title: Construction content: and "impure" or "strategic" alliances. The focus on co-operation is to ameliorate the many problems that arise from the often highly competitive and adversarial practices within the construction industry. This is the most common method of construction procurement and is well established and recognized. In this arrangement, the architect or engineer acts as the project coordinator. His or her role is to design the works, prepare the specifications and produce construction drawings, administer the contract, tender the works, and manage the works from inception to completion. There are direct contractual links between the architect's client and the main contractor. Any


title: Construction content: subcontractor has a direct contractual relationship with the main contractor. The procedure continues until the building is ready to occupy. This approach has become more common in recent years, and also involves the client contracting a single entity that both provides a design and builds it. In some cases, the design-build package can also include finding the site, arranging funding and applying for all necessary statutory consents. The owner produces a list of requirements for a project, giving an overall view of the project's goals. Several D&B contractors present different ideas about how to accomplish these goals. The owner selects


title: Construction content: the ideas they like best and hires the appropriate contractor. Often, it is not just one contractor, but a consortium of several contractors working together. Once these have been hired, they begin building the first phase of the project. As they build phase 1, they design phase 2. This is in contrast to a design-bid-build contract, where the project is completely designed by the owner, then bid on, then completed. Kent Hansen pointed out that state departments of transportation usually use design build contracts as a way of progressing projects when states lack the skills-resources. In such departments, design build


title: Construction content: contracts are usually employed for very large projects. In this arrangement the client plays an active role in the procurement system by entering into separate contracts with the designer (architect or engineer), the construction manager, and individual trade contractors. The client takes on the contractual role, while the construction or project manager provides the active role of managing the separate trade contracts, and ensuring that they complete all work smoothly and effectively together. Management procurement systems are often used to speed up the procurement processes, allow the client greater flexibility in design variation throughout the contract, give the ability to


title: Construction content: appoint individual work contractors, separate contractual responsibility on each individual throughout the contract, and to provide greater client control. In recent time, construction software starts to get traction—as it digitizes construction industry. Among solutions, there are for example: Procore, GenieBelt, PlanGrid, bouw7, etc. Sustainability during the construction phase is one of the aspects of “green building," defined by the United States Environmental Protection Agency (EPA) as "the practice of creating structures and using processes that are environmentally responsible and resource-efficient throughout a building's life-cycle from siting to design, construction, operation, maintenance, renovation and deconstruction." In construction, the authority having jurisdiction


title: Construction content: (AHJ) is the governmental agency or sub-agency that regulates the construction process. In most cases, this is the municipality where the building is located. However, construction performed for supra-municipal authorities are usually regulated directly by the owning authority, which becomes the AHJ. Before the foundation can be dug, contractors are typically required to verify and have existing utility lines marked, either by the utilities themselves or through a company specializing in such services. This lessens the likelihood of damage to the existing electrical, water, sewage, phone, and cable facilities, which could cause outages and potentially hazardous situations. During the construction


title: Construction content: of a building, the municipal building inspector inspects the building periodically to ensure that the construction adheres to the approved plans and the local building code. Once construction is complete and a final inspection has been passed, an occupancy permit may be issued. An operating building must remain in compliance with the fire code. The fire code is enforced by the local fire department or a municipal code enforcement office. Changes made to a building that affect safety, including its use, expansion, structural integrity, and fire protection items, usually require approval of the AHJ for review concerning the building code.


title: Construction content: In the United States, the industry in 2014 has around $960 billion in annual revenue according to statistics tracked by the Census Bureau, of which $680 billion is private (split evenly between residential and nonresidential) and the remainder is government. In 2005, there were about 667,000 firms employing 1 million contractors (200,000 general contractors, 38,000 heavy, and 432,000 specialty); the average contractor employed fewer than 10 employees. As a whole, the industry employed an estimated 5.8 million in April 2013, with a 13.2% unemployment rate. In the United States, approximately 828,000 women were employed in the construction industry as of


title: Construction content: 2011. There are many routes to the different careers within the construction industry. These three main tiers are based on educational background and training, which vary by country: Skilled occupations include carpenters, electricians, plumbers, ironworkers, masons, and many other manual crafts, as well as those involved in project management. In the UK these require further education qualifications, often in vocational subject areas. These qualifications are either obtained directly after the completion of compulsory education or through "on the job" apprenticeship training. In the UK, 8500 construction-related apprenticeships were commenced in 2007. Technical and specialized occupations require more training as a


title: Construction content: greater technical knowledge is required. These professions also hold more legal responsibility. A short list of the main careers with an outline of the educational requirements are given below: In 2010 a salary survey revealed the differences in remuneration between different roles, sectors and locations in the construction and built environment industry. The results showed that areas of particularly strong growth in the construction industry, such as the Middle East, yield higher average salaries than in the UK, for example. The average earning for a professional in the construction industry in the Middle East, across all sectors, job types and


title: Construction content: levels of experience, is £42,090, compared to £26,719 in the UK. This trend is not necessarily due to the fact that more affluent roles are available; however, as architects with 14 or more years' experience working in the Middle East earn on average £43,389 per annum, compared to £40,000 in the UK. Some construction workers in the US/Canada have made more than $100,000 annually, depending on their trade. Construction is one of the most dangerous occupations in the world, incurring more occupational fatalities than any other sector in both the United States and in the European Union. In 2009, the


title: Construction content: fatal occupational injury rate among construction workers in the United States was nearly three times that for all workers, with Falls being one of the most common causes of fatal and non-fatal injuries among construction workers. Proper safety equipment such as harnesses, hard hats and guardrails and procedures such as securing ladders and inspecting scaffolding can curtail the risk of occupational injuries in the construction industry. Other major causes of fatalities in the construction industry include electrocution, transportation accidents, and trench cave-ins. Other safety risks for workers in construction include hearing loss due to high noise exposure, musculoskeletal injury, chemical


title: Construction content: exposure, and high levels of stress. Construction has been identified by the National Institute for Occupational Safety and Health (NIOSH) as a priority industry sector in the National Occupational Research Agenda (NORA) to identify and provide intervention strategies regarding occupational health and safety issues. The first huts and shelters were constructed by hand or with simple tools. As cities grew during the Bronze Age, a class of professional craftsmen, like bricklayers and carpenters, appeared. Occasionally, slaves were used for construction work. In the Middle Ages, the artisan craftsmen were organized into guilds. In the 19th century, steam-powered machinery appeared, and,


title: Construction content: later, diesel- and electric-powered vehicles such as cranes, excavators and bulldozers. Fast-track construction has been increasingly popular in the 21st century. Some estimates suggest that 40% of construction projects are now fast-track construction. Construction Construction is the process of constructing a building or infrastructure. Construction differs from manufacturing in that manufacturing typically involves mass production of similar items without a designated purchaser, while construction typically takes place on location for a known client. Construction as an industry comprises six to nine percent of the gross domestic product of developed countries. Construction starts with planning, design, and financing; it continues until


title: BitTorrent content: a system through the distributed hash table (DHT) method. An alternative and incompatible DHT system, known as Mainline DHT, was released in the Mainline BitTorrent client three weeks later (though it had been in development since 2002) and subsequently adopted by the µTorrent, Transmission, rTorrent, KTorrent, BitComet, and Deluge clients. After the DHT was adopted, a "private" flag – analogous to the broadcast flag – was unofficially introduced, telling clients to restrict the use of decentralized tracking regardless of the user's desires. The flag is intentionally placed in the info section of the torrent so that it cannot be disabled


title: "Field of the Cloth of Gold" content: lords, ladies and gentlemen to attend the King and Queen at the interview with Francis I". The latter source lists the following: "For the King: The cardinal of York, with 300 servants, of whom 12 shall be chaplains and 50 gentlemen, with 50 horses; one archbishop with 70 servants, of whom 5 shall be chaplains and 10 gentlemen, with 30 horses; 2 dukes, each with 70 servants, 5 to be chaplains and 10 gentlemen, with 30 horses. 1 marquis with 56 servants, 4 to be chaplains and 8 gentlemen; 26 horses. 10 earls, each with 42 servants, 3 to be


title: Jordanhill content: school. The school is unique in the Scottish state sector in that it contains both Primary and Secondary departments, providing education for children from 4 to 18, and in that it has Grant Maintained status and is independent from local government control. It had previously been an independent demonstration school for Jordanhill College. Private school the High School of Glasgow is also located in the Jordanhill vicinity. Saint Thomas Aquinas Secondary School is a Catholic secondary school located on Mitre Road in the newer part of Jordanhill. It has several feeder primary schools, including Corpus Christi (Knightswood), Notre Dame (Dowanhill),


title: "Serbian Empire" content: the top and bottom and white in the center. Emperor Dušan also adopted the Imperial "divelion", which was purple and had a golden cross in the center. Another of Dušan's flags was the Imperial cavalry flag, kept at the Hilandar monastery on Mount Athos; a triangular bicolored flag, of red and yellow. Education, to which St. Sava had given the first impulse, progressed remarkably during Dušan's reign. Schools and monasteries secured royal favor. True seats of culture, they became institutions in perpetuating Serbian national traditions. The fine arts, influenced by Italians, were not neglected. Fragments of frescoes and mosaics testify


title: "Battle of the Spurs" content: On 15 September the wives and children of the townspeople were ordered to repair damage to the walls caused by the besieger's cannon. On the same day the town council proposed a vote whether the town should declare for France or the Empire. The vote was suspended ("mis en surseance") and the people appointed deputies to treat with Henry VIII. Charles Brandon captured one of the gatehouses and took away two of its statues as trophies, and the garrison negotiated with Henry and Richard Foxe Bishop of Winchester on the 20 September 1513. The events within the town were misunderstood


title: "Common tern" content: Common tern The common tern ("Sterna hirundo") is a seabird in the family Laridae. This bird has a circumpolar distribution, its four subspecies breeding in temperate and subarctic regions of Europe, Asia and North America. It is strongly migratory, wintering in coastal tropical and subtropical regions. Breeding adults have light grey upperparts, white to very light grey underparts, a black cap, orange-red legs, and a narrow pointed bill. Depending on the subspecies, the bill may be mostly red with a black tip or all black. There are a number of similar species, including the partly sympatric Arctic tern, which can


title: "Common tern" content: be separated on plumage details, leg and bill colour, or vocalisations. Breeding in a wider range of habitats than any of its relatives, the common tern nests on any flat, poorly vegetated surface close to water, including beaches and islands, and it readily adapts to artificial substrates such as floating rafts. The nest may be a bare scrape in sand or gravel, but it is often lined or edged with whatever debris is available. Up to three eggs may be laid, their dull colours and blotchy patterns providing camouflage on the open beach. Incubation is by both sexes, and the


title: "Common tern" content: eggs hatch in around 21–22 days, longer if the colony is disturbed by predators. The downy chicks fledge in 22–28 days. Like most terns, this species feeds by plunge-diving for fish, either in the sea or in freshwater, but molluscs, crustaceans and other invertebrate prey may form a significant part of the diet in some areas. Eggs and young are vulnerable to predation by mammals such as rats and American mink, and large birds including gulls, owls and herons. Common terns may be infected by lice, parasitic worms, and mites, although blood parasites appear to be rare. Its large population


title: "Common tern" content: and huge breeding range mean that this species is classed as being of least concern, although numbers in North America have declined sharply in recent decades. Despite international legislation protecting the common tern, in some areas populations are threatened by habitat loss, pollution or the disturbance of breeding colonies. The terns are small to medium-sized seabirds closely related to the gulls, skimmers and skuas. They are gull-like in appearance, but typically have a lighter build, long pointed wings (which give them a fast, buoyant flight), a deeply forked tail, slender legs, and webbed feet. Most species are grey above and


title: "Common tern" content: white below, and have a black cap which is reduced or flecked with white in the non-breeding season. The common tern's closest relatives appear to be the Antarctic tern, followed by the Eurasian Arctic and roseate terns. Genetic evidence suggests that the common tern may have diverged from an ancestral stock earlier than its relatives. No fossils are known from North America, and those claimed in Europe are of uncertain age and species. The common tern was first described by Linnaeus in his "Systema Naturae" in 1758 under its current scientific name, "Sterna hirundo". The word "stearn" was used in


title: "Common tern" content: Old English and a similar word was used by the Frisians for tern. "Stearn" appears in the poem "The Seafarer", written around 1000 AD. Linnaeus adopted this word for the genus name "Sterna". The Latin for swallow is "hirundo" and refers here to the tern's superficial likeness to that unrelated bird, which has a similar light build and long forked tail. This resemblance also leads to the informal name "sea swallow", recorded from at least the seventeenth century. The Scots names "picktarnie", "tarrock" and their many variants are also believed to be onomatopoeic, derived from the distinctive call. Due to


title: "Common tern" content: the difficulty in distinguishing the two species, all the informal common names are shared with the Arctic tern. Four subspecies of the common tern are generally recognized, although "S. h. minussensis" is sometimes considered to be an intergrade between "S. h. hirundo" and "S. h. longipennis". The nominate subspecies of the common tern is long, including a fork in the tail, with a wingspan. It weighs . Breeding adults have pale grey upperparts, very pale grey underparts, a black cap, orange-red legs, and a narrow pointed bill that can be mostly red with a black tip, or all black, depending


title: "Common tern" content: on the subspecies. The common tern's upperwings are pale grey, but as the summer wears on, the dark feather shafts of the outer flight feathers become exposed, and a grey wedge appears on the wings. The rump and tail are white, and on a standing bird the long tail extends no further than the folded wingtips, unlike the Arctic and roseate terns in which the tail protrudes beyond the wings. There are no significant differences between the sexes. In non-breeding adults the forehead and underparts become white, the bill is all black or black with a red base, and the


title: "Common tern" content: legs are dark red or black. The upperwings have an obvious dark area at the front edge of the wing, the carpal bar. Terns that have not bred successfully may start moulting into non-breeding adult plumage from June, but late July is more typical, with the moult suspended during migration. There is also some geographical variation, Californian birds often being in non-breeding plumage during migration. Juvenile common terns have pale grey upperwings with a dark carpal bar. The crown and nape are brown, and the forehead is ginger, wearing to white by autumn. The upperparts are ginger with brown and


title: "Common tern" content: white scaling, and the tail lacks the adult's long outer feathers. Birds in their first post-juvenile plumage, which normally remain in their wintering areas, resemble the non-breeding adult, but have a duskier crown, dark carpal bar, and often very worn plumage. By their second year, most young terns are either indistinguishable from adults, or show only minor differences such as a darker bill or white forehead. The common tern is an agile flyer, capable of rapid turns and swoops, hovering, and vertical take-off. When commuting with fish, it flies close to the surface in a strong head wind, but above


title: "Common tern" content: the water in a following wind. Unless migrating, normally it stays below , and averages in the absence of a tail wind. Its average flight speed during the nocturnal migration flight is at a height of . The juvenile starts moulting into adult plumage in its first October; the head, tail and body plumage is replaced first, mostly by February, then the wing feathers. The primaries are replaced in stages; the innermost feathers moult first, then replacement is suspended during the southern winter (birds of this age staying in their wintering areas) and recommences in the autumn. In May to


title: "Common tern" content: June of the second year a similar moult sequence starts, with a pause during primary moult for birds that return north, but not for those that stay in the winter quarters. A major moult to adult breeding plumage occurs in the next February to June, between 40–90% of feathers being replaced. Old primary feathers wear away to reveal the blackish barbs beneath. The moult pattern means that the oldest feathers are those nearest the middle of the wing, so as the northern summer progresses, a dark wedge appears on the wing due to this feather ageing process. Terns are unusual


title: "Common tern" content: in the frequency in which they moult their primaries, which are replaced at least twice, occasionally three times in a year. The visible difference in feather age is accentuated in the greater ultraviolet reflectance of new primaries, and the freshness of the wing feathers is used by females in mate selection. Experienced females tend to accept mates which best show their fitness through the quality of their wing feathers. Rarely, a very early moult at the nesting colony may be linked to breeding failure, both the onset of moult and reproductive behaviour being linked to falling levels of the hormone


title: "Common tern" content: prolactin. There are several terns of a similar size and general appearance to the common tern. A traditionally difficult species to separate is the Arctic tern, and until the key characteristics were clarified, distant or flying birds of the two species were often jointly recorded as "commic terns". Although similar in size, the two terns differ in structure and flight. The common tern has a larger head, thicker neck, longer legs, and more triangular and stiffer wings than its relative, and has a more powerful, direct flight. The Arctic tern has greyer underparts than the common, which make its white


title: "Common tern" content: cheeks more obvious, whereas the rump of the common tern can be greyish in non-breeding plumage, compared to the white of its relative. The common tern develops a dark wedge on the wings as the breeding season progresses, but the wings of Arctic stay white throughout the northern summer. All the flight feathers of the Arctic tern are translucent against a bright sky, only the four innermost wing feathers of the common tern share this property. The trailing edge of the outer flight feathers is a thin black line in the Arctic tern, but thicker and less defined in the


title: "Common tern" content: common. The bill of an adult common tern is orange-red with a black tip, except in black-billed "S. h. longipennis", and its legs are bright red, while both features are a darker red colour in the Arctic tern, which also lacks the black bill tip. In the breeding areas, the roseate tern can be distinguished by its pale plumage, long, mainly black bill and very long tail feathers. The non-breeding plumage of roseate is pale above and white, sometimes pink-tinged, below. It retains the long tail streamers, and has a black bill. In flight, the roseate's heavier head and neck,


title: "Common tern" content: long bill and faster, stiffer wingbeats are also characteristic. It feeds further out to sea than the common tern. In North America, the Forster's tern in breeding plumage is obviously larger than the common, with relatively short wings, a heavy head and thick bill, and long, strong legs; in all non-breeding plumages, its white head and dark eye patch make the American species unmistakable. In the wintering regions, there are also confusion species, including the Antarctic tern of the southern oceans, the South American tern, the Australasian white-fronted tern and the white-cheeked tern of the Indian Ocean. Identification may be


title: "Common tern" content: aided by the plumage differences due to "opposite" breeding seasons. The Antarctic tern is more sturdy than the common, with a heavier bill. In breeding condition, its dusky underparts and full black cap outline a white cheek stripe. In non-breeding plumages, it lacks, or has only an indistinct, carpal bar, and young birds show dark bars on the tertials, obvious on the closed wing and in flight. The South American tern is larger than the common, with a larger, more curved red bill, and has a smoother, more extensive black cap in non-breeding plumage. Like Antarctic, it lacks a strong


title: "Common tern" content: carpal bar in non-breeding plumages, and it also shares the distinctive barring of the tertials in young birds. The white-fronted tern has a white forehead in breeding plumage, a heavier bill, and in non-breeding plumage is paler below than the common, with white underwings. The white-cheeked tern is smaller, has uniform grey upperparts, and in breeding pumage is darker above with whiter cheeks. Juvenile common terns are easily separated from similar-aged birds of related species. They show extensive ginger colouration to the back, and have a pale base to the bill. Young Arctic terns have a grey back and black


title: "Common tern" content: bill, and juvenile roseate terns have a distinctive scalloped "saddle". Hybrids between common and roseate terns have been recorded, particularly from the US, and the intermediate plumage and calls shown by these birds is a potential identification pitfall. Such birds may have more extensive black on the bill, but confirmation of mixed breeding may depend on the exact details of individual flight feathers. The common tern has a wide repertoire of calls, which have a lower pitch than the equivalent calls of Arctic terns. The most distinctive sound is the alarm "KEE-yah", stressed on the first syllable, in contrast to


title: "Common tern" content: the second-syllable stress of the Arctic tern. The alarm call doubles up as a warning to intruders, although serious threats evoke a "kyar", given as a tern takes flight, and quietens the usually noisy colony while its residents assess the danger. A down-slurred "keeur" is given when an adult is approaching the nest while carrying a fish, and is possibly used for individual recognition (chicks emerge from hiding when they hear their parents giving this call). Another common call is a "kip" uttered during social contact. Other vocalizations include a "kakakakaka" when attacking intruders, and a staccato "kek-kek-kek" from fighting


title: "Common tern" content: males. Parents and chicks can locate one another by call, and siblings also recognise each other's vocalisations from about the twelfth day from hatching, which helps to keep the brood together. Most populations of the common tern are strongly migratory, wintering south of their temperate and subarctic Northern Hemisphere breeding ranges. First summer birds usually remain in their wintering quarters, although a few return to breeding colonies some time after the arrival of the adults. In North America, the common tern breeds along the Atlantic coast from Labrador to North Carolina, and inland throughout much of Canada east of the


title: "Common tern" content: Rocky Mountains. In the United States, some breeding populations can also be found in the states bordering the Great Lakes, and locally on the Gulf coast. There are small, only partially migratory, colonies in the Caribbean; these are in The Bahamas and Cuba, and off Venezuela in the Los Roques and Las Aves archipelagos. New World birds winter along both coasts of Central and South America, to Argentina on the east coast and to Northern Chile on the west coast. Records from South America and the Azores show that some birds may cross the Atlantic in both directions on their


title: "Common tern" content: migration. The common tern breeds across most of Europe, with the highest numbers in the north and east of the continent. There are small populations on the north African coast, and in the Azores, Canary Islands and Madeira. Most winter off western or southern Africa, birds from the south and west of Europe tending to stay north of the equator and other European birds moving further south. The breeding range continues across the temperate and taiga zones of Asia, with scattered outposts on the Persian Gulf and the coast of Iran. Small populations breed on islands off Sri Lanka, and


title: "Common tern" content: in the Ladakh region of the Tibetan plateau. Western Asian birds winter in the northern Indian Ocean, and "S. h. tibetana" appears to be common off East Africa during the northern hemisphere winter. Birds from further north and east in Asia, such as "S. h. longipennis", move through Japan, Thailand and the western Pacific as far as southern Australia. There are small and erratic colonies in West Africa, in Nigeria and Guinea-Bissau, unusual in that they are within what is mainly a wintering area. Only a few common terns have been recorded in New Zealand, and this species' status in


title: "Common tern" content: Polynesia is unclear. A bird ringed at the nest in Sweden was found dead on Stewart Island, New Zealand, five months later, having flown an estimated 25,000 km (15,000 mi). As long distance migrants, common terns sometimes occur well outside their normal range. Stray birds have been found inland in Africa (Zambia and Malawi), and on the Maldives and Comoros islands; the nominate subspecies has reached Australia, the Andes, and the interior of South America. Asian "S. h. longipennis" has recent records from western Europe. The common tern breeds over a wider range of habitats than any of its relatives,


title: "Common tern" content: nesting from the taiga of Asia to tropical shores, and at altitudes up to in Armenia, and in Asia. It avoids areas which are frequently exposed to excessive rain or wind, and also icy waters, so it does not breed as far north as the Arctic tern. The common tern breeds close to freshwater or the sea on almost any open flat habitat, including sand or shingle beaches, firm dune areas, salt marsh, or, most commonly, islands. Flat grassland or heath, or even large flat rocks may be suitable in an island environment. In mixed colonies, common terns will tolerate


title: "Common tern" content: somewhat longer ground vegetation than Arctic terns, but avoid the even taller growth acceptable to roseate terns; the relevant factor here is the different leg lengths of the three species. Common terns adapt readily to artificial floating rafts, and may even nest on flat factory roofs. Unusual nest sites include hay bales, a stump above the water, and floating logs or vegetation. There is a record of a common tern taking over a spotted sandpiper nest and laying its eggs with those of the wader. Outside the breeding season, all that is needed in terms of habitat is access to


title: "Common tern" content: fishing areas, and somewhere to land. In addition to natural beaches and rocks, boats, buoys and piers are often used both as perches and night-time roosts. The common tern breeds in colonies which do not normally exceed 2,000 pairs, but may occasionally number more than 20,000 pairs. Colonies inland tend to be smaller than on the coast. Common terns often nest alongside other coastal species, such as Arctic, roseate and Sandwich terns, black-headed gulls, and black skimmers. Especially in the early part of the breeding season, for no known reason, most or all of the terns will fly in silence


title: "Common tern" content: low and fast out to sea. This phenomenon is called a "dread". On their return to the breeding sites, the terns may loiter for a few days before settling into a territory, and the actual start of nesting may be linked to a high availability of fish. Terns defend only a small area, with distances between nests sometimes being as little as , although is more typical. As with many birds, the same site is re-used year after year, with a record of one pair returning for 17 successive breeding seasons. Around 90% of experienced birds reuse their former territory,


title: "Common tern" content: so young birds must nest on the periphery, find a bereaved mate, or move to another colony. A male selects a nesting territory a few days after his arrival in the spring, and is joined by his previous partner unless she is more than five days late, in which case the pair may separate. The defence of the territory is mainly by the male, who repels intruders of either sex. He gives an alarm call, opens his wings, raises his tail and bows his head to show the black cap. If the intruder persists, the male stops calling and fights


title: "Common tern" content: by bill grappling until the intruder submits by raising its head to expose the throat. Aerial trespassers are simply attacked, sometimes following a joint upward spiralling flight. Despite the aggression shown to adults, wandering chicks are usually tolerated, whereas in a gull colony they would be attacked and killed. The nest is defended until the chicks have fledged, and all the adults in the colony will collectively repel potential predators. Pairs are established or confirmed through aerial courtship displays in which a male and a female fly in wide circles up to or more, calling all the while, before the


title: "Common tern" content: two birds descend together in zigzag glides. If the male is carrying a fish, he may attract the attention of other males too. On the ground, the male courts the female by circling her with his tail and neck raised, head pointing down, and wings partially open. If she responds, they may both adopt a posture with the head pointed skywards. The male may tease a female with the fish, not parting with his offering until she has displayed to him sufficiently. Once courtship is complete, the male makes a shallow depression in the sand, and the female scratches in


title: "Common tern" content: the same place. Several trials may take place until the pair settle on a site for the actual nest. The eggs may be laid on bare sand, gravel or soil, but a lining of debris or vegetation is often added if available, or the nest may be rimmed with seaweed, stones or shells. The saucer-shaped scrape is typically deep and across, but may extend to as much as wide including the surrounding decorative material. Breeding success in areas prone to flooding has been enhanced by the provision of artificial mats made from eelgrass, which encourage the terns to nest in


title: "Common tern" content: higher, less vulnerable areas, since many prefer the mats to bare sand. The common tern tends to use more nest material than roseate or Arctic terns, although roseate often nests in areas with more growing vegetation. Terns are expert at locating their nests in a large colony. Studies show that terns can find and excavate their eggs when they are buried, even if the nest material is removed and the sand smoothed over. They will find a nest placed from its original site, or even further if it is moved in several stages. Eggs are accepted if reshaped with plasticine


title: "Common tern" content: or coloured yellow (but not red or blue). This ability to locate the eggs is an adaptation to life in an unstable, wind-blown and tidal environment. The peak time for egg production is early May, with some birds, particularly first-time breeders, laying later in the month or in June. The clutch size is normally three eggs; larger clutches probably result from two females laying in the same nest. Egg size averages , although each successive egg in a clutch is slightly smaller than the first laid. The average egg weight is , of which 5% is shell. The egg weight


title: "Common tern" content: depends on how well-fed the female is, as well as on its position in the clutch. The eggs are cream, buff, or pale brown, marked with streaks, spots or blotches of black, brown or grey which help to camouflage them. Incubation is by both sexes, although more often by the female, and lasts 21–22 days, extending to 25 days if there are frequent disturbances at the colony which cause the adults to leave the eggs unattended; nocturnal predation may lead to incubation taking up to 34 days. On hot days the incubating parent may fly to water to wet its


title: "Common tern" content: belly feathers before returning to the eggs, thus affording the eggs some cooling. Except when the colony suffers disaster, 90% of the eggs hatch. The precocial downy chick is yellowish with black or brown markings, and like the eggs, is similar to the equivalent stage of the Arctic tern. The chicks fledge in 22–28 days, usually 25–26. Fledged juveniles are fed at the nest for about five days, and then accompany the adults on fishing expeditions. The young birds may receive supplementary feeds from the parents until the end of the breeding season, and beyond. Common terns have been recorded


title: "Common tern" content: feeding their offspring on migration and in the wintering grounds, at least until the adults move further south in about December. Like many terns, this species is very defensive of its nest and young, and will harass humans, dogs, muskrats and most diurnal birds, but unlike the more aggressive Arctic tern, it rarely hits the intruder, usually swerving off at the last moment. Adults can discriminate between individual humans, attacking familiar people more intensely than strangers. Nocturnal predators do not elicit similar attacks; colonies can be wiped out by rats, and adults desert the colony for up to eight hours


title: "Common tern" content: when great horned owls are present. Common terns usually breed once a year. Second clutches are possible if the first is lost. Rarely, a second clutch may be laid and incubated while some chicks from the first clutch are still being fed. The first breeding attempt is usually at four years of age, sometimes at three years. The average number of young per pair surviving to fledging can vary from zero in the event of the colony being flooded to over 2.5 in a good year. In North America, productivity was between 1.0 and 2.0 on islands, but less than


title: "Common tern" content: 1.0 at coastal and inland sites. Birds become more successful at raising chicks with age. This continues throughout their breeding lives, but the biggest increase is in the first five years. The maximum documented lifespan in the wild is 23 years in North America and 33 years in Europe, but 12 years is a more typical lifespan. Like all "Sterna" terns, the common tern feeds by plunge-diving for fish, from a height of , either in the sea or in freshwater lakes and large rivers. The bird may submerge for a second or so, but to no more than below


title: "Common tern" content: the surface. When seeking fish, this tern flies head-down and with its bill held vertically. It may circle or hover before diving, and then plunges directly into the water, whereas the Arctic tern favours a "stepped-hover" technique, and the roseate tern dives at speed from a greater height, and submerges for longer. The common tern typically forages up to away from the breeding colony, sometimes as far as . It will follow schools of fish, and its west African migration route is affected by the location of huge shoals of sardines off the coast of Ghana; it will also track


title: "Common tern" content: groups of predatory fish or dolphins, waiting for their prey to be driven to the sea's surface. Terns often feed in flocks, especially if food is plentiful, and the fishing success rate in a flock is typically about one-third higher than for individuals. Terns have red oil droplets in the cone cells of the retinas of their eyes. This improves contrast and sharpens distance vision, especially in hazy conditions. Birds that have to see through an air/water interface, such as terns and gulls, have more strongly coloured carotenoid pigments in the cone oil drops than other avian species. The improved


title: "Common tern" content: eyesight helps terns to locate shoals of fish, although it is uncertain whether they are sighting the phytoplankton on which the fish feed, or observing other terns diving for food. Tern's eyes are not particularly ultraviolet sensitive, an adaptation more suited to terrestrial feeders like the gulls. The common tern preferentially hunts fish long. The species caught depend on what is available, but if there is a choice, terns feeding several chicks will take larger prey than those with smaller broods. The proportion of fish fed to chicks may be as high as 95% in some areas, but invertebrate prey


title: "Common tern" content: may form a significant part of the diet elsewhere. This may include worms, leeches, molluscs such as small squid, and crustaceans (prawns, shrimp and mole crabs). In freshwater areas, large insects may be caught, such as beetles, cockchafers and moths. Adult insects may be caught in the air, and larvae picked from the ground or from the water surface. Prey is caught in the bill and either swallowed head-first, or carried back to the chicks. Occasionally, two or more small fish may be carried simultaneously. When adults take food back to the nest, they recognise their young by call, rather


title: "Common tern" content: than visual identification. The common tern may attempt to steal fish from Arctic terns, but might itself be harassed by kleptoparasitic skuas, laughing gulls, roseate terns, or by other common terns while bringing fish back to its nest. In one study, two males whose mates had died spent much time stealing food from neighbouring broods. Terns normally drink in flight, usually taking seawater in preference to freshwater, if both are available. Chicks do not drink before fledging, reabsorbing water, and, like adults, excreting excess salt in a concentrated solution from a specialised nasal gland. Fish bones and the hard exoskeletons


title: "Common tern" content: of crustaceans or insects are regurgitated as pellets. Adults fly off the nest to defecate, and even small chicks walk a short distance from the scrape to deposit their faeces. Adults attacking animals or humans will often defecate as they dive, often successfully fouling the intruder. Rats will take tern eggs, and may even store large numbers in caches, and the American mink is an important predator of hatched chicks, both in North America, and in Scotland where it has been introduced. The red fox can also be a local problem. Because common terns nest on islands, the most common


title: "Common tern" content: predators are normally other birds rather than mammals. The ruddy turnstone will take eggs from unattended nests, and gulls may take chicks. Great horned owls and short-eared owls will kill both adults and chicks, and black-crowned night herons will also eat small chicks. Merlins and peregrine falcons may attack flying terns; as with other birds, it seems likely that one advantage of flocking behaviour is to confuse fast-flying predators. The common tern hosts feather lice, which are quite different from those found in Arctic terns, despite the close relationship of the two birds. It may also be infected by parasitic


title: "Common tern" content: worms, such as the widespread "Diphyllobothrium" species, the duck parasite "Ligula intestinalis", and "Schistocephalus" species carried initially by fish. Tapeworms of the family Cyclophyllidea may also infect this species. The mite "Reighardia sternae" has been found in common terns from Italy, North America and China. A study of 75 breeding common terns found that none carried blood parasites. Colonies have been affected by avian cholera and ornithosis, and it is possible that the common tern may be threatened in the future by outbreaks of avian influenza to which it is susceptible. In 1961 the common tern was the first wild


title: "Common tern" content: bird species identified as infected with avian influenza, the H5N3 variant being found in an outbreak of South African birds. The common tern is classed as least concern on the IUCN Red List. It has a large population of 1,600,000–4,600,000 mature individuals and a huge breeding range estimated at . Breeding numbers have been estimated at 250,000–500,000 pairs, the majority breeding in Asia. Up to 140,000 pairs breed in Europe. Fewer than 80,000 pairs breed in North America, with most breeding on the northeast Atlantic coast and a declining population of less than 10,000 pairs breeding in the Great Lakes


title: "Common tern" content: region. In the nineteenth century, the use of tern feathers and wings in the millinery trade was the main cause of large reductions in common tern populations in both Europe and North America, especially on the Atlantic coasts and inland. Sometimes entire stuffed birds were used to make hats. Numbers largely recovered early in the twentieth century mainly due to legislation and the work of conservation organizations. Although some Eurasian populations are stable, numbers in North America have fallen by more than 70% in the last 40 years, and there is an overall negative trend in the global estimates for


title: "Common tern" content: this species. Threats come from habitat loss through building, pollution or vegetation growth, or disturbance of breeding birds by humans, vehicles, boats or dogs. Local natural flooding may lead to nest losses, and some colonies are vulnerable to predation by rats and large gulls. Gulls also compete with terns for nest sites. Some birds are hunted in the Caribbean for commercial sale as food. Breeding success may be enhanced by the use of floating nest rafts, man-made islands or other artificial nest sites, and by preventing human disturbance. Overgrown vegetation may be burned to clear the ground, and gulls can


title: "Common tern" content: be killed or discouraged by deliberate disturbance. Contamination with polychlorinated biphenyls (PCBs) resulted in enhanced levels of feminisation in male embryos, which seemed to disappear prior to fledging, with no effect on colony productivity, but dichlorodiphenyldichloroethylene (DDE), which results from the breakdown of DDT, led to very low levels of successful breeding in some US locations. The common tern is one of the species to which the Agreement on the Conservation of African-Eurasian Migratory Waterbirds (AEWA) and the US-Canada Migratory Bird Treaty Act of 1918 apply. Parties to the AWEA agreement are required to engage in a wide range of


title: "Common tern" content: conservation strategies described in a detailed action plan. The plan is intended to address key issues such as species and habitat conservation, management of human activities, research, education, and implementation. The North American legislation is similar, although there is a greater emphasis on protection. Common tern The common tern ("Sterna hirundo") is a seabird in the family Laridae. This bird has a circumpolar distribution, its four subspecies breeding in temperate and subarctic regions of Europe, Asia and North America. It is strongly migratory, wintering in coastal tropical and subtropical regions. Breeding adults have light grey upperparts, white to very light


title: Macaque content: Macaque The macaques ( or ) constitute a genus (Macaca) of Old World monkeys of the subfamily Cercopithecinae. The 23 species of macaques are distributed throughout Asia, North Africa and (in one instance) Gibraltar. Macaques are principally frugivorous, although their diet also includes seeds, leaves, flowers, and tree bark, and some, such as the crab-eating macaque, subsist on a diet of invertebrates and occasionally small vertebrates. Macaques are found in a variety of habitats throughout the Asian continent, and are extremely adaptable. All macaque social groups are arranged around dominant, matriarchal females. They also have learned to live with humans,


title: Macaque content: and have become an invasive species in some human inhabited landscapes, such as the island of Mauritius and Silver Springs State Park in Florida. Macaques can be a threat to conservation, along with a threat to human wellbeing through carrying transmittable and fatal diseases. Currently, macaques as an invasive species are handled with several control methods. Aside from humans (genus "Homo"), the macaques are the most widespread primate genus, ranging from Japan to the Indian subcontinent, and in the case of the barbary macaque ("Macaca sylvanus"), to North Africa and Southern Europe. Twenty-three macaque species are currently recognized, all of


title: Macaque content: which are Asian except for the Barbary Macaque; including some of the monkeys best known to non-zoologists, such as the rhesus macaque ("M. mulatta"), and the barbary macaque, a colony of which lives on the Rock of Gibraltar in Southern Europe. Macaques are robust primates whose arms and legs are about the same in length. The fur of these animals is typically varying shades of brown or black and their muzzles are rounded in profile with nostrils on the upper surface. The tail varies among each species, which can be long, moderate, short or totally absent. " "Although several species


title: Macaque content: lack tails, and their common names refer to them as apes, these are true monkeys, with no greater relationship to the true apes than any other Old World monkeys. Instead, this comes from an earlier definition of 'ape' that included primates generally. In some species, skin folds join the second through fifth toes, almost reaching the first metatarsal joint. The monkey’s size differs depending on sex and species. Males from all species can range from 16 to 28 inches in head and body length, and in weight from 8-40 lb. Females can range from a weight of 5-36 lb. These


title: Macaque content: primates live in troops that vary in size, where males dominate, however the rank order of dominance frequently shifts. Female ranking lasts longer and depends upon their genealogical position. Macaques are able to swim and spend most of their time on the ground, along with some time in trees. They have large pouches in their cheeks where they carry extra food. They are considered highly intelligent and are often used in the medical field for experimentation. Adults also are notorious for tending to be bad tempered. Macaques are highly adaptable to different habitats and climates and can tolerate a wide


title: Macaque content: fluctuation of temperatures and live in varying landscape settings. They easily adapt to humans and can survive well in urban settings if they are able to steal food. They can also survive in completely natural settings with no humans present. The ecological and geographic ranges of the Macaque are the widest of any non-human primate. Their habitats include the tropical rainforests of southeast Asia, deserts of Rajasthan, agricultural plains in northern India, arid mountains of Pakistan and Afghanistan, and temperate mountains in Japan, northern China, Morocco, and Nepal. Some species also inhabit villages and towns in cities in Asia. The


title: Macaque content: diet of Macaque is one that is mainly vegetarian, although some species have been observed feeding on insects. In natural habitats, they have been observed to consume certain parts of over one hundred species of plants including the buds, fruit, young leaves, bark, roots, and flowers. When Macaques live amongst people, they raid agricultural crops such as wheat, rice or sugar cane; and garden crops like tomatoes, bananas, melons, mangos, or papayas. In human settings, they also rely heavily on direct handouts from people. This includes peanuts, rice, legumes, or even prepared food. Macaques live in established social groups that


title: Macaque content: can range from a few individuals to several hundred; as they are social animals. A typical social group possess between twenty to fifty individuals of all ages and of both sexes. Typical composition consists of 15% adult males, 35% adult females, 20% infants, and 30% juveniles, though there exists variation in structure and size of groups across populations. The reproductive potential of each species differs. Populations of the rhesus macaque can grow at rates of 10% to 15% per year if the environmental conditions are favorable. However, some forest-dwelling species are endangered with much lower reproductive rates. After one year


title: Macaque content: of age, macaques move from being dependent on their mother during infancy, to the juvenile stage, where they begin to associate more with other juveniles through rough tumble and playing activities. They sexually mature between three to five years of age. Females will usually stay with the social group in which they were born, however young adult males tend to disperse and attempt to enter other social groups. Not all males succeed in joining other groups, and can become solitary; attempting to join other social groups for many years. Macaques have a typical lifespan of twenty to thirty years. Certain


title: Macaque content: macaques have become invasive species in different parts of the world, while others that survive in forest habitats remain threatened. The long-tailed macaque ("Macaca fascicularis") is listed as a threat and invasive alien species in Mauritius along with the rhesus macaques ("Macaca mulatta") in Florida. The long-tailed macaque causes severe damage to parts of its range where it has been introduced because the populations grow unchecked due to a lack of predators. On the island Mauritius, they have created serious conservation concerns for other endemic species. They consume seeds of native plants and aid in the spread of exotic weeds


title: Macaque content: throughout the forests. This changes the composition of the habitats and allows them to be rapidly overrun by invasive plants. Macaques are also responsible for the near extinction of several bird species on Mauritius by destroying the nests of the birds as they move through their home ranges and eat the eggs of critically endangered species such as the pink pigeon and Mauritian green parrot. They can be serious agricultural pests because they raid crops and gardens and humans often shoot the monkeys which can eliminate entire local populations. In Florida, a group of macaques inhabit Silver Springs State Park.


title: Macaque content: Humans often feed them, which may alter their movement and keep them close to the river on weekends where high human traffic is present. Macaques can become aggressive toward humans, and also carry potentially fatal human diseases, including the B-virus. Management techniques have historically been controversial, and public disapproval can hinder control efforts. Previously, efforts to remove Macaque individuals were met with public resistance. One management strategy that is currently being explored is that of sterilization. Natural resource managers are being educated by scientific studies in the proposed strategy. Effectiveness of this strategy is estimated to succeed in keeping populations


title: Macaque content: in check. For example, if 80% of females are sterilized every five years, or 50% every two years, it could effectively reduce the population. Other control strategies include planting specific trees to provide protection to native birds from macaque predation, live trapping, and the vaccine Porcine Zona Pellucida (PZP), which causes infertility in females Macaques have a very intricate social structure and hierarchy. If a macaque of a lower level in the social chain has eaten berries and none are left for a higher-level macaque, then the one higher in status can, within this social organization, remove the berries from


title: Macaque content: the other monkey's mouth. Several species of macaque are used extensively in animal testing, particularly in the neuroscience of visual perception and the visual system. Nearly all (73–100%) pet and captive rhesus macaques are carriers of the herpes B virus. This virus is harmless to macaques, but infections of humans, while rare, are potentially fatal, a risk that makes macaques unsuitable as pets. Urban performing macaques also carried simian foamy virus, suggesting they could be involved in the species-to-species jump of similar retroviruses to humans. In Vietnam, macaque is eaten by some people as bushmeat. In January 2018, scientists in


title: Macaque content: China reported in the journal "Cell" the creation of two crab-eating macaque monkey clones, named "Zhong Zhong" and "Hua Hua", using the complex DNA transfer method that produced "Dolly" the sheep, for the first time. As of 2005, the authors of "Mammal Species of the World" recognized the following species and species groups, aside from the white-cheeked macaque which was described in 2015: Later studies disputed some of the species groupings. For example, Li, "et al", based on DNA testing, do not recognize the "M. fascularis" group. Rather, they place the crab-eating macaque within the "M. mulatta" group and the


title: Macaque content: stump-tailed macaque within the "M. sinica" group. Prehistoric (fossil) species: Macaque The macaques ( or ) constitute a genus (Macaca) of Old World monkeys of the subfamily Cercopithecinae. The 23 species of macaques are distributed throughout Asia, North Africa and (in one instance) Gibraltar. Macaques are principally frugivorous, although their diet also includes seeds, leaves, flowers, and tree bark, and some, such as the crab-eating macaque, subsist on a diet of invertebrates and occasionally small vertebrates. Macaques are found in a variety of habitats throughout the Asian continent, and are extremely adaptable. All macaque social groups are arranged around dominant,


title: "Coconut oil" content: industrial, and pharmaceutical purposes. RBD coconut oil can be processed further into partially or fully hydrogenated oil to increase its melting point. Since virgin and RBD coconut oils melt at 24 °C (76 °F), foods containing coconut oil tend to melt in warm climates. A higher melting point is desirable in these warm climates, so the oil is hydrogenated. The melting point of hydrogenated coconut oil is 36–40 °C (97–104 °F). In the process of hydrogenation, unsaturated fats (monounsaturated and polyunsaturated fatty acids) are combined with hydrogen in a catalytic process to make them more saturated. Coconut oil contains only


title: Femininity content: exertion" and to project "shyness, reserve and a display of frailty, fear and incompetence." Second-wave feminists, influenced by de Beauvoir, believed that although biological differences between females and males were innate, the concepts of femininity and masculinity had been culturally constructed, with traits such as passivity and tenderness assigned to women and aggression and intelligence assigned to men. Girls, second-wave feminists said, were then socialized with toys, games, television and school into conforming to feminine values and behaviours. In her significant 1963 book "The Feminine Mystique", American feminist Betty Friedan wrote that the key to women's subjugation lay in the


title: "Weekend Update" content: segments: science edition, hosted by Dr. Jonathan Lear (Mark King), arts and leisure correspondent Bill Murray, and news by Rocket. Rocket signed off each week by saying "Good night and watch out." Prior to the final episode of the season, Jean Doumanian and most of the cast, including Rocket, were fired. Chase hosted the last episode and anchored Weekend Update, as he had on his previous appearances as host. The anchor position changed hands frequently under Dick Ebersol, executive producer of "SNL" from 1981 to 1985. Brian Doyle-Murray was teamed first with Mary Gross, then going solo for three months,


title: "Bloody Friday (1972)" content: claimed the security forces wilfully ignored some of the warnings for its own ends. The security forces denied this and said they were overstretched by the sheer number of bombs and bomb warnings, some of which were hoaxes. The bombings were partly a response to the breakdown of talks between the IRA and the British government. Since the beginning of its campaign in 1970, the IRA had carried out a bombing campaign against economic, military and political targets in Northern Ireland. It carried out a total of 1,300 bombings in 1972. However, Bloody Friday was a major setback for the


title: "Bloody Friday (1972)" content: of the deaths were caused by two of the bombs: at Oxford Street bus depot, and at Cavehill Road. The Oxford Street bomb killed two British soldiers and four Ulsterbus employees. One of these employees was a Royal Ulster Constabulary (RUC) reservist; one was an Ulster loyalist paramilitary; and the other two were civilians. The Cavehill Road bomb killed three civilians. The accounts of the events that appeared in the first editions of local and national newspapers were, naturally enough, somewhat confused about the details of the events of the day. The timetable below is approximate and given in BST


title: Caprinae content: Caprinae The subfamily Caprinae is part of the ruminant family Bovidae, and consists of mostly medium-sized bovids. A member of this subfamily is called a caprine. A member is also sometimes referred to as a goat-antelope, however, this term "goat-antelope" does not mean that these animals are true antelopes: a true antelope is a bovid with a cervid-like or antilocaprid-like morphology. Within this subfamily Caprinae, a prominent tribe Caprini includes sheep, goat, and ibex. Some earlier taxonomies considered Caprinae a separate family called Capridae (whence a caprid), but now it is usually considered a subfamily within the family Bovidae, whence


title: "Shreveport Pirates" content: end of 1995, anticipating that the Pirates would not continue beyond that season, a group of investors dubbing itself the "Ark-La-Tex Football Association" proposed purchasing the Birmingham Barracudas, an on-field success but one that had not found an audience in Alabama, and moving it to Shreveport. The association reached an agreement to buy the Barracudas franchise from its owner Arthur L. Williams Jr. for a significant discount, provided that the league approve the sale. The sale would have brought the team closer to the San Antonio Texans and what would have been the Houston Stallions (as Baltimore had proposed moving


title: "Renault in Formula One" content: Jerez the new Renault engines showed problems with both the turbo unit and the energy recovery systems. Partial fixes were introduced for the last pre-season tests in Bahrain, especially software upgrades. In the early part of the season, the Energy F1-2014 was the subject of various criticisms for its poor reliability and lack of top speed, including one by Red Bull's boss Christian Horner which described the performance as "unacceptable" after an unsuccessful team's home race in Austria. Renault introduced revised components and more software upgrades trying to reduce the gap with rivals. In 2015, Red Bull unilaterally terminated their


title: "Brand equity" content: equity metrics is to measure the value of a brand. A brand encompasses the name, logo, image, and perceptions that identify a product, service, or provider in the minds of customers. It takes shape in advertising, packaging, and other marketing communications, and becomes a focus of the relationship with consumers. In time, a brand comes to embody a promise about the goods it identifies—a promise about quality, performance, or other dimensions of value, which can influence consumers' choices among competing products. When consumers trust a brand and find it relevant, they may select the offerings associated with that brand over


title: "Invasion of the Waikato" content: the government restored a quarter of the 1,202,172 acres (486,500 hectares) originally seized and paid almost ₤23,000 compensation, the Waikato confiscations had been "excessive". The Waitangi Tribunal in 1985 declared the Tainui people of the Waikato had never rebelled, but had been forced into a defensive war. In the early 1990s Tainui opted to bypass the Waitangi Tribunal and concluded a treaty claims settlement with the Crown through direct negotiation. In May 1995 the Crown signed a deed of settlement with Waikato–Tainui that included cash and land valued at $170 million. The settlement included an admission by the Crown that


title: "Snow bunting" content: Snow bunting The snow bunting ("Plectrophenax nivalis") is a passerine bird in the family Calcariidae. It is an Arctic specialist, with a circumpolar Arctic breeding range throughout the northern hemisphere. There are small isolated populations on a few high mountain tops south of the Arctic region, including the Cairngorms in central Scotland and the Saint Elias Mountains on the southern Alaska-Yukon border, and also Cape Breton Highlands. The snow bunting is the most northerly recorded passerine in the world. The snow bunting is a sexually dimorphic medium size passerine bird. This passerine is a ground-dwelling species that walks, runs and


title: "Snow bunting" content: could potentially jump if needed. It is fairly large and long-winged for a bunting. It measures 15 cm with a wingspan of and weights 30 to 40 grams. The bill is yellow with a black tip, and is all black in summer for males. The plumage is white in the underparts and the wings and back have black and white on them. The female and male have a different plumage. During the mating season: the male is completely black and white with black tips in the wings, while the female will have the same colouration than the male in the


title: "Snow bunting" content: wings but will have a red-brownish colour in her back. During the winter season they will both have a rufous colouration in the back. In the spring, the buntings will not go through a moult as other passerines birds do, instead the breeding colouration comes with the wearing and abrasion of the feathers. Unlike most passerines, it has feathered tarsi, an adaptation to its harsh environment. No other passerine can winter as far north as this species apart from the common raven. This species is often confused with the McKay's bunting ("Plectrophenax hyperboreus") due to the similar colouration of their


title: "Snow bunting" content: plumage. Even more, the challenge of identification becomes harder when this two species hybridize in the boundaries of their territories. Another similar species is the horned lark, although it has a larger black tail and it has a smaller white patch on the wings. The snow bunting was formerly part of the Emberizidae family that includes American sparrows, buntings, towhees and finches. This family was formed after a broad geologically recent radiation of passerine birds. However, it is now part of the family Calcariidae which contains the longspurs. Despite the wide distribution of this species there is no a significant


title: "Snow bunting" content: difference that exists among different phenotypes. The genus name "Plectrophenax" is from Ancient Greek "plektron", "cock’s spur", and "phenax" "imposter", and the specific "nivalis" is Latin for "snow-white". There are four subspecies, which differ slightly in the plumage pattern of breeding males: It is very closely related to the Beringian McKay's bunting, which differs in having even more white in the plumage. Hybrids between the two occur in Alaska, and they have been considered conspecific by some authors, though they are generally treated as separate species. The species also mated with a Lapland Longspur creating a hybrid. The first photographs


title: "Snow bunting" content: of this hybrid were taken in April 2011, during its spring migration. The snow bunting lives in very high latitudes in the Arctic tundra. There is no apparent limit to its northern range, while the southern range is limited by the duration of daylight, which influences their reproductive activity. This species is found in the high Arctic tundra of North America, Ellesmere Island, Iceland, higher mountains of Scotland, Norway, Russia, North Greenland, Siberia, Novaya Zemlya, and Franz Josef Land. During the winter, this bird migrates to the circumglobal northern temperate zone including the south of Canada, north of the United


title: "Snow bunting" content: States, north of Germany, Poland, Ukraine, and east to central Asia. During the last ice age, the snow bunting was widespread throughout continental Europe. During the breeding period the snow bunting looks for rocky habitats in the Arctic. Since the vegetation in the tundra is low growing, this bird and its nestlings are exposed to predators, and in order to ensure the survival of its offspring, the snow bunting nests in cavities in order to protect the nestlings from any threat. During this period, buntings also look for a habitat rich in vegetation such as wet sedge meadows and areas


title: "Snow bunting" content: rich in dryas and lichens. In the winter, they look for open habitats such as farms and fields where they feed on seeds in the ground. The snow buntings migrate to the Arctic to reproduce and they are the first migrant species that arrives to these territories. They must gain at least 30% of body mass before migration. The males will arrive first at the beginning of April, when temperature could reach -30 degrees Celsius. This early migration could be explained by the fact that this species is highly territorial and the quality of the nesting area is crucial to


title: "Snow bunting" content: their reproductive success. Females will arrive four to six weeks later, when the snow starts to melt. They tend to migrate in small flocks and have an undulate flight at a moderate height. This passerine bird overwinters in northern temperate zones in open fields forming moving flocks. They will leave the Arctic at the middle and end of September, although some will start the migration at the beginning of November. The female leaves first and tends to winter in more southern territories than the male, while the juveniles will leave the Arctic even later than the adults. The migration of


title: "Snow bunting" content: this bird is nocturnal and they are able to detect the geomagnetic field of the earth in order to guide themselves to their breeding and overwinter territory. The orientation of the snow bunting during migration is independent of any type of visual cue. Furthermore, studies have shown that only those individuals with adequate energy storage will be able to select seasonally appropriate directions during their migration. From the fall to the spring the snow bunting eats a variety of weeds such as knotweed, ragweed, amaranth, goosefoot, aster, and goldenrod and also eats various types of grass seeds. During this season


title: "Snow bunting" content: it will forage in the snow collecting seeds from lower stems. During the summer their diet includes seeds of crowberry, bilberry, bistort, dock, poppy, purple saxifrage and invertebrates such as butterflies, true bugs, flies, wasps and spiders. The nestlings are fed exclusively on invertebrates. Snow buntings also prey on basking spiders by throwing rocks around and less regularly they will try to catch invertebrates in flight. The call is a distinctive rippling whistle, "per,r,r,rit" and the typical "Plectrophenax" warble "hudidi feet feet feew hudidi". Snow buntings use vocalizations to communicate among each other and males will have a song to


title: "Snow bunting" content: attract the female. The communication calls are done by both the male and the female and they tend to be emitted in flight or in the ground, while the males will often emit the song from a perching position or in a flight display. The males will start singing as soon as they will reach the breeding grounds, and will stop once they find a mate. Studies have shown that the quality and the rate at which a song is emitted affect the reproductive success of a male. The rate of a song measured by the number of strophes per


title: "Snow bunting" content: minute is limited by the foraging needs of the male; therefore, a male that is able to sing more frequently shows that he is more successful and effective in his foraging behavior. The song becomes an indicator of the parental care qualities of the male, since having an effective foraging behavior will provide a better probability of survival of the nestlings. Females will then choose their mates based on their song rate. Within snow buntings, vocalizations in males are unique to each individual, although there is certain syllable sharing between one another. The uniqueness of each song reveals a capacity


title: "Snow bunting" content: of recognition between individuals and has an effect in the individual fitness and reproductive success. The songs have duration of 2 seconds and have a frequency of 2 to 6 kHz. Each song is composed of similar and dissimilar figures that create different motifs that will alternate and repeat, resulting in a unique pattern for every male individual. Snow buntings have a monogamous behaviour in which the males have a positive impact in the reproductive success of the female, although they are not essential to the survival of the nestling. The male will follow the female during her fertile period


title: "Snow bunting" content: to make sure that she will not mate with any other male. The nest sites provide safety but bring other challenges to snow buntings, since in rock cracks and fissures the microclimate could be harsh, the incubation time might be longer for this species and there is a risk that the lower temperatures kill the embryo. To overcome this challenge, the male will bring food to the female during the incubation time, in this way she will be able to constantly control the temperatures of the nest microclimate improving the hatching success and reducing the incubation time. This passerine lays


title: "Snow bunting" content: eggs as soon as the ambient temperature is above 0 degrees Celsius The eggs are blue-green, spotted brown, and hatch in 12–13 days, and the young are already ready to fly after a further 12–14 days. The courtship behaviour of snow buntings varies in different parts of the world. In Greenland, the male will have a threat display to ensure his territory. This display will consist of very loud calls, the male will lower its head down and will turn completely to face the newcomer. The males will also have a ceremonial flight to attract the female, in which they


title: "Snow bunting" content: will reach a height of 30 to 50 feet, then they will glide, they will sing the song very loudly and will then keep on singing from a perching position. Several index suggest that climate change could potentially have an important impact in the snow buntings populations. The Arctic oscillation index (AO) is a regional climate index that helps to predict ecological processes. In the Arctic, when the AO index is in a positive phase there are higher winter temperatures and precipitations, there are earlier and warmer springs and in the summer it is cloudy, humid and there are lower


title: "Snow bunting" content: temperatures. Usually the AO index tends to oscillate from a positive to a negative phase, but during the last past 40 years, the AO index has remained in the positive phase. Studies have shown that warmer springs trigger an early breeding behavior in the snow buntings that mismatches the peak of their food sources, leading to a lower success rate of the hatchlings. Even more, the higher temperatures will bring to the Arctic other species that will compete with the snow bunting, it is also thought that higher temperatures might allow a better survival of second broods in the snow


title: "Snow bunting" content: bunting species. Snow bunting The snow bunting ("Plectrophenax nivalis") is a passerine bird in the family Calcariidae. It is an Arctic specialist, with a circumpolar Arctic breeding range throughout the northern hemisphere. There are small isolated populations on a few high mountain tops south of the Arctic region, including the Cairngorms in central Scotland and the Saint Elias Mountains on the southern Alaska-Yukon border, and also Cape Breton Highlands. The snow bunting is the most northerly recorded passerine in the world. The snow bunting is a sexually dimorphic medium size passerine bird. This passerine is a ground-dwelling species that walks,


title: "Peroneus longus" content: the tibialis posterior, antagonizing the tibialis anterior and peroneus tertius, which are dorsiflexors of the foot. The peroneus longus also everts the sole of the foot, and from the oblique direction of the tendon across the sole of the foot is an important agent in the maintenance of the transverse arch. Taking their fixed points below, the peroneus muscles serve to steady the leg upon the foot. This is especially the case in standing upon one leg, when the tendency of the superincumbent weight is to throw the leg medialward; the peroneus longus overcomes this tendency by drawing on the


title: "Delusional parasitosis" content: and this fixation may then develop into delusional parasitosis. Secondary forms of delusional parasitosis are addressed by treatment of the primary associated psychological or physical condition. The primary form is treated much as other delusional disorders and schizophrenia. In the past, pimozide was the drug of choice when selecting from the typical antipsychotics. Currently, atypical antipsychotics such as olanzapine or risperidone are used as first line treatment. Notably, sufferers often will reject the professional medical diagnosis of delusional parasitosis, and few patients willingly undergo treatment, despite demonstrable efficacy. The founder of the Morgellons Research Foundation, Mary Leitao, coined the name


title: "Sea cucumber" content: Sea cucumber Like all echinoderms, sea cucumbers have an endoskeleton just below the skin, calcified structures that are usually reduced to isolated microscopic ossicles (or sclerietes) joined by connective tissue. In some species these can sometimes be enlarged to flattened plates, forming an armour. In pelagic species such as "Pelagothuria natatrix" (Order Elasipodida, family Pelagothuriidae), the skeleton is absent and there is no calcareous ring. The sea cucumbers are named after their resemblance to the fruit of the cucumber plant. Most sea cucumbers, as their name suggests, have a soft and cylindrical body, more or less lengthened, rounded off and


title: "Sea cucumber" content: occasionally fat in the extremities, and generally without solid appendages. Their shape ranges from almost spherical for "sea apples" (genus "Pseudocolochirus") to serpent-like for Apodida or the classic sausage-shape, while others resemble caterpillars. The mouth is surrounded by tentacles, which can be pulled back inside the animal. Holothurians measure generally between 10 and 30 centimetres long, with extremes of some millimetres for "Rhabdomolgus ruber" and up to more than 3 metres for "Synapta maculata". The largest American species, "Holothuria floridana", which abounds just below low-water mark on the Florida reefs, has a volume of well over , and long. Most


title: "Sea cucumber" content: possess five rows of tube feet (called "podia"), but Apodida lacks these and moves by crawling; the podia can be of smooth aspect or provided with fleshy appendages (like "Thelenota ananas"). The podia on the dorsal surface generally have no locomotive role, and are transformed into papillae. At one of the extremities opens a rounded mouth, generally surrounded with a crown of tentacles which can be very complex in some species (they are in fact modified podia); the anus is postero-dorsal. Holothurians do not look like other echinoderms at first glance, because of their tubular body, without visible skeleton nor


title: "Sea cucumber" content: hard appendixes. Furthermore, the fivefold symmetry, classical for echinoderms, although preserved structurally, is doubled here by a bilateral symmetry which makes them look like chordates. However, a central symmetry is still visible in some species through five 'radii', which extend from the mouth to the anus (just like for sea urchins), on which the tube feet are attached. There is thus no "oral" or "aboral" face as for sea stars and other echinoderms, but the animal stands on one of its sides, and this face is called "trivium" (with three rows of tube feet), while the dorsal face is named


title: "Sea cucumber" content: "bivium". A remarkable feature of these animals is the "catch" collagen that forms their body wall. This can be loosened and tightened at will, and if the animal wants to squeeze through a small gap, it can essentially liquefy its body and pour into the space. To keep itself safe in these crevices and cracks, the sea cucumber will hook up all its collagen fibers to make its body firm again. The most common way to separate the subclasses is by looking at their oral tentacles. Order Apodida have a slender and elongate body lacking tube feet, with up to


title: "Sea cucumber" content: 25 simple or pinnate oral tentacles. Aspidochirotida are the most common sea cucumbers encountered, with a strong body and 10–30 leaf like or shield like oral tentacles. Dendrochirotida are filter-feeders, with plump bodies and 8–30 branched oral tentacles (which can be extremely long and complex). Sea cucumbers are typically in length, although the smallest known species are just long, and the largest can reach . The body ranges from almost spherical to worm-like, and lacks the arms found in many other echinoderms, such as starfish. The anterior end of the animal, containing the mouth, corresponds to the oral pole of


title: "Sea cucumber" content: other echinoderms (which, in most cases, is the underside), while the posterior end, containing the anus, corresponds to the aboral pole. Thus, compared with other echinoderms, sea cucumbers can be said to be lying on their side. The body of a holothurian is roughly cylindrical. It is radially symmetrical along its longitudinal axis, and has weak bilateral symmetry transversely with a dorsal and a ventral surface. As in other Echinozoans, there are five ambulacra separated by five ambulacral grooves, the interambulacra. The ambulacral grooves bear four rows of tube feet but these are diminished in size or absent in some


title: "Sea cucumber" content: holothurians, especially on the dorsal surface. The two dorsal ambulacra make up the bivium while the three ventral ones are known as the trivium. At the anterior end, the mouth is surrounded by a ring of tentacles which are usually retractable into the mouth. These are modified tube feet and may be simple, branched or arborescent. They are known as the introvert and posterior to them there is an internal ring of large calcareous ossicles. Attached to this are five bands of muscle running internally longitudinally along the ambulacra. There are also circular muscles, contraction of which cause the animal


title: "Sea cucumber" content: to elongate and the introvert to extend. Anterior to the ossicles lie further muscles, contraction of which cause the introvert to retract. The body wall consists of an epidermis and a dermis and contains smaller calcareous ossicles, the types of which are characteristics which help to identify different species. Inside the body wall is the coelom which is divided by three longitudinal mesenteries which surround and support the internal organs. A pharynx lies behind the mouth and is surrounded by a ring of ten calcareous plates. In most sea cucumbers, this is the only substantial part of the skeleton, and


title: "Sea cucumber" content: it forms the point of attachment for muscles that can retract the tentacles into the body for safety as for the main muscles of the body wall. Many species possess an oesophagus and stomach, but in some the pharynx opens directly into the intestine. The intestine is typically long and coiled, and loops through the body three times before terminating in a cloacal chamber, or directly as the anus. Sea cucumbers have no true brain. A ring of neural tissue surrounds the oral cavity, and sends nerves to the tentacles and the pharynx. The animal is, however, quite capable of


title: "Sea cucumber" content: functioning and moving about if the nerve ring is surgically removed, demonstrating that it does not have a central role in nervous coordination. In addition, five major nerves run from the nerve ring down the length of the body beneath each of the ambulacral areas. Most sea cucumbers have no distinct sensory organs, although there are various nerve endings scattered through the skin, giving the animal a sense of touch and a sensitivity to the presence of light. There are, however, a few exceptions: members of the Apodida order are known to possess statocysts, while some species possess small eye-spots


title: "Sea cucumber" content: near the bases of their tentacles. Sea cucumbers extract oxygen from water in a pair of "respiratory trees" that branch in the cloaca just inside the anus, so that they "breathe" by drawing water in through the anus and then expelling it. The trees consist of a series of narrow tubules branching from a common duct, and lie on either side of the digestive tract. Gas exchange occurs across the thin walls of the tubules, to and from the fluid of the main body cavity. Together with the intestine, the respiratory trees also act as excretory organs, with nitrogenous waste


title: "Sea cucumber" content: diffusing across the tubule walls in the form of ammonia and phagocytic coelomocytes depositing particulate waste. Like all echinoderms, sea cucumbers possess both a water vascular system that provides hydraulic pressure to the tentacles and tube feet, allowing them to move, and a "haemal system". The latter is more complex than that in other echinoderms, and consists of well-developed vessels as well as open sinuses. A central haemal ring surrounds the pharynx next to the ring canal of the water vascular system, and sends off additional vessels along the radial canals beneath the ambulacral areas. In the larger species, additional


title: "Sea cucumber" content: vessels run above and below the intestine and are connected by over a hundred small muscular ampullae, acting as miniature hearts to pump blood around the haemal system. Additional vessels surround the respiratory trees, although they contact them only indirectly, via the coelomic fluid. Indeed, the blood itself is essentially identical with the coelomic fluid that bathes the organs directly, and also fills the water vascular system. Phagocytic coelomocytes, somewhat similar in function to the white blood cells of vertebrates, are formed within the haemal vessels, and travel throughout the body cavity as well as both circulatory systems. An additional


title: "Sea cucumber" content: form of coelomocyte, not found in other echinoderms, has a flattened discoid shape, and contains hemoglobin. As a result, in many (though not all) species, both the blood and the coelomic fluid are red in colour. Vanadium has been reported in high concentrations in holothurian blood, however researchers have been unable to reproduce these results. Like all echinoderms, sea cucumbers possess pentaradial symmetry, with their bodies divided into five nearly identical parts around a central axis. However, because of their posture, they have secondarily evolved a degree of bilateral symmetry. For example, because one side of the body is typically


title: "Sea cucumber" content: pressed against the substratum, and the other is not, there is usually some difference between the two surfaces (except for Apodida). Like sea urchins, most sea cucumbers have five strip-like ambulacral areas running along the length of the body from the mouth to the anus. The three on the lower surface have numerous tube feet, often with suckers, that allow the animal to crawl along; they are called "trivium". The two on the upper surface have under-developed or vestigial tube feet, and some species lack tube feet altogether; this face is called "bivium". In some species, the ambulacral areas can


title: "Sea cucumber" content: no longer be distinguished, with tube feet spread over a much wider area of the body. Those of the order Apodida have no tube feet or ambulacral areas at all, and burrow through sediment with muscular contractions of their body similar to that of worms, however five radial lines are generally still obvious along their body. Even in those sea cucumbers that lack regular tube feet, those that are immediately around the mouth are always present. These are highly modified into retractile tentacles, much larger than the locomotive tube feet. Depending on the species, sea cucumbers have between ten and


title: "Sea cucumber" content: thirty such tentacles and these can have a wide variety of shapes depending on the diet of the animal and other conditions. Many sea cucumbers have papillae, conical fleshy projections of the body wall with sensory tube feet at their apices. These can even evolve into long antennae-like structures, especially on the abyssal genus "Scotoplanes". Echinoderms typically possess an internal skeleton composed of plates of calcium carbonate. In most sea cucumbers, however, these have become reduced to microscopic ossicles embedded beneath the skin. A few genera, such as "Sphaerothuria", retain relatively large plates, giving them a scaly armour. Sea cucumbers


title: "Sea cucumber" content: can be found in great numbers on the deep seafloor, where they often make up the majority of the animal biomass. At depths deeper than , sea cucumbers comprise 90% of the total mass of the macrofauna. Sea cucumbers form large herds that move across the bathygraphic features of the ocean, hunting food. The body of some deep water holothurians, such as "Enypniastes eximia", "Peniagone leander" and "Paelopatides confundens", is made of a tough gelatinous tissue with unique properties that makes the animals able to control their own buoyancy, making it possible for them to either live on the ocean


title: "Sea cucumber" content: floor or to actively swim or float over it in order to move to new locations, in a manner similar to how the group Torquaratoridae floats through water. Holothurians appear to be the echinoderms best adapted to extreme depths, and are still very diversified beyond 5,000 m deep: several species from the family Elpidiidae ("sea pigs") can be found deeper than 9,500 m, and the record seems to be some species of the genus "Myriotrochus" (in particular "Myriotrochus bruuni"), identified down to 10,687 meters deep. In more shallow waters, sea cucumbers can form dense populations. The strawberry sea cucumber ("Squamocnus


title: "Sea cucumber" content: brevidentis") of New Zealand lives on rocky walls around the southern coast of the South Island where populations sometimes reach densities of 1,000 animals per square meter (93 /sq ft). For this reason, one such area in Fiordland is called the strawberry fields. Some abyssal species in the abyssal order Elasipodida have evolved to a "benthopelagic" behaviour: their body is nearly the same density as the water around them, so they can make long jumps (up to high), before falling slowly back to the ocean floor. Most of them have specific swimming appendages, such as some kind of umbrella (like


title: "Sea cucumber" content: "Enypniastes"), or a long lobe on top of the body ("Psychropotes"). Only one species is known as a true completely pelagic species, that never comes close to the bottom: "Pelagothuria natatrix". Holothuroidea are generally scavengers, feeding on debris in the benthic zone of the ocean. Exceptions include some pelagic cucumbers and the species "Rynkatorpa pawsoni", which has a commensal relationship with deep-sea anglerfish. The diet of most cucumbers consists of plankton and decaying organic matter found in the sea. Some sea cucumbers position themselves in currents and catch food that flows by with their open tentacles. They also sift through


title: "Sea cucumber" content: the bottom sediments using their tentacles. Other species can dig into bottom silt or sand until they are completely buried. They then extrude their feeding tentacles, ready to withdraw at any hint of danger. In the South Pacific sea cucumbers may be found in densities of 40 individuals per square meter (33 /sq yd). These populations can process 19 kilograms of sediment per square meter (34 lb /sq yd) per year. The shape of the tentacles is generally adapted to the diet, and to the size of the particles to be ingested: the filter-feeding species mostly have complex arborescent tentacles,


title: "Sea cucumber" content: intended to maximize the surface area available for filtering, while the species feeding on the substratum will more often need digitate tentacles to sort out the nutritional material; the detritivore species living on fine sand or mud more often need shorter "peltate" tentacles, shaped like shovels. A single specimen can swallow more than 45 kg of sediment a year, and their excellent digestive capacities allow them to reject a finer, purer and homogeneous sediment. Therefore, sea cucumbers play a major role in the biological processing of the sea bed (bioturbation, purge, homogenization of the substratum etc.). Most sea cucumbers reproduce


title: "Sea cucumber" content: by releasing sperm and ova into the ocean water. Depending on conditions, one organism can produce thousands of gametes. Sea cucumbers are typically dioecious, with separate male and female individuals, but some species are protandric. The reproductive system consists of a single gonad, consisting of a cluster of tubules emptying into a single duct that opens on the upper surface of the animal, close to the tentacles. At least 30 species, including the red-chested sea cucumber ("Pseudocnella insolens"), fertilize their eggs internally and then pick up the fertilized zygote with one of their feeding tentacles. The egg is then inserted


title: "Sea cucumber" content: into a pouch on the adult's body, where it develops and eventually hatches from the pouch as a juvenile sea cucumber. A few species are known to brood their young inside the body cavity, giving birth through a small rupture in the body wall close to the anus. In all other species, the egg develops into a free-swimming larva, typically after around three days of development. The first stage of larval development is known as an auricularia, and is only around in length. This larva swims by means of a long band of cilia wrapped around its body, and somewhat


title: "Sea cucumber" content: resembles the bipinnaria larva of starfish. As the larva grows it transforms into the doliolaria, with a barrel-shaped body and three to five separate rings of cilia. The "pentacularia" is the third larval stage of sea cucumber, where the tentacles appear. The tentacles are usually the first adult features to appear, before the regular tube feet. Numerous small animals can live in symbiosis or commensalism with sea cucumbers, as well as some parasites. Some cleaner shrimps can live on the tegument of holothurians, in particular several species of the genus "Periclimenes" (genus which is specialized in echinoderms), in particular "Periclimenes


title: "Sea cucumber" content: imperator". A variety of fish, most commonly pearl fish, have evolved a commensalistic symbiotic relationship with sea cucumbers in which the pearl fish will live in sea cucumber's cloaca using it for protection from predation, a source of food (the nutrients passing in and out of the anus from the water), and to develop into their adult stage of life. Many polychaete worms (family Polynoidae) and crabs (like "Lissocarcinus orbicularis") have also specialized to use the mouth or the cloacal respiratory trees for protection by living inside the sea cucumber. Nevertheless, holothurians species of the genus "Actinopyga" have anal teeth


title: "Sea cucumber" content: that prevent visitors from penetrating their anus. Sea cucumbers can also shelter bivalvia as endocommensals, such as "Entovalva sp". Sea cucumbers are often scorned by most of the marine predators because of the toxins they contain (in particular holothurin) and because of their often spectacular defensive systems. However, they remain a prey for some highly specialized predators which are not affected by their toxins, such as the big mollusks "Tonna galea" and "Tonna perdix", which paralyzes them using powerful poison before swallowing them completely. Some other less specialized and opportunist predators can also prey on sea cucumbers sometimes when they


title: "Sea cucumber" content: cannot find any better food, such as certain species of fish (triggerfish, pufferfish) and crustaceans (crabs, lobsters, hermit crabs). Some species of coral-reef sea cucumbers within the order Aspidochirotida can defend themselves by expelling their sticky cuvierian tubules (enlargements of the respiratory tree that float freely in the coelom) to entangle potential predators. When startled, these cucumbers may expel some of them through a tear in the wall of the cloaca in an autotomic process known as evisceration. Replacement tubules grow back in one and a half to five weeks, depending on the species. The release of these tubules can


title: "Sea cucumber" content: also be accompanied by the discharge of a toxic chemical known as holothurin, which has similar properties to soap. This chemical can kill animals in the vicinity and is one more method by which these sedentary animals can defend themselves. If the water temperature becomes too high, some species of sea cucumber from temperate seas can aestivate. While they are in this state of dormancy they stop feeding, their gut atrophies, their metabolism slows down and they lose weight. The body returns to its normal state when conditions improve. Holothuroidea (sea cucumbers) are one of five extant classes that make


title: "Sea cucumber" content: up the phylum Echinodermata. Echinodermata is known as one of the most distinctive and diverse phyla ranging from starfish to urchins to sea cucumbers and many other organisms. The echinoderms are mainly distinguished from other phyla by their body plan and organization. While the organisms in this phylum may not all look the same from the outside, their make-up is another story. There are three main characteristics that all echinoderms share. When mature, echinoderms have a pentamerous radial symmetry. While this can easily be seen in a sea star or brittle star, in the sea cucumber it is less distinct


title: "Sea cucumber" content: and seen in their five primary tentacles. The pentamerous radial symmetry can also be seen in their five ambulacral canals. The ambulacral canals are used in their water vascular system which is another characteristic that binds this phylum together. The water vascular system that develops from their middle coelom or hydrocoel. Echinoderms use this system for many things including movement by pushing water in and out of their podia or "tube feet". Echinoderms tube feet (including sea cucumbers) can be seen aligned along the side of their axes. While echinoderms are invertebrates, meaning they do not have a spine, they