title: "Common cuckoo" content: by different ancestors. One hypothesis for the inheritance of egg appearance mimicry is that this trait is inherited from the female only, suggesting that it is carried on the sex-determining W chromosome (females are WZ, males ZZ). A genetic analysis of gentes supports this proposal by finding significant differentiation in mitochondrial DNA, but not in microsatellite DNA. A second proposal for the inheritance of this trait is that the genes controlling egg characteristics are carried on autosomes rather than just the W chromosome. Another genetic analysis of sympatric gentes supports this second proposal by finding significant genetic differentiation in both


title: "Common cuckoo" content: microsatellite DNA and mitochondrial DNA. Considering the tendency for common cuckoo males to mate with multiple females and produce offspring raised by more than one host species, it appears as though males do not contribute to the maintenance of common cuckoo gentes. However, it was found that only nine percent of offspring were raised outside of their father's presumed host species. Therefore, both males and females may contribute to the maintenance of common cuckoo egg mimicry polymorphism. It is notable that most non-parasitic cuckoo species lay white eggs, like most non-passerines other than ground-nesters. As the common cuckoo evolves to


title: "Common cuckoo" content: lay eggs that better imitate the host's eggs, the host species adapts and is more able to distinguish the cuckoo egg. A study of 248 common cuckoo and host eggs demonstrated that female cuckoos that parasitised common redstart nests laid eggs that matched better than those that targeted dunnocks. Spectroscopy was used to model how the host species saw the cuckoo eggs. Cuckoos that target dunnock nests lay white, brown-speckled eggs, in contrast to the dunnock's own blue eggs. The theory suggests that common redstarts have been parasitised by common cuckoos for longer, and so have evolved to be better


title: "Common cuckoo" content: than the dunnocks at noticing the cuckoo eggs. Studies were made of 90 great reed warbler nests in central Hungary. There was an ""unusually high"" frequency of common cuckoo parasitism, with 64% of the nests parasitised. Of the nests targeted by cuckoos, 64% contained one cuckoo egg, 23% had two, 10% had three and 3% had four common cuckoo eggs. In total, 58% of the common cuckoo eggs were laid in nests that were multiply parasitised. When laying eggs in nests already parasitised, the female cuckoos removed one egg at random, showing no discrimination between the great reed warbler eggs


title: "Common cuckoo" content: and those of other cuckoos. It was found that nests close to cuckoo perches were most vulnerable: multiple parasitised nests were closest to the vantage points, and unparasitised nests were farthest away. Nearly all the nests ""in close vicinity"" to the vantage points were parasitised. More visible nests were more likely to be selected by the common cuckoos. Female cuckoos use their vantage points to watch for potential hosts and find it easier to locate the more visible nests while they are egg-laying. The great reed warblers' responses to the common cuckoo eggs varied: 66% accepted the egg(s); 12% ejected


title: "Common cuckoo" content: them; 20% abandoned the nests entirely; 2% buried the eggs. 28% of the cuckoo eggs were described as ""almost perfect"" in their mimesis of the host eggs, and the warblers rejected ""poorly mimetic"" cuckoo eggs more often. The degree of mimicry made it difficult for both the great reed warblers and the observers to tell the eggs apart. The egg measures and weighs , of which 7% is shell. Research has shown that the female common cuckoo is able to keep its egg inside its body for an extra 24 hours before laying it in a host's nest. This means


title: "Common cuckoo" content: the cuckoo chick can hatch before the host's chicks do, and it can eject the unhatched eggs from the nest. Scientists incubated common cuckoo eggs for 24 hours at the bird's body temperature of , and examined the embryos, which were found "much more advanced" than those of other species studied. The idea of 'internal incubation' was first put forward in 1802 and 18th and 19th Century egg collectors had reported finding that cuckoo embryos were more advanced than those of the host species. The naked, altricial chick hatches after 11–13 days. It methodically evicts all host progeny from host


title: "Common cuckoo" content: nests. It is a much larger bird than its hosts, and needs to monopolize the food supplied by the parents. The chick will roll the other eggs out of the nest by pushing them with its back over the edge. If the host's eggs hatch before the cuckoo's, the cuckoo chick will push the other chicks out of the nest in a similar way. At 14 days old, the common cuckoo chick is about three times the size of an adult Eurasian reed warbler. The necessity of eviction behavior is unclear. One hypothesis is that competing with host chicks leads


title: "Common cuckoo" content: to decreased cuckoo chick weight, which is selective pressure for eviction behavior. An analysis of the amount of food provided to common cuckoo chicks by host parents in the presence and absence of host siblings showed that when competing against host siblings, cuckoo chicks did not receive enough food, showing an inability to compete. Selection pressure for eviction behavior may come from cuckoo chicks lacking the correct visual begging signals, hosts distributing food to all nestlings equally, or host recognition of the parasite. Another hypothesis is that decreased cuckoo chick weight is not selective pressure for eviction behavior. An analysis


title: "Common cuckoo" content: of resources provided to cuckoo chick in the presence and absence of host siblings also showed that the weights of cuckoos raised with host chicks were much smaller upon fledging than cuckoos raised alone, but within 12 days cuckoos raised with siblings grew faster than cuckoos raised alone and made up for developmental differences, showing a flexibility that would not necessarily select for eviction behavior. Species whose broods are parasitised by the common cuckoo have evolved to discriminate against cuckoo eggs but not chicks. Experiments have shown that common cuckoo chicks persuade their host parents to feed them by making


title: "Common cuckoo" content: a rapid begging call that sounds ""remarkably like a whole brood of host chicks."" The researchers suggested that ""the cuckoo needs vocal trickery to stimulate adequate care to compensate for the fact that it presents a visual stimulus of just one gape."" However, a cuckoo chick needs the amount of food of a whole brood of host nestlings, and it struggles to elicit that much from the host parents with only the vocal stimulus. This may reflect a tradeoff—the cuckoo chick benefits from eviction by receiving all the food provided, but faces a cost in being the only one influencing


title: "Common cuckoo" content: feeding rate. For this reason, cuckoo chicks exploit host parental care by remaining with the host parent longer than host chicks do, both before and after fledging. Common cuckoo chicks fledge about 17–21 days after hatching, compared to 12–13 days for Eurasian reed warblers. If the hen cuckoo is out-of-phase with a clutch of Eurasian reed warbler eggs, she will eat them all so that the hosts are forced to start another brood. The common cuckoo's behaviour was firstly observed and described by Aristotle and the combination of behaviour and anatomical adaptation by Edward Jenner, who was elected as Fellow


title: "Common cuckoo" content: of the Royal Society in 1788 for this work rather than for his development of the smallpox vaccine. It was first documented on film in 1922 by Edgar Chance and Oliver G Pike, in their film 'The Cuckoo's Secret'. A study in Japan found that young common cuckoos probably acquire species-specific feather lice from body-to-body contact with other cuckoos between the time of leaving the nest and returning to the breeding area in spring. A total of 21 nestlings were examined shortly before they left their hosts' nests and none carried feather lice. However, young birds returning to Japan for


title: "Common cuckoo" content: the first time were found just as likely as older individuals to be lousy. The occurrence of common cuckoo in Europe is a good surrogate for biodiversity facets including taxonomic diversity and functional diversity in bird communities, and better than the traditional use of top predators as bioindicators. The reason for this is the strong correlation between the cuckoo's host species richness and overall bird species richness, due to co-evolutionary relationships. This may be useful for citizen science. Aristotle was aware of the old tale that cuckoos turned into hawks in winter. The tale was an explanation for their absence


title: "Common cuckoo" content: outside the summer season, later accepted by Pliny the Elder in his "Natural History". Aristotle rejected the claim, observing in his "History of Animals" that cuckoos do not have the predators' talons or hooked bills. These Classical era accounts were known to the Early Modern English naturalist, William Turner. The 13th century medieval English round, "Sumer Is Icumen In", celebrates the cuckoo as a sign of spring, the beginning of summer, in the first stanza, and in the chorus: <poem> Svmer is icumen in Lhude sing cuccu Groweþ sed and bloweþ med and springþ þe wde nu Sing cuccu </poem>


title: "Common cuckoo" content: <poem> Summer has arrived, Sing loudly, cuckoo! The seed is growing And the meadow is blooming, And the wood is coming into leaf now, Sing, cuckoo! </poem> In England, William Shakespeare alludes to the common cuckoo's association with spring, and with cuckoldry, in the courtly springtime song in his play "Love's Labours Lost": In Europe, hearing the call of the common cuckoo is regarded as the first harbinger of spring. Many local legends and traditions are based on this. In Scotland, Gowk Stones (cuckoo stones) sometimes associated with the arrival of the first cuckoo of spring. "Gowk" is an old


title: "Common cuckoo" content: name for the common cuckoo in northern England, derived from the harsh repeated ""gowk"" call the bird makes when excited. The well-known cuckoo clock features a mechanical bird and is fitted with bellows and pipes that imitate the call of the common cuckoo. Cuckoos feature in traditional rhymes, such as '"In April the cuckoo comes, In May she'll stay, In June she changes her tune, In July she prepares to fly, Come August, go she must,"' quoted Peggy. 'But you haven't said it all,' put in Bobby. '"And if the cuckoo stays till September, It's as much as the oldest


title: "Common cuckoo" content: man can remember."' Two English folk songs feature cuckoos. One usually called "The Cuckoo" starts: The cuckoo is a fine bird and she sings as she flies,
 She brings us good tidings, she tells us no lies.
 She sucks little birds' eggs to make her voice clear,
 And never sings cuckoo till the summer draws near
 The second, "The Cuckoo's Nest" is a song about a courtship, with the eponymous (and of course, non-existent) nest serving as a metaphor: Me darling, says she, I can do no such thing
 For me mother often told me it was committing sin
 Me


title: "Common cuckoo" content: maidenhead to lose and me sex to be abused
 So have no more to do with me cuckoo's nest
 One of the tales of the Wise Men of Gotham tells how they built a hedge round a tree in order to trap a cuckoo so that it would always be summer. Common cuckoo The common cuckoo ("Cuculus canorus") is a member of the cuckoo order of birds, "Cuculiformes", which includes the roadrunners, the anis and the coucals. This species is a widespread summer migrant to Europe and Asia, and winters in Africa. It is a brood parasite, which means it


title: Citigroup content: dividend to 16 cent a share and approving a $8.6 billion stock repurchase program, Citi Capital Advisors (CCA), formerly Citi Alternative Investments, was a hedge fund that offered various investment strategies across multiple asset classes. To comply with the Volcker Rule, which limits bank ownership in hedge funds to no more than 3%, Citi spun off its hedge fund unit in 2013 and gave a majority of the company to its managers. The spin-off of CCA created Napier Park Global Capital, a $6.8 billion hedge fund with more than 100 employees in New York and London and managed by Jim


title: "Nuclear power plant" content: Nuclear power plant A nuclear power plant or nuclear power station is a thermal power station in which the heat source is a nuclear reactor. As it is typical of thermal power stations, heat is used to generate steam that drives a steam turbine connected to a generator that produces electricity. , the IAEA report there are 450 nuclear power reactors in operation operating in 31 countries. Nuclear plants are usually considered to be base load stations since fuel is a small part of the cost of production and because they cannot be easily or quickly dispatched. Their operations and


title: "Nuclear power plant" content: maintenance (O&M) and fuel costs are, along with hydropower stations, at the low end of the spectrum and make them suitable as base-load power suppliers. The cost of spent fuel management, however, is somewhat uncertain. Electricity was generated by a nuclear reactor for the first time ever on September 3, 1948 at the X-10 Graphite Reactor in Oak Ridge, Tennessee in the United States, which was the first nuclear power station to power a light bulb. The second, larger experiment occurred on December 20, 1951 at the EBR-I experimental station near Arco, Idaho in the United States. On June 27,


title: "Nuclear power plant" content: 1954, the world's first nuclear power station to generate electricity for a power grid started operations at the Soviet city of Obninsk. The world's first full scale power station, Calder Hall in England, opened on October 17, 1956. The world's first full scale power station solely devoted to electricity production (Calder Hall was also meant to produce plutonium), Shippingport power plant in the United States, connected to the grid on December 18, 1957. The key components common to current nuclear power plants are: The conversion to electrical energy takes place indirectly, as in conventional thermal power stations. The fission in


title: "Nuclear power plant" content: a nuclear reactor heats the reactor coolant. The coolant may be water or gas or even liquid metal depending on the type of reactor. The reactor coolant then goes to a steam generator and heats water to produce steam. The pressurized steam is then usually fed to a multi-stage steam turbine. After the steam turbine has expanded and partially condensed the steam, the remaining vapor is condensed in a condenser. The condenser is a heat exchanger which is connected to a secondary side such as a river or a cooling tower. The water is then pumped back into the steam


title: "Nuclear power plant" content: generator and the cycle begins again. The water-steam cycle corresponds to the Rankine cycle. The nuclear reactor is the heart of the station. In its central part, the reactor's core produces heat due to nuclear fission. With this heat, a coolant is heated as it is pumped through the reactor and thereby removes the energy from the reactor. Heat from nuclear fission is used to raise steam, which runs through turbines, which in turn powers the electrical generators. Nuclear reactors usually rely on uranium to fuel the chain reaction. Uranium is a very heavy metal that is abundant on Earth


title: "Nuclear power plant" content: and is found in sea water as well as most rocks. Naturally occurring uranium is found in two different isotopes: uranium-238 (U-238), accounting for 99.3% and uranium-235 (U-235) accounting for about 0.7%. Isotopes are atoms of the same element with a different number of neutrons. Thus, U-238 has 146 neutrons and U-235 has 143 neutrons. Different isotopes have different behaviours. For instance, U-235 is fissile which means that it is easily split and gives off a lot of energy making it ideal for nuclear energy. On the other hand, U-238 does not have that property despite it being the same


title: "Nuclear power plant" content: element. Different isotopes also have different half-lives. A half-life is the amount of time it takes for half of a sample of a radioactive element to decay. U-238 has a longer half-life than U-235, so it takes longer to decay over time. This also means that U-238 is less radioactive than U-235. Since nuclear fission creates radioactivity, the reactor core is surrounded by a protective shield. This containment absorbs radiation and prevents radioactive material from being released into the environment. In addition, many reactors are equipped with a dome of concrete to protect the reactor against both internal casualties and


title: "Nuclear power plant" content: external impacts. The purpose of the steam turbine is to convert the heat contained in steam into mechanical energy. The engine house with the steam turbine is usually structurally separated from the main reactor building. It is so aligned to prevent debris from the destruction of a turbine in operation from flying towards the reactor. In the case of a pressurized water reactor, the steam turbine is separated from the nuclear system. To detect a leak in the steam generator and thus the passage of radioactive water at an early stage, an activity meter is mounted to track the outlet


title: "Nuclear power plant" content: steam of the steam generator. In contrast, boiling water reactors pass radioactive water through the steam turbine, so the turbine is kept as part of the radiologically controlled area of the nuclear power station. The generator converts mechanical power supplied by the turbine into electrical power. Low-pole AC synchronous generators of high rated power are used. A cooling system removes heat from the reactor core and transports it to another area of the station, where the thermal energy can be harnessed to produce electricity or to do other useful work. Typically the hot coolant is used as a heat source


title: "Nuclear power plant" content: for a boiler, and the pressurized steam from that drives one or more steam turbine driven electrical generators. In the event of an emergency, safety valves can be used to prevent pipes from bursting or the reactor from exploding. The valves are designed so that they can derive all of the supplied flow rates with little increase in pressure. In the case of the BWR, the steam is directed into the suppression chamber and condenses there. The chambers on a heat exchanger are connected to the intermediate cooling circuit. The main condenser is a large cross-flow tube-and-shell heat exchanger that


title: "Nuclear power plant" content: takes wet vapor, a mixture of liquid water and steam at saturation conditions, from the turbine-generator exhaust and condenses it back into sub-cooled liquid water so it can be pumped back to the reactor by the condensate and feedwater pumps. In the main condenser the wet vapor turbine exhaust come into contact with thousands of tubes that have much colder water flowing through them on the other side. The cooling water typically come from a natural body of water such as a river or lake. Palo Verde Nuclear Generating Station, located in the desert about 60 miles west of Phoenix,


title: "Nuclear power plant" content: Arizona, is the only nuclear facility that does not use a natural body of water for cooling, instead it uses treated sewage from the greater Phoenix metropolitan area. The water coming from the cooling body of water is either pumped back to the water source at a warmer temperature or returns to a cooling tower where it either cools for more uses or evaporates into water vapor that rises out the top of the tower. The water level in the steam generator and the nuclear reactor is controlled using the feedwater system. The feedwater pump has the task of taking


title: "Nuclear power plant" content: the water from the condensate system, increasing the pressure and forcing it into either the steam generators (in the case of a pressurized water reactor) or directly into the reactor (for boiling water reactors). Most nuclear stations require two distinct sources of offsite power feeding station service transformers that are sufficiently separated in the station's switchyard and can receive power from multiple transmission lines. In addition in some nuclear stations, the turbine generator can power the station's house loads while the station is online via station service transformers which tap power from the generator output bus bars before they reach


title: "Nuclear power plant" content: the step-up transformer (these stations also have station service transformers that receive offsite power directly from the switch yard). Even with the redundancy of two power sources total loss of offsite power is still possible. Nuclear power stations are equipped with emergency power. In the United States and Canada, workers except for management, professional (such as engineers) and security personnel are likely to be members of either the International Brotherhood of Electrical Workers (IBEW) or the Utility Workers Union of America (UWUA), or one of the various trades and labor unions representing Machinist, laborers, boilermakers, millwrights, ironworkers etc. The economics


title: "Nuclear power plant" content: of new nuclear power stations is a controversial subject, and multibillion-dollar investments ride on the choice of an energy source. Nuclear power stations typically have high capital costs, but low direct fuel costs, with the costs of fuel extraction, processing, use and spent fuel storage internalized costs. Therefore, comparison with other power generation methods is strongly dependent on assumptions about construction timescales and capital financing for nuclear stations. Cost estimates take into account station decommissioning and nuclear waste storage or recycling costs in the United States due to the Price Anderson Act. With the prospect that all spent nuclear fuel/"nuclear


title: "Nuclear power plant" content: waste" could potentially be recycled by using future reactors, generation IV reactors are being designed to completely close the nuclear fuel cycle. However, up to now, there has not been any actual bulk recycling of waste from a NPP, and on-site temporary storage is still being used at almost all plant sites due to waste repository construction problems. Only Finland has stable repository plans, therefore from a worldwide perspective, long-term waste storage costs are uncertain. On the other hand, construction, or capital cost aside, measures to mitigate global warming such as a carbon tax or carbon emissions trading, increasingly favor


title: "Nuclear power plant" content: the economics of nuclear power. Further efficiencies are hoped to be achieved through more advanced reactor designs, Generation III reactors promise to be at least 17% more fuel efficient, and have lower capital costs, while futuristic Generation IV reactors promise 10000-30000% greater fuel efficiency and the elimination of nuclear waste. In Eastern Europe, a number of long-established projects are struggling to find finance, notably Belene in Bulgaria and the additional reactors at Cernavoda in Romania, and some potential backers have pulled out. Where cheap gas is available and its future supply relatively secure, this also poses a major problem for


title: "Nuclear power plant" content: nuclear projects. Analysis of the economics of nuclear power must take into account who bears the risks of future uncertainties. To date all operating nuclear power stations were developed by state-owned or regulated utility monopolies where many of the risks associated with construction costs, operating performance, fuel price, and other factors were borne by consumers rather than suppliers. Many countries have now liberalized the electricity market where these risks and the risk of cheaper competitors emerging before capital costs are recovered, are borne by station suppliers and operators rather than consumers, which leads to a significantly different evaluation of the


title: "Nuclear power plant" content: economics of new nuclear power stations. Following the 2011 Fukushima I nuclear accidents, costs are likely to go up for currently operating and new nuclear power stations, due to increased requirements for on-site spent fuel management and elevated design basis threats. However many designs, such as the currently under construction AP1000, use passive nuclear safety cooling systems, unlike those of Fukushima I which required active cooling systems, which largely eliminates the need to spend more on redundant back up safety equipment. In his book, "Normal accidents", Charles Perrow says that multiple and unexpected failures are built into society's complex and


title: "Nuclear power plant" content: tightly-coupled nuclear reactor systems. Such accidents are unavoidable and cannot be designed around. An interdisciplinary team from MIT has estimated that given the expected growth of nuclear power from 2005 – 2055, at least four serious nuclear accidents would be expected in that period. However the MIT study does not take into account improvements in safety since 1970. To date, there have been five serious accidents (core damage) in the world since 1970 (one at Three Mile Island in 1979; one at Chernobyl in 1986; and three at Fukushima-Daiichi in 2011), corresponding to the beginning of the operation of generation


title: "Nuclear power plant" content: II reactors. This leads to on average one serious accident happening every eight years worldwide. Modern nuclear reactor designs have had numerous safety improvements since the first-generation nuclear reactors. Nuclear power plants cannot explode like a nuclear bomb because the fuel for uranium reactors is not enriched enough, and nuclear weapons require precision explosives to force fuel into a small enough volume to go supercritical. Most reactors require continuous temperature control to prevent a core meltdown, which has occurred on a few occasions through accident or natural disaster, releasing radiation and making the surrounding area uninhabitable. Plants must be defended


title: "Nuclear power plant" content: against theft of nuclear material (for example to make a dirty bomb) and attack by enemy military (which has occurred) planes or missiles, or planes hijacked by terrorists. The nuclear power debate is about the controversy which has surrounded the deployment and use of nuclear fission reactors to generate electricity from nuclear fuel for civilian purposes. The debate about nuclear power peaked during the 1970s and 1980s, when it "reached an intensity unprecedented in the history of technology controversies", in some countries. Proponents argue that nuclear power is a sustainable energy source which reduces carbon emissions and can increase energy


title: "Nuclear power plant" content: security if its use supplants a dependence on imported fuels. Proponents advance the notion that nuclear power produces virtually no air pollution, in contrast to the chief viable alternative of fossil fuel. Proponents also believe that nuclear power is the only viable course to achieve energy independence for most Western countries. They emphasize that the risks of storing waste are small and can be further reduced by using the latest technology in newer reactors, and the operational safety record in the Western world is excellent when compared to the other major kinds of power plants. Opponents say that nuclear power


title: "Nuclear power plant" content: poses many threats to people and the environment, and that costs do not justify benefits. Threats include health risks and environmental damage from uranium mining, processing and transport, the risk of nuclear weapons proliferation or sabotage, and the unsolved problem of radioactive nuclear waste. Another environmental issue is discharge of hot water into the sea. The hot water modifies the environmental conditions for marine flora and fauna. They also contend that reactors themselves are enormously complex machines where many things can and do go wrong, and there have been many serious nuclear accidents. Critics do not believe that these risks


title: "Nuclear power plant" content: can be reduced through new technology. They argue that when all the energy-intensive stages of the nuclear fuel chain are considered, from uranium mining to nuclear decommissioning, nuclear power is not a low-carbon electricity source. Those countries that do not contain uranium mines cannot achieve energy independence through existing nuclear power technologies. Actual construction costs often exceed estimates, and spent fuel management costs do not have a clear time limit. Nuclear reprocessing technology was developed to chemically separate and recover fissionable plutonium from irradiated nuclear fuel. Reprocessing serves multiple purposes, whose relative importance has changed over time. Originally reprocessing was


title: "Nuclear power plant" content: used solely to extract plutonium for producing nuclear weapons. With the commercialization of nuclear power, the reprocessed plutonium was recycled back into MOX nuclear fuel for thermal reactors. The reprocessed uranium, which constitutes the bulk of the spent fuel material, can in principle also be re-used as fuel, but that is only economic when uranium prices are high or disposal is expensive. Finally, the breeder reactor can employ not only the recycled plutonium and uranium in spent fuel, but all the actinides, closing the nuclear fuel cycle and potentially multiplying the energy extracted from natural uranium by more than 60


title: "Nuclear power plant" content: times. Nuclear reprocessing reduces the volume of high-level waste, but by itself does not reduce radioactivity or heat generation and therefore does not eliminate the need for a geological waste repository. Reprocessing has been politically controversial because of the potential to contribute to nuclear proliferation, the potential vulnerability to nuclear terrorism, the political challenges of repository siting (a problem that applies equally to direct disposal of spent fuel), and because of its high cost compared to the once-through fuel cycle. In the United States, the Obama administration stepped back from President Bush's plans for commercial-scale reprocessing and reverted to a


title: "Nuclear power plant" content: program focused on reprocessing-related scientific research. The Vienna Convention on Civil Liability for Nuclear Damage puts in place an international framework for nuclear liability. However states with a majority of the world's nuclear power stations, including the U.S., Russia, China and Japan, are not party to international nuclear liability conventions. In the U.S., insurance for nuclear or radiological incidents is covered (for facilities licensed through 2025) by the Price-Anderson Nuclear Industries Indemnity Act. Under the Energy policy of the United Kingdom through its Nuclear Installations Act 1965, liability is governed for nuclear damage for which a UK nuclear licensee is


title: "Nuclear power plant" content: responsible. The Act requires compensation to be paid for damage up to a limit of £150 million by the liable operator for ten years after the incident. Between ten and thirty years afterwards, the Government meets this obligation. The Government is also liable for additional limited cross-border liability (about £300 million) under international conventions (Paris Convention on Third Party Liability in the Field of Nuclear Energy and Brussels Convention supplementary to the Paris Convention). Nuclear decommissioning is the dismantling of a nuclear power station and decontamination of the site to a state no longer requiring protection from radiation for the


title: "Nuclear power plant" content: general public. The main difference from the dismantling of other power stations is the presence of radioactive material that requires special precautions to remove and safely relocate to a waste repository. Generally speaking, nuclear stations were originally designed for a life of about 30 years. Newer stations are designed for a 40 to 60-year operating life. The Centurion Reactor is a future class of nuclear reactor that is being designed to last 100 years. One of the major limiting wear factors is the deterioration of the reactor's pressure vessel under the action of neutron bombardment, however in 2018 Rosatom announced


title: "Nuclear power plant" content: it had developed a thermal annealing technique for reactor pressure vessels which ameliorates radiation damage and extends service life by between 15 and 30 years. Decommissioning involves many administrative and technical actions. It includes all clean-up of radioactivity and progressive demolition of the station. Once a facility is decommissioned, there should no longer be any danger of a radioactive accident or to any persons visiting it. After a facility has been completely decommissioned it is released from regulatory control, and the licensee of the station no longer has responsibility for its nuclear safety. The Chernobyl disaster occurred in April 1986,


title: "Nuclear power plant" content: it is considered the worst nuclear accident in history. An experiment was being carried out on one of the reactors in the plant. The purpose of the experiment was to find out the reactor's safety in the event of the failure of the main electricity supply to the plant. Right after the experiment began there was a steam explosion which exposed the reactor's graphite moderator to air, which caused it to ignite. The resulting fire sent highly radioactive plumes of smoke into the atmosphere for about ten days. The radioactive plume spread over large areas of Europe. Approximately 350,000 people


title: "Nuclear power plant" content: were evacuated from the 3200 kilometers squared exclusion zone. The accident caused 31 direct deaths from the explosion and radiation poisoning, and several more deaths in the population exposed to high radiation doses. The nuclear industry says that new technology and oversight have made nuclear station much safer, but 57 small accidents have occurred since the Chernobyl disaster in 1986 until 2008. Two thirds of these mishaps occurred in the US. The French Atomic Energy Agency (CEA) has concluded that technical innovation cannot eliminate the risk of human errors in nuclear station operation. According to Benjamin Sovacool, an interdisciplinary team


title: "Nuclear power plant" content: from MIT in 2003 estimated that given the expected growth of nuclear power from 2005 – 2055, at least four serious nuclear accidents would be expected in that period. However the MIT study does not take into account improvements in safety since 1970. Nuclear stations are used primarily for base load because of economic considerations. The fuel cost of operations for a nuclear station is smaller than the fuel cost for operation of coal or gas plants. Since most of the cost of nuclear power plant is capital cost, there is almost no cost saving by running it at less


title: "Nuclear power plant" content: than full capacity. Nuclear power plants are routinely used in load following mode on a large scale in France, although "it is generally accepted that this is not an ideal economic situation for nuclear stations." Unit A at the German Biblis Nuclear Power Plant is designed to in- and decrease its output 15% per minute between 40 and 100% of its nominal power. Boiling water reactors normally have load-following capability, implemented by varying the recirculation water flow. A new generation of designs for nuclear power stations, known as the Generation IV reactors, are the subject of active research. Many of


title: "Nuclear power plant" content: these new designs specifically attempt to make fission reactors cleaner, safer and/or less of a risk to the proliferation of nuclear weapons. Passively safe stations (such as the ESBWR) are available to be built and other reactors that are designed to be nearly fool-proof are being pursued. Fusion reactors, which are still in the early stages of development, diminish or eliminate some of the risks associated with nuclear fission. Two 1600 MWe European Pressurized Reactors (EPRs) are being built in Europe, and two are being built in China. The reactors are a joint effort of French AREVA and German Siemens


title: "Nuclear power plant" content: AG, and will be the largest reactors in the world. One EPR is in Olkiluoto, Finland, as part of the Olkiluoto Nuclear Power Plant. The reactor was originally scheduled to go online in 2009, but has been repeatedly delayed, and as of September 2014 has been pushed back to 2018. Preparatory work for the EPR at the Flamanville Nuclear Power Plant in Flamanville, Manche, France was started in 2006, with a scheduled completion date of 2012. The French reactor has also been delayed, and was projected, in 2013, to launch in 2016. The two Chinese EPRs are part of the


title: "Nuclear power plant" content: Taishan Nuclear Power Plant in Taishan, Guangdong. The Taishan reactors were scheduled to go online in 2014 and 2015, but that has been delayed to 2017. , there are seven nuclear power stations under construction in India, and five in China. In November 2011 Gulf Power stated that by the end of 2012 it hopes to finish buying off 4000 acres of land north of Pensacola, Florida in order to build a possible nuclear power station. In 2010 Russia launched a floating nuclear power station. The £100 million vessel, the Akademik Lomonosov, is the first of seven stations that will


title: "Nuclear power plant" content: bring vital energy resources to remote Russian regions. By 2025, Southeast Asia nations plan to have a total of 29 nuclear power stations: Indonesia will have 4 nuclear power stations, Malaysia 4, Thailand 5 and Vietnam 16 from nothing at all in 2011. In 2013 China had 32 nuclear reactors under construction, the highest number in the world. Expansion at two nuclear power stations in the United States, Vogtle and V. C. Summer Nuclear Power Station, located in Georgia and South Carolina, respectively, were scheduled to be completed between 2016 and 2019. The construction of the two South Carolina reactors


title: "Nuclear power plant" content: have been abandoned due to cost overruns and the bankruptcy of Westinghouse Electric Company (who designed and was building the reactors) in March 2017. The two new Vogtle reactors, and the two new reactors at Virgil C. Summer Nuclear Station, represented the first nuclear power construction projects in the United States since the Three Mile Island nuclear accident in 1979. The UK government has given the go-ahead for the Hinkley Point C nuclear power station. Several countries have begun thorium-based nuclear power programs. Thorium is four times more abundant in the earth's crust than uranium. Over 60% of thorium's ore


title: "Nuclear power plant" content: monazite is found in five countries: Australia, the United States, India, Brazil, and Norway. These thorium resources are enough to power current energy needs for thousands of years. The thorium fuel cycle is able to generate nuclear energy with a lower output of radiotoxic waste than the uranium fuel cycle. Nuclear power plant A nuclear power plant or nuclear power station is a thermal power station in which the heat source is a nuclear reactor. As it is typical of thermal power stations, heat is used to generate steam that drives a steam turbine connected to a generator that produces


title: "Magnetic stripe card" content: with payment terminals that do not include a smart card reader. Cards with all three features: magnetic stripe, smart card chip, and RFID chip are also becoming common as more activities require the use of such cards. During DEF CON 24, Weston Hecker presented "Hacking Hotel Keys, and Point Of Sales Systems." In the talk, Hecker described the way magnetic strip cards function and utilised spoofing software, and an Arduino to obtain administrative access from hotel keys, via service staff walking past him. Hecker claims he used administrative keys from POS systems on other systems, effectively providing access to any


title: "Doug Gilmour" content: in 1981. In 1982–83, Gilmour was named the most outstanding player in the OHL after he scored 177 points, one of the highest totals in league history. Gilmour returned to the OHL following his playing career as he joined the Frontenacs as head coach in 2008 and was promoted to general manager in 2011. Gilmour was inducted into the Hockey Hall of Fame and the Ontario Sports Hall of Fame in 2011 and his uniform number 93 is retired by the Toronto Maple Leafs. Doug Gilmour was born June 25, 1963, in Kingston, Ontario. He is the younger son of


title: Hemiptera content: Hemiptera The Hemiptera or true bugs are an order of insects comprising some 50,000 to 80,000 species of groups such as the cicadas, aphids, planthoppers, leafhoppers, and shield bugs. They range in size from to around , and share a common arrangement of sucking mouthparts. The name "true bugs" is sometimes limited to the suborder Heteroptera. Many insects commonly known as "bugs" belong to other orders; for example, the lovebug is a fly, while the May bug and ladybug are beetles. Most hemipterans feed on plants, using their sucking and piercing mouthparts to extract plant sap. Some are parasitic while


title: Hemiptera content: others are predators that feed on other insects or small invertebrates. They live in a wide variety of habitats, generally terrestrial, though some species are adapted to life in or on the surface of fresh water. Hemipterans are hemimetabolous, with young nymphs that somewhat resemble adults. Many aphids are capable of parthenogenesis, producing young from unfertilised eggs; this helps them to reproduce extremely rapidly in favourable conditions. Humans have interacted with the Hemiptera for millennia. Some species, including many aphids, are important agricultural pests, damaging crops by the direct action of sucking sap, but also harming them indirectly by being


title: Hemiptera content: the vectors of serious viral diseases. Other species have been used for biological control of insect pests. Hemipterans have been cultivated for the extraction of the dyestuff cochineal (also known as carmine) and for shellac. The bed bug is a persistent parasite of humans. Cicadas have been used as food, and have appeared in literature from the "Iliad" in Ancient Greece. Hemiptera is the largest order of hemimetabolous insects (not undergoing complete metamorphosis; though some examples such as male scale insects do undergo a form of complete metamorphosis ) containing over 75,000 named species; insect orders with more species all


title: Hemiptera content: have a pupal stage (i.e. they do undergo complete metamorphosis or "holometabolism"), Coleoptera (370,000 described species), Lepidoptera (160,000), Diptera (100,000) and Hymenoptera (100,000). The group is very diverse. The majority of species are terrestrial, including a number of important agricultural pests, but some are found in freshwater habitats. These include the water boatmen, pond skaters, and giant water bugs. The fossil record of hemipterans goes back to the Carboniferous (Moscovian). The oldest fossils are of the Archescytinidae from the Lower Permian and are thought to be basal to the Auchenorrhyncha. Fulguromorpha and Cicadomorpha appear in the Upper Permian, as do


title: Hemiptera content: Sternorrhyncha of the Psylloidea and Aleurodoidea. Aphids and Coccoids appear in the Triassic. The Coleorrhyncha extend back to the Lower Jurassic. The Heteroptera first appeared in the Triassic. The present members of the order Hemiptera (sometimes referred to as Rhynchota) were historically placed into two orders, the so-called Homoptera and Heteroptera/Hemiptera, based on differences in wing structure and the position of the rostrum. The order is now divided into four or more suborders, after the "Homoptera" were established as paraphyletic (now the Auchenorrhyncha and the Sternorrhyncha). The cladogram is based on one analysis of the phylogeny of the Paraneoptera by


title: Hemiptera content: Hu Li and colleagues in 2015, using mitochondrial genome sequences and homogeneous models. It places the Sternorrhyncha as sister clade to the Thysanoptera and the lice, making the Hemiptera as traditionally understood non-monophyletic. However, when heterogeneous models were used, Hemiptera was found to be monophyletic. The result where Hemiptera was found to be non-monophyletic is likely due to phylogenetic artifacts, such as elevated substitution rates in Sternorrhyncha compared with the other suborders of Hemiptera. English names are given in parentheses where possible. The defining feature of hemipterans is their "beak" in which the modified mandibles and maxillae form a "stylet"


title: Hemiptera content: which is sheathed within a modified labium. The stylet is capable of piercing tissues and sucking liquids, while the labium supports it. The stylet contains a channel for the outward movement of saliva and another for the inward movement of liquid food. A salivary pump drives saliva into the prey; a cibarial pump extracts liquid from the prey. Both pumps are powered by substantial dilator muscles in the head. The beak is usually folded under the body when not in use. The diet is typically plant sap, but some hemipterans such as assassin bugs are blood-suckers, and a few are


title: Hemiptera content: predators. Both herbivorous and predatory hemipterans inject enzymes to begin digestion extraorally (before the food is taken into the body). These enzymes include amylase to hydrolyse starch, polygalacturonase to weaken the tough cell walls of plants, and proteinases to break down proteins. Although the Hemiptera vary widely in their overall form, their mouthparts form a distinctive "rostrum". Other insect orders with mouthparts modified into anything like the rostrum and stylets of the Hemiptera include some Phthiraptera, but for other reasons they generally are easy to recognize as non-hemipteran. Similarly, the mouthparts of Siphonaptera, some Diptera and Thysanoptera superficially resemble the


title: Hemiptera content: rostrum of the Hemiptera, but on closer inspection the differences are considerable. Aside from the mouthparts, various other insects can be confused with Hemiptera, but they all have biting mandibles and maxillae instead of the rostrum. Examples include cockroaches and psocids, both of which have longer, many-segmented antennae, and some beetles, but these have fully hardened forewings which do not overlap. The forewings of Hemiptera are either entirely membranous, as in the Sternorrhyncha and Auchenorrhyncha, or partially hardened, as in most Heteroptera. The name "Hemiptera" is from the Greek ('; "half") and ('; "wing"), referring to the forewings of many


title: Hemiptera content: heteropterans which are hardened near the base, but membranous at the ends. Wings modified in this manner are termed "hemelytra" (singular: "hemelytron"), by analogy with the completely hardened elytra of beetles, and occur only in the suborder Heteroptera. In all suborders, the hindwings – if present at all – are entirely membranous and usually shorter than the forewings. The forewings may be held "roofwise" over the body (typical of Sternorrhyncha and Auchenorrhyncha), or held flat on the back, with the ends overlapping (typical of Heteroptera). The antennae in Hemiptera typically consist of four or five segments, although they can still


title: Hemiptera content: be quite long, and the tarsi of the legs have two or three segments. Many hemipterans can produce sound for communication. The "song" of male cicadas, the loudest of any insect, is produced by tymbal organs on the underside of the abdomen, and is used to attract mates. The tymbals are drumlike disks of cuticle, which are clicked in and out repeatedly, making a sound in the same way as popping the metal lid of a jam jar in and out. Stridulatory sounds are produced among the aquatic Corixidae and Notonectidae (backswimmers) using tibial combs rubbed across rostral ridges. Hemipterans


title: Hemiptera content: are hemimetabolous, meaning that they do not undergo metamorphosis, the complete change of form between a larval phase and an adult phase. Instead, their young are called nymphs, and resemble the adults to a greater or lesser degree. The nymphs moult several times as they grow, and each instar resembles the adult more than the previous one. Wing buds grow in later stage nymphs; the final transformation involves little more than the development of functional wings (if they are present at all) and functioning sexual organs, with no intervening pupal stage as in holometabolous insects. Many aphids are parthenogenetic during


title: Hemiptera content: part of the life cycle, such that females can produce unfertilized eggs, which are clones of their mother. All such young are females (thelytoky), so 100% of the population at these times can produce more offspring. Many species of aphid are also viviparous: the young are born live rather than laid as eggs. These adaptations enable aphids to reproduce extremely rapidly when conditions are suitable. Hemipterans make use of a variety of modes of locomotion including swimming, skating on a water surface and jumping, as well as walking and flying like other insects. Several families of Heteroptera are "water bugs",


title: Hemiptera content: adapted to an aquatic lifestyle, such as the water boatmen (Corixidae), water scorpions (Nepidae), and backswimmers (Notonectidae). They are mostly predatory, and have legs adapted as paddles to help the animal move through the water. The pondskaters or water striders (Gerridae) are also associated with water, but use the surface tension of standing water to keep them above the surface; they include the sea skaters in the genus "Halobates", the only truly marine group of insects. Marangoni effect propulsion exploits the change in surface tension when a soap-like surfactant is released on to a water surface, in the same way


title: Hemiptera content: that a toy soap boat propels itself. Water bugs in the genus "Microvelia" (Veliidae) can travel at up to 17 cm/s, twice as fast as they can walk, by this means. Flight is well developed in the Hemiptera although mostly used for short distance movement and dispersal. Wing development is sometimes related to environmental conditions. In aphids, both winged and wingless forms occur with winged forms produced in greater numbers when food resources are depleted. Aphids and whiteflies can sometimes be transported very long distances by atmospheric updrafts and high altitude winds. Many Auchenorrhyncha including representatives of the cicadas, leafhoppers,


title: Hemiptera content: treehoppers, planthoppers, and froghoppers are adapted for jumping (saltation). Treehoppers, for example, jump by rapidly depressing their hind legs. Before jumping, the hind legs are raised and the femora are pressed tightly into curved indentations in the coxae. Treehoppers can attain a take-off velocity of up to 2.7 metres per second and an acceleration of up to 250 g. The instantaneous power output is much greater than that of normal muscle, implying that energy is stored and released to catapult the insect into the air. Cicadas, which are much larger, extend their hind legs for a jump in under a


title: Hemiptera content: millisecond, again implying elastic storage of energy for sudden release. Instead of relying on any form of locomotion, most Sternorrhyncha females are sedentary or completely sessile, attached to their host plants by their thin feeding stylets which cannot be taken out of the plant quickly. Most hemipterans are phytophagous, using their sucking and piercing mouthparts to feed on plant sap. These include cicadas, leafhoppers, treehoppers, planthoppers, froghoppers, aphids, whiteflies, scale insects, and some other groups. Some are monophages, being host specific and only found on one plant taxon, others are oligophages, feeding on a few plant groups, while others again


title: Hemiptera content: are less discriminating polyphages and feed on many species of plant. The relationship between hemipterans and plants appears to be ancient, with piercing and sucking of plants evident in the Early Devonian period. Hemipterans can dramatically cut the mass of affected plants, especially in major outbreaks. They sometimes also change the mix of plants by predation on seeds or feeding on roots of certain species. Some sap-suckers move from one host to another at different times of year. Many aphids spend the winter as eggs on a woody host plant and the summer as parthogenetically reproducing females on a herbaceous


title: Hemiptera content: plant. Phloem sap, which has a higher concentration of sugars and nitrogen, is under positive pressure unlike the more dilute xylem sap. Most of the Sternorrhyncha and a number of Auchenorrhynchan groups feed on phloem. Phloem feeding is common in the Fulgoromorpha, most Cicadellidae and in the Heteroptera. The Typhlocybine Cicadellids specialize in feeding on non-vascular mesophyll tissue of leaves, which is more nutritious than the leaf epidermis. Most Heteroptera also feed on mesophyll tissue where they are more likely to encounter defensive secondary plant metabolites which often leads to the evolution of host specificity. Obligate xylem feeding is a


title: Hemiptera content: special habit that is found in the Auchenorrhyncha among Cicadoidea, Cercopoidea and in Cicadelline Cicadellids. Some phloem feeders may take to xylem sap facultatively, especially when facing dehydration. Xylem feeders tend to be polyphagous; to overcome the negative pressure of xylem requires a special cibarial pump. Phloem feeding hemiptera typically have symbiotic micro-organisms in their gut that help to convert amino acids. Phloem feeders produce honeydew from their anus. A variety of organisms that feed on honeydew form symbiotic associations with phloem-feeders. Phloem sap is a sugary liquid low in amino acids, so insects have to process large quantities to


title: Hemiptera content: meet their nutritional requirements. Xylem sap is even lower in amino acids and contains monosaccharides rather than sucrose, as well as organic acids and minerals. No digestion is required (except for the hydrolysis of sucrose) and 90% of the nutrients in the xylem sap can be utilised. Some phloem sap feeders selectively mix phloem and xylem sap to control the osmotic potential of the liquid consumed. A striking adaptation to a very dilute diet is found in many hemipterans: a filter chamber, a part of the gut looped back on itself as a countercurrent exchanger, which permits nutrients to be


title: Hemiptera content: separated from excess water. The residue, mostly water with sugars and amino acids, is quickly excreted as sticky "honey dew", notably from aphids but also from other Auchenorrhycha and Sternorrhyncha. Some Sternorrhyncha including Psyllids and some aphids are gall formers. These sap-sucking hemipterans inject fluids containing plant hormones into the plant tissues inducing the production of tissue that covers to protects the insect and also act as sinks for nutrition that they feed on. The hackleberry gall psyllid for example, causes a woody gall on the leaf petioles of the hackleberry tree it infests, and the nymph of another psyllid


title: Hemiptera content: produces a protective lerp out of hardened honeydew. Most other hemipterans are predatory, feeding on other insects, or even small vertebrates. This is true of many aquatic species which are predatory, either as nymphs or adults. The predatory shield bug for example stabs caterpillars with its beak and sucks out the body fluids. The saliva of predatory heteropterans contains digestive enzymes such as proteinase and phospholipase, and in some species also amylase. The mouthparts of these insects are adapted for predation. There are toothed stylets on the mandibles able to cut into and abrade tissues of their prey. There are


title: Hemiptera content: further stylets on the maxillae, adapted as tubular canals to inject saliva and to extract the pre-digested and liquified contents of the prey. Some species attack pest insects and are used in biological control. One of these is the spined soldier bug ("Podisus maculiventris") that sucks body fluids from larvae of the Colorado beetle and the Mexican bean beetle. A few hemipterans are haematophagic (often described as "parasites"), feeding on the blood of larger animals. These include bedbugs and the triatomine kissing bugs of the assassin bug family Reduviidae, which can transmit the dangerous "Chagas disease". The first known hemipteran


title: Hemiptera content: to feed in this way on vertebrates was the extinct assassin bug "Triatoma dominicana" found fossilized in amber and dating back about twenty million years. Faecal pellets fossilised beside it show that it transmitted a disease-causing "Trypanosoma" and the amber included hairs of the likely host, a bat. Some species of ant protect and farm aphids (Sternorrhyncha) and other sap-sucking hemipterans, gathering and eating the honeydew that these hemipterans secrete. The relationship is symbiotic, as both ant and aphid benefit. Ants such as the yellow anthill ant, "Lasius flavus", breed aphids of at least four species, "Geoica utricularia", "Tetraneura ulmi",


title: Hemiptera content: "Forda marginata" and "Forda formicaria", taking eggs with them when they found a new colony; in return, these aphids are obligately associated with the ant, breeding mainly or wholly asexually inside anthills. Ants may also protect the plant bugs from their natural enemies, removing the eggs of predatory beetles and preventing access by parasitic wasps. Some leafhoppers (Auchenorrhyncha) are similarly "milked" by ants. In the Corcovado rain forest of Costa Rica, wasps compete with ants to protect and milk leafhoppers; the leafhoppers preferentially give more honeydew, more often, to the wasps, which are larger and may offer better protection. Hemiptera


title: Hemiptera content: form prey to predators including vertebrates, such as birds, and other invertebrates such as ladybirds. In response, hemipterans have evolved antipredator adaptations. "Ranatra" may feign death (thanatosis). Others such as "Carpocoris purpureipennis" secrete toxic fluids to ward off arthropod predators; some Pentatomidae such as "Dolycoris" are able to direct these fluids at an attacker. Toxic cardenolide compounds are accumulated by the heteropteran "Oncopeltus fasciatus" when it consumes milkweeds, while the coreid stinkbug "Amorbus rubiginosus" acquires 2-hexenal from its food plant, "Eucalyptus". Some long-legged bugs mimic twigs, rocking to and fro to simulate the motion of a plant part in the


title: Hemiptera content: wind. The nymph of the Masked hunter bug camouflages itself with sand grains, using its hind legs and tarsal fan to form a double layer of grains, coarser on the outside. The Amazon rain forest cicada "Hemisciera maculipennis" display bright red deimatic flash coloration on their hindwings when threatened; the sudden contrast helps to startle predators, giving the cicadas time to escape. The coloured patch on the hindwing is concealed at rest by an olive green patch of the same size on the forewing, enabling the insect to switch rapidly from cryptic to deimatic behaviour. Some hemipterans such as firebugs


title: Hemiptera content: have bold aposematic warning coloration, often red and black, which appear to deter passerine birds. Many hemipterans including aphids, scale insects and especially the planthoppers secrete wax to protect themselves from threats such as fungi, parasitoidal insects and predators, as well as abiotic factors like desiccation. Hard waxy coverings are especially important in the sedentary Sternorrhyncha such as scale insects, which have no means of escape from predators; other Sternorrhyncha evade detection and attack by creating and living inside plant galls. Nymphal Cicadoidea and Cercopoidea have glands attached to the Malpighian tubules in their proximal segment that produce mucopolysaccharides, which


title: Hemiptera content: form the froth around spittlebugs, offering a measure of protection. Parental care is found in many species of Hemiptera especially in members of the Membracidae and numerous Heteroptera. In many species of shield bug, females stand guard over their egg clusters to protect them from egg parasitoids and predators. In the aquatic Belostomatidae, females lay their eggs on the back of the male which guards the eggs. Protection provided by ants is common in the Auchenorrhyncha. Although many species of Hemiptera are significant pests of crops and garden plants, including many species of aphid and scale insects, other species are


title: Hemiptera content: harmless. The damage done is often not so much the deprivation of the plant of its sap, but the fact that they transmit serious viral diseases between plants. They often produce copious amounts of honeydew which encourages the growth of sooty mould. Significant pests include the cottony cushion scale, a pest of citrus fruit trees, the green peach aphid and other aphids which attack crops worldwide and transmit diseases, and jumping plant lice which are often host plant-specific and transmit diseases. Members of the families Reduviidae, Phymatidae and Nabidae are obligate predators. Some predatory species are used in biological pest


title: Hemiptera content: control; these include various nabids, and even some members of families that are primarily phytophagous, such as the genus "Geocoris" in the family Lygaeidae. Other hemipterans are omnivores, alternating between a plant-based and an animal-based diet. For example, "Dicyphus hesperus" is used to control whitefly on tomatoes but also sucks sap, and if deprived of plant tissues will die even if in the presence of whiteflies. Other hemipterans have positive uses for humans, such as in the production of the dyestuff carmine (cochineal). The FDA has created guidelines for how to declare when it has been added to a product.


title: Hemiptera content: The scale insect "Dactylopius coccus" produces the brilliant red-coloured carminic acid to deter predators. Up to 100,000 scale insects need to be collected and processed to make a kilogram (2.2 lbs) of cochineal dye. A similar number of lac bugs are needed to make a kilogram of shellac, a brush-on colourant and wood finish. Additional uses of this traditional product include the waxing of citrus fruits to extend their shelf-life, and the coating of pills to moisture-proof them, provide slow-release or mask the taste of bitter ingredients. Chagas disease is a modern-day tropical disease caused by "Trypanosoma cruzi" and transmitted


title: Hemiptera content: by kissing bugs, so-called because they suck human blood from around the lips while a person sleeps. The bed bug, "Cimex lectularius", is an external parasite of humans. It lives in bedding and is mainly active at night, feeding on human blood, generally without being noticed. Bed bugs mate by traumatic insemination; the male pierces the female's abdomen and injects his sperm into a secondary genital structure, the spermalege. The sperm travel in the female's blood (haemolymph) to sperm storage structures (seminal conceptacles); they are released from there to fertilise her eggs inside her ovaries. Some larger hemipterans such as


title: Hemiptera content: cicadas are used as food in Asian countries such as China, and they are much esteemed in Malawi and other African countries. Insects have a high protein content and good food conversion ratios, but most hemipterans are too small to be a useful component of the human diet. At least nine species of Hemiptera are eaten worldwide. Cicadas have featured in literature since the time of Homer's "Iliad", and as motifs in decorative art from the Chinese Shang dynasty (1766–1122 B.C.). They are described by Aristotle in his "History of Animals" and by Pliny the Elder in his "Natural History";


title: Hemiptera content: their mechanism of sound production is mentioned by Hesiod in his poem "Works and Days" "when the Skolymus flowers, and the tuneful "Tettix" sitting on his tree in the weary summer season pours forth from under his wings his shrill song". Among the bugs, cicadas in particular have been used as money, in folk medicine, to forecast the weather, to provide song (in China), and in folklore and myths around the world. Large-scale cultivation of the oil palm "Elaeis guineensis" in the Amazon basin damages freshwater habitats and reduces the diversity of aquatic and semi-aquatic Heteroptera. Climate change may be


title: Hemiptera content: affecting the global migration of hemipterans including the potato leafhopper, "Empoasca fabae". Warming is correlated with the severity of potato leafhopper infestation, so increased warming may worsen infestations in future. Hemiptera The Hemiptera or true bugs are an order of insects comprising some 50,000 to 80,000 species of groups such as the cicadas, aphids, planthoppers, leafhoppers, and shield bugs. They range in size from to around , and share a common arrangement of sucking mouthparts. The name "true bugs" is sometimes limited to the suborder Heteroptera. Many insects commonly known as "bugs" belong to other orders; for example, the lovebug


title: Meerkat content: Meerkat The meerkat or suricate ("Suricata suricatta") is a small carnivoran belonging to the mongoose family (Herpestidae). It is the only member of the genus Suricata. Meerkats live in all parts of the Kalahari Desert in Botswana, in much of the Namib Desert in Namibia and southwestern Angola, and in South Africa. A group of meerkats is called a "mob", "gang" or "clan". A meerkat clan often contains about 20 meerkats, but some super-families have 50 or more members. In captivity, meerkats have an average life span of 12–14 years, and about half this in the wild. "Meerkat" is a


title: Meerkat content: loanword from Afrikaans (). The name has a Dutch origin, but by misidentification. In Dutch, "meerkat" means the guenon, a monkey of the genus "Cercopithecus". The word "meerkat" is Dutch for "lake cat", but although the suricata is a feliform, it is not of the cat family; the word possibly started as a Dutch adaptation of a derivative of Sanskrit "markaṭa" = "ape", perhaps in Africa via an Indian sailor on board a Dutch East India Company ship. In early literature, suricates were referred as "mierkat". In colloquial Afrikaans, "mier" means termite, and "kat" means cat. It has been speculated


title: Meerkat content: that the name comes from their frequent association with termite mounds or the termites they eat. Three subspecies are currently recognized: The meerkat is a small diurnal herpestid (mongoose) weighing on average about . Its long slender body and limbs give it a body length of and an added tail length of around . The meerkat uses its tail to balance when standing upright, as well as for signaling. Its face tapers, coming to a point at the nose, which is brown. The eyes always have black patches around them, and they have small black crescent-shaped ears. Like cats, meerkats


title: Meerkat content: have binocular vision, their eyes being on the front of their faces. At the end of each of a meerkat's "fingers" is a claw used for digging burrows and digging for prey. Claws are also used with muscular hindlegs to help climb trees. Meerkats have four toes on each foot and long slender limbs. The coat is usually peppered gray, tan, or brown with silver. They have short parallel stripes across their backs, extending from the base of the tail to the shoulders. The patterns of stripes are unique to each meerkat. The underside of the meerkat has no markings,


title: Meerkat content: but the belly has a patch which is only sparsely covered with hair and shows the black skin underneath. The meerkat uses this area to absorb heat while standing on its rear legs, usually early in the morning after cold desert nights. Meerkats are primarily insectivores, but also eat other animals (lizards, snakes, scorpions, spiders, eggs, small mammals, millipedes, centipedes and, more rarely, small birds), plants and fungi (the desert truffle "Kalaharituber pfeilii"). Meerkats are immune to certain types of venom, including the very strong venom of the scorpions of the Kalahari Desert. Baby meerkats do not start foraging for


title: Meerkat content: food until they are about 1 month old, and do so by following an older member of the group who acts as the pup's tutor. Meerkats forage in a group with one "sentry" on guard watching for predators while the others search for food. Sentry duty is usually approximately an hour long. The meerkat standing guard makes peeping sounds when all is well. A meerkat has the ability to dig through a quantity of sand equal to its own weight in just seconds. Digging is done to create burrows, to get food and also to create dust clouds to distract


title: Meerkat content: predators. Martial eagles, tawny eagles and jackals are the main predators of meerkats. Meerkats sometimes die of snakebite in confrontations with snakes (puff adders and Cape cobras). Meerkats become sexually mature at about two years of age and can have one to four pups in a litter, with three pups being the most common litter size. Meerkats are iteroparous and can reproduce any time of the year. The pups are allowed to leave the burrow at two to three weeks old. There is no precopulatory display; the male may fight with the female until she submits to him and copulation


title: Meerkat content: begins. Gestation lasts approximately 11 weeks and the young are born within the underground burrow and are altricial (undeveloped). The young's ears open at about 10 days of age, and their eyes at 10–14 days. They are weaned around 49 to 63 days. Usually, the alpha pair reserves the right to mate and normally kills any young not its own, to ensure that its offspring have the best chance of survival. The dominant couple may also evict, or kick out the mothers of the offending offspring. New meerkat groups are often formed by evicted females joining a group of males.


title: Meerkat content: Females appear to be able to discriminate the odour of their kin from the odour of their non-kin. Kin recognition is a useful ability that facilitates cooperation among relatives and the avoidance of inbreeding. When mating does occur between meerkat relatives, it often results in negative fitness consequences or inbreeding depression. Inbreeding depression was evident for a variety of traits: pup mass at emergence from the natal burrow, hind-foot length, growth until independence and juvenile survival. These negative effects are likely due to the increased homozygosity that arises from inbreeding and the consequent expression of deleterious recessive mutations. The avoidance


title: Meerkat content: of inbreeding and the promotion of outcrossing allow the masking of deleterious recessive mutations. (Also see Complementation (genetics).) Meerkats are small burrowing animals, living in large underground networks with multiple entrances which they leave only during the day, except to avoid the heat of the afternoon. They are very social creatures and they live in colonies together. Animals in the same group groom each other regularly. The alpha pair often scent-mark subordinates of the group to express their authority. There may be up to 30 meerkats in a group. To look out for predators, one or more meerkats stand sentry,


title: Meerkat content: to warn others of approaching dangers. When a predator is spotted, the meerkat performing as sentry gives a warning bark or whistle, and other members of the group run and hide in one of the many holes they have spread across their territory. Meerkats also babysit the young in the group. Females that have never produced offspring of their own often lactate to feed the alpha pair's young. They also protect the young from threats, often endangering their own lives. On warning of danger, the babysitter takes the young underground to safety and is prepared to defend them if the


title: Meerkat content: danger follows. Meerkats are also known to share their burrow with the yellow mongoose and ground squirrel. Like many species, meerkat young learn by observing and mimicking adult behaviour, though adults also engage in active instruction. For example, meerkat adults teach their pups how to eat a venomous scorpion: they will remove the stinger and help the pup learn how to handle the creature. Despite this altruistic behaviour, meerkats sometimes kill young members of their group. Subordinate meerkats have been seen killing the offspring of more senior members in order to improve their own offspring's position. When colonies are exposed


title: Meerkat content: to human presence for a long time, they will become habituated, which allows for documentation of their natural behavior. It is not unusual for camera crews, who must largely stay still for long periods while filming, to be utilized as convenient sentry posts. Meerkat calls may carry specific meanings, with particular calls indicating the type of predator and the urgency of the situation. In addition to alarm calls, meerkats also make panic calls, recruitment calls, and moving calls. They chirrup, trill, growl, or bark, depending on the circumstances. Meerkats make different alarm calls depending upon whether they see an aerial


title: Meerkat content: or a terrestrial predator. Moreover, acoustic characteristics of the call will change with the urgency of the potential predatory episode. Therefore, six different predatory alarm calls with six different meanings have been identified: aerial predator with low, medium, and high urgency; and terrestrial predator with low, medium, and high urgency. Meerkats respond differently after hearing a terrestrial predator alarm call than after hearing an aerial predator alarm call. For example, upon hearing a high-urgency terrestrial predator alarm call, meerkats are most likely to seek shelter and scan the area. On the other hand, upon hearing a high-urgency aerial predator alarm


title: Meerkat content: call, meerkats are most likely to crouch down. On many occasions under these circumstances, they also look towards the sky. Meerkats, being wild animals, make poor pets. They can be aggressive, especially toward guests and they may also bite. They will scent-mark their owner and the house (their "territory"). Meerkat The meerkat or suricate ("Suricata suricatta") is a small carnivoran belonging to the mongoose family (Herpestidae). It is the only member of the genus Suricata. Meerkats live in all parts of the Kalahari Desert in Botswana, in much of the Namib Desert in Namibia and southwestern Angola, and in South


title: "Lake Lucerne" content: Lake Lucerne Lake Lucerne (, literally "Lake of the Four Forested Settlements", , ) is a lake in central Switzerland and the fourth largest in the country. The lake has a complicated shape, with several sharp bends and four arms. It starts in the south-north bound Reuss Valley between steep cliffs above the "Urnersee" from Flüelen towards Brunnen to the north before it makes a sharp bend to the west where it continues into the "Gersauer Becken". Here is also the deepest point of the lake with . Even more west of it is the "Buochser Bucht", but the lake


title: "Lake Lucerne" content: sharply turns north again through the narrow opening between the "Unter Nas" (lower nose) of the Bürgenstock to the west and the "Ober Nas" (upper nose) of the Rigi to the east to reach the "Vitznauer Bucht". In front of Vitznau below the Rigi the lake turns sharply west again to reach the center of a four-arm cross, called the "Chrütztrichter" (Cross Funnel). Here converge the "Vitznauer Bucht" with the "Küssnachtersee" from the north, the "Luzernersee" from the west, and the "Horwer Bucht" and the "Stanser Trichter" to the south, which is to be found right below the northeast side


title: "Lake Lucerne" content: of the Pilatus and the west side of the Bürgenstock. At the very narrow pass between the east dropper of the Pilatus (called "Lopper") and Stansstad the lake reaches its southwestern arm at Alpnachstad on the steep southern foothills of the Pilatus, the "Alpnachersee". The lake drains its water into the Reuss in Lucerne from its arm called "Luzernersee" (which literally translates as "Lake of Lucerne"). The entire lake has a total area of 114 km² (44 sq mi) at an elevation of a.s.l., and a maximum depth of . Its volume is 11.8 km³. Much of the shoreline rises


title: "Lake Lucerne" content: steeply into mountains up to 1,500 m above the lake, resulting in many picturesque views including those of the mountains Rigi and Pilatus. The Reuss enters the lake at Flüelen, in the part called "Urnersee" ("Lake of Uri", in the canton of Uri) and exits at Lucerne. The lake also receives the Muota at Brunnen, the Engelberger Aa at Buochs, and the Sarner Aa at Alpnachstad. It is possible to circumnavigate the lake by train and road, though the railway route circumvents the lake even on the north side of the Rigi via Arth-Goldau. Since 1980, the A2 motorway leads


title: "Lake Lucerne" content: through the Seelisberg Tunnel in order to reach the route to the Gotthard Pass in just half an hour in Altdorf, Uri right south of the beginning of the lake in Flüelen. Steamers and other passenger boats ply between the different villages and towns on the lake. It is a popular tourist destination, both for native Swiss and foreigners, and there are many hotels and resorts along the shores. In addition, the meadow of the Rütli, traditional site of the founding of the Swiss Confederation, is on the "Urnersee" shore. A 35 km commemorative walkway, the Swiss Path, was built


title: "Lake Lucerne" content: around the Lake of Uri to celebrate the country's 700th anniversary in 1991. The name of "Vierwaldstättersee" is first used in the 16th century. The (three) "Waldstätte(n)" (lit.: "Forested Sites/Settlements") since the 14th century were the confederate allies of Uri, Schwyz and Unterwalden. The notion of "Four Waldstätten" ("Vier Waldstätten"), with the addition of the canton of Lucerne, is first recorded in the 1450s, in an addition to the "Silver Book" of Egloff Etterlin of Lucerne. Each part of the lake has it own designation: Lake Lucerne borders on the three original Swiss cantons of Uri, Schwyz, and Unterwalden (which


title: "Lake Lucerne" content: today is divided into the cantons of Obwalden and Nidwalden), as well as the canton of Lucerne, thus the name "Vierwaldstättersee" (lit.: Lake of the Four Forested Settlements). Many of the oldest communities of Switzerland are along the shore, including Küssnacht, Weggis, Vitznau, Gersau, Brunnen, Altdorf, Buochs, and Treib. Lake Lucerne is singularly irregular and appears to lie in four different valleys, all related to the conformation of the adjoining mountains. The central portion of the lake lies in two parallel valleys whose direction is from west to east, the one lying north, the other south of the ridge of


title: "Lake Lucerne" content: the Bürgenstock. These are connected through a narrow strait, scarcely one kilometre wide, between the two rocky promontories called respectively "Unter Nas" and "Ober Nas" (Lower and Upper Nose). It is not unlikely that the southern of these two divisions of the lake—called "Buochser Bucht"—formerly extended to the west over the isthmus whereon stands the town of Stans, thus forming an island of the Bürgenstock. The west end of the main branch of the lake, whence a comparatively shallow bay extends to the town of Lucerne, is intersected obliquely by a deep trench whose south-west end is occupied by the


title: "Lake Lucerne" content: branch called "Alpnachersee", while the north-east branch forms the long arm of Küssnacht, "Küssnachtersee". These both lie in the direct line of a valley that stretches with scarcely a break in between the Uri Alps and the Emmental Alps. At the eastern end of the Gersauer Becken, where the containing walls of the lake-valley are directed from east to west, it is joined at an acute angle by the arm of Uri, or the "Urnersee", lying in the northern prolongation of the deep cleft that gives a passage to the Reuss, between the Uri Alps and the Glarus Alps. The


title: "Lake Lucerne" content: Urnersee occupies the northernmost and deep portion of the great cleft of the Reuss Valley, which has cut through the Alpine ranges from the St Gotthard Pass to the neighbourhood of Schwyz. From its eastern shore the mountains rise in almost bare walls of rock to a height of from above the water. The two highest summits are the Fronalpstock and the Rophaien (2078 m). Between them the steep glen or ravine of the Riemenstaldener Tal descends to Sisikon, the only village with Flüelen right on the shore on that side of the Urnersee. On the opposite or western shore,


title: "Lake Lucerne" content: the mountains attain still greater dimensions. The Niederbauen Chulm is succeeded by the Oberbauenstock, and farther south, above the ridge of the Scharti, appear the snowy peaks of the Gitschen and the Uri Rotstock (2,928 m). In the centre opens the Reuss Valley, backed by the rugged summits of the Urner and Glarner Alps. The breadth of these various sections of the lake is very variable, but is usually between one and two miles (3 km). The lake's surface, whose mean height above the sea is 434 metres, is the lowest point of the cantons of Uri, Obwalden and Nidwalden.


title: "Lake Lucerne" content: Originally the lake was susceptible to variations in level and flooding along its shoreline. Between 1859 and 1860, the introduction of a needle dam in the Reuss in the city of Lucerne, just upstream from the Spreuerbrücke, allowed the lake level to be stabilised. The culminating point of the lake's drainage basin, as well as Central Switzerland, is the Dammastock at 3,630 metres above sea level. The lake is navigable, and has formed an important part of Switzerland's transport system for many centuries, and at least since the opening of the first track across the Gotthard Pass in 1230. This


title: "Lake Lucerne" content: trade grew with the opening of a new mail coach road across the pass in 1830. This road had its northern terminus at Flüelen at the extreme eastern end of the lake, and the lake provided the only practical onward link to Lucerne, and hence the cities of northern Switzerland and beyond. Whilst the development of Switzerland's road and rail networks has relieved the lake of much of its through traffic, it continues to be used by a considerable number of vessels, both private and public. Much of this usage is tourist or leisure oriented, but the lake continues to


title: "Lake Lucerne" content: provide practical public and cargo transport links between the smaller lakeside communities. Passenger boats of the Schifffahrtsgesellschaft des Vierwaldstättersees (SGV) provide services on the lake, including many run by historic paddle steamers. The SGV serves 32 places along the shore of the lake, with interchange to both main line and mountain railways at various points. Under separate management, the Autofähre Beckenried-Gersau provides a car ferry service between Beckenried, on the south bank of the lake, and Gersau on the north. Cargo barges, to a local design known as "Nauen", are still used on the lake. Some have been converted for


title: "Lake Lucerne" content: use as party boats. Other barges are used by the gravel dredging industry that operates on the lake, using large dredgers to obtain sand and gravel for use in the construction industry. Beethoven's "Moonlight" Sonata derives its name from an 1832 description of the first movement by music critic Ludwig Rellstab, who compared it to moonlight shining upon Lake Lucerne. Gioacchino Rossini uses this in his "William Tell" Overture Section A: Sunrise over the Alps. Lake Lucerne has twice been used as a venue for the European Rowing Championships: in 1908 and then in 1926. The nearby Rotsee has since


title: "Lake Lucerne" content: 1933 been used for rowing regattas instead. Lake Lucerne Lake Lucerne (, literally "Lake of the Four Forested Settlements", , ) is a lake in central Switzerland and the fourth largest in the country. The lake has a complicated shape, with several sharp bends and four arms. It starts in the south-north bound Reuss Valley between steep cliffs above the "Urnersee" from Flüelen towards Brunnen to the north before it makes a sharp bend to the west where it continues into the "Gersauer Becken". Here is also the deepest point of the lake with . Even more west of it


title: "Boat-billed heron" content: Boat-billed heron The boat-billed heron ("Cochlearius cochlearius"), colloquially known as the boatbill, is an atypical member of the heron family, and was formerly thought to be in a monotypic family, the Cochlearidae. It lives in mangrove swamps from Mexico south to Peru and Brazil. It is a nocturnal bird, and breeds semicolonially in mangrove trees, laying two to four bluish-white eggs in a twig nest. The boat-billed heron grows to about 54 cm long. Adults are pale grey to white in color, with chestnut-colored abdomens and black flanks. The massive, broad, scoop-like bill, which gives rise to this species' name,


title: "Boat-billed heron" content: is mainly black. Tis bird is also adorned with a crest which is thought to be used in mate attraction as it is larger in males. The sexes are similar in appearance, the main differences being that females are slightly smaller, grayer in appearance, and have shorter crests than males. Newly hatched nestlings have green-yellow skin, with their upperparts covered in gray down feathers. Their upper bill is black and they have green-yellow legs. Juveniles are darker in color than adults and lack a crest. Boat-billed herons range from Mexico to Peru, Brazil, and northeastern Argentina. They are nonmigratory birds


title: "Boat-billed heron" content: that tend to live in seasonal lagoons and estuaries, and nest in mangroves. Boat-billed herons feed on shrimp and small fish such as "Dormitator latifrons", a species of sleeper goby. They tend to forage in vegetative streams, shallow water, and lagoons. When foraging in streams, they low-hanging branches and mangrove roots to stand over the water. In ponds they will walk slowly through the water up to 10 cm deep or will forage near the water's edge. In order to capture prey they will lunge at fish or scoop the surface of the water with their bills which are uniquely


title: "Boat-billed heron" content: shaped for this method of capture. Additionally, they have been observed using two different feeding techniques; standing and slowly stalking prey, or disturbing the water and chasing prey. Boat-billed herons will forage nocturnally, and have been seen leaving the roost 30 minutes after sundown to feed. It has been observed that they do not feed when a light source is present such as daylight, moonlight, or artificial light. One study hypothesized that in order to forage for food in the dark and in shallow, muddy water, their bills are sensitive to touch which helps them feel for their prey. Boat-billed


title: "Boat-billed heron" content: herons breed during the rainy season and have been recorded as producing two clutches during this time, laying their first clutch in February during the end of the dry season. Their clutch sizes range from two to four eggs, with more eggs being laid during the first nesting period than the second. They usually nest in colonies, but have been observed nesting solitarily. Human disturbance can lead to a decrease in reproductive success, as herons tend to avoid human contact and will abandon nests if necessary. Boat-billed heron The boat-billed heron ("Cochlearius cochlearius"), colloquially known as the boatbill, is an


title: Shoebill content: Shoebill The shoebill ("Balaeniceps rex") also known as whalehead, is a very large stork-like bird. It derives its name from its enormous shoe-shaped bill. It has a somewhat stork-like overall form and has previously been classified with the storks in the order Ciconiiformes based on this morphology. However, genetic evidence places it with the Pelecaniformes. The adult is mainly grey while the juveniles are browner. It lives in tropical east Africa in large swamps from Sudan to Zambia. The shoebill was known to both ancient Egyptians and Arabs but was not classified until the 19th century, after skins and eventually


title: Shoebill content: live specimens were brought to Europe. Traditionally allied with the storks (Ciconiiformes), it was retained there in the Sibley-Ahlquist taxonomy which lumped a massive number of unrelated taxa into their "Ciconiiformes". More recently, the shoebill has been considered to be closer to the pelicans (based on anatomical comparisons) or the herons (based on biochemical evidence; Hagey "et al.", 2002). Microscopic analysis of eggshell structure by Konstantin Mikhailov in 1995 found that the eggshells of shoebills closely resembled those of other Pelecaniformes in having a covering of thick microglobular material over the crystalline shells. A recent DNA study reinforces their membership


title: Shoebill content: of the Pelecaniformes. So far, two fossil relatives of the shoebill have been described: "Goliathia" from the early Oligocene of Egypt and "Paludavis" from the Early Miocene of the same country. It has been suggested that the enigmatic African fossil bird "Eremopezus" was a relative too, but the evidence for that is unconfirmed. All that is known of "Eremopezus" is that it was a very large, probably flightless bird with a flexible foot, allowing it to handle either vegetation or prey. The shoebill is a tall bird, with a typical height range of and some specimens reaching as much as


title: Shoebill content: . Length from tail to beak can range from and wingspan is . Weight has reportedly ranged from . A male will weigh on average around and is larger than a typical female of . The signature feature of the species is its huge, bulbous bill, which is straw-coloured with erratic greyish markings. The exposed culmen (or the measurement along the top of the upper mandible) is , the third longest bill among extant birds after pelicans and large storks, and can outrival the pelicans in bill circumference, especially if the bill is considered as the hard, bony keratin portion.


title: Shoebill content: The sharp edges in the mandibles help the shoebill to decapitate their prey and also to discard any vegetation after prey has been caught. As in the pelicans, the upper mandible is strongly keeled, ending in a sharp nail. The dark coloured legs are fairly long, with a tarsus length of . The shoebill's feet are exceptionally large, with the middle toe reaching in length, likely assisting the species in its ability to stand on aquatic vegetation while hunting. The neck is relatively shorter and thicker than other long-legged wading birds such as herons and cranes. The wings are broad,


title: Shoebill content: with a wing chord length of , and well-adapted to soaring. The plumage of adult birds is blue-grey with darker slaty-grey flight feathers. The breast presents some elongated feathers, which have dark shafts. The juvenile has a similar plumage colour, but is a darker grey with a brown tinge. When they are first born, shoebills have a more modestly-sized bill, which is initially silvery-grey. The bill becomes more noticeably large when the chicks are 23 days old and becomes well developed by 43 days. Its wings are held flat while soaring and, as in the pelicans and the storks of


title: Shoebill content: the genus "Leptoptilos", the shoebill flies with its neck retracted. Its flapping rate, at an estimated 150 flaps per minute, is one of the slowest of any bird, with the exception of the larger stork species. The pattern is alternating flapping and gliding cycles of approximately seven seconds each, putting its gliding distance somewhere between the larger storks and the Andean condor ("Vultur gryphus"). When flushed, shoebills usually try to fly no more than . Long flights of the shoebill are rare, and only a few flights beyond its minimum foraging distance of have been recorded. At close range, it


title: Shoebill content: can be easily identified by its unique features. In flight, if its unique bill cannot be seen, the shoebill's silhouette resembles that of a stork or condor, but its feathers are a distinctive medium blue-grey. Also unusual, its tail is the same colour as its wings. Under poor viewing conditions, its size and wingspan can distinguish it from other birds in its habitat. Its legs, roughly the length of storks', extend straight back far past its tail when in flight. The wing to tail size cannot be used for identification; it is similar to those of several other birds. The


title: Shoebill content: shoebill is distributed in freshwater swamps of central tropical Africa, from southern Sudan through parts of eastern Congo, Rwanda, Uganda, western Tanzania and northern Zambia. The species is most numerous in the West Nile sub-region and adjacent areas of the south Sudan; it is also significant in wetlands of Uganda and western Tanzania. More isolated records have been reported of shoebills in Kenya, the Central African Republic, northern Cameroon, south-western Ethiopia, Malawi. Vagrant strays to the Okavango Basin, Botswana and the upper Congo River have also been sighted. The distribution of this species seems to largely coincide with that of


title: Shoebill content: papyrus and lungfish. The shoebill is non-migratory with limited seasonal movements due to habitat changes, food availability and disturbance by humans. The shoebill occurs in extensive, dense freshwater marshes. Almost all wetlands that attract the species have undisturbed "Cyperus papyrus" and reed beds of "Phragmites" and "Typha". Although their distribution largely seems to correspond with the distribution of papyrus in central Africa, the species seems to avoid pure papyrus swamps and is often attracted to areas with mixed vegetation. More rarely, the species has been seen foraging in rice fields and flooded plantations. The shoebill is noted for its slow


title: Shoebill content: movements and tendency to stay still for long periods, resulting in descriptions of the species as "statue-like". They are quite sensitive to human disturbance and may abandon their nests if flushed by humans. However, while foraging, if dense vegetation stands between it and humans, this wader can be fairly tame. The shoebill is attracted to poorly oxygenated waters where fish frequently surface to breathe. Exceptionally for a bird this large, the shoebill often stands and perches on floating vegetation, making them appear somewhat like a giant jacana, although the similarly-sized and occasionally sympatric Goliath heron ("Ardea goliath") is also known


title: Shoebill content: to stand on aquatic vegetation. Shoebills typically feed in muddy waters and, being solitary, forage at or more from one another even where relatively densely populated. This species stalks its prey patiently, in a slow and lurking fashion. While hunting, the shoebill strides very slowly and is frequently motionless. Unlike some other large waders, this species hunts entirely using vision and is not known to engage in tactile hunting. When prey is spotted, it launches a quick violent strike. However, depending on the size of the prey, handling time after the strike can exceed 10 minutes. Around 60% of strikes


title: Shoebill content: yield prey. Frequently water and vegetation is snatched up during the strike and is spilled out from the edges of the mandibles. The activity of hippopotamus may inadvertently benefit the shoebill, as submerged hippos occasionally force fish to the surface. Shoebills are largely piscivorous but are assured predators of a considerable range of wetland vertebrates. Preferred prey species have reportedly included marbled lungfish ("Protopterus aethiopicus") and Senegal bichir ("Polypterus senegalus") and various "Tilapia" species and catfish, the latter mainly in the genus "Clarias". Other prey eaten by this species has included frogs, water snakes, Nile monitors ("Varanus niloticus") and baby


title: Shoebill content: crocodiles. More rarely, turtles, snails, rodents and small waterfowl have reportedly been eaten. There is a single unconfirmed report of shoebills feeding on lechwe ("Kobus leche") calves. Given its sharp-edged beak, huge bill and wide gape, the shoebill can hunt large prey, often targeting prey bigger than is taken by other large wading birds. Fish eaten by this species are commonly in the range of long and weigh around , though lungfish of as much as have been attacked. Snakes preyed upon are commonly from long. In the Bangweulu Swamps of Zambia, the main prey items fed to young by


title: Shoebill content: the parents were the catfish "Clarias gariepinus" (syn. "C. mossambicus") and water snakes. In Uganda, lungfish and catfish were mainly fed to the young. The big beak is sometimes used to dig into pond-bottom mud to extract lungfish from their aestivation burrows. The solitary nature of shoebills extends to their breeding habits. Nests typically occur at less than three nests per square kilometre, unlike herons, cormorants, pelicans and storks which predominantly nest in colonies. The breeding pair of shoebills vigorously defends a territory of from conspecifics. In the extreme north and south of the species' range, nesting starts right after


title: Shoebill content: the rains end. In more central regions of the range, it may nest near end of wet season in order to hatch around the beginning of the following wet season. Both parents engage in building the nest on floating platform, after clearing out an area of approximately across. The large, flattish nesting platform is often partially submerged in water and can be as much as deep. The nest itself is about wide. Both the nest and platform are made of aquatic vegetation. In Sudan, the nests apparently were able to support the weight of an adult man, although this was