title: Woodpecker content: DNA sequence analyses have confirmed that Pici and Galbuli are sister groups. The family Picidae was introduced by the English zoologist William Elford Leach in a guide to the contents of the British Museum published in 1820. The phylogeny has been updated according to new knowledge about convergence patterns and evolutionary history. Most notably, the relationship of the picine genera has been largely clarified, and it was determined that the Antillean piculet is a surviving offshoot of proto-woodpeckers. Genetic analysis supports the monophyly of Picidae, which seems to have originated in the Old World, but the geographic origins of the


title: Woodpecker content: Picinae is unclear. The Picumninae is returned as paraphyletic. Morphological and behavioural characters, in addition to DNA evidence highlights genus "Hemicircus" as the sister group of all remaining true woodpeckers, besides a sister-group relationship between the true woodpecker tribes Dendropicini and Malarpicini. The evolutionary history of this group is not well documented, but the known fossils allow some preliminary conclusions: the earliest known modern picids were piculet-like forms of the Late Oligocene, about 25 million years ago (mya). By that time, however, the group was already present in the Americas and Europe, and it is hypothesized that they actually evolved


title: Woodpecker content: much earlier, maybe as early as the Early Eocene (50 mya). The modern subfamilies appear to be rather young by comparison; until the mid-Miocene (10–15 mya), all picids seem to have been small or mid-sized birds similar to a mixture between a piculet and a wryneck. On the other hand, there exists a feather enclosed in fossil amber from the Dominican Republic, dated to about 25 mya, which seems to indicate that the Nesoctitinae were already a distinct lineage by then. Stepwise adaptations for drilling, tapping and climbing head first on vertical surfaces have been suggested. The last common ancestor


title: Woodpecker content: of woodpeckers (Picidae) was incapable of climbing up tree trunks or excavating nest cavities by drilling with its beak. The first adaptations for drilling (including reinforced rhamphotheca, frontal overhang and processus dorsalis pterygoidei) evolved in the ancestral lineage of piculets and true woodpeckers. Additional adaptations for drilling and tapping (enlarged condylus lateralis of the quadrate and fused lower mandible) have evolved in the ancestral lineage of true woodpeckers ("Hemicircus" excepting). The inner rectrix pairs became stiffened, and the pygostyle lamina was enlarged in the ancestral lineage of true woodpeckers ("Hemicircus" included), which facilitated climbing head first up tree limbs. Genus


title: Woodpecker content: "Hemicircus" excepting, the tail feathers were further transformed for specialized support, the pygostyle disc became greatly enlarged, and the ectropodactyl toe arrangement evolved. These latter characters may have facilitated enormous increases in body size in some lineages. Prehistoric representatives of the extant Picidae genera are treated in the genus articles. An enigmatic form based on a coracoid found in Pliocene deposits of New Providence in the Bahamas, has been described as "Bathoceleus hyphalus" and probably also is a woodpecker. The phylogeny of woodpeckers is still being refined and the positions of some genera continue to be unclear and there are


title: Woodpecker content: conflicting findings from analyses as of 2016. Family: Picidae In general, humans consider woodpeckers in a favourable light; they are viewed as interesting birds and fascinating to watch as they drum or forage. However, their activities are not universally appreciated. Many woodpecker species are known to excavate holes in buildings, fencing and utility poles, creating health and/or safety issues for affected buildings and utility poles. Such activity is very difficult to discourage and can be costly to repair. Woodpeckers also drum on various reverberatory structures on buildings such as gutters, downspouts, chimneys, vents and aluminium sheeting. Drumming is a less-forceful


title: Woodpecker content: type of pecking that serves to establish territory and attract mates. Houses with shingles or wooden boarding are also attractive as possible nesting or roosting sites, especially when close to large trees or woodland. Several exploratory holes may be made, especially at the junctions of vertical boards or at the corners of tongue-and-groove boarding. The birds may also drill holes in houses as they forage for insect larvae and pupae hidden behind the woodwork. Woodpeckers sometimes cause problems when they raid fruit crops, but their foraging activities are mostly beneficial as they control forest insect pests such as the woodboring


title: Woodpecker content: beetles that create galleries behind the bark and can kill trees. They also eat ants, which may be tending sap-sucking pests such as mealybugs, as is the case with the rufous woodpecker in coffee plantations in India. Woodpeckers can serve as indicator species, demonstrating the quality of the habitat. Their hole-making abilities make their presence in an area an important part of the ecosystem, because these cavities are used for breeding and roosting by many bird species that are unable to excavate their own holes, as well as being used by various mammals and invertebrates. The spongy bones of the


title: Woodpecker content: woodpecker's skull and the flexibility of its beak, both of which provide protection for the brain when drumming, have provided inspiration to engineers; a black box needs to survive intact when a plane falls from the sky, and modelling the black box with regard to a woodpecker's anatomy has increased the resistance of this device to damage sixty-fold. The design of protective helmets is another field being influenced by the study of woodpeckers. One of the accounts of the Founding of Rome, preserved in the work known as "Origo Gentis Romanae", refers to a legend of a woodpecker bringing food


title: Woodpecker content: to the boys Romulus and Remus during the time they were abandoned in the wild - thus enabling them to survive and play their part in history. In a global survey of the risk of extinction faced by the various bird families, woodpeckers were the only bird family to have significantly fewer species at risk than would be expected. Nevertheless, several woodpeckers are under threat as their habitats are destroyed. Being woodland birds, deforestation and clearance of land for agriculture and other purposes can reduce populations dramatically. Some species adapt to living in plantations and secondary growth, or to open


title: Woodpecker content: countryside with forest remnants and scattered trees, but some do not. A few species have even flourished when they have adapted to man-made habitats. There are few conservation projects directed primarily at woodpeckers, but they benefit whenever their habitat is conserved. The red-cockaded woodpecker has been the focus of much conservation effort in the southeastern United States, with artificial cavities being constructed in the longleaf pines they favour as nesting sites. Two species of woodpeckers in the Americas, the ivory-billed woodpecker and the imperial woodpecker, have been considered extinct since the mid-to-late 20th century, though there have been possible but


title: Woodpecker content: disputed sightings of ivory-billed woodpeckers in the United States since 2004, and a small population may survive in Cuba. Another critically endangered species is the Okinawa woodpecker from Japan, with a single declining population of a few hundred birds. It is threatened by deforestation, golf course, dam and helipad construction, road building and agricultural development. Woodpecker Woodpeckers are part of the family Picidae, a group of near-passerine birds that also consist of piculets, wrynecks, and sapsuckers. Members of this family are found worldwide, except for Australia, New Guinea, New Zealand, Madagascar, and the extreme polar regions. Most species live in


title: "Radio (LL Cool J album)" content: has plenty of both." Released November 18, 1985, on Def Jam Recordings in the United States, "Radio" earned a significant amount of commercial success and sales for a hip hop record at the time. It sold over 500,000 copies in its first five months, eventually selling over 1 million copies by 1988, according to the Recording Industry Association of America. "Radio" peaked at number 6 on the Top R&B/Hip-Hop Albums chart and at number 46 on the "Billboard" 200 albums chart. It entered the Top R&B/Hip-Hop Albums chart on December 28, 1985, and remained there for forty-seven weeks, while also


title: "Leo Minor" content: Leo Minor Leo Minor is a small and faint constellation in the northern celestial hemisphere. Its name is Latin for "the smaller lion", in contrast to Leo, the larger lion. It lies between the larger and more recognizable Ursa Major to the north and Leo to the south. Leo Minor was not regarded as a separate constellation by classical astronomers; it was designated by Johannes Hevelius in 1687. There are 37 stars brighter than apparent magnitude 6.5 in the constellation; three are brighter than magnitude 4.5. 46 Leonis Minoris, an orange giant of magnitude 3.8, is located some 95 light-years


title: "Belgian cuisine" content: gehaktbal or kroket are sold alongside. In some cases, the fries are served in the form of a baguette sandwich along with their sauce and meat; this is known as a "mitraillette". In areas with immigration, the same combination is also available in a wrap called a dürüm instead of on a baguette. The vast majority of Belgian households have a deep fryer, allowing them to make their own fries and other deep-fried foods at home. Supermarkets sell a range of liquid and solid animal- and plant-based fats for use in home deep fryers; beef fat is particularly prized. In


title: "Eurasian golden oriole" content: Eurasian golden oriole The Eurasian golden oriole ("Oriolus oriolus") or simply golden oriole, is the only member of the oriole family of passerine birds breeding in Northern Hemisphere temperate regions. It is a summer migrant in Europe and western Asia and spends the winter season in central and southern Africa. Golden orioles have an extremely large range with large populations that are apparently stable. Therefore, they are evaluated as least concern by BirdLife International. The Eurasian golden oriole was described by the Swedish naturalist Carl Linnaeus in 1758 in the tenth edition of his "Systema Naturae" and given the binomial


title: "Eurasian golden oriole" content: name "Coracias oriolus". The Eurasian golden oriole and the Indian golden oriole were formerly considered as conspecific, but in 2005 they were treated as separate species by the ornithologists Pamela Rasmussen and John Anderton in the first edition of their "Birds of South Asia". Support for this split was provided by a molecular phylogenetic study published in 2010, and most ornitholists now treat the Indian golden oriole as a separate species. Alternate names for the Eurasian golden oriole include the European golden oriole and western Eurasian golden oriole. The species is monotypic. The name "oriole" was first used in the


title: "Eurasian golden oriole" content: 18th century and is an adaptation of the scientific Latin genus name, which is derived from the Classical Latin "aureolus" meaning "golden". Various forms of "oriole" have existed in Romance languages since the 12th and 13th centuries. Albertus Magnus used the Latin form "oriolus" in about 1250 and erroneously stated that it was onomatopoeic because of the golden oriole's song. In medieval England its name, derived from the song, was the "woodwele". The male is striking in the typical oriole black and yellow plumage, but the female is a drabber green bird. Orioles are shy, and even the male is


title: "Eurasian golden oriole" content: remarkably difficult to see in the dappled yellow and green leaves of the canopy. In flight they look somewhat like a thrush, strong and direct with some shallow dips over longer distances. The New World orioles are similar in appearance to the Oriolidae, but are icterids and unrelated to the Old World birds. The male of the Indian golden oriole ("Oriolus ") has the black eye-stripe extending behind the eye, has a longer and paler red bill and has more yellow in the plumage. Their call is a screech like a jay, but the song is a beautiful fluting "weela-wee-ooo"


title: "Eurasian golden oriole" content: or "or-iii-ole", unmistakable once heard. The breeding range of this species spans from western Europe and Scandinavia east to China. They winter in central and southern Africa. They generally migrate during the night, but may travel during the day in the spring migration. During the autumn migration they migrate via the Eastern Mediterranean where they feed on fruit; they are often considered a pest in this region because of this. The Eurasian golden oriole inhabits a range of habitats. In Western Europe they prefer open broadleaf forests and plantations, copses, riverine forest, orchards, large gardens; in Eastern Europe they may


title: "Eurasian golden oriole" content: inhabit more continuous forest as well as mixed or coniferous forests. They generally avoid treeless habitats but may forage there. In their wintering habitat they are found in semi-arid to humid woodland, tall forests, riverine forest, woodland/savanna mosaic and savanna. Eurasian golden orioles may delay breeding until they are 2 or 3 years of age. Males usually arrive at breeding area several days before the females. The fidelity to a territory or even to a specific nest site suggests that the pair-bond may continue from one breeding season to the next. The nest is placed high in a tree towards


title: "Eurasian golden oriole" content: the edge of the crown. The deep cup-shaped nest is suspended below a horizontal fork of thin branches. It is built by the female, but the male will sometimes gather some of the material. The nest is held in place by plant fibres up to in length and lined with fine grass, feathers and wool. The clutch is usually between 3 and 5 eggs. These are laid at daily intervals early in the morning. The eggs are on average with a calculated weight of . They can be white, cream or very pale pink and are decorated with black marks


title: "Eurasian golden oriole" content: which are sometimes concentrated at the larger end. The eggs are mainly incubated by the female but the male will incubate for short periods to allow the female to feed. The eggs hatch after 16–17 days. The young are fed by both parents but are mostly brooded by the female. The young fledge after 16–17 days. The clutch is only rarely lost to predators as the parents vigorously defend their nest. The greatest recorded age for a Eurasian golden oriole is 10 years and 1 month for a male that was ringed in Lincolnshire in 1986 and seen alive in


title: "Eurasian golden oriole" content: Cambridgeshire in 1996. They feed on insects and fruit, using their bills to pick insects out of crevices. Eurasian golden oriole The Eurasian golden oriole ("Oriolus oriolus") or simply golden oriole, is the only member of the oriole family of passerine birds breeding in Northern Hemisphere temperate regions. It is a summer migrant in Europe and western Asia and spends the winter season in central and southern Africa. Golden orioles have an extremely large range with large populations that are apparently stable. Therefore, they are evaluated as least concern by BirdLife International. The Eurasian golden oriole was described by the


title: "Power station" content: Power station A power station, also referred to as a power plant or powerhouse and sometimes generating station or generating plant, is an industrial facility for the generation of electric power. Most power stations contain one or more generators, a rotating machine that converts mechanical power into electrical power. The relative motion between a magnetic field and a conductor creates an electrical current. The energy source harnessed to turn the generator varies widely. Most power stations in the world burn fossil fuels such as coal, oil, and natural gas to generate electricity. Others use nuclear power, but there is an


title: "Power station" content: increasing use of cleaner renewable sources such as solar, wind, wave and hydroelectric. In 1870 a hydroelectric power station was designed and built by Lord Armstrong at Cragside, England. It used water from lakes on his estate to power Siemens dynamos. The electricity supplied power to lights, heating, produced hot water, ran an elevator as well as labor-saving devices and farm buildings. In the early 1870s Belgian inventor Zénobe Gramme invented a generator powerful enough to produce power on a commercial scale for industry. In the autumn of 1882, a central station providing public power was built in Godalming, England.


title: "Power station" content: It was proposed after the town failed to reach an agreement on the rate charged by the gas company, so the town council decided to use electricity. It used hydroelectric power for street lighting and household lighting. The system was not a commercial success and the town reverted to gas. In 1882 the world's first coal-fired public power station, the Edison Electric Light Station, was built in London, a project of Thomas Edison organized by Edward Johnson. A Babcock & Wilcox boiler powered a 125-horsepower steam engine that drove a 27-ton generator. This supplied electricity to premises in the area


title: "Power station" content: that could be reached through the culverts of the viaduct without digging up the road, which was the monopoly of the gas companies. The customers included the City Temple and the Old Bailey. Another important customer was the Telegraph Office of the General Post Office, but this could not be reached though the culverts. Johnson arranged for the supply cable to be run overhead, via Holborn Tavern and Newgate. In September 1882 in New York, the Pearl Street Station was established by Edison to provide electric lighting in the lower Manhattan Island area. The station ran until destroyed by fire


title: "Power station" content: in 1890. The station used reciprocating steam engines to turn direct-current generators. Because of the DC distribution, the service area was small, limited by voltage drop in the feeders. In 1886 George Westinghouse began building an alternating current system that used a transformer to step up voltage for long-distance transmission and then stepped it back down for indoor lighting, a more efficient and less expensive system which is similar to modern system. The War of Currents eventually resolved in favor of AC distribution and utilization, although some DC systems persisted to the end of the 20th century. DC systems with


title: "Power station" content: a service radius of a mile (kilometer) or so were necessarily smaller, less efficient of fuel consumption, and more labor-intensive to operate than much larger central AC generating stations. AC systems used a wide range of frequencies depending on the type of load; lighting load using higher frequencies, and traction systems and heavy motor load systems preferring lower frequencies. The economics of central station generation improved greatly when unified light and power systems, operating at a common frequency, were developed. The same generating plant that fed large industrial loads during the day, could feed commuter railway systems during rush hour


title: "Power station" content: and then serve lighting load in the evening, thus improving the system load factor and reducing the cost of electrical energy overall. Many exceptions existed, generating stations were dedicated to power or light by the choice of frequency, and rotating frequency changers and rotating converters were particularly common to feed electric railway systems from the general lighting and power network. Throughout the first few decades of the 20th century central stations became larger, using higher steam pressures to provide greater efficiency, and relying on interconnections of multiple generating stations to improve reliability and cost. High-voltage AC transmission allowed hydroelectric power


title: "Power station" content: to be conveniently moved from distant waterfalls to city markets. The advent of the steam turbine in central station service, around 1906, allowed great expansion of generating capacity. Generators were no longer limited by the power transmission of belts or the relatively slow speed of reciprocating engines, and could grow to enormous sizes. For example, Sebastian Ziani de Ferranti planned what would have been the largest reciprocating steam engine ever built for a proposed new central station, but scrapped the plans when turbines became available in the necessary size. Building power systems out of central stations required combinations of engineering


title: "Power station" content: skill and financial acumen in equal measure. Pioneers of central station generation include George Westinghouse and Samuel Insull in the United States, Ferranti and Charles Hesterman Merz in UK, and many others. In thermal power stations, mechanical power is produced by a heat engine that transforms thermal energy, often from combustion of a fuel, into rotational energy. Most thermal power stations produce steam, so they are sometimes called steam power stations. Not all thermal energy can be transformed into mechanical power, according to the second law of thermodynamics; therefore, there is always heat lost to the environment. If this loss


title: "Power station" content: is employed as useful heat, for industrial processes or district heating, the power plant is referred to as a cogeneration power plant or CHP (combined heat-and-power) plant. In countries where district heating is common, there are dedicated heat plants called heat-only boiler stations. An important class of power stations in the Middle East uses by-product heat for the desalination of water. The efficiency of a thermal power cycle is limited by the maximum working fluid temperature produced. The efficiency is not directly a function of the fuel used. For the same steam conditions, coal-, nuclear- and gas power plants all


title: "Power station" content: have the same theoretical efficiency. Overall, if a system is on constantly (base load) it will be more efficient than one that is used intermittently (peak load). Steam turbines generally operate at higher efficiency when operated at full capacity. Besides use of reject heat for process or district heating, one way to improve overall efficiency of a power plant is to combine two different thermodynamic cycles in a combined cycle plant. Most commonly, exhaust gases from a gas turbine are used to generate steam for a boiler and a steam turbine. The combination of a "top" cycle and a "bottom"


title: "Power station" content: cycle produces higher overall efficiency than either cycle can attain alone. Power plants that can be dispatched (scheduled) to provide energy to a system include: Non-dispatchable plants include such sources as wind and solar energy; while their long-term contribution to system energy supply is predictable, on a short-term (daily or hourly) base their energy must be used as available since generation cannot be deferred. Contractual arrangements ("take or pay") with independent power producers or system interconnections to other networks may be effectively non-dispatchable. All thermal power plants produce waste heat energy as a byproduct of the useful electrical energy produced.


title: "Power station" content: The amount of waste heat energy equals or exceeds the amount of energy converted into useful electricity. Gas-fired power plants can achieve as much as 65 percent conversion efficiency, while coal and oil plants achieve around 30 to 49 percent. The waste heat produces a temperature rise in the atmosphere, which is small compared to that produced by greenhouse-gas emissions from the same power plant. Natural draft wet cooling towers at many nuclear power plants and large fossil fuel-fired power plants use large hyperboloid chimney-like structures (as seen in the image at the right) that release the waste heat to


title: "Power station" content: the ambient atmosphere by the evaporation of water. However, the mechanical induced-draft or forced-draft wet cooling towers in many large thermal power plants, nuclear power plants, fossil-fired power plants, petroleum refineries, petrochemical plants, geothermal, biomass and waste-to-energy plants use fans to provide air movement upward through downcoming water, and are not hyperboloid chimney-like structures. The induced or forced-draft cooling towers are typically rectangular, box-like structures filled with a material that enhances the mixing of the upflowing air and the downflowing water. In areas with restricted water use, a dry cooling tower or directly air-cooled radiators may be necessary, since the


title: "Power station" content: cost or environmental consequences of obtaining make-up water for evaporative cooling would be prohibitive. These coolers have lower efficiency and higher energy consumption to drive fans, compared to a typical wet, evaporative cooling tower. Electric companies often prefer to use cooling water from the ocean, a lake, or a river, or a cooling pond, instead of a cooling tower. This single pass or once-through cooling system can save the cost of a cooling tower and may have lower energy costs for pumping cooling water through the plant's heat exchangers. However, the waste heat can cause thermal pollution as the water


title: "Power station" content: is discharged. Power plants using natural bodies of water for cooling are designed with mechanisms such as fish screens, to limit intake of organisms into the cooling machinery. These screens are only partially effective and as a result billions of fish and other aquatic organisms are killed by power plants each year. For example, the cooling system at the Indian Point Energy Center in New York kills over a billion fish eggs and larvae annually. A further environmental impact is that aquatic organisms which adapt to the warmer discharge water may be injured if the plant shuts down in cold


title: "Power station" content: weather. Water consumption by power stations is a developing issue. In recent years, recycled wastewater, or grey water, has been used in cooling towers. The Calpine Riverside and the Calpine Fox power stations in Wisconsin as well as the Calpine Mankato power station in Minnesota are among these facilities. Power stations can also generate electrical energy from renewable energy sources. In a hydroelectric power station water flows through turbines using hydropower to generate hydroelectricity. Power is captured from the gravitational force of water falling through penstocks to water turbines connected to generators. The amount of power available is a combination


title: "Power station" content: of height and flow. A wide range of Dams may be built to raise the water level, and create a lake for storing water. Hydropower is produced in 150 countries, with the Asia-Pacific region generating 32 percent of global hydropower in 2010. China is the largest hydroelectricity producer, with 721 terawatt-hours of production in 2010, representing around 17 percent of domestic electricity use. Solar energy can be turned into electricity either directly in solar cells, or in a concentrating solar power plant by focusing the light to run a heat engine. A solar photovoltaic power plant converts sunlight into direct


title: "Power station" content: current electricity using the photoelectric effect. Inverters change the direct current into alternating current for connection to the electrical grid. This type of plant does not use rotating machines for energy conversion. Solar thermal power plants are another type of solar power plant. They use either parabolic troughs or heliostats to direct sunlight onto a pipe containing a heat transfer fluid, such as oil. The heated oil is then used to boil water into steam, which turns a turbine that drives an electrical generator. The central tower type of solar thermal power plant uses hundreds or thousands of mirrors, depending


title: "Power station" content: on size, to direct sunlight onto a receiver on top of a tower. Again, the heat is used to produce steam to turn turbines that drive electrical generators. Wind turbines can be used to generate electricity in areas with strong, steady winds, sometimes offshore. Many different designs have been used in the past, but almost all modern turbines being produced today use a three-bladed, upwind design. Grid-connected wind turbines now being built are much larger than the units installed during the 1970s. They thus produce power more cheaply and reliably than earlier models. With larger turbines (on the order of


title: "Power station" content: one megawatt), the blades move more slowly than older, smaller, units, which makes them less visually distracting and safer for birds. Marine energy or marine power (also sometimes referred to as ocean energy or ocean power) refers to the energy carried by ocean waves, tides, salinity, and ocean temperature differences. The movement of water in the world’s oceans creates a vast store of kinetic energy, or energy in motion. This energy can be harnessed to generate electricity to power homes, transport and industries. The term marine energy encompasses both wave power — power from surface waves, and tidal power —


title: "Power station" content: obtained from the kinetic energy of large bodies of moving water. Offshore wind power is not a form of marine energy, as wind power is derived from the wind, even if the wind turbines are placed over water. The oceans have a tremendous amount of energy and are close to many if not most concentrated populations. Ocean energy has the potential of providing a substantial amount of new renewable energy around the world. Salinity gradient energy is called pressure-retarded osmosis. In this method, seawater is pumped into a pressure chamber that is at a pressure lower than the difference between


title: "Power station" content: the pressures of saline water and fresh water. Freshwater is also pumped into the pressure chamber through a membrane, which increases both the volume and pressure of the chamber. As the pressure differences are compensated, a turbine is spun creating energy. This method is being specifically studied by the Norwegian utility Statkraft, which has calculated that up to 25 TWh/yr would be available from this process in Norway. Statkraft has built the world's first prototype osmotic power plant on the Oslo fiord which was opened on November 24, 2009. Biomass energy can be produced from combustion of waste green material


title: "Power station" content: to heat water into steam and drive a steam turbine. Bioenergy can also be processed through a range of temperatures and pressures in gasification, pyrolysis or torrefaction reactions. Depending on the desired end product, these reactions create more energy-dense products (syngas, wood pellets, biocoal) that can then be fed into an accompanying engine to produce electricity at a much lower emission rate when compared with open burning. It is possible to store energy and produce the electricity at a later time like in Pumped-storage hydroelectricity, Thermal energy storage, Flywheel energy storage, Battery storage power station and so on. The worlds


title: "Power station" content: largest form of storage for excess electricity, pumped-storage is a reversible hydroelectric plant. They are a net consumer of energy but provide storage for any source of electricity, effectively smoothing peaks and troughs in electricity supply and demand. Pumped storage plants typically use "spare" electricity during off peak periods to pump water from a lower reservoir to an upper reservoir. Because the pumping takes place "off peak", electricity is less valuable than at peak times. This less valuable "spare" electricity comes from uncontrolled wind power and base load power plants such as coal, nuclear and geothermal, which still produce power


title: "Power station" content: at night even though demand is very low. During daytime peak demand, when electricity prices are high, the storage is used for peaking power, where water in the upper reservoir is allowed to flow back to a lower reservoir through a turbine and generator. Unlike coal power stations, which can take more than 12 hours to start up from cold, a hydroelectric generator can be brought into service in a few minutes, ideal to meet a peak load demand. Two substantial pumped storage schemes are in South Africa, Palmiet Pumped Storage Scheme and another in the Drakensberg, Ingula Pumped Storage


title: "Power station" content: Scheme. The power generated by a power station is measured in multiples of the watt, typically megawatts (10 watts) or gigawatts (10 watts). Power stations vary greatly in capacity depending on the type of power plant and on historical, geographical and economic factors. The following examples offer a sense of the scale. Many of the largest operational onshore wind farms are located in the USA. As of 2011, the Roscoe Wind Farm is the second largest onshore wind farm in the world, producing 781.5 MW of power, followed by the Horse Hollow Wind Energy Center (735.5 MW). As of July


title: "Power station" content: 2013, the London Array in United Kingdom is the largest offshore wind farm in the world at 630 MW, followed by Thanet Offshore Wind Project in United Kingdom at 300 MW. , the largest photovoltaic (PV) power plants in the world are led by Longyangxia Dam Solar Park in China, rated at 850 megawatts. Solar thermal power stations in the U.S. have the following output: Large coal-fired, nuclear, and hydroelectric power stations can generate hundreds of megawatts to multiple gigawatts. Some examples: Gas turbine power plants can generate tens to hundreds of megawatts. Some examples: The rated capacity of a


title: "Power station" content: power station is nearly the maximum electrical power that that power station can produce. Some power plants are run at almost exactly their rated capacity all the time, as a non-load-following base load power plant, except at times of scheduled or unscheduled maintenance. However, many power plants usually produce much less power than their rated capacity. In some cases a power plant produces much less power than its rated capacity because it uses an intermittent energy source. Operators try to pull maximum available power from such power plants, because their marginal cost is practically zero, but the available power varies


title: "Power station" content: widely—in particular, it may be zero during heavy storms at night. In some cases operators deliberately produce less power for economic reasons. The cost of fuel to run a load following power plant may be relatively high, and the cost of fuel to run a peaking power plant is even higher—they have relatively high marginal costs. Operators keep power plants turned off ("operational reserve") or running at minimum fuel consumption ("spinning reserve") most of the time. Operators feed more fuel into load following power plants only when the demand rises above what lower-cost plants (i.e., intermittent and base load plants)


title: "Power station" content: can produce, and then feed more fuel into peaking power plants only when the demand rises faster than the load following power plants can follow. Operating staff at a power station have several duties. Operators are responsible for the safety of the work crews that frequently do repairs on the mechanical and electrical equipment. They maintain the equipment with periodic inspections and log temperatures, pressures and other important information at regular intervals. Operators are responsible for starting and stopping the generators depending on need. They are able to synchronize and adjust the voltage output of the added generation with the


title: "Power station" content: running electrical system, without upsetting the system. They must know the electrical and mechanical systems to troubleshoot problems in the facility and add to the reliability of the facility. Operators must be able to respond to an emergency and know the procedures in place to deal with it. Power station A power station, also referred to as a power plant or powerhouse and sometimes generating station or generating plant, is an industrial facility for the generation of electric power. Most power stations contain one or more generators, a rotating machine that converts mechanical power into electrical power. The relative motion


title: "Lisbon Cathedral" content: Lisbon Cathedral The Lisbon Cathedral ( or '; "Patriarchal Cathedral of St. Mary Major"), often called simply the Sé, is a Roman Catholic church located in Lisbon, Portugal. The oldest church in the city is the see of the Archdiocese of Lisbon. Since the beginning of the construction of the cathedral, in the year 1147, the building has been modified several times and survived many earthquakes. It is nowadays a mix of different architectural styles. It has been classified as a National Monument since 1910. Lisbon has been the seat of a bishopric since the 4th century (see Patriarch of


title: "Lisbon Cathedral" content: Lisbon). After the period of Visigothic domination the city was conquered by the Moors and stayed under Arab control from the 8th to the 12th century, although Christians were allowed to live in Lisbon and its surroundings. In the year 1147, the city was reconquered by an army composed of Portuguese soldiers led by King Afonso Henriques and North European crusaders taking part on the Second Crusade (see Siege of Lisbon). An English crusader named Gilbert of Hastings was placed as bishop, and a new cathedral was built on the site of the main mosque of Lisbon. This first building


title: "Lisbon Cathedral" content: was completed between 1147 and the first decades of the 13th century in Late Romanesque style. At that time the relics of St Vincent of Saragossa, patron saint of Lisbon, were brought to the cathedral from Southern Portugal. In the end of the 13th century King Dinis of Portugal built a Gothic cloister, and his successor Afonso IV of Portugal had the main chapel converted into a royal pantheon in Gothic style for him and his family. In 1498, Queen Eleanor of Viseu founded the "" ("Brotherhood of Invocation to Our Lady of Mercy of Lisbon ") in one of


title: "Lisbon Cathedral" content: the chapels of the cloister of the cathedral. This brotherhood evolved into the "Santa Casa da Misericórdia de Lisboa", a Catholic charitable institution that later spread to other cities and had a very important role in Portugal and its colonies. Earthquakes have always been a problem for Lisbon and its cathedral. During the 14th and 16th centuries there were several of them, but the worst of all was the 1755 Lisbon earthquake, which destroyed the Gothic main chapel along with the royal pantheon. The cloisters and many chapels were also ruined by the quake and the fire that followed. The


title: "Lisbon Cathedral" content: cathedral was partially rebuilt and, in the beginning of the 20th century, was given the appearance that it has today after a profound renovation. In recent years the central courtyard of the cloister has been excavated and shows signs of the Roman, Arab and mediaeval periods. Excavations started in Cathedral Cloister in 1990. They have revealed a Roman road with shops on either site. A part of a Roman kitchen and a "cloaca" (sewage system). and traces of later Visigoth buildings. A very visible part of a Moorish building with red walls related to the former mosque that once stood


title: "Lisbon Cathedral" content: on this site was also excavated. The cathedral is a Latin cross building with three aisles, a transept and a main chapel surrounded by an ambulatory. The church is connected with a cloister on the Eastern side. The main façade of the cathedral looks like a fortress, with two towers flanking the entrance and crenellations over the walls. This menacing appearance, also seen in other Portuguese cathedrals of the time, is a relic from the Reconquista period, when the cathedral could be used as a base to attack the enemy during a siege. From its first building period (1147 until


title: "Lisbon Cathedral" content: the first decades of the 13th century), Lisbon cathedral has preserved the West façade with a rose window (rebuilt from fragments in the 20th century), the main portal, the North lateral portal and the nave of the cathedral. The portals have interesting sculptured capitals with Romanesque motifs. The nave is covered by barrel vaulting and has an upper, arched gallery (triforium). Light gets in through the rose windows of the West façade and transept, the narrow windows of the lateral aisles of the nave as well as the windows of the lantern tower of the transept. The general plan of


title: "Lisbon Cathedral" content: the cathedral is very similar to that of the Old Cathedral of Coimbra, which dates from the same period. One of the chapels of the ambulatory has an interesting Romanesque iron gate. At the end of the 13th century King Dinis of Portugal ordered the construction of a cloister in Gothic style, which became severely damaged by the 1755 earthquake. Near the entrance of the cathedral, a rich merchant, Bartolomeu Joanes, built a funerary chapel for himself in the beginning of the 14th century. His tomb with his laying figure is still inside. Somewhat later, King Afonso IV of Portugal


title: "Lisbon Cathedral" content: had the Romanesque apse replaced by a Gothic main chapel surrounded by an ambulatory with radiating chapels. The king and his family were buried in the main chapel, but their tombs and the chapel itself were destroyed in the 1755 earthquake. The ambulatory has survived and is an important work in the history of Portuguese Gothic. It consists of a circular aisle – not connected to the main chapel – with a series of radiating chapels. The second storey of the ambulatory is covered by ribbed vaulting and has a series of windows (clerestory) that bathe the interior with abundant


title: "Lisbon Cathedral" content: light. The ambulatory contains three outstanding Gothic tombs from the mid-14th century. One tomb belongs to "Lopo Fernandes Pacheco", 7th Lord of Ferreira de Aves, a nobleman at the service of King Afonso IV. His laying figure appears holding his sword and is guarded by a dog. His wife, "Maria de Vilalobos", appears over her tomb reading a Book of Hours. The third tomb belongs to an unidentified royal princess. All tombs are decorated with coats-of-arms. In the last quarter of the 15th century it is believed that the famous Saint Vincent Panels, painted by Nuno Gonçalves, were placed in


title: "Lisbon Cathedral" content: the St Vincent chapel of the ambulatory. They remained there at least until 1690 and were set aside in the Cathedral until 1742. They were then transferred to the palace of Mitra. The panels are now in the Museu Nacional de Arte Antiga (National Museum of Ancient Art) in Lisbon. During the 17th century a fine sacristy was built in Baroque architectural style and, after 1755, the main chapel was rebuilt in neoclassical and Rococo styles (including the tombs of King Afonso IV and his family). Machado de Castro, Portugal's foremost sculptor in the late 18th century, is the author


title: "Lisbon Cathedral" content: of a magnificent crib in the Gothic chapel of Bartomoleu Joanes. In the beginning of the 20th century, much of the neoclassical decoration from outside and inside of the cathedral was removed to give the cathedral a more "mediaeval" appearance. Lisbon Cathedral The Lisbon Cathedral ( or '; "Patriarchal Cathedral of St. Mary Major"), often called simply the Sé, is a Roman Catholic church located in Lisbon, Portugal. The oldest church in the city is the see of the Archdiocese of Lisbon. Since the beginning of the construction of the cathedral, in the year 1147, the building has been modified


title: Coagulation content: etiologically elusive hemophilia A; it was identified in the 1950s and is alternatively called "antihemophilic globulin" due to its capability to correct hemophilia A. Factor IX was discovered in 1952 in a young patient with hemophilia B named Stephen Christmas (1947–1993). His deficiency was described by Dr. Rosemary Biggs and Professor R.G. MacFarlane in Oxford, UK. The factor is, hence, called Christmas Factor. Christmas lived in Canada, and campaigned for blood transfusion safety until succumbing to transfusion-related AIDS at age 46. An alternative name for the factor is "plasma thromboplastin component", given by an independent group in California. Hageman factor,


title: "Northern wheatear" content: Northern wheatear The northern wheatear or wheatear ("Oenanthe oenanthe") is a small passerine bird that was formerly classed as a member of the thrush family Turdidae, but is now more generally considered to be an Old World flycatcher, Muscicapidae. It is the most widespread member of the wheatear genus "Oenanthe" in Europe and Asia. The northern wheatear is a migratory insectivorous species breeding in open stony country in Europe and Asia with footholds in northeastern Canada and Greenland as well as in northwestern Canada and Alaska. It nests in rock crevices and rabbit burrows. All birds spend most of their


title: "Northern wheatear" content: winter in Africa. The northern wheatear was first formally described by the Swedish naturalist Carl Linnaeus in 1758 in the 10th edition of his "Systema Naturae" as "Motacilla oenanthe". The genus "Oenanthe" was introduced by the French ornithologist Louis Jean Pierre Vieillot in 1816. The generic name, "Oenanthe", is also the name of a plant genus, the water dropworts, and is derived from the Greek "ainos" "wine" and "anthos" "flower", from the wine-like scent of the flowers. In the case of the wheatear, it refers to these birds' return to Greece in the spring just as the grapevines blossom. Its


title: "Northern wheatear" content: English name has nothing to do with wheat or ears, but is an altered (perhaps bowdlerised) form of white-arse, which refers to its prominent white rump. The four subspecies with their breeding range are as follows: The northern wheatear is larger than the European robin at in length. Both sexes have a white rump and tail, with a black inverted T-pattern at the end of the tail. The plumage of the summer male has grey upperparts, buff throat and black wings and face mask. In autumn it resembles the female apart from the black wings. The female is pale brown


title: "Northern wheatear" content: above and buff below with darker brown wings. The male has a whistling, crackly song. Its call is a typical chat "chack" noise, and the flight call is the same. The northern wheatear makes one of the longest journeys of any small bird, crossing ocean, ice, and desert. It migrates from Sub-Saharan Africa in spring over a vast area of the Northern Hemisphere that includes northern and central Asia, Europe, Greenland, Alaska, and parts of Canada. In autumn all return to Africa, where their ancestors had wintered. Arguably, some of the birds that breed in north Asia could take a


title: "Northern wheatear" content: shorter route and winter in south Asia; however, their inherited inclination to migrate takes them back to Africa. Birds of the large, bright Greenland race, "leucorhoa", makes one of the longest transoceanic crossings of any passerine. In spring most migrate along a route (commonly used by waders and waterfowl) from Africa via continental Europe, the British Isles, and Iceland to Greenland. However, autumn sightings from ships suggest that some birds cross the North Atlantic directly from Canada and Greenland to southwest Europe, a distance of up to . Birds breeding in eastern Canada are thought to fly from Baffin Island


title: "Northern wheatear" content: and Newfoundland via Greenland, Ireland, and Portugal to the Azores, crossing of the North Atlantic) before flying onwards to Africa. Other populations from western Canada and Alaska migrate by flying over much of Eurasia to Africa. Miniature tracking devices have recently shown that the northern wheatear has one of the longest migratory flights known - 30,000 km (18,640 miles), from sub-Saharan Africa to their Arctic breeding grounds. "The Alaskan birds travelled almost 15,000km (9,000 miles) each way - crossing Siberia and the Arabian Desert, and travelling, on average, 290km per day. "This is the longest recorded migration for a songbird


title: "Northern wheatear" content: as far as we know," said Dr Schmaljohann. Northern wheatears first breed when they are one year old. The nest is built entirely by the female while the male perches nearby, sings and sometimes performs song-flights. The nest is placed in a cavity such as a rabbit burrow, a crevice among rocks or in a man-made object such as a wall or pipe. The nest typically has a foundation of untidy plant material. The nest cup is constructed of finer grasses, leaves, moss and lichen. The female lays eggs at daily intervals. The clutch is 4-7 smooth but not glossy


title: "Northern wheatear" content: eggs that are around in size with an average weight of . The eggs are very pale blue in colour and sometimes have a few red-brown marks at the larger end. They are incubated almost entirely by the female beginning after the penultimate or final egg has been laid. The eggs hatch after approximately 13 days. The chicks are fed by both parents and are brooded by the female for the first five or six days. They fledge after 15 days and become independent of their parents when they are between 28 and 32 days old. Normally only a single


title: "Northern wheatear" content: brood is raised each year but when a clutch of eggs is lost, the female will lay a second clutch. The northern wheatear has an extensive range, estimated at 2.3 million square kilometres (0.87 million square miles), and a large population estimated at 2.9 million individuals in the Old World and the Americas combined. The species is not believed to approach the thresholds for the population decline criterion of the IUCN Red List (i.e., declining more than 30% in ten years or three generations), and is therefore evaluated as least concern. Northern wheatear The northern wheatear or wheatear ("Oenanthe oenanthe")


title: "Richard Sorge" content: thought that Sorge had been discovered passing secret information on the Japan-US negotiations to the German Embassy, and also that the arrest could be due to anti-German elements in the Japanese government. Nonetheless, he immediately agreed with Japanese authorities to "investigate the incident fully". It was not until a few months later that Japanese authorities announced that Sorge had in fact been indicted as a Soviet agent. He was incarcerated in Sugamo Prison. Initially, the Japanese believed that, due to his Nazi Party membership and German ties, Sorge was an "Abwehr" agent. However, the "Abwehr" denied that he was one


title: "Richard Sorge" content: the West, especially Germany, from the time of their publication to the present. In 1954, West German film director Veit Harlan wrote and directed the film "" about Sorge's espionage in Japan. Harlan had been the favorite filmmaker of Nazi propaganda minister Joseph Goebbels, and directed many propaganda films, including "Jud Süss". Harlan's film is a romantic drama, starring Harlan's wife Kristina Söderbaum, as Sorge's love interest. The film was publicly premiered by the distributor before it passed the rating system, hence withdrawn from more public performances and finally released after some editing was done. In 1961, a movie called


title: "Pied crow" content: Pied crow The pied crow ("Corvus albus") is a widely distributed African bird species in the crow genus. Like most crows and ravens, it is an adaptable, generalist species with a broad diet. Its plumage is a striking black and white, somewhat resembling its much larger relatives the thick-billed raven and white-necked raven; unlike these ravens, it also has a white belly. It is approximately the size of the European carrion crow (46–52 cm in length) but has a longer bill, slightly longer tail and wings, and longer legs. As its name suggests, its glossy black head and neck are


title: "Pied crow" content: interrupted by a large area of white feathering from the shoulders down to the lower breast, but the tail, bill and wings are black. The eyes of a fully matured bird are dark brown. The white plumage of immature birds is often mixed with black. It resembles the White-necked and thick-billed ravens but is much smaller, less stocky and has a smaller bill. Structurally, the pied crow is better thought of as a small crow-sized raven (although it exhibits some crow-like traits such as a lack of throat hackles and a fan-shaped tail), especially as it can hybridise with the


title: "Pied crow" content: Somali crow (sometimes called the dwarf raven) where their ranges meet in the Horn of Africa. Its behaviour, though, is more typical of the Eurasian carrion crows, and it may be a modern link (along with the Somali crow) between the Eurasian crows and the common raven. In southern Africa the range overlaps with the white-necked raven. The pied crow is smaller and has a white chest and belly with a black, more delicate beak compared to the black chest and belly of the larger white-necked raven which also has a white tipped and weightier beak. The voice is described


title: "Pied crow" content: as a harsh ""ar-ar-ar-ar"" or ""karh-karh-karh"" and lacks the whispering note of the White-necked raven. The pied crow was first described in 1776 by Statius Muller. Its specific name is the Latin adjective "albus", meaning "white". Recent findings indicate that based on mitochondrial DNA, common ravens ("C. corax") from the north of the United States are more closely related to those in Europe and Asia than to those in the California clade, and that common ravens in the California clade ("C. corax sinuatus") are more closely related to the Chihuahuan raven ("C. cryptoleucus") than to those in the Holarctic clade.


title: "Pied crow" content: while ravens in the Holarctic clade are more closely related to the pied crow ("C. albus") than they are to the California clade. Thus, the common raven species as traditionally delimited is considered to be paraphyletic. This species, Africa's most widespread member of the genus "Corvus", occurs from Sub-Saharan Africa, specifically Senegal, Sudan, Somalia and Eritrea down to the Cape of Good Hope and on the large island of Madagascar, the Comoros islands, Aldabra group islands, Zanzibar, Pemba and Fernando Po. Although the species is still a vagrant north of the Sahara, a breeding case and a number of long-staying


title: "Pied crow" content: birds were observed during the last few years in Morocco. It inhabits mainly open country with villages and towns nearby. It does not occur in the equatorial rainforest region. It is rarely seen very far from human habitation, though it is not as tied to the urban way of life as the house crow ("Corvus splendens") of Asia, and may be encountered far from human habitation in Eritrea. Pied crows are generally encountered in pairs or small groups, although an abundant source of food may bring large numbers of birds. The species behaves in a similar manner to the hooded


title: "Pied crow" content: and carrion crows. In Dakar, birds have been observed mobbing passing ospreys and snake eagles but avoiding black kites. All of its food is obtained from the ground such as insects and other small invertebrates, small reptiles, small mammals, young birds and eggs, grain, peanuts, carrion and any scraps of human food and sometimes fruit and even mushrooms. It has been recorded killing and eating roosting bats and is frequently seen scavenging around slaughterhouses in large numbers. The nest is usually built in tall, isolated trees, though sometimes smaller ones are used, depending on availability. The cross supports of telephone


title: "Pied crow" content: poles are also frequently used, and both sexes build the nest. A clutch of 3–6 eggs is laid from September to November (depending on latitude) and are pale green spotted with various shades of brown. The eggs are normally covered when the incubating female leaves the nest. Incubation is 18–19 days and the young are usually fledged by around 45 days. Both sexes rear the young. Pied crow The pied crow ("Corvus albus") is a widely distributed African bird species in the crow genus. Like most crows and ravens, it is an adaptable, generalist species with a broad diet. Its


title: "Western jackdaw" content: Western jackdaw The western jackdaw ("Coloeus monedula"), also known as the Eurasian jackdaw, European jackdaw, or simply jackdaw, is a passerine bird in the crow family. Found across Europe, western Asia and North Africa, it is mostly resident, although northern and eastern populations migrate south in winter. Four subspecies are recognised, which mainly differ in the colouration of the plumage on the head and nape. Linnaeus first described it formally, giving it the name "Corvus monedula". The common name derives from the word "jack", denoting "small", and daw, a less common synonym for "jackdaw", and the native English name for


title: "Western jackdaw" content: the bird. Measuring in length, the western jackdaw is a black-plumaged bird with a grey nape and distinctive pale-grey irises. It is gregarious and vocal, living in small groups with a complex social structure in farmland, open woodland, on coastal cliffs, and in urban settings. Like its relatives, Jackdaws are intelligent birds, and have been observed using tools. An omnivorous and opportunistic feeder, it eats a wide variety of plant material and invertebrates, as well as food waste from urban areas. Western jackdaws are monogamous and build simple nests of sticks in cavities in trees, cliffs, or buildings. About five


title: "Western jackdaw" content: pale blue or blue-green eggs with brown speckles are laid and incubated by the female. The young fledge in four to five weeks. The western jackdaw was one of the many species originally described by Carl Linnaeus in his 18th century work "Systema Naturae". Owing to its supposed fondness for picking up coins, Linnaeus gave it the binomial name "Corvus monedula", choosing the specific name "mǒnēdŭla", which is derived from "moneta", the Latin stem of the word "money". Jackdaws are sometimes placed in the genus "Coloeus", from the Ancient Greek κολοιός ("koloios") for jackdaw, though most subsequent works have retained


title: "Western jackdaw" content: the two jackdaw species in "Corvus". The original Old English word "ċēo" (pronounced with initial "ch") gave modern English "chough"; Chaucer sometimes used this word to refer to the western jackdaw, as did Shakespeare in "Hamlet" although there has been debate about which species he was referring to. This onomatopoeic name, based on the western jackdaw's call, now refers to corvids of the genus "Pyrrhocorax"; the red-billed chough ("Pyrrhocorax pyrrhocorax"), formerly particularly common in Cornwall, became known initially as the "Cornish chough" and then just the "chough", the name transferring from one species to the other. The common name "jackdaw"


title: "Western jackdaw" content: first appeared in the 16th century, and is thought to be a compound of the forename "Jack", used in animal names to signify a small form (e.g. jack snipe), and the archaic native English word "daw". Formerly, western jackdaws were simply called "daws". The metallic "chyak" call may be the origin of the "jack" part of the common name, but this is not supported by the "Oxford English Dictionary". "Daw", first used for the bird in the 15th century, is held by the "Oxford English Dictionary" to be derived from the postulated Old English "dawe", citing the cognates in Old


title: "Western jackdaw" content: High German "tāha", Middle High German "tāhe" or "tāchele", and modern German "Dahle" or "Dohle", and dialectal "Tach, Dähi, Däche" and "Dacha". Names in English dialects are numerous. Scottish and north English dialects have included "ka" or "kae" since the 14th century. The Midlands form of this word was "co" or "coo". "Caddow" is potentially a compound of "ka" and "dow", a variant of "daw". Other dialectal or obsolete names include "caddesse", "cawdaw", "caddy", "chauk", "college-bird", "jackerdaw", "jacko", "ka-wattie", "chimney-sweep bird" (from their nesting propensities), and "sea-crow" (from the frequency with which they are found on coasts). It was also


title: "Western jackdaw" content: frequently known quasi-nominally as "Jack". An archaic collective noun for a group of jackdaws is a "clattering". Another name for a flock is a "train". A study in 2000 found that the genetic distance between jackdaws and the other members of "Corvus" was greater than that within the rest of the genus. This led Pamela Rasmussen to reinstate the genus name "Coloeus", created by Johann Kaup in 1829, in her "Birds of South Asia" (2005), a treatment also used in a 1982 systematic list in German by Hans Edmund Wolters. A study of corvid phylogeny undertaken in 2007 compared DNA


title: "Western jackdaw" content: sequences in the mitochondrial control region of several corvids. It found that the western jackdaw, and the closely related Daurian jackdaw ("C. dauuricus") of eastern Russia and China, were basal to the core "Corvus" clade. The names "Coloeus monedula" and "Coloeus dauuricus" have since been adopted by the International Ornithological Congress in their official list. The two species of jackdaw have been reported to hybridise in the Altai Mountains, southern Siberia, and Mongolia. Analysis of the mitochondrial DNA of specimens of the two species from their core ranges show them to be genetically distinct. There are four recognised subspecies of


title: "Western jackdaw" content: the western jackdaw. All European subspecies intergrade where their populations meet. "C. m. monedula" intergrades into "C. m. soemmerringii" in a transition zone running from Finland south across the Baltic and eastern Poland to Romania and Croatia. Measuring in length, the western jackdaw is the second smallest member of the genus "Corvus". Most of the plumage is a shiny black, with a purple (in subspecies "monedula" and "spermologus") or blue (in subspecies "cirtensis" and "soemmerringii") sheen on the crown, forehead, and secondaries, and a green-blue sheen on the throat, primaries, and tail. The cheeks, nape and neck are light grey


title: "Western jackdaw" content: to greyish-silver, and the underparts are slate-grey. The legs are black, as is the short stout bill, the length of which is about 75% of the length of the rest of the head. There are rictal bristles covering around 40% of the maxilla and 25% of the lower mandible. The irises of adults are greyish or silvery white while those of juveniles are light blue, becoming brownish before whitening at around one year of age. The sexes look alike, though the head and neck plumage of male birds fades more with age and wear, particularly just before moulting. Western jackdaws


title: "Western jackdaw" content: undergo a complete moult from June to September in the western parts of their range, and a month later in the east. The purplish sheen of the cap is most prominent just after moulting. Immature birds have duller and less demarcated plumage. The head is a sooty black, sometimes with a faint greenish sheen and brown feather bases visible; the back and side of the neck are dark grey and the underparts greyish or sooty black. The tail has narrower feathers and a greenish sheen. There is very little geographic variation in size. The main differences are the presence or


title: "Western jackdaw" content: absence of a whitish partial collar at the base of the nape, the variations in the shade of the nape and the tone of the underparts. Populations in central Asia have slightly larger wings and western populations have a slightly heavier bill. Body colour becomes darker further north, in mountain regions and humid climates, and paler elsewhere. However, individual variation, particularly in juveniles and also during the months before moulting, can often be greater than geographic differences. A skilled flyer, the western jackdaw can manoeuvre tightly as well as tumble and glide. It has characteristic jerky wing beats when flying,


title: "Western jackdaw" content: though these are not evident when birds are migrating. Wind tunnel experiments show that the preferred gliding speed is between per second and that the wingspan decreases as the bird flies faster. On the ground, western jackdaws have an upright posture and strut briskly, their short legs giving them a rapid gait. They feed with their heads held down or horizontally. Within its range, the western jackdaw is unmistakable; its short bill and grey nape are distinguishing features. From a distance, it can be confused with a rook ("Corvus frugilegus"), or when in flight, with a pigeon or chough. Flying


title: "Western jackdaw" content: western jackdaws are distinguishable from other corvids by their smaller size, faster and deeper wingbeats and proportionately narrower and less fingered wing tips. They also have shorter, thicker necks, much shorter bills and frequently fly in tighter flocks. They can be distinguished from choughs by their uniformly grey underwings and their black beaks and legs. The western jackdaw is very similar in morphology, behaviour, and calls to the Daurian jackdaw, with which its range overlaps in western Asia. Adults are readily distinguished, since the Daurian has a pied plumage, but immature birds are much more similar, both species having dark


title: "Western jackdaw" content: plumage and dark eyes. The Daurian tends to be darker, with a less contrasting nape than the Western. Western jackdaws are voluble birds. The main call, frequently given in flight, is a metallic and squeaky "chyak-chyak" or "kak-kak". This is a contact or greeting call. A feeding call made by adults to call young, or males when offering food to their mates, has been transcribed as "kiaw" or "kyow". Females in return give a more drawn out version when begging for food from males, written as "kyaay", "tchaayk" or "giaaaa". Perched birds often chatter together, and before settling for the


title: "Western jackdaw" content: night, large roosting flocks make a cackling noise. Western jackdaws also have a hoarse, drawn-out alarm call, "arrrrr" or "kaaaarr", used when warning of predators or when mobbing them. Nestlings begin making a soft "cheep" at about a week of age. As they grow, their voice becomes louder until their call is a penetrating screech around day 18. After this, the voice deepens and softens. From day 25, the young cease calling and become silent if they hear an unfamiliar noise. The European jackdaw can be trained to imitate human speech. The western jackdaw is found from north-west Africa through


title: "Western jackdaw" content: all of Europe, except for the extreme north, and eastwards through central Asia to the eastern Himalayas and Lake Baikal. To the east, it occurs throughout Turkey, the Caucasus, Iran, Iraq, Afghanistan, Pakistan, and north-west India. However, it is regionally extinct in Malta and Tunisia. The range is vast, with an estimated global extent of between 1 million and 10 million square kilometres (4 hundred thousand to 4 million square miles). It has a large global population, with an estimated 15.6 to 45 million individuals in Europe alone. Censuses of bird populations in marginal uplands in Britain show that western


title: "Western jackdaw" content: jackdaws greatly increased in numbers between the 1970s and 2010, although this increase may be related to recovery from previous periods when they were regarded as pests. The UK population was estimated at 2.5 million individuals in 1998, up from 780,000 in 1970. Most populations are resident, but the northern and eastern populations are more migratory, relocating to wintering areas between September and November and returning between February and early May. Their range expands northwards into Russia to Siberia during summer, and retracts in winter. They are vagrants to the Faroe Islands, particularly in the winter and spring, and occasionally


title: "Western jackdaw" content: to Iceland. Elsewhere, western jackdaws congregate over winter in the Ural Valley in north-western Kazakhstan, the north Caspian, and the Tian Shan region of western China. They are winter visitors to the Quetta Valley in western Pakistan, and are winter vagrants to Lebanon, where they were first recorded in 1962. In Syria, they are winter vagrants and rare residents with some confirmed breeding taking place. The "soemmerringii" subspecies occurs in south-central Siberia and extreme north-west China and is accidental to Hokkaido, Japan. A small number of western jackdaws reached the north-east of North America in the 1980s and have been


title: "Western jackdaw" content: found from Atlantic Canada to Pennsylvania. They have also occurred as vagrants in Gibraltar, Mauritania, and Saint Pierre and Miquelon, and one is reported to have been seen in Egypt. Western jackdaws inhabit wooded steppes, pastures, cultivated land, coastal cliffs, and towns. They thrive when forested areas are cleared and converted to fields and open areas. Habitats with a mix of large trees, buildings, and open ground are preferred; open fields are left to the rook, and more wooded areas to the Eurasian jay ("Garrulus glandarius"). Along with other corvids such as the rook, common raven ("Corvus corax"), and hooded


title: "Western jackdaw" content: crow ("C. cornix"), some western jackdaws spend the winter in urban parks; populations measured in three urban parks in Warsaw show increases from October to December, possibly due to western jackdaws migrating there from areas further north. The same data from Warsaw, collected from 1977 to 2003, showed that the wintering western jackdaw population had increased four-fold. The cause of the increase is unknown, but a reduction in the number of rooks may have benefited the species locally, or rooks overwintering in Belarus may have caused western jackdaws to relocate to Warsaw. Generally wary of people in the forest or


title: "Western jackdaw" content: countryside, western jackdaws are much tamer in urban areas. Like magpies, they are known to show interest in shiny objects such as jewellery. John Gay, in his "Beggar's Opera", notes that "A covetous fellow, like a jackdaw, steals what he was never made to enjoy, for the sake of hiding it". In Tobias Smollett's "The Expedition of Humphry Clinker", a scathing character assassination runs, "He is ungracious as a hog, greedy as a vulture, and thievish as a jackdaw." Highly gregarious, western jackdaws are generally seen in flocks of varying sizes, though males and females pair-bond for life and pairs


title: "Western jackdaw" content: stay together within flocks. Flocks increase in size in autumn and birds congregate at dusk for communal roosting, with up to several thousand individuals gathering at one site. At Uppsala, Sweden, 40,000 birds have been recorded at a single winter roost with mated pairs often settling together for the night. Western jackdaws frequently congregate with hooded crows or rooks, the latter particularly when migrating or roosting. They have been recorded foraging with the common starling ("Sturnus vulgaris"), Northern lapwing ("Vanellus vanellus"), and common gull ("Larus canus") in northwestern England. Flocks are targets of coordinated hunting by pairs of lanner falcons


title: "Western jackdaw" content: ("Falco biarmicus"), although larger groups are more able to elude the predators. Western jackdaws sometimes mob and drive off larger birds such as European magpies, common ravens, or Egyptian vultures ("Neophron percnopterus"); one gives an alarm call which alerts its conspecifics to gather and attack as a group. Occasionally, a sick or injured western jackdaw is mobbed until it is killed. In his book "King Solomon's Ring", Konrad Lorenz described and analysed the complex social interactions in a western jackdaw flock that lived around his house in Altenberg, Austria. He ringed them for identification and caged them in the winter


title: "Western jackdaw" content: to prevent their annual migration. He found that the birds have a linear hierarchical group structure, with higher-ranked individuals dominating lower-ranked birds, and pair-bonded birds sharing the same rank. Young males establish their individual status before pairing with females. Upon pairing, the female assumes the same social position as her partner. Unmated females are the lowest members in the pecking order, and are the last to have access to food and shelter. Lorenz noted one case in which a male, absent during the dominance struggles and pair bondings, returned to the flock, became the dominant male, and chose one of


title: "Western jackdaw" content: two unpaired females for a mate. This female immediately assumed a dominant position in the social hierarchy and demonstrated this by pecking others. According to Lorenz, the most significant factor in social behaviour was the immediate and intuitive grasp of the new hierarchy by each of the western jackdaws in the flock. Social hierarchy in western jackdaw flocks is determined by supplanting, fighting, and threat displays—several of which have been described. In the "bill-up posture", the western jackdaw tilts its bill and head upwards and sleeks its plumage. Indicating both appeasement and assertiveness, the posture is used by birds intending


title: "Western jackdaw" content: to enter feeding flocks. A "bill-down posture" is another commonly used agonistic behaviour. In this display, a bird lowers its bill and erects its nape and head feathers, and sometimes slightly lifts its wings. Western jackdaws often face off in this posture until one backs down or a fight ensues. In the "forward-threat posture", a bird holds its body horizontally and thrusts its head forwards. In intense versions, the bird ruffles its feathers and spreads or raises its tail and wings. This extreme is seen when facing off over nests or females. In the "defensive-threat posture", the bird lowers its


title: "Western jackdaw" content: head and bill, spreads its tail and ruffles its feathers. "Supplanting" is where one bird moves in and displaces another from a perch-site. The second bird usually retreats without resorting to a fight. Western jackdaws fight by launching themselves at each other feet-first and then wrestling with their feet intertwined and pecking at each other. Other individuals gather and call noisily. Western jackdaws entreat their partners to preen them by showing their nape and ruffling their head feathers. Birds mainly preen each other's head and neck. Known as "allopreening", this behaviour is almost always done between birds of a mated


title: "Western jackdaw" content: pair. Western jackdaws become sexually mature in their second year. Genetic analysis of pairs and offspring shows no evidence of extra-pair copulation and there is little evidence for couple separation even after multiple instances of reproductive failure. Some pairs do separate in the first few months, but almost all pairings of over six months' duration are lifelong, ending only when a partner dies. Widowed or separated birds fare badly, often being ousted from nests or territories and unable to rear broods alone. Western jackdaws usually breed in colonies with pairs collaborating to find a nest site, which they then defend


title: "Western jackdaw" content: from other pairs and predators during most of the year. They nest in cavities in trees or cliffs, in ruined or occupied buildings and in chimneys, the common feature being a sheltered site for the nest. The availability of suitable sites influences their presence in a locale. They may also use church steeples for nesting, a fact reported in verse by 18th century English poet William Cowper: Nest platforms can attain a great size. A mated pair usually constructs a nest by improving a crevice by dropping sticks into it; it is then built on top of the platform formed.


title: "Western jackdaw" content: This behaviour has led to the blocking of chimneys and even resulted in nests crashing down into fireplaces, sometimes with birds still on them. In his "The Natural History of Selborne", Gilbert White notes that western jackdaws used to nest in crevices beneath the lintels of Stonehenge, and describes an example of the bird using a rabbit burrow for nesting. The species has been recorded outcompeting the tawny owl ("Strix aluco") for nest sites in the Netherlands. They can take over old nest sites of the black woodpecker ("Dryocopus martius") and stock dove ("Columba oenas"). Breeding colonies may also edge


title: "Western jackdaw" content: out those of the red-billed chough, but in turn be ousted by larger corvids such as the carrion crow, rook or magpie. Nests are lined with hair, wool, dead grass and many other materials. The eggs are a lighter colour than those of other corvids, being smooth, a glossy pale blue or blue-green with darker speckles ranging from dark brown to olive or grey-violet. Egg size and weight varies slightly between subspecies; those of subspecies "monedula" average and in weight, those of subspecies "soemmerringii" in size and in weight, and those of subspecies "spermologus" in size and in weight. Clutches


title: "Western jackdaw" content: usually contain 4 or 5 eggs, although a Slovakian study found clutch sizes ranging from 2 to 9 eggs. The eggs are incubated by the female for 17–18 days until hatching as naked altricial chicks, which are completely dependent on the adults for food. They fledge after 28–35 days, and the parents continue to feed them for another four weeks or so. Western jackdaws hatch asynchronously and incubation begins before clutch completion, which often leads to the death of the last-hatched young. If the supply of food is low, parental investment in the brood is kept to a minimum as


title: "Western jackdaw" content: little energy is wasted on feeding a chick that is unlikely to survive. Replacement clutches are very rarely laid in the event of clutch failure. The great spotted cuckoo ("Clamator glandarius") has been recorded as a brood parasite of the western jackdaw, depositing its eggs in their nests in Spain and Israel. Nest robbers include the common raven in Spain, tawny owl, and least weasel ("Mustela nivalis") in England, and brown rat ("Rattus norvegicus") in Finland. The European pine marten ("Martes martes") raids isolated nests in Sweden but is less successful when nests are part of a colony. Foraging takes


title: "Western jackdaw" content: place mostly on the ground in open areas and to some extent in trees. Landfill sites, bins, streets, and gardens are also visited, more often early in the morning when there are fewer people about. Various feeding methods are employed, such as jumping, pecking, clod-turning and scattering, probing the soil, and occasionally, digging. Flies around cow pats are caught by jumping from the ground or at times by dropping vertically from a few metres onto the cow pat. Earthworms are not usually extracted from the ground by western jackdaws but are eaten from freshly ploughed soil. Jackdaws will ride on


title: "Western jackdaw" content: the backs of sheep and other mammals, seeking ticks as well as actively gathering wool or hair for nests, and will catch flying ants in flight. Compared with other corvids, the western jackdaw spends more time exploring and turning over objects with its bill; it also has a straighter and less downturned bill and increased binocular vision which are advantageous for this foraging strategy. The western jackdaw tends to feed on small invertebrates up to in length that are found above ground, including various species of beetle (particularly cockchafers of the genus "Melolontha", and weevil larvae and pupae.), "Diptera", and


title: "Western jackdaw" content: "Lepidoptera" species, as well as snails and spiders. Also eaten are small rodents, bats, the eggs and chicks of birds, and carrion such as roadkill. Vegetable items consumed include farm grains (barley, wheat and oats), weed seeds, elderberries, acorns, and various cultivated fruits. Examination of the gizzards of western jackdaws shot in Cyprus in spring and summer revealed a diet of cereals (predominantly wheat) and insects (notably cicadas and beetles). The diet averages 84% plant material except when breeding, when the main food source is insects. A study in southern Spain examining western jackdaw pellets found that they contained significant


title: "Western jackdaw" content: amounts of silicaceous and calcareous grit to aid digestion of vegetable food and supply dietary calcium. Opportunistic and highly adaptable, the western jackdaw varies its diet markedly depending on available food sources. They have been recorded taking eggs and nestlings from the nests of the skylark ("Alauda arvensis"), Manx shearwater ("Puffinus puffinus"), razorbill ("Alca torda"), common murre ("Uria aalge"), grey heron ("Ardea cinerea"), rock pigeon ("Columba livia"), and Eurasian collared dove ("Streptopelia decaocto"). A field study of a large city dump on the outskirts of León in northwestern Spain showed that western jackdaws forage there in the early morning and


title: "Western jackdaw" content: at dusk, and engage in some degree of kleptoparasitism. The saker falcon ("Falco cherrug") has been reported stealing food from western jackdaws on powerlines in Vojvodina in Serbia. Western jackdaws practice active food sharing – where the initiative for the transfer lies with the donor – with a number of individuals, regardless of sex or kinship. They also share more of a preferred food than a less preferred food. The active giving of food by most birds is found mainly in the context of parental care and courtship. Western jackdaws show much higher levels of active giving than has been


title: "Western jackdaw" content: documented for other species, including chimpanzees. The function of this behaviour is not fully understood, though it has been found to be detached from nutrition and compatible with hypotheses of mutualism, reciprocity and harassment avoidance. It has also been proposed that food sharing may be motivated by prestige enhancement. Western jackdaws have learned to peck open the foil caps of milk bottles left on the doorsteps after delivery by the milkman. The bacterium "Campylobacter jejuni" has been isolated from their beaks and cloacae so milk can become contaminated as they drink. This activity was linked to cases of "Campylobacter" gastroenteritis


title: "Western jackdaw" content: in Gateshead in northeast England and led the Department of Health to suggest that milk from bottles which had been pecked open should be discarded. It was recommended that steps be taken to prevent birds from pecking open bottles in the future. An outbreak of a gastrointestinal illness in Spain which was causing mortalities in humans has been linked to western jackdaws. During a post-mortem on an affected bird, a polyomavirus was isolated from the spleen. The illness appeared to be a co-infection of this with "Salmonella" and the virus has been provisionally named the crow polyomavirus (CPyV). Segmented filamentous


title: "Western jackdaw" content: bacteria have been isolated from the small intestine of a western jackdaw, although their pathogenicity or role is unknown. The western jackdaw has been hunted as vermin, though not as heavily culled as other species of corvid. After a series of poor harvests in the early 1500s, introduced a Vermin Act in 1532 "ordeyned to dystroye Choughes (i.e. jackdaws), Crowes and Rokes" to protect grain crops from their predations. Western jackdaws were notorious as they also favoured fruit, especially cherries. This act was taken up in a piecemeal fashion, but passed the "Act for the Preservation of Grayne" in 1566


title: "Western jackdaw" content: that was taken up with more vigour. The species was hunted for its threat to grain crops and for propensity for nesting in belfries until the mid-20th century. Particularly large numbers were culled in the county of Norfolk. Western jackdaws were also culled on game estates as they raid nests of other birds for eggs. In a 2003 dissertation on public opinion of corvids, Antonia Hereth notes that the German naturalist Alfred Brehm considered the western jackdaw to be a lovable bird, and did not describe any negative impacts of this species on agriculture. The western jackdaw is one of


title: "Western jackdaw" content: a very small number of birds that it is legal to use as a decoy or to trap in a cage in the United Kingdom. The other pest species that can be controlled by trapping are the crow, jay, magpie and rook. An authorised person must comply with the requirements of the Wildlife and Countryside Act 1981 and does not need to show that the birds were a nuisance before trapping them. As of 2003 the western jackdaw was listed as a potential species for targeted hunting in the European Union Birds Directive, and hunting has been encouraged by German


title: "Western jackdaw" content: hunting associations. Permission to shoot western jackdaws in spring and summer exists in Cyprus as they are thought (incorrectly) to prey on gamebirds. An ancient Greek and Roman adage runs "The swans will sing when the jackdaws are silent", meaning that educated or wise people will speak only after the foolish have become quiet. In Ancient Greek folklore, a jackdaw can be caught with a dish of oil. A narcissistic creature, it falls in while looking at its own reflection. The mythical Princess Arne Sithonis was bribed with gold by King Minos of Crete, and was punished by the gods


title: "Western jackdaw" content: for her greed by being transformed into an equally avaricious jackdaw, who still seeks shiny things. The Roman poet Ovid described jackdaws as harbingers of rain in his poetic work "Amores". Pliny notes how the Thessalians, Illyrians, and Lemnians cherished jackdaws for destroying grasshoppers' eggs. The Veneti are fabled to have bribed the jackdaws to spare their crops. In some cultures, a jackdaw on the roof is said to predict a new arrival; alternatively, a jackdaw settling on the roof of a house or flying down a chimney is an omen of death, and coming across one is considered a


title: "Western jackdaw" content: bad omen. A jackdaw standing on the vanes of a cathedral tower is said to foretell rain. The 12th-century historian William of Malmesbury records the story of a woman who, upon hearing a jackdaw chattering "more loudly than usual," grew pale and became fearful of suffering a "dreadful calamity", and that "while yet speaking, the messenger of her misfortunes arrived". Czech superstition formerly held that if jackdaws are seen quarreling, war will follow, and that jackdaws will not build nests at Sázava after being banished by Saint Procopius. The jackdaw was considered sacred in Welsh folklore as it nested in


title: "Western jackdaw" content: church steeples – it was shunned by the Devil because of its choice of residence. Nineteenth century belief in the Fens held that seeing a jackdaw on the way to a wedding was a good omen for a bride. The jackdaw is featured on the Ukrainian town of Halych's ancient coat of arms, the town's name allegedly being derived from the East Slavic word for the bird. In "The Book of Laughter and Forgetting" (1979), Milan Kundera notes that Franz Kafka's father Hermann had a sign in front of his shop with a jackdaw painted next to his name, since


title: "Western jackdaw" content: "kavka" means "jackdaw" in Czech. Western jackdaw The western jackdaw ("Coloeus monedula"), also known as the Eurasian jackdaw, European jackdaw, or simply jackdaw, is a passerine bird in the crow family. Found across Europe, western Asia and North Africa, it is mostly resident, although northern and eastern populations migrate south in winter. Four subspecies are recognised, which mainly differ in the colouration of the plumage on the head and nape. Linnaeus first described it formally, giving it the name "Corvus monedula". The common name derives from the word "jack", denoting "small", and daw, a less common synonym for "jackdaw", and


title: "House crow" content: House crow The house crow ("Corvus splendens"), also known as the Indian, greynecked, Ceylon or Colombo crow, is a common bird of the crow family that is of Asian origin but now found in many parts of the world, where they arrived assisted by shipping. It is between the jackdaw and the carrion crow in size ( in length) but is slimmer than either. The forehead, crown, throat and upper breast are a richly glossed black, whilst the neck and breast are a lighter grey-brown in colour. The wings, tail and legs are black. There are regional variations in the


title: "House crow" content: thickness of the bill and the depth of colour in areas of the plumage. The nominate race "C. s. splendens" is found in Pakistan, India, Nepal and Bangladesh and has a grey neck collar. The subspecies "C. s. zugmayeri" is found in the dry parts of South Asia and Iran and has a very pale neck collar. The subspecies "C. s. protegatus" is found in southern India, the Maldives (sometimes separated as "maledivicus") and Sri Lanka and is darker grey. "C. s. insolens", found in Myanmar, is the darkest form and lacks the grey collar. It has a widespread distribution


title: "House crow" content: in southern Asia, being native to Nepal, Bangladesh, India, Pakistan, Sri Lanka, Maldives and Laccadive Islands, South West Thailand and coastal southern Iran. It was introduced to East Africa around Zanzibar (about 1897) and Port Sudan. It arrived in Australia via ship but has up to now been exterminated. Recently, it has made its arrival in Europe and has been breeding in the Dutch harbour town Hook of Holland since 1998. A population between 200 and 400 birds has been present in Sham Shui Po, New Kowloon, Hong Kong, in particular Lai Kok Estate and Sham Shui Po Park, as


title: "House crow" content: well as Kowloon Tsai Park in Kowloon Tsai. An individual has been present in Cork Harbour on the south coast of Ireland since early September 2010. In the New World, a small population of house crows is established in the area around St. Petersburg, Florida. It is associated with human settlements throughout its range, from small villages to large cities. In Singapore, there was a density of 190 birds/km in 2001 with efforts to suppress the population in planning. Due to a human population explosion in the areas it inhabits, this species has also proportionately multiplied. Being an omnivorous scavenger


title: "House crow" content: has enabled it to thrive in such circumstances. The invasive potential for the species is great all over the tropics. This species is able to make use of resources with great flexibility and appears to be associated with humans, and no populations are known to exist independently of humans. House crows feed largely on refuse around human habitations, small reptiles and mammals, and other animals such as insects and other small invertebrates, eggs, nestlings, grain and fruits. House crows have also been observed swooping down from the air and snatching baby squirrels. Most food is taken from the ground, but


title: "House crow" content: also from trees as opportunity arises. They are highly opportunistic birds and given their omnivorous diet, they can survive on nearly anything that is edible. These birds can be seen near marketplaces and garbage dumps, foraging for scraps. They have also been observed to eat sand after feeding on carcasses. At least some trees in the local environment seem to be necessary for successful breeding although house crows occasionally nest on telephone towers. It lays 3–5 eggs in a typical stick nest, and occasionally there are several nests in the same tree. In South Asia they are parasitized by the


title: "House crow" content: Asian koel. Peak breeding in India as well as Peninsular Malaysia is from April to July. Large trees with big crowns are preferred for nesting. House crows roost communally near human habitations and often over busy streets. A study in Singapore found that the preferred roost sites were in well-lit areas with a lot of human activity, close to food sources and in tall trees with dense crowns that were separated from other trees. The roost sites were often enclosed by tall buildings. Before flying into roost trees, crows make pre-roosting aggregations perched on TV antennas, roof tops, wayside trees,


title: "House crow" content: open fields, and feed or preen during this time. The voice is a harsh "kaaw-kaaw". It is suspected that paramyxoviruses, such as PMV 1 that causes of Newcastle disease may be spread by "Corvus splendens". Outbreaks of Newcastle disease in India were often preceded by mortality in crows. They have also been found to carry "Cryptococcus neoformans", which can cause cryptococcosis in humans. House crows in Tanzania curiously showed an absence of blood parasites, although some species such as "Trypanosoma corvi" have been first described from this species. Pathologist T.R. Lewis expressed surprise at the numbers of haematozoa present in


title: "House crow" content: the blood of house crows from Calcutta. House crow The house crow ("Corvus splendens"), also known as the Indian, greynecked, Ceylon or Colombo crow, is a common bird of the crow family that is of Asian origin but now found in many parts of the world, where they arrived assisted by shipping. It is between the jackdaw and the carrion crow in size ( in length) but is slimmer than either. The forehead, crown, throat and upper breast are a richly glossed black, whilst the neck and breast are a lighter grey-brown in colour. The wings, tail and legs are


title: "Western grebe" content: Western grebe The western grebe ("Aechmophorus occidentalis") is a species in the grebe family of water birds. Folk names include "dabchick", "swan grebe" and "swan-necked grebe". Western grebe fossils from the Late Pleistocene of SW North America were described as a distinct species, but later ranked as a paleosubspecies "Aechmophorus occidentalis lucasi". More recent study found them to fall within the variation now known to exist in today's birds. The western grebe is the largest North American grebe. It is long, weighs and measures across the wings. It is black-and-white, with a long, slender, swan-like neck and red eyes. It


title: "Western grebe" content: is easily confused with Clark's grebe, which shares similar features, body size, behavior and habitat, and hybrids are known.Western Grebes nest in colonies on lakes that are mixed with marsh vegetation and open water. Western Grebe nests are made of plant debris and sodden materials, and the nest building begins roughly around late April through June. The construction is done by both sexes and is continued on throughout laying and incubation. This species of waterbirds is widespread in western North America, so there is no specific place of abundance. Its subspecies, Clark's grebe generally populate more of the southern part


title: "Western grebe" content: of North America Other differences are whiter flanks and paler gray backs when comparing A.o.clarkii to A.o.occidentalis. The western grebe has black around the eyes and a straight greenish-yellow bill whereas the Clark's grebe has white around the eyes and an up-turned bright yellow bill. The downy young of Western are grey; Clark's downy young are white. In 1858 George Newbold Lawrence recognised "Podiceps occidentalis" based on darker coloured specimens, and "P. clarkii" based on three paler coloured specimens -two from California and one from Chihuahua. These two colour morphs were found to occur, roost and even interbreed together, and


title: "Western grebe" content: were long regarded to be synonyms (although it is unclear why "P. clarkii" was regarded as the junior synonym, coming alphabetically first). Deignan designated the Mexican specimen as the holotype of the taxon "P. clarkii" in 1961. In 1963 Dickerman reinstated the taxon as "Aechmophorus clarkii", which he defined as the smaller birds, both dark and pale coloured, from Mexico. In 1979 a comprehensive study by Ratti demonstrated the apparent existence of reproductive barriers between different phases of the grebes. In 1986 Dickerman recognised the taxonomic significance of the distinctions between the dark and pale phase, and classified these phases


title: "Western grebe" content: as different subspecies: Multiple lines of evidence suggest that the differently colored western grebes (darker and lighter) are different taxa -in a single population in which sympatric speciation somehow persists. These forms were reported to mate according to their own colors and the mixing between dark and light-faced individuals is rare. This type of assortative mating derives from possible isolating mechanisms such as differential responses to advertising calls and spatial distribution. Each of the forms tended to stay closer to their own type, thus making their colony nesting be non-randomly distributed. By 1992 Storer & Nuechterlein were promoting another concept


title: "Western grebe" content: to the taxon "A. clarkii", now regarding the pale morphs from the USA and Canada to be this taxon (Dickerman's "A. occidentalis" ssp. "ephemeralis"). Western grebes nest in colonies of hundreds on large inland lakes, sometimes using coastal marshes, in western North America. It has a spectacular courtship display; two birds will rear up and patter across the water's surface. Northern birds migrate west to coastal ocean in winter; birds in the southwest and Mexico may be permanent residents. During the breeding season, the birds advertise themselves through ceremonies. Rushing Ceremony, which can be also called as water dance, race


title: "Western grebe" content: or run, is a ceremony that is the most frequent display to form a pair-bond. This is performed in pairs of either both male Western grebes or one male and one female. One of two individuals initiates Rushing, and the paired individual follows immediately and performs in synchromy. The birds lift their wings stiffly to the side and run in an upright position with its head held forward and neck curved. The males seem to perform the rushing together to attract attentions of females, and when one of two males attracts a female from his rushing behavior, a competition arises