stabilization or restoration and these zones are important natural biofilters, protecting aquatic environments from excessive sedimentation, polluted surface runoff and erosion. They supply shelter and food for aquatic animals and shade that limits stream temperature change. When riparian zones are damaged by construction, agriculture or silviculture, biological restoration can take place, usually by human intervention in erosion control and revegetation. If the area adjacent to a watercourse has standing water or saturated soil for as long as a season, because of their prominent role in supporting a diversity of species, riparian zones are often the subject of national protection in a Biodiversity Action Plan. These are also known as a Plant or Vegetation Waste Buffer, research shows that riparian zones are instrumental in water quality improvement for both surface runoff and water flowing into streams through subsurface or groundwater flow. Particularly, the attenuation of nitrate or denitrification of the nitrates from fertilizer in this zone is important. The use of wetland riparian zones shows a high rate of removal of nitrate entering a stream. The meandering curves of a river, combined with vegetation and root systems, slow the flow of water, sediment is trapped, reducing suspended solids to create less turbid water, replenish soils, and build stream banks. Pollutants are filtered from surface runoff, enhancing water quality via biofiltration, the riparian zones also provide wildlife habitat, increased biodiversity, and wildlife corridors, enabling aquatic and riparian organisms to move along river systems avoiding isolated communities. Riparian vegetation can also forage for wildlife and livestock. They provide native landscape irrigation by extending seasonal or perennial flows of water, nutrients from terrestrial vegetation are transferred to aquatic food webs. The vegetation surrounding the stream helps to shade the water, mitigating water temperature changes, the vegetation also contributes wood debris to streams, which is important to maintaining geomorphology. From a social aspect, riparian zones contribute to nearby property values through amenity and views, space is created for riparian sports such as fishing, swimming and launching for vessels and paddlecraft. The protection of zones is often a consideration in logging operations. The undisturbed soil, soil cover, and vegetation provide shade, plant litter, and woody material, factors such as soil types and root structures, climatic conditions and vegetative cover determine the effectiveness of riparian buffering
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Willow
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Most species are known as willow, but some narrow-leaved shrub species are called osier, and some broader-leaved species are referred to as sallow. Some willows are low-growing or creeping shrubs, for example, the dwarf willow rarely exceeds 6 cm in height, though it spreads widely across the ground. Willows all have abundant watery bark sap, which is charged with salicylic acid, soft, usually pliant, tough wood, slender branches. The roots are remarkable for their toughness, size, and tenacity to life, the leaves are typically elongated, but may also be round to oval, frequently with serrated edges. Most species are deciduous, semievergreen willows with coriaceous leaves are rare, e. g. Salix micans, all the buds are lateral, no absolutely terminal bud is ever formed. The buds are covered by a single scale, usually, the bud scale is fused into a cap-like shape, but in some species it wraps around and the edges overlap. The leaves are simple, feather-veined, and typically linear-lanceolate, usually they are serrate, rounded at base, acute or acuminate. The leaf petioles are short, the often very conspicuous, resembling tiny, round leaves. On some species, however, they are small, inconspicuous, in color, the leaves show a great variety of greens, ranging from yellowish to bluish. Willows are dioecious, with male and female flowers appearing as catkins on separate plants and this scale is square, entire, and very hairy. The anthers are rose-colored in the bud, but orange or purple after the flower opens, they are two-celled, the filaments are threadlike, usually pale brown, and often bald. The ovary is one-celled, the style two-lobed, and the ovules numerous, almost all willows take root very readily from cuttings or where broken branches lie on the ground. The few exceptions include the willow and peachleaf willow. One famous example of such growth from cuttings involves the poet Alexander Pope and this twig was planted and thrived, and legend has it that all of Englands weeping willows are descended from this first one. Willows are often planted on the borders of streams so their interlacing roots may protect the bank against the action of the water, frequently, the roots are much larger than the stem which grows from them. Willows are very cross-compatible, and numerous hybrids occur, both naturally and in cultivation, a well-known ornamental example is the weeping willow, which is a hybrid of Peking willow from China and white willow from Europe. The hybrid cultivar Boydii has gained the Royal Horticultural Societys Award of Garden Merit, Willows are used as food plants by the larvae of some Lepidoptera species, such as the mourning cloak butterfly. Ants, such as ants, are common on willows inhabited by aphids, coming to collect aphid honeydew
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Aspen
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Aspen is a common name for certain tree species, some, but not all, are classified by botanists in the section Populus, of the Populus genus. They are all medium-sized deciduous trees reaching 15–30 m tall, each individual tree can live for 40–150 years above ground, but the root system of the colony is long-lived. In some cases, this is for thousands of years, sending up new trunks as the older trunks die off above ground, for this reason, it is considered to be an indicator of ancient woodlands. One such colony in Utah, given the nickname of Pando, is estimated to be 80,000 years old, some aspen colonies become very large with time, spreading about 1 m per year, eventually covering many hectares. They are able to survive forest fires, because the roots are below the heat of the fire, aspens do not thrive in the shade, and it is difficult for seedlings to grow in an already mature aspen stand. Fire indirectly benefits aspen trees, since it allows the saplings to flourish in open sunlight in the burned landscape, young aspen bark is an important seasonal forage for the European hare and other animals in early spring. Aspen is also a tree of choice of the European beaver, aspen wood is white and soft, but fairly strong, and has low flammability. It has a number of uses, notably for making matches, shredded aspen wood is used for packing and stuffing, sometimes called excelsior. It is also a popular animal bedding, since it lacks the phenols associated with pine and juniper, heat-treated aspen is a popular material for the interiors of a sauna. Trees portal Fox, Mark, Linda E. Tackaberry, Pascal Drouin, Yves Bergeron, Robert L. Bradley, microbial community structure of soils under four productivity classes of aspen forests in Northern British Columbia
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Populus sect. Aigeiros
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Populus section Aigeiros is a section of three species in the genus Populus, the poplars. Like some other species in the genus Populus, they are known as cottonwoods. The species are native to North America, Europe, and western Asia, in the past, as many as six species were recognized, but recent trends have been to accept just three species, treating the others as subspecies of P. deltoides. An important feature of the leaves is the petiole, which is flattened sideways so that the leaves have a type of movement in the wind. Male and female flowers are in catkins, appearing before the leaves in spring. The seeds are borne on cottony structures that allow them to be blown long distances in the air before settling to ground, the cottonwoods are exceptionally tolerant of flooding, erosion, and flood deposits filling around the trunk. Although each of the three species has a different leaf pattern, they all have the same general diamond leaf shape. Eastern cottonwood is one of the largest North American hardwood trees and it is a riparian zone tree. It occurs throughout the eastern United States and in extreme southern Canada, the leaves are alternate and simple, with coarsely toothed edges, and subcordate at the base. The leaf shape is triangular, hence the species name. In the typical subspecies P. d. deltoides, the leaves are broad and triangular, further west, the subspecies P. d. monilifera has somewhat narrower leaves, 5–10 cm wide at the base. This is also the tree of Nebraska, Wyoming. In West Texas, New Mexico, and Colorado, the subspecies P. d. wislizeni occurs, fremonts cottonwood is native to the southwestern United States and western Mexico. In the United States, the species can be found in California, Nevada, arizona, New Mexico, Texas and Colorado. In Mexico, it can be found in the states of Baja California, Baja California Sur, Sonora, Chihuahua, Coahuila, Nuevo León, Mexico State, and Puebla. It differs from the eastern cottonwood mainly in the leaves having fewer, larger serrations on the edge, some taxonomists formerly considered P. fremontii to be a subspecies of P. deltoides. Black poplar is native to Europe and Western Asia, is distinct in its smaller leaves, 5–11 centimetres across. Cottonwoods are widely grown for timber production along wet river banks, the wood is coarse and of fairly low value, used for pallet boxes, shipping crates, and similar purposes where a cheap but strong enough wood is suitable
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Habitat
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A habitat is an ecological or environmental area that is inhabited by a particular species of animal, plant, or other type of organism. The term typically refers to the zone in which the organism lives and it is the natural environment in which an organism lives, or the physical environment that surrounds a species population. Every organism has certain habitat needs for the conditions in which it will thrive, habitat types include polar, temperate, subtropical and tropical. The terrestrial vegetation type may be forest, steppe, grassland, the word habitat has been in use since about 1755 and derives from the Latin third-person singular present indicative of habitāre, to inhabit, from habēre, to have or to hold. Habitat can be defined as the environment of an organism. It is similar in meaning to a biotope, an area of environmental conditions associated with a particular community of plants. Generally speaking, animal communities are reliant on specific types of plant communities, some plants and animals are generalists, and their habitat requirements are met in a wide range of locations. The small white butterfly for example is found on all the continents of the world apart from Antarctica and its larvae feed on a wide range of Brassicas and various other plant species, and it thrives in any open location with diverse plant associations. Disturbance is important in the creation of biodiverse habitats, in the absence of disturbance, a climax vegetation cover develops that prevents the establishment of other species. Lightning strikes and toppled trees in tropical forests allow species richness to be maintained as pioneering species move in to fill the gaps created. Similarly coastal habitats can become dominated by kelp until the seabed is disturbed by a storm, another cause of disturbance is when an area may be overwhelmed by an invasive introduced species which is not kept under control by natural enemies in its new habitat. Terrestrial habitat types include forests, grasslands, wetlands and deserts, within these broad biomes are more specific habitats with varying climate types, temperature regimes, soils, altitudes and vegetation types. Many of these habitats grade into each other and each one has its own communities of plants. A habitat may suit a particular species well, but its presence or absence at any particular location depends to some extent on chance, on its dispersal abilities, freshwater habitats include rivers, streams, lakes, ponds, marshes and bogs. Although some organisms are found across most of these habitats, the majority have more specific requirements, similarly, aquatic plants can be floating, semi-submerged, submerged or grow in permanently or temporarily saturated soils besides bodies of water. Marine habitats include brackish water, estuaries, bays, the sea, the intertidal zone. Further variations include rock pools, sand banks, mudflats, brackish lagoons, sandy and pebbly beaches, the benthic zone or seabed provides a home for both static organisms, anchored to the substrate, and for a large range of organisms crawling on or burrowing into the surface. A desert is not the kind of habitat that favours the presence of amphibians, with their requirement for water to keep their skins moist, nevertheless, some frogs live in deserts, creating moist habitats underground and hibernating while conditions are adverse
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North American beaver
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The North American beaver is one of two extant beaver species. It is native to North America and introduced to Patagonia in South America, other vernacular names, including American beaver and Canadian beaver, distinguish this species from the other extant beaver species, Castor fiber, which is native to Eurasia. The North American beaver is an animal symbol of Canada. Adults usually weigh from 11 to 32 kg, with 20 kg being typical, the head-and-body length is 74–90 cm, with the tail adding a further 20–35 cm. Very old individuals can exceed normal sizes, weighing more than 40 kg or even as much as 50 kg. Like the capybara, the beaver is semiaquatic, the beaver has many traits suited to this lifestyle. It has a large, flat, paddle-shaped tail and large, the unwebbed front paws are smaller, with claws. The eyes are covered by a membrane which allows the beaver to see under water. The nostrils and ears are sealed while submerged, a thick layer of fat under its skin insulates the beaver from its coldwater environment. The beavers fur consists of long, coarse hairs and short. The fur has a range of colours, but usually is dark brown, scent glands near the genitals secrete an oily substance known as castoreum, which the beaver uses to waterproof its fur. Physician naturalist Edgar Alexander Mearns 1907 report of beaver on the Sonora River may be the southernmost extent of the range of this North American aquatic mammal. However, beavers have also been reported both historically and contemporaneously in Mexico on the Colorado River, Bavispe River, and San Bernardino River, beavers are active mainly at night. They are excellent swimmers and may remain submerged up to 15 minutes, more vulnerable on land, they tend to remain in the water as much as possible. They use their flat, scaly tail both to signal danger by slapping the surface of the water and as a location for fat storage. They construct their homes, or lodges, out of sticks, twigs, rocks, and mud in lakes, streams and these lodges may be surrounded by water, or touching land, including burrows dug into river banks. Beavers are well known for building dams across streams and constructing their lodges in the ponds which form. When building in a pond, the beavers first make a pile of sticks and then eat out one or more underwater entrances, the first is used for drying off
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Moose
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The moose or elk, Alces alces, is the largest extant species in the deer family. Moose are distinguished by the broad, flat antlers of the males, Moose typically inhabit boreal forests and temperate broadleaf and mixed forests of the Northern Hemisphere in temperate to subarctic climates. Hunting and other activities have caused a reduction in the size of the mooses range over time. Moose have been reintroduced to some of their former habitats, currently, most moose are found in Canada, Alaska, New England, Fennoscandia, Latvia, Estonia and Russia. Their diet consists of terrestrial and aquatic vegetation. The most common predators are the gray wolf along with bears. Unlike most other species, moose are solitary animals and do not form herds. Although generally slow-moving and sedentary, moose can become aggressive and move quickly if angered or startled and their mating season in the autumn features energetic fights between males competing for a female. Alces alces is called a moose in North American English, and that same word elk in North American English refers to a completely different species of deer, the Cervus canadensis, also called the wapiti. A mature male moose is called a bull, a female a cow. The word elk originated from Proto-Germanic languages, from which Old English evolved, the British English word elk has cognates in other Indo-European languages, for example elg in Danish/Norwegian, älg in Swedish, alnis in Latvian, Elch in German, and łoś in Polish. In the continental-European languages, these forms of the word elk almost always refer to the Alces alces, the word moose first entered English by 1606 and is borrowed from the Algonquian languages, and possibly involved forms from multiple languages mutually reinforcing one another. The term moose is a name of North American origin, the animal is known in British English as the elk. The moose became extinct in Britain during the Bronze Age, long before the Europeans discovery of America, the youngest bones were found in Scotland and are roughly 3900 years old. Dictionaries of the 18th century simply described elk as a deer that was as large as a horse, confusingly, the word elk is used in North America to refer to a different animal, Cervus canadensis, which is also called by the Algonkian indigenous name, wapiti. The British began colonizing America in the 17th century, and found two common species of deer for which they had no names, the wapiti appeared very similar to the red deer of Europe although it was much larger and was not red. The moose was a rather strange-looking deer to the colonists, the wapiti is very similar to the red deer of central and western Europe, although it is distinctly different behaviorally and genetically. Early European explorers in North America, particularly in Virginia where there were no moose, called the wapiti elk because of its size, the moose resembled the German elk, which was less familiar to the British colonists
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Vulnerable species
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Vulnerability is mainly caused by habitat loss or destruction of the species home. Vulnerable habitat or species are monitored and can become increasingly threatened, some species listed as vulnerable may be common in captivity, an example being the military macaw. There are currently 5196 animals and 6789 plants classified as vulnerable, compared with 1998 levels of 2815 and 3222, practices such as Cryoconservation of animal genetic resources have been enforced in efforts to conserve vulnerable breeds of livestock specifically. The International Union for Conservation of Nature uses several criteria to enter species in this category, a reduction of at least 20%, projected or suspected to be met within the next ten years or three generations, whichever is the longer, based on any of, or above. Population is characterised by a restriction in its area of occupancy or in the number of locations. E) Quantitative analysis showing the probability of extinction in the wild is at least 10% within 100 years
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Grizzly bear
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The grizzly bear, less commonly known as the silvertip bear, is a large subspecies of brown bear inhabiting North America. Scientists generally do not use the name grizzly bear but call it the North American brown bear, on average bears near the coast tend to be larger while inland Grizzlies tend to be smaller. The Ussuri brown bear inhabiting Russia, Northern China, and Korea is sometimes referred to as black grizzly although it is a different subspecies from the bears in America, meriwether Lewis and William Clark named it to be grisley or grizzly, which could have meant grizzled or fear-inspiring. Nonetheless, after study, naturalist George Ord formally classified it in 1815 – not for its hair. Classification has been revised along genetic lines, there are two morphological forms of Ursus arctos, the grizzly and the coastal brown bears, but these morphological forms do not have distinct mtDNA lineages. Brown bears originated in Eurasia and traveled to North America approximately 50,000 years ago, in the 19th century, the grizzly was classified as 86 distinct species. However, by 1928 only seven grizzlies remained and by 1953 only one species remained globally, however, modern genetic testing reveals the grizzly to be a subspecies of the brown bear. Rausch found that North America has but one species of grizzly, therefore, everywhere it is the brown bear, in North America, it is the grizzly, but these are all the same species, Ursus arctos. Kodiak grizzly bears were also at one time considered distinct, therefore, at one time there were five different species of brown bear, including three in North America. Most adult female grizzlies weigh 130–180 kg, while males weigh on average 180–360 kg. Average total length in this subspecies is 198 cm, with a shoulder height of 102 cm. Newborn bears may weigh less than 500 grams, in the Yukon River area, mature female grizzlies can weigh as little as 100 kg. One study found that the weight for an inland male grizzly was around 272 kilograms. For a female, these average weights would be 136 kilograms inland and 227 kilograms coastal, on the other hand, an occasional huge male grizzly has been recorded which greatly exceeds ordinary size, with weights reported up to 680 kg. A large coastal male of this size may stand up to 3 metres tall on its hind legs, although variable in color from blond to nearly black, grizzly bear fur is typically brown with darker legs and commonly white or blond tipped fur on the flank and back. A pronounced hump appears on their shoulders, the hump is a way to distinguish a grizzly bear from a black bear. Aside from the distinguishing hump a grizzly bear can be identified by a dished in profile of their face with short, rounded ears, whereas a black bear has a straight face profile and longer ears. A grizzly bear can also be identified by its rump, which is lower than its shoulders, a grizzly bears front claws measure about 2-4 inches in length and a black bears measure about 1-2 inches in length
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Hibernation
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Hibernation is a state of inactivity and metabolic depression in endotherms. Hibernation refers to a season of heterothermy that is characterized by low temperature, slow breathing and heart rate. Many experts believe that the processes of daily torpor and hibernation form a continuum, the equivalent during the summer months is known as aestivation. Some reptile species are said to brumate, or undergo brumation, some insects, such as the wasp Polistes exclamans, hibernate by aggregating together in groups in protected places called hibernacula. Often associated with low temperatures, the function of hibernation is to conserve energy during a period when sufficient food is unavailable, to achieve this energy saving, an endotherm will first decrease its metabolic rate, which then decreases body temperature. Hibernation may last several days, weeks, or months depending on the species, ambient temperature, time of year, before entering hibernation, animals need to store enough energy to last through the entire winter. Larger species become hyperphagic and eat a large amount of food, in many small species, food caching replaces eating and becoming fat. Some species of mammals hibernate while gestating young, which are born while the mother hibernates or shortly afterwards. For example, the polar bear goes into hibernation during the cold winter months to give birth to her offspring. She loses 15–27% of her weight and uses stored fats for energy during times of food scarcity. It is evident that pregnant female polar bears significantly increase body mass prior to hibernation, the fat accumulation prior to hibernation in female polar bears enables them to provide a sufficient and warm, nurturing environment for their newborns. Malagasy winter temperatures sometimes rise to over 30 °C, so hibernation is not exclusively an adaptation to low ambient temperatures, dausmann found that hypometabolism in hibernating animals is not necessarily coupled to a low body temperature. Hibernating bears are able to recycle their proteins and urine, allowing both to stop urinating for months and to avoid muscle atrophy. Obligate hibernators are animals that spontaneously, and annually, enter hibernation regardless of ambient temperature and these undergo what has been traditionally called hibernation, the physiological state where the body temperature drops to near ambient temperature, and heart and respiration rates slow drastically. The cause and purpose of these arousals is still not clear, the question of why hibernators may experience the periodic arousals has plagued researchers for decades, and while there is still no clear-cut explanation, there are myriad hypotheses on the topic. One favored hypothesis is that hibernators build a sleep debt during hibernation and this has been supported by evidence in the Arctic ground squirrel. Another theory states that the periods of high body temperature during hibernation are used by the animal to restore its available energy sources. Yet another theory states that the frequent returns to high body temperature allow mammals to initiate an immune response, historically there was a question of whether or not bears truly hibernate, since they experience only a modest decline in body temperature compared with what other hibernators undergo
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Scavenger
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Scavenging or Saprophagy is both a carnivorous and a herbivorous feeding behavior in which the scavenger feeds on dead animal and plant material present in its habitat. The eating of carrion from the species is referred to as cannibalism. Scavengers play an important role in the ecosystem by consuming the dead animal, decomposers and detritivores complete this process, by consuming the remains left by scavengers. Obligate scavenging is very rare in the kingdom, due to the difficulty of finding enough carrion without expending too much energy. In vertebrates, only vultures and possibly some pterosaurs are obligate scavengers, well-known invertebrate scavengers of animal material include burying beetles and blowflies, which are obligate scavengers, and yellowjackets. Most scavenging animals are facultative scavengers that gain most of their food through other methods, especially predation. Many large carnivores that hunt regularly, such as hyenas, but also animals rarely thought of as scavengers, such as African lions, leopards, jackals and they may also use their size and ferocity to intimidate the original hunters. Scavenger wild dogs and crows frequently exploit roadkill, scavengers of dead plant material include termites that build nests in grasslands and then collect dead plant material for consumption within the nest. The interaction between scavenging animals and humans is today most commonly in suburban settings with animals such as opossums, polecats. In some African towns and villages, scavenging from hyenas is also common, animals which consume feces, such as dung beetles, are referred to as coprovores. Animals that collect particles of dead organic material of both animal and plant origin are referred to as detritivores. In humans, necrophagy is taboo in most societies, many instances have occurred in history, especially in war times, where necrophagy was a survival behavior. In the 1950s, Louis Binford suggested that humans were obtaining meat via scavenging. In 2010, Dennis Bramble and Daniel Lieberman however proposed that humans used long-distance running to hunt, pursuing a single animal until it died of exhaustion. Such behavior has been suggested as an adaptation to ensure a supply that in turn made large brains possible. The eating of meat, a practice known as anthropophagy, is extremely taboo in almost every culture. Scavenger appears as an occupation in the 1911 Census of England and this job title was used to describe someone who cleans the streets and removes refuse, generally a workman employed by the local public health authority. Young people in developing countries revert to scavenging to develop skills in order to operate in hostile economic contexts
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American black bear
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The American black bear is a medium-sized bear native to North America. It is the continents smallest and most widely distributed bear species, Black bears are omnivores, with their diets varying greatly depending on season and location. They typically live in forested areas, but do leave forests in search of food. Sometimes they become attracted to human communities because of the availability of food. The American black bear is the worlds most common bear species, along with the brown bear, it is one of only two of the eight modern bear species not considered globally threatened with extinction by the IUCN. American black bears often mark trees using their teeth and claws as a form of communication with other bears, a behavior common to many species of bears. Despite living in North America, American black bears are not closely related to bears and polar bears. American and Asian black bears are considered sister taxa, and are closely related to each other than to other species of bear. Reportedly, the sun bear is also a recent split from this lineage. A small primitive bear called Ursus abstrusus is the oldest known North American fossil member of the genus Ursus and this suggests that U. abstrusus may be the direct ancestor of the American black bear, which evolved in North America. Although Wolverton and Lyman still consider U. vitabilis an apparent precursor to modern black bears, the ancestors of American black bears and Asiatic black bears diverged from sun bears 4.58 mya. The American black bear then split from the Asian black bear 4.08 mya, the earliest American black bear fossils, which were located in Port Kennedy, Pennsylvania, greatly resemble the Asiatic species, though later specimens grew to sizes comparable to grizzlies. From the Holocene to present, American black bears seem to have shrunk in size, the American black bear lived during the same period as short-faced bears and the Florida spectacled bear. These Tremarctine bears evolved from bears that had emigrated from Asia to North America 7–8 ma, however, both Arctodus and Tremarctos had survived several other ice ages. American black bears are reproductively compatible with several other bear species, according to Jack Hannas Monkeys on the Interstate, a bear captured in Sanford, Florida, was thought to have been the offspring of an escaped female Asian black bear and a male American black bear. In 1859, a bear and a Eurasian brown bear were bred together in the London Zoological Gardens. In the reports published since this date three species have produced young, a black bear shot in autumn 1986 in Michigan was thought by some to be a black bear/grizzly bear hybrid, due to its unusually large size and its proportionately larger braincase and skull. DNA testing was unable to determine whether it was a black bear or grizzly
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Human
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Modern humans are the only extant members of Hominina tribe, a branch of the tribe Hominini belonging to the family of great apes. Several of these hominins used fire, occupied much of Eurasia and they began to exhibit evidence of behavioral modernity around 50,000 years ago. In several waves of migration, anatomically modern humans ventured out of Africa, the spread of humans and their large and increasing population has had a profound impact on large areas of the environment and millions of native species worldwide. Humans are uniquely adept at utilizing systems of communication for self-expression and the exchange of ideas. Humans create complex structures composed of many cooperating and competing groups, from families. Social interactions between humans have established a wide variety of values, social norms, and rituals. These human societies subsequently expanded in size, establishing various forms of government, religion, today the global human population is estimated by the United Nations to be near 7.5 billion. In common usage, the word generally refers to the only extant species of the genus Homo—anatomically and behaviorally modern Homo sapiens. In scientific terms, the meanings of hominid and hominin have changed during the recent decades with advances in the discovery, there is also a distinction between anatomically modern humans and Archaic Homo sapiens, the earliest fossil members of the species. The English adjective human is a Middle English loanword from Old French humain, ultimately from Latin hūmānus, the words use as a noun dates to the 16th century. The native English term man can refer to the species generally, the species binomial Homo sapiens was coined by Carl Linnaeus in his 18th century work Systema Naturae. The generic name Homo is a learned 18th century derivation from Latin homō man, the species-name sapiens means wise or sapient. Note that the Latin word homo refers to humans of either gender, the genus Homo evolved and diverged from other hominins in Africa, after the human clade split from the chimpanzee lineage of the hominids branch of the primates. The closest living relatives of humans are chimpanzees and gorillas, with the sequencing of both the human and chimpanzee genome, current estimates of similarity between human and chimpanzee DNA sequences range between 95% and 99%. The gibbons and orangutans were the first groups to split from the leading to the humans. The splitting date between human and chimpanzee lineages is placed around 4–8 million years ago during the late Miocene epoch, during this split, chromosome 2 was formed from two other chromosomes, leaving humans with only 23 pairs of chromosomes, compared to 24 for the other apes. There is little evidence for the divergence of the gorilla, chimpanzee. Each of these species has been argued to be an ancestor of later hominins
43.
Recreation
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Recreation is an activity of leisure, leisure being discretionary time. The need to do something for recreation is an element of human biology and psychology. Recreational activities are often done for enjoyment, amusement, or pleasure and are considered to be fun. The term recreation appears to have used in English first in the late 14th century, first in the sense of refreshment or curing of a sick person. Other factors that account for a role of recreation are affluence, population trends. This direction of thought has even extended to the view that leisure is the purpose of work, and a reward in itself. Leisure is considered a right under the Universal Declaration of Human Rights. Recreation is difficult to separate from the concept of play. Children may playfully imitate activities that reflect the realities of adult life, a traditional view holds that work is supported by recreation, recreation being useful to recharge the battery so that work performance is improved. Many activities may be work for one person and recreation for another, or, at a level, over time recreational activity may become work. Thus, for a musician, playing an instrument may be at one time a profession, similarly, it may be difficult to separate education from recreation as in the case of recreational mathematics. Recreation is an part of human life and finds many different forms which are shaped naturally by individual interests. Recreational activities can be communal or solitary, active or passive, outdoors or indoors, healthy or harmful, a significant section of recreational activities are designated as hobbies which are activities done for pleasure on a regular basis. Some recreational activities - such as gambling, recreational use, or delinquent activities - may violate societal norms. Public space such as parks and beaches are venues for many recreational activities. Tourism has recognized that many visitors are attracted by recreational offerings. In support of recreational activities government has taken an important role in their creation, maintenance, and organization, many recreational activities are organized, typically by public institutions, voluntary group-work agencies, private groups supported by membership fees, and commercial enterprises. Examples of each of these are the National Park Service, the YMCA, the Kiwanis, Recreation has many health benefits, and, accordingly, Therapeutic Recreation has been developed to take advantage of this effect
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Burundi
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It is also considered part of Central Africa. The southwestern border is adjacent to Lake Tanganyika, the Twa, Hutu and Tutsi peoples have lived in Burundi for at least 500 years. For more than 200 of those years, Burundi was an independent kingdom, until the beginning of the twentieth century, after the First World War and Germanys defeat, it ceded the territory to Belgium. Both Germans and Belgians ruled Burundi and Rwanda as a European colony known as Ruanda-Urundi, despite common misconceptions, Burundi and Rwanda had never been under common rule until the time of European colonisation. The European intervention exacerbated social differences between the Tutsi and Hutu, and contributed to political unrest in the region. Bouts of ethnic cleansing and ultimately two civil wars and genocides during the 1970s and again in the 1990s left the country undeveloped, Burundis political system is that of a presidential representative democratic republic based upon a multi-party state. The President of Burundi is the head of state and head of government, there are currently 21 registered parties in Burundi. On 13 March 1992, Tutsi coup leader Pierre Buyoya established a constitution, six years later, on 6 June 1998, the constitution was changed, broadening National Assemblys seats and making provisions for two vice-presidents. Because of the Arusha Accord, Burundi enacted a government in 2000. In October 2016, Burundi informed the UN of its intention to withdraw from the International Criminal Court, Burundi remains an overwhelmingly rural society, with just 13% of the population living in urban areas in 2013. The population density of around 315 people per kilometre is the second highest in Sub-Saharan Africa. Roughly 85% of the population are of Hutu ethnic origin, 15% are Tutsi, the official languages of Burundi are French and Kirundi, although Swahili can be found spoken along the Tanzanian border. One of the smallest countries in Africa, Burundi has an equatorial climate, Burundi is a part of the Albertine Rift, the western extension of the East African Rift. The country lies on a plateau in the centre of Africa. The highest peak, Mount Heha at 2,685 m, lies to the southeast of the capital, there are two national parks, Kibira National Park to the northwest, Ruvubu National Park to the northeast. Both were established in 1982 to conserve wildlife populations, Burundis lands are mostly agricultural or pasture. Settlement by rural populations has led to deforestation, soil erosion, deforestation of the entire country is almost completely due to overpopulation, with a mere 600 km2 remaining and an ongoing loss of about 9% per annum. In addition to poverty, Burundians often have to deal with corruption, weak infrastructure, poor access to health and education services, Burundi is densely populated and has had substantial emigration as young people seek opportunities elsewhere
45.
Iceland
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Iceland is a Nordic island country in the North Atlantic Ocean. It has a population of 332,529 and an area of 103,000 km2, the capital and largest city is Reykjavík. Reykjavík and the areas in the southwest of the country are home to over two-thirds of the population. Iceland is volcanically and geologically active, the interior consists of a plateau characterised by sand and lava fields, mountains and glaciers, while many glacial rivers flow to the sea through the lowlands. Iceland is warmed by the Gulf Stream and has a climate, despite a high latitude just outside the Arctic Circle. Its high latitude and marine influence still keeps summers chilly, with most of the archipelago having a tundra climate. According to the ancient manuscript Landnámabók, the settlement of Iceland began in the year 874 AD when the Norwegian chieftain Ingólfr Arnarson became the first permanent settler on the island. In the following centuries, Norwegians, and to a lesser extent other Scandinavians, emigrated to Iceland, the island was governed as an independent commonwealth under the Althing, one of the worlds oldest functioning legislative assemblies. Following a period of strife, Iceland acceded to Norwegian rule in the 13th century. The establishment of the Kalmar Union in 1397 united the kingdoms of Norway, Denmark, Iceland thus followed Norways integration to that Union and came under Danish rule after Swedens secession from that union in 1523. In the wake of the French revolution and the Napoleonic wars, Icelands struggle for independence took form and culminated in independence in 1918, until the 20th century, Iceland relied largely on subsistence fishing and agriculture, and was among the poorest in Europe. Industrialisation of the fisheries and Marshall Plan aid following World War II brought prosperity, in 1994, it became a part of the European Economic Area, which further diversified the economy into sectors such as finance, biotechnology, and manufacturing. Iceland has an economy with relatively low taxes compared to other OECD countries. It maintains a Nordic social welfare system that provides health care. Iceland ranks high in economic, political and social stability and equality, in 2013, it was ranked as the 13th most-developed country in the world by the United Nations Human Development Index. Iceland runs almost completely on renewable energy, some bankers were jailed, and the economy has made a significant recovery, in large part due to a surge in tourism. Icelandic culture is founded upon the nations Scandinavian heritage, most Icelanders are descendants of Germanic and Gaelic settlers. Icelandic, a North Germanic language, is descended from Old Norse and is related to Faroese
46.
Anchovy
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An anchovy is a small, common salt-water forage fish of the family Engraulidae. The 144 species are placed in 17 genera, they are found in the Atlantic, Indian, and Pacific Oceans, and in the Black Sea, Anchovies are usually classified as oily fish. Anchovies are small, green fish with blue reflections due to a longitudinal stripe that runs from the base of the caudal fin. They range from 2 to 40 cm in length. The snout is blunt with tiny, sharp teeth in both jaws, the snout contains a unique rostral organ, believed to be sensory in nature, although its exact function is unknown. The mouth is larger than that of herrings and silversides, two fish which anchovies closely resemble in other respects, the anchovy eats plankton and recently hatched fish. Anchovies are found in scattered areas throughout the oceans, but are concentrated in temperate waters. They are generally accepting of a wide range of temperatures. Large schools can be found in shallow, brackish areas with muddy bottoms, as in estuaries and they are abundant in the Mediterranean, particularly in the Alboran Sea, Aegean Sea and the Black Sea. The species is caught along the coasts of Crete, Greece, Sicily, Italy, France, Turkey. They are also found on the coast of northern Africa, the range of the species also extends along the Atlantic coast of Europe to the south of Norway. Spawning occurs between October and March, but not in water colder than 12 °C, the anchovy appears to spawn at least 100 km from the shore, near the surface of the water. The anchovy is a significant food source for almost every predatory fish in its environment, including the California halibut, rock fish, yellowtail, shark, chinook, and coho salmon. It is also important to marine mammals and birds, for example, breeding success of California brown pelicans. Anchovies, like most clupeoids, are filter-feeders that open their mouths as they swim, as water passes through the mouth and out the gills, food particles are sieved by gill rakers and transferred into the esophagus. * Type species On average, the Turkish commercial fishing fleet catches around 300,000 tons per year, the largest catch is in November and December. The Peruvian anchovy fishery is one of the largest in the world, in 1973 it collapsed catastrophically due to the combined effects of overfishing and El Niño and did not recover fully for two decades. A traditional method of processing and preserving anchovies is to gut and salt them in brine, allow them to mature and this results in a characteristic strong flavor and the flesh turns deep grey
47.
Pig
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A pig is any of the animals in the genus Sus, within the Suidae family of even-toed ungulates. Pigs include the domestic pig and its ancestor, the common Eurasian wild boar, along with species, related creatures outside the genus include the peccary, the babirusa. Pigs, like all suids, are native to the Eurasian and African continents, juvenile pigs are known as piglets. Pigs are highly social and intelligent animals, with around 1 billion individuals alive at any time, the domesticated pig is one of the most numerous large mammals on the planet. Pigs are omnivores and can consume a range of food. Pigs can harbour a range of parasites and diseases that can be transmitted to humans, because of the similarities between pigs and humans, pigs are used for human medical research. The Online Etymology Dictionary provides anecdotal evidence as well as linguistic, saying that the term derives probably from Old English *picg, found in compounds, apparently related to Low German bigge, Dutch big. Another Old English word for pig was fearh, related to furh furrow, from PIE *perk- dig and this reflects a widespread IE tendency to name animals from typical attributes or activities. Synonyms grunter, porker are from sailors and fishermens euphemistic avoidance of uttering the word pig at sea, a superstition perhaps based on the fate of the Gadarene swine and it is entirely likely that the word to call pigs, soo-ie, is similarly derived. A typical pig has a head with a long snout which is strengthened by a special prenasal bone. The snout is used to dig into the soil to find food and is an acute sense organ. There are four hoofed toes on each trotter, with the two larger central toes bearing most of the weight, but the two also being used in soft ground. The dental formula of adult pigs is 3.1.4.33.1.4.3, the rear teeth are adapted for crushing. In the male, the teeth form tusks, which grow continuously and are sharpened by constantly being ground against each other. Occasionally, captive mother pigs may savage their own piglets, often if they become severely stressed, some attacks on newborn piglets are non-fatal. Others may cause the death of the piglets and sometimes, the mother may eat the piglets and it is estimated that 50% of piglet fatalities are due to the mother attacking, or unintentionally crushing, the newborn pre-weaned animals. Scientists have recently discovered that pigs can exhibit a bias and are optimists or pessimests. In a study by the University of Lincoln,36 pigs were tested and they were placed in a room with two food bowls at each end of the room
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