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83-452: Falco milvus Linnaeus, 1758 Milvus regalis ( Pall. , 1811) The red kite ( Milvus milvus ) is a medium-large bird of prey in the family Accipitridae , which also includes many other diurnal raptors such as eagles , buzzards , and harriers . The species currently breeds only in Europe, though it formerly also bred in west Asia and northwest Africa . Historically, it

166-523: A detested kite , and he wrote "when the kite builds, look to your lesser linen" in reference to them stealing washing hung out to dry in the nesting season. In the mid-15th century, King James II of Scotland decreed that they should be "killed wherever possible", but they remained protected in England and Wales for the next 100 years as they kept the streets free of carrion and rotting food. Under Tudor "vermin laws" many creatures were seen as competitors for

249-415: A 175–195 cm (69–77 in) wingspan; males weigh 800–1,200 g (28–42 oz), and females 1,000–1,300 g (35–46 oz). It is an elegant bird, soaring on long wings held at a dihedral , and long forked tail, twisting as it changes direction. The body, upper tail and wing coverts are rufous . The white primary flight feathers contrast with the black wing tips and dark secondaries. Apart from

332-639: A city in Volgograd Oblast , is named after him, and his monument stands there. An asteroid is named after him: 21087 Petsimpallas . A Belgian astronomer, Eric Elst chose the name "Sarapul 26851" for an asteroid because in Pallas's writings, he mentioned his liking of the city of Sarapul , Russia. Pallas was elected a member of the American Philosophical Society in 1791. Dihedral (aircraft) Dihedral angle has

415-512: A disturbance causes an aircraft to roll away from its normal wings-level position as in Figure 1, the aircraft will begin to move somewhat sideways toward the lower wing. In Figure 2, the airplane's flight path has started to move toward its left while the nose of the airplane is still pointing in the original direction. This means that the oncoming air is arriving somewhat from the left of the nose. The airplane now has sideslip angle in addition to

498-496: A greater or lesser degree. Wing sweepback also increases the dihedral effect, for roughly 1° of effective dihedral with every 10° of sweepback. This is one reason for anhedral configuration on aircraft with high sweep angle, as well as on some airliners, even on low-wing aircraft such as the Tu-134 and Tu-154 . In any case, wing sweepback can also occur with a dihedral configuration. For instance, two small biplanes produced from

581-632: A large estate at Simferopol , where Pallas lived until the death of his second wife in 1810. He was then granted permission to leave Russia by Emperor Alexander , and returned to Berlin, where he died in the following year. His grave is preserved in the Protestant Friedhof I der Jerusalems- und Neuen Kirchengemeinde (Cemetery No. I of the congregations of Jerusalem's Church and New Church ) in Berlin-Kreuzberg , south of Hallesches Tor . In 1809 he became an associate member of

664-536: A number of incidents of red kites and other raptors being targeted by wildlife criminals. On occasion, red kites may directly steal food from humans. One such occurrence took place in Marlow , Buckinghamshire (a town near a major reintroduction site for the species in the UK in the nearby village of Stokenchurch ), in which red kites swooped down to steal sandwiches from people in one of the town's parks. In another incident,

747-641: A red kite was reported as having stolen a wasabi-coated pea from a spectator at a cricket match in Wormsley, Buckinghamshire. Red kites inhabit broadleaf woodlands, pastures, mixed farmland, valleys and wetland edges, up to at least 1,600 metres (5,200 ft) elevation. They are native to the western Palearctic , with all of the currently known 32,200–37,700 breeding pairs being in Europe. There also used to be breeding populations in western Asia (northern Iran, Syria and Turkey) and northwestern Africa (Algeria, Morocco and Tunisia), but most of these were extirpated in

830-771: A site in north Scotland and four Swedish and one Welsh bird in Buckinghamshire . Altogether, 93 birds of Swedish and Spanish origin were released at each of the sites. In the second stage of reintroduction in 1995 and 1996, further birds were brought from Germany to populate areas of Dumfries and Galloway . Between 2004 and 2006, 94 birds were brought from the Chilterns and introduced into the Derwent Valley in north East England. In Northern Ireland, 80 birds from wild stock in Wales were released between 2008 and 2010, and

913-426: A strong influence on dihedral effect , which is named after it. Dihedral effect is the amount of roll moment produced in proportion to the amount of sideslip . Dihedral effect is a critical factor in the stability of an aircraft about the roll axis (the spiral mode ). It is also pertinent to the nature of an aircraft's Dutch roll oscillation and to maneuverability about the roll axis. Longitudinal dihedral

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996-419: A strong influence on the dihedral effect. Dihedral effect of an aircraft is a rolling moment resulting from the vehicle having a non-zero angle of sideslip . Increasing the dihedral angle of an aircraft increases the dihedral effect on it. However, many other aircraft parameters also have a strong influence on dihedral effect. Some of these important factors are: wing sweep , vertical center of gravity , and

1079-563: A stronghold for the red kite. Thirty Spanish birds were introduced into Rockingham Forest near Corby in 2000, and by 2010, the RSPB estimated that over 200 chicks had been reared from the initial release. So successful has the reintroduction been that 30 chicks have been transported from Rockingham Forest for release in Cumbria . From the Chilterns they have spread as far east as Essex and can be seen over Harlow . By 2021 they had spread along

1162-502: A white ground and red-brown spots. The average size is 57 mm × 45 mm (2.2 in × 1.8 in) with a calculated weight of 63 g (2.2 oz). In Britain and central Europe, laying begins at the end of March but in the Mediterranean area laying begins in early March. The eggs are mainly incubated by the female, but the male will relieve her for short periods while she feeds. The male will also bring food for

1245-1026: Is 25 years and 8 months for a ringed bird in Germany. The BTO longevity record for Britain and Ireland is also 25 years and 8 months for a bird found dead in Buckinghamshire in 2018. In 2023, one of the first red kites reintroduced to the UK was found injured in Oxfordshire and later died, aged 29. The red kites are generalist scavengers and predators. Their diet consists mainly of carrions of large domestic animals such as sheep and pigs , roadkills, and shored fish. They also take small mammals such as mice , voles , shrews , stoats , young hares and rabbits . Live birds are also taken, especially young or wounded, such as crows , doves , starlings , thrushes , larks , gulls , and waterfowls . Occasionally reptiles and amphibians are taken and invertebrates such as earthworms form an important part of

1328-507: Is a comparatively obscure term related to the pitch axis of an airplane. It is the angle between the zero-lift axis of the wing and the zero-lift axis of the horizontal tail. Longitudinal dihedral can influence the nature of controllability about the pitch axis and the nature of an aircraft's phugoid -mode oscillation. When the term "dihedral" (of an aircraft) is used by itself it is usually intended to mean "dihedral angle ". However, context may otherwise indicate that "dihedral effect "

1411-589: Is almost certainly extinct. The genus Milvus contains two other species: the black kite ( M. migrans ) and the yellow-billed kite ( M. aegyptius ). The red kite has been known to successfully hybridize with the black kite in captivity where both species were kept together, and in the wild on the Cape Verde Islands and infrequently in other places. The red kites on the Cape Verde Islands are (or rather were) quite distinct in morphology , being somewhat intermediate with black kites. The question whether

1494-478: Is caused by the center of lift and drag being further above the CG and having a longer moment arm. So, the same forces that change as sideslip changes (primarily sideforce, but also lift and drag) produce a larger moment about the CG of the aircraft. This is sometimes referred to as the pendulum effect . An extreme example of the effect of vertical CG on dihedral effect is a paraglider . The dihedral effect created by

1577-440: Is included in their common names, including: Pallas's glass lizard , Pallas's viper , Pallas's cat , Pallas's long-tongued bat , Pallas's tube-nosed bat , Pallas's squirrel , Pallas's leaf warbler , Pallas's cormorant , Pallas's fish-eagle , Pallas's gull , Pallas's sandgrouse , Pallas's rosefinch , and Pallas's grasshopper warbler . Also, he is honoured in the scientific names of animals described by others, including:

1660-437: Is less-ambiguously termed "spiral mode stability" and dihedral effect is a contributing factor to it. The dihedral angle contributes to the total dihedral effect of the aircraft. In turn, the dihedral effect contributes to stability of the spiral mode . A stable spiral mode will cause the aircraft to eventually return to a nominally "wings level" bank angle when the angle of the wings is disturbed to become off-level. If

1743-466: Is mentioned by Geoffrey Chaucer in his Knight's Tale . The early 15th century Hengwrt manuscript contains the lines: "Ther cam a kyte, whil þt they were so wrothe That bar awey the boon bitwix hem bothe." The first recorded use of the word "kite" for a toy that is attached to a length of string and flown in the air dates from the 17th century. Red kites are 60 to 70 cm (24 to 28 in) long with

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1826-451: Is needed to get the amount of dihedral effect needed. Dihedral effect is defined simply to be the rolling moment caused by sideslip and nothing else. Rolling moments caused by other things that may be related to sideslip have different names. Dihedral effect is not caused by yaw rate , nor by the rate of sideslip change . Since dihedral effect is noticed by pilots when "rudder is applied", many pilots and other near-experts explain that

1909-475: Is not known, and the genetic relationship of red kites is confusing, with geographical proximity being no indicator of genetic relatedness and the overall genetic similarity high, perhaps indicating a relict species. Given the morphological distinctness of the Cape Verde birds and that the Cape Verde population was isolated from other populations of red kites, it cannot be conclusively resolved as to whether

1992-427: Is the balance point of an aircraft. If suspended at this point and allowed to rotate, a body (aircraft) will be balanced. The front-to-back location of the CG is of primary importance for the general stability of the aircraft, but the vertical location has important effects as well. The vertical location of the CG changes the amount of dihedral effect. As the "vertical CG" moves lower, dihedral effect increases. This

2075-475: Is the intended meaning. Dihedral angle is the upward angle from horizontal of the wings of a fixed-wing aircraft , or of any paired nominally-horizontal surfaces on any aircraft . The term can also apply to the wings of a bird . Dihedral angle is also used in some types of kites such as box kites. Wings with more than one angle change along the full span are said to be polyhedral . Dihedral angle has important stabilizing effects on flying bodies because it has

2158-576: The Beriev Be-12 were designed with gull wings bent near the root. Others, such as the Vought F4U Corsair , used an inverted gull wing design, which allowed for shorter landing struts and extra ground clearance for large propellers and external payloads, such as external fuel tanks or bombs. Modern polyhedral wing designs generally bend upwards near the wingtips (also known as tip dihedral ), increasing dihedral effect without increasing

2241-518: The Dutch Republic and to London , improving his medical and surgical knowledge. He then settled at The Hague , and his new system of animal classification was praised by Georges Cuvier . Pallas wrote Miscellanea Zoologica (1766), which included descriptions of several vertebrates new to science which he had discovered in the Dutch museum collections. A planned voyage to Southern Africa and

2324-576: The East Indies fell through when his father recalled him to Berlin. There, he began work on his Spicilegia Zoologica (1767–1780). In 1767, Pallas was invited by Catherine II of Russia to become a professor at the St Petersburg Academy of Sciences and, between 1768 and 1774, he led an expedition to central Russian provinces , Povolzhye , Urals , West Siberia , Altay , and Transbaikal , collecting natural history specimens for

2407-545: The Flora Rossica (1784–1815), a Russian flora , and started work on his Zoographica Rosso-Asiatica (1811–31), a zoography of Russia and Asia . He also published an account of Johann Anton Güldenstädt 's travels in the Caucasus . The Empress bought Pallas's large natural history collection for 2,000 rubles, 500 more than his asking price, and allowed him to keep them for life. During this period, Pallas helped plan

2490-731: The Kullaberg Nature Preserve near Mölle . In Switzerland, they are a common sight in all rural areas, excluding the Alps and its foothills. Some of the best places to see them in the United Kingdom are Gigrin Farm near Rhayader , mid Wales , where hundreds are fed by the local farmer as a tourist attraction, a Red Kite Feeding Station at Llanddeusant in the Brecon Beacons , visited daily by over 50 birds, and

2573-633: The Mulovsky expedition , which was cancelled in October 1787. Between 1793 and 1794, Pallas led a second expedition to southern Russia, visiting the Crimea and the Black Sea . He was accompanied by his daughter (by his first wife who had died in 1782) and his new wife, an artist, servants, and a military escort. In February 1793, they travelled to Saratov and then downriver to Tsaritsyn . They explored

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2656-644: The Royal Institute of the Netherlands . In 1772, Pallas was shown a 680-kg lump of metal that had been found near Krasnoyarsk . Pallas arranged for it to be transported to St Petersburg. Subsequent analysis of the metal showed it to be a new type of stony-iron meteorite . This new type of meteorite was called pallasite after him; the meteorite itself is named Krasnojarsk or sometimes Pallas Iron (the name given to it by Ernst Chladni in 1794). Several animals were described by Pallas, and his surname

2739-607: The Russian Empire between 1767 and 1810. Peter Simon Pallas was born in Berlin , Kingdom of Prussia , the son of Professor of Surgery Simon Pallas . He studied with private tutors and took an interest in natural history , later attending the University of Halle and the University of Göttingen . In 1760, he moved to the University of Leiden and passed his doctor's degree at the age of 19. Pallas travelled throughout

2822-422: The keel effect ) and so additional dihedral angle is often not required. Such designs can have excessive dihedral effect and so be excessively stable in the spiral mode, so anhedral angle on the wing is added to cancel out some of the dihedral effect so that the aircraft can be more easily maneuvered. Most aircraft have been designed with planar wings with simple dihedral (or anhedral). Some older aircraft such as

2905-628: The native Eurasian peoples and their indigenous religions , and descriptions of new plants and animals. In 1776, Pallas was elected a foreign member of the Royal Swedish Academy of Sciences . Pallas settled in St Petersburg , becoming a favourite of Catherine II and teaching natural history to the Grand Dukes Alexander and Constantine. He was provided with the plants collected by other naturalists to compile

2988-411: The "leveling" direction more strongly, and less dihedral effect tries to roll the wings in the "leveling" direction less strongly. Dihedral effect helps stabilize the spiral mode by tending to roll the wings toward level in proportion to the amount of sideslip that builds up. It is not the whole picture however. At the same time that angle of sideslip is building up, the vertical fin is trying to turn

3071-539: The 1930s to 1945 by Bücker Flugzeugbau in Germany, the Bücker Jungmann two-seat trainer and the Bücker Jungmeister aerobatic competition biplane, were designed with sweepbacks of approximately 11 degrees, which provided significant dihedral effect – in addition to their small dihedral angles having a similar but lesser effect. The center of mass , usually called the center of gravity or "CG",

3154-523: The 19th century or earlier; the only non-European breeding population in recent decades was in Morocco where the last known pair was in 2004. Today it breeds from Portugal and Spain, through the central part of the continent east to European Russia , north to southern Scandinavia , Latvia and the United Kingdom, and south to southern Italy; few if any breeders remain in Balkan . Most red kites that breed in

3237-640: The Bwlch Nant yr Arian forest visitor centre in Ceredigion where the rare leucistic variant can be seen. In England, the Oxfordshire part of the Chilterns has many red kites, especially near Henley-on-Thames and Watlington , where they were introduced on John Paul Getty 's estate. Red Kites are also becoming common in Buckinghamshire , often being seen near Stokenchurch , where a population

3320-422: The Cape Verde kite should be considered a distinct species ( Milvus fasciicauda ) or a red kite subspecies has not been settled. A mitochondrial DNA study on museum specimens suggested that Cape Verde birds did not form a monophyletic lineage among or next to red kites. This interpretation is problematic: mtDNA analysis is susceptible to hybridization events, the evolutionary history of the Cape Verde population

3403-473: The Cape Verde population was not a distinct subspecies (as M. migrans fasciicauda ) or even a species that frequently absorbed stragglers from the migrating European populations into its gene pool. The Cape Verde population became effectively extinct since 2000, all surviving birds being hybrids with black kites . The English word "kite" is from the Old English cyta which is of unknown origin. A kite

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3486-696: The Dagestani tortoise ( Testudo graeca pallasi ), Pallas's pika ( Ochotona pallasi ), Pallas's reed bunting ( Emberiza pallasi ), the East Siberian grayling ( Thymallus pallasii ) and the Pacific herring ( Clupea pallasii ). He was also honoured in the name of a plant genus, Petrosimonia which is a genus of flowering plants belonging to the family Amaranthaceae . Streets in Berlin and Castrop-Rauxel are named Pallasstraße . Pallasovka ,

3569-607: The Environment, Heritage and Local Government Dick Roche announced an agreement to bring at least 100 birds from Wales to restock the population as part of a five-year programme in the Wicklow Mountains , similar to the earlier golden eagle reintroduction programme. On 19 July 2007, the first 30 red kites were released in County Wicklow . On 22 May 2010, two newly hatched red kite chicks were discovered in

3652-946: The M4 as far as the Cotswold Edge overlooking the Severn near Bristol. A sighting of the first red kite in London for 150 years was reported in The Independent newspaper in January 2006 and in June of that year, the UK-based Northern Kites Project reported that kites had bred in the Derwent Valley in and around Rowlands Gill , Tyne and Wear for the first time since the re-introduction. In 1999,

3735-598: The UK and the final re-introduction phase in England. The stated aims of the Grizedale project were: As of July 2011, non-breeding birds are regularly seen in all parts of Britain, and the number of breeding pairs is too large for the RSPB to continue to survey them on an annual basis. Red kites were extinct in Ireland by the middle 19th century due to persecution, poisoning and woodland clearance. In May 2007, Minister for

3818-535: The Wicklow Mountains, bringing the number of chicks hatched since reintroduction to seven. The following figures (mostly estimates) have been collated from various sources. They cover most of the countries in which red kites are believed to have bred. One of the best places to see the red kite in Scandinavia is Scania in southern Sweden. It may be observed in one of its breeding locations such as

3901-647: The academy. He explored the Caspian Sea , the Ural and Altai Mountains , and the upper Amur River , reaching as far eastward as Lake Baikal . The regular reports which Pallas sent to St Petersburg were collected and published as Reise durch verschiedene Provinzen des Russischen Reichs ("Journey through various provinces of the Russian Empire", 3 vols., 1771–1776). They covered a wide range of topics, including geology and mineralogy , ethnographic reports on

3984-412: The angle the wings meet at the root, which may be restricted to meet other design criteria. Polyhedral is seen on gliders and some other aircraft. The McDonnell Douglas F-4 Phantom II is one such example, unique among jet fighters for having dihedral wingtips. This was added after flight testing of the flat winged prototype showed the need to correct some unanticipated spiral mode instability – angling

4067-416: The bank angle. Figure 2 shows the airplane as it presents itself to the oncoming air. In Figure 2, the sideslip conditions produce greater angle of attack on the forward-yawed wing and smaller angle of attack on the rearward-yawed wing. This alteration of angle of attack by sideslip is visible in Figure 2. As greater angle of attack produces more lift (in the usual case, when the wing is not near stalling),

4150-424: The change in rolling moment coefficient (the " C l ") per degree (or radian) of change in sideslip angle (the " β {\displaystyle \beta } "). The purpose of dihedral effect is to contribute to stability in the roll axis. It is an important factor in the stability of the spiral mode which is sometimes called "roll stability". The dihedral effect does not contribute directly to

4233-1039: The country to the east, and in August travelled along the banks of the Caspian Sea and into the Caucasus Mountains. In September, they travelled to the Crimea, wintering in Simferopol . Pallas spent early 1794 exploring to the southeast, and in July travelled up the valley of the Dnieper , arriving back in St Petersburg in September. Pallas gave his account of the journey in his P. S. Pallas Bemerkungen auf einer Reise in die Südlichen Statthalterschaften des Russischen Reichs (1799–1801). Catherine II gave him

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4316-507: The diet, especially in spring . In some parts of the United Kingdom, red kites are also deliberately fed in domestic gardens , explaining the presence of red kites in urban areas. Here, up to 5% of householders have provided supplementary food for red kites, with chicken the predominant meat provided. As scavengers, red kites are particularly susceptible to poisoning. Illegal poison baits set for foxes or crows are indiscriminate and kill protected birds and other animals. There have also been

4399-432: The dihedral angle on the horizontal tail. During design of a fixed-wing aircraft (or any aircraft with horizontal surfaces), changing dihedral angle is usually a relatively simple way to adjust the overall dihedral effect. This is to compensate for other design elements' influence on the dihedral effect. These other elements (such as wing sweep, vertical mount point of the wing, etc.) may be more difficult to change than

4482-438: The dihedral angle. As a result, differing amounts of dihedral angle can be found on different types of fixed-wing aircraft. For example, the dihedral angle is usually greater on low-wing aircraft than on otherwise-similar high-wing aircraft. This is because "highness" of a wing (or "lowness" of vertical center of gravity compared to the wing) naturally creates more dihedral effect itself. This makes it so less dihedral angle

4565-419: The female. Incubation starts as soon as the first egg is laid. Each egg hatches after 31 to 32 days but as they hatch asynchronously a clutch of three eggs requires 38 days of incubation. The chicks are cared for by both parents. The female broods them for the first 14 days while the male brings food to the nest which the female feeds to the chicks. Later both parents bring items of food which are placed in

4648-512: The female. The nest is lined with grass and sometimes also with sheep's wool. Unlike the black kite, no greenery is added to the nest. Both sexes continue to add material to the nest during the incubation and nestling periods. Nests vary greatly in size and can become large when the same nest is occupied for several seasons. The eggs are laid at three-day intervals. The clutch is usually between one and three eggs but four and even five eggs have occasionally been recorded. The eggs are non-glossy with

4731-579: The first successful breeding was recorded in 2010. The reintroductions in the Chilterns Area of Outstanding Natural Beauty have been a success. Between 1989 and 1993, 90 birds were released there and by 2002, 139 pairs were breeding. They can commonly be seen taking advantage of thermals from the M40 motorway . Another successful reintroduction has been in Northamptonshire , which has become

4814-431: The first year of a bird's life. Usually red kites first breed when they are two years old, although exceptionally they can successfully breed when they are only one year old. They are monogamous and the pair-bond in resident populations is probably maintained during the winter, particularly when the pair remain on their breeding territory. For migrant populations the fidelity to a particular nesting site means that

4897-403: The forward wing will have more lift and the rearward wing will have less lift. This difference in lift between the wings is a rolling moment, and it is caused by the sideslip. It is a contribution to the total dihedral effect of the aircraft. The rolling moment created by the sideslip (labeled as "P") tends to roll the aircraft back to wings level. More dihedral effect tries to roll the wings in

4980-410: The height and size of anything on an aircraft that changes its sidewards force as sideslip changes. Dihedral angle on an aircraft almost always implies the angle between two paired surfaces, one on each side of the aircraft . Even then, it is almost always between the left and right wings . However, mathematically dihedral means the angle between any two planes. So, in aeronautics, in one case,

5063-581: The last two countries, those populations remain well below their historical peaks. In contrast, red kite populations are increasing in parts of northern Europe, such as Denmark, Poland, Sweden and the United Kingdom. The red kite is the official landscape bird of the Swedish province of Scania , and depicted on the coat of arms of the municipality of Tomelilla . In the United Kingdom, red kites were ubiquitous scavengers that lived on carrion and rubbish. Shakespeare's King Lear describes his daughter Goneril as

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5146-436: The nest to allow the chicks to feed themselves. The nestlings begin climbing onto branches around their nest from 45 days but they rarely fledge before 48–50 days and sometimes not until they are 60–70 days of age. The young spend a further 15–20 days in the neighbourhood of the nest being fed by their parents. Only a single brood is raised each year but if the eggs are lost the female will relay. The maximum age recorded

5229-443: The northeast, but seem to be stable in southwest and central France and Corsica . Populations elsewhere are stable or undergoing increases. In Sweden, the species has increased from 30 to 50 pairs in the 1970s to 1,200 breeding pairs in 2003 and has continued growing. In Switzerland, populations have been increasing since the 1990s. Red kites have declined in their traditional strongholds of Spain, France and Germany; while now stable in

5312-473: The northern European mainland used to move south or west in winter, typically wintering in Spain and other parts of western Europe with a mild climate, as well as northwestern Africa (Algeria, Morocco and Tunisia) and Turkey. In recent decades, an increasing number of red kites from the northern European mainland have stayed in the region year-round. The populations in Germany (which alone is home to almost half of

5395-580: The northern foothills of the Harz Mountains (the most densely populated part of its range) suffered an estimated 50% decline from 1991 to 2001. In Spain, the species showed an overall decline in breeding population of up to 43% for the period 1994 to 2001–02, and surveys of wintering birds in 2003–04 suggest a similarly large decline in core wintering areas. The Balearic Islands population has declined from 41 to 47 breeding pairs in 1993 to just 10 in 2003. In France, breeding populations have decreased in

5478-437: The nose back into the wind, much like a weathervane, minimizing the amount of sideslip that can be present. If there is no sideslip, there can be no restoring rolling moment. If there is less sideslip, there is less restoring rolling moment. Yaw stability created by the vertical fin opposes the tendency for dihedral effect to roll the wings back level by limiting sideslip. The spiral mode is the tendency to slowly diverge from, or

5561-441: The pair-bond is likely to be renewed each breeding season. The nest is normally placed in a fork of a large hardwood tree at a height of between 12 and 15 m (39 and 49 ft) above the ground. A pair will sometimes use a nest from the previous year and can occasionally occupy an old nest of the common buzzard . The nest is built by both sexes. The male brings dead twigs 30–50 cm (12–20 in) in length which are placed by

5644-478: The positive, up angle between the left and right wings, while usage with the prefix "an-" (as in " an hedral") evolved to mean the negative, down angle between the wings. The aerodynamic stabilizing qualities of a dihedral angle were described in an influential 1810 article by Sir George Cayley . In analysis of aircraft stability, the dihedral effect is also a stability derivative called C l β {\displaystyle \beta } meaning

5727-591: The produce of the countryside and bounties were paid by the parish for their carcasses. By the 20th century, the breeding population was restricted to a handful of pairs in South Wales , but recently the Welsh population has been supplemented by re-introductions in England and Scotland. In 2004, from 375 occupied territories identified, at least 216 pairs were thought to have hatched eggs and 200 pairs reared at least 286 young. In 1989, six Swedish birds were released at

5810-457: The red kite was named 'Bird of the Century' by the British Trust for Ornithology . According to the Welsh Kite Trust, it has been voted "Wales's favourite bird". In June 2010, the Forestry Commission North West England announced a three-year project to release 90 red kites in Grizedale Forest , Cumbria under a special licence issued by Natural England . The Grizedale programme was the ninth reintroduction of red kites into different regions of

5893-643: The restoring of "wings level", but it indirectly helps restore "wings level" through its effect on the spiral mode of motion described below. Aircraft designers may increase dihedral angle to provide greater clearance between the wing tips and the runway. This is of particular concern with swept-wing aircraft, whose wingtips could hit the runway on rotation/touchdown. In military aircraft dihedral angle space may be used for mounting materiel and drop-tanks on wing hard points, especially in aircraft with low wings. The increased dihedral effect caused by this design choice may need to be compensated for, perhaps by decreasing

5976-443: The rolling moment is caused by one wing moving more quickly through the air and one wing less quickly. Indeed, these are actual effects, but they are not the dihedral effect, which is caused by being at a sideslip angle, not by getting to one. These other effects are called "rolling moment due to yaw rate" and "rolling moment due to sideslip rate" respectively. Dihedral effect is not roll stability in and of itself. Roll stability

6059-422: The root chords of the two surfaces. This is the more meaningful usage because the directions of zero-lift are pertinent to trim and stability while the directions of the root chords are not. This measurement is also often referred to as decalage . In geometry, dihedral angle is the angle between two planes. Aviation usage differs slightly from usage in geometry. In aviation, the usage " di hedral" evolved to mean

6142-422: The stability of the spiral mode. This increases maneuverability which is desirable in fighter-type aircraft. Anhedral angles are also seen on aircraft with a high mounted wing, such as the very large Antonov An-124 and Lockheed C-5 Galaxy cargo aircraft. In such designs, the high mounted wing is above the aircraft's center of gravity which confers extra dihedral effect due to the pendulum effect (also called

6225-508: The tendency to slowly return to wings level. If the spiral mode is stable, the aircraft will slowly return to wings-level, if it is unstable, the aircraft will slowly diverge from wings-level. Dihedral effect and yaw stability are the two primary factors that affect the stability of the spiral mode, although there are other factors that affect it less strongly. Factors of design other than dihedral angle also contribute to dihedral effect. Each increases or decreases total aircraft dihedral effect to

6308-413: The term "dihedral" is applied to mean the difference in angles between two front-to-back surfaces: Longitudinal dihedral is the difference between the angle of incidence of the wing root chord and angle of incidence of the horizontal tail root chord. Longitudinal dihedral can also mean the angle between the zero-lift axis of the wing and the zero-lift axis of the horizontal tail instead of between

6391-762: The very low vertical CG more than compensates for the negative dihedral effect created by the strong anhedral of the necessarily strongly downward curving wing. The wing location on a fixed-wing aircraft will also influence its dihedral effect. A high-wing configuration provides about 5° of effective dihedral over a low-wing configuration. A side effect of too much dihedral effect, caused by excessive dihedral angle among other things, can be yaw-roll coupling (a tendency for an aircraft to Dutch roll ). This can be unpleasant to experience, or in extreme conditions it can lead to loss of control or can overstress an aircraft. Military fighter aircraft often have near zero or even anhedral angle reducing dihedral effect and hence reducing

6474-460: The weight difference, the sexes are similar, but juveniles have a buff breast and belly. Its call is a thin piping sound, similar to but less mewling than the common buzzard . There is a rare white leucistic form accounting for approximately 1% of hatchlings in the Welsh population, but this variation confers a disadvantage in the survival stakes. Adults differ from juveniles in a number of characteristics: These differences hold throughout most of

6557-479: The wintering ranges in France and Spain, and changes in agricultural practices causing a reduction in food resources. Other threats include electrocution, hunting and trapping, deforestation, egg-collection (on a local scale) and possibly competition with the generally more successful black kite M. migrans . German populations declined by 25%–30% between 1991 and 1997, but have remained stable since. The populations of

6640-428: The world's breeding pairs), France and Spain declined between 1990 and 2000, and overall the species declined by almost 20% over those ten years. Populations in Germany and France have subsequently stabilised, and because of growth in other countries, the overall population is now increasing. The main threats to red kites are poisoning, through illegal direct poisoning and indirect poisoning from pesticides, particularly in

6723-509: Was described by the Swedish naturalist Carl Linnaeus in 1758 in the 10th edition of his Systema Naturae under the binomial name Falco milvus . The word milvus was the Latin name for the bird. In 1799 the French naturalist Bernard Germain de Lacépède moved the species to the genus Milvus creating the tautonym . Two subspecies are recognised: The subspecies M. m. fasciicauda

6806-400: Was only resident in the milder parts of its range in western Europe and northwestern Africa, whereas all or most red kites in northern mainland Europe wintered to the south and west, some also reaching western Asia, but an increasing number of northern birds now remain in that region year-round. Vagrants have reached north to Finland and south to Israel , Libya and Gambia . The red kite

6889-572: Was released in the 1990s, and Flackwell Heath near High Wycombe . They can also be seen around Harewood near Leeds where they were re-introduced in 1999. In Ireland they can be best observed at Redcross, near Avoca, County Wicklow . Pall. Peter Simon Pallas FRS FRSE (22 September 1741 – 8 September 1811) was a Prussian zoologist , botanist , ethnographer , explorer , geographer , geologist , natural historian , and taxonomist . He studied natural sciences at various universities in early modern Germany and worked primarily in

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