Red-billed chough

Template:Short description Template:Featured article Template:Protection padlock Template:EngvarB Template:Use dmy dates Template:Speciesbox The red-billed chough, Cornish chough or simply chough (Template:IPAc-en Template:Respell; Pyrrhocorax pyrrhocorax), is a bird in the crow family, one of only two species in the genus Pyrrhocorax. Its eight subspecies breed on mountains and coastal cliffs from the western coasts of Ireland and Britain east through southern Europe and North Africa to Central Asia, India and China.

This bird has glossy black plumage, a long curved red bill, red legs, and a loud, ringing call. It has a buoyant acrobatic flight with widely spread primaries. The red-billed chough pairs for life and displays fidelity to its breeding site, which is usually a cave or crevice in a cliff face. It builds a wool-lined stick nest and lays three eggs. It feeds, often in flocks, on short grazed grassland, taking mainly invertebrate prey.

Although it is subject to predation and parasitism, the main threat to this species is changes in agricultural practices, which have led to population decline, some local extinction and range fragmentation in Europe; however, it is not threatened globally. The red-billed chough, which derived its common name 'chough' from the jackdaw, was formerly associated with fire-raising, and has links with Saint Thomas Becket and Cornwall.

Taxonomy

The red-billed chough was first described by Carl Linnaeus in his 1758 10th edition of Systema Naturae as Upupa pyrrhocorax.<ref>Template:Cite book</ref> It was moved to its current genus, Pyrrhocorax, by Marmaduke Tunstall in his 1771 Ornithologia Britannica.<ref>Template:Cite book</ref> The genus name is derived from Greek πυρρός (pyrrhos), "flame-coloured", and κόραξ (korax), "raven".<ref name = BTO>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref> The only other member of the genus is the Alpine chough Pyrrhocorax graculus;<ref name=ioc>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref> hybrids with Alpine chough are known.<ref name=Shirihai>Template:Cite book</ref>

Traditionally, the closest relatives of the choughs have been thought to be the typical crows Corvus and the jackdaws Coloeus,<ref>Template:Cite book</ref> but more recent genetic studies have suggested the choughs are basal to a group of Asian jay genera (Crypsirina, Dendrocitta, Platysmurus, Temnurus),<ref name=Ericson>Template:Cite journal</ref> or most recently, basal in the entire Corvidae.<ref name=Fjeldså>Template:Cite book</ref>

Subspecies

There are eight extant subspecies, although differences between them are slight.<ref name= Madge94>Template:Cite book</ref><ref name=ioc/>

• P. p. pyrrhocorax, the nominate subspecies and smallest form, is endemic to the British Isles,<ref name= Madge94/> where it is restricted to Ireland, the Isle of Man, and the west of Wales, southwest Scotland, and Cornwall, which it recolonised in 2001 after an absence of 50 years.<ref name = CCC>{{#invoke:citation/CS1|citation

|CitationClass=web }}</ref>

• P. p. erythroramphos, described by Louis Pierre Vieillot in 1817 as Coracia erythrorhamphos,<ref name= Vieillot >Template:Cite book</ref> occurs in the red-billed chough's continental European range, excluding Greece. It is larger and slightly greener than the nominate race.<ref name= Madge94/>
• P. p. barbarus, described by Charles Vaurie under its current name in 1954, is resident in North Africa and on La Palma in the Canary Islands. Compared to P. p. erythroramphos, it is larger, has a longer tail and wings, and its plumage has a greener gloss. It is the longest-billed form, both absolutely and relatively.<ref name=Vaurie >Template:Cite journal</ref>
• P. p. baileyi described by Austin Loomer Rand and Charles Vaurie under its current name in 1955,<ref name= Rand >Template:Cite journal</ref> is a dull-plumaged subspecies endemic to Ethiopia, where it occurs in two separate areas. The two populations could possibly represent different subspecies.<ref name= Madge94/>
• P. p. docilis, described by Johann Friedrich Gmelin as Corvus docilis in 1774,<ref name=Gmelin >Template:Cite book</ref> breeds from Greece to Afghanistan. It is larger than the African subspecies, but it has a smaller bill and its plumage is very green-tinted, with little gloss.<ref name= Madge94/>
• P. p. himalayanus, described by John Gould in 1862 as Fregilus himalayanus,<ref name= Gould>Template:Cite journal</ref> is found from the Himalayas to western China, but intergrades with P. p. docilis in the west of its range. It is the largest subspecies, long-tailed, and with blue or purple-blue glossed feathers.<ref name= Madge94/>
• P. p. centralis, described by Erwin Stresemann in 1928 under its current name,<ref name= Stresemann >Template:Cite journal</ref> breeds in Central Asia. It is smaller and less strongly blue than P. p. himalayanus,<ref name= Madge94/> but its distinctness from the next subspecies has been questioned.<ref name = Vaurie/>
• P. p. brachypus, described by Robert Swinhoe in 1871 as Fregilus graculus var. brachypus,<ref name=Swinhoe>Template:Cite journal</ref> breeds in central and northern China, Mongolia and southern Siberia. It is similar to P. p. centralis but with a weaker bill.<ref name= Madge94/>

The small population in Brittany has often been included with British and Irish birds in the nominate subspecies P. p. pyrrhocorax, but is now included with other mainland Western European populations in P. p. erythroramphos;<ref name="e094">Template:Cite journal</ref><ref name=ioc/> in some aspects it is intermediate between the two subspecies.<ref name=Shirihai/>

Detailed analysis of call similarity suggests that the Asiatic and Ethiopian races diverged from the western subspecies early in evolutionary history, and that Italian red-billed choughs are more closely allied to the North African subspecies than to those of the rest of Europe.<ref name= Laiolo>Template:Cite journal</ref>

There is one known prehistoric form of the red-billed chough. P. p. primigenius, a subspecies that lived in Europe during the last ice age, which was described in 1875 by Alphonse Milne-Edwards from finds in southwest France.<ref name=Milne >Template:Cite book</ref><ref name=Mourer>Template:Cite journal</ref>

• Pyrrhocorax pyrrhocorax -Penwith -Cornwall -flying-8b.jpg

  Nominate subspecies P. p. pyrrhocorax in flight in Cornwall, UK

• Pyrrhocorax pyrrhocorax -standing-8.jpg

  Adult of subspecies P. p. barbarus on La Palma, Canary Islands

• Red-billed Chough I IMG 7083.jpg

  Immature P. p. himalayanus at Template:Convert at Tilla Lotani, India

• Pyrrhocorax pyrrhocorax erythroramphus MHNT.ZOO.2010.11.171.6.jpg

  Eggs of Pyrrhocorax pyrrhocorax erythroramphos – (MHNT)

• Pyrrhocorax pyrrhocorax MWNH 1378.JPG

  Egg, collection Museum Wiesbaden

Etymology

"Chough" was originally an alternative onomatopoeic name for the jackdaw Coloeus monedula, based on its call. The similar red-billed species, formerly particularly common in Cornwall, became known initially as "Cornish chough" and then just "chough", the name transferring from one species to the other.<ref name= Cocker >Template:Cite book 406–8</ref>

The Australian white-winged chough Corcorax melanorhamphos, despite its similar shape and habits, is in a separate family Corcoracidae only moderately related to the Corvidae and not notably to the true choughs, and is an example of convergent evolution.<ref name=Fjeldså/><ref name=ioc/>

Description

The adult of the "nominate" subspecies of the red-billed chough, P. p. pyrrhocorax, is Template:Convert in length, has a Template:Convert wingspan,<ref name=BWP/> and weighs an average 310 grammes (10.9 oz).<ref name=BTO/> Its plumage is velvet-black, green-glossed on the body, and it has a long curved red bill and red legs. The sexes are similar (although adults can be sexed in the hand using a formula involving tarsus length and bill width<ref name=Blanco6>Template:Cite journal</ref>) but the juvenile has an orange bill and pink legs until its first autumn, and less glossy plumage.<ref name= Madge94/>

The red-billed chough is unlikely to be confused with any other species of bird. Although the jackdaw and Alpine chough share its range, the jackdaw is smaller and has unglossed grey plumage, and the Alpine chough has a short yellow bill. Even in flight, the two choughs can be distinguished by Alpine's less rectangular wings, and longer, less square-ended tail.<ref name=Madge94/>

The red-billed chough's loud, ringing chee-ow call is clearer and louder than the similar vocalisation of the jackdaw, and always very different from that of its yellow-billed congener, which has rippling preep and whistled sweeeooo calls.<ref name= Madge94/> Small subspecies of the red-billed chough have higher frequency calls than larger races, as predicted by the inverse relationship between body size and frequency.<ref name= Laiolo2001 >Template:Cite journal</ref>

Distribution and habitat

The red-billed chough breeds in Ireland, western Great Britain, the Isle of Man, Brittany, La Palma in the Canary Islands, across southern Europe and the Mediterranean basin, the Alps, and in mountainous country across Central Asia, India and China, with two separate populations in the Ethiopian Highlands. It is a non-migratory resident throughout its range.<ref name= Madge94/>

Its main habitat is high mountains; it is found between Template:Convert in North Africa, and mainly between Template:Convert in the Himalayas. In that mountain range it reaches Template:Convert in the summer, and has been recorded at Template:Convert altitude on Mount Everest.<ref name= Madge94/> In the British Isles and Brittany it also breeds on coastal sea cliffs, feeding on adjacent short grazed grassland or machair. It was formerly more widespread on coasts but has suffered from the loss of its specialised habitat.<ref name =RSPB >{{#invoke:citation/CS1|citation |CitationClass=web }}</ref><ref name =RSPB2 >{{#invoke:citation/CS1|citation |CitationClass=web }}</ref> It tends to breed at a lower elevation than the Alpine chough,<ref name = BWP/> that species having a diet better adapted to high altitudes.<ref name =Rolando2/>

Behaviour and ecology

Breeding

The red-billed chough breeds from three years of age, and normally raises only one brood a year,<ref name = BTO/> although the age at first breeding is greater in large populations.<ref name= Reid>Template:Cite journal</ref> A pair exhibits strong mate and site fidelity once a bond is established.<ref name = "Roberts 1985"/> The bulky nest is composed of roots and stems of heather, furze or other plants, and is lined with wool or hair;<ref name = BWP/> in central Asia, the hair may be taken from live Himalayan tahr.Template:Citation needed The nest is constructed in a cave or similar fissure in a crag or cliff face.<ref name = BWP/> In soft sandstone, the birds themselves excavate holes nearly a metre deep.<ref>Template:Cite book</ref> Old buildings may be used, and in Tibet working monasteries provide sites, as occasionally do modern buildings in Mongolian towns, including Ulaanbaatar.<ref name = Madge94/> The red-billed chough will utilise other artificial sites, such as quarries and mineshafts for nesting where they are available.<ref name = JNCC/>

The chough lays three to five eggs Template:Convert in size and weighing 15.7 grammes (0.55 oz), of which 6% is shell.<ref name = BTO/> They are spotted, not always densely, in various shades of brown and grey on a creamy or slightly tinted ground.<ref name = BWP/> The egg size is independent of the clutch size and the nest site, but may vary between different females.<ref name= Stillman >Template:Cite journal</ref> The female incubates for 17–18 days before the altricial downy chicks are hatched, and is fed at the nest by the male. The female broods the newly hatched chicks for around ten days,<ref>Template:Cite journal</ref> and then both parents share feeding and nest sanitation duties. The chicks fledge 31–41 days after hatching.<ref name = BTO/>

Juveniles have a 43% chance of surviving their first year, and the annual survival rate of adults is about 80%. Choughs generally have a lifespan of about seven years,<ref name = BTO/> although an age of 17 years has been recorded.<ref name = "Roberts 1985">Template:Cite journal</ref> The temperature and rainfall in the months preceding breeding correlates with the number of young fledging each year and their survival rate. Chicks fledging under good conditions are more likely to survive to breeding age, and have longer breeding lives than those fledging under poor conditions.<ref name= Reid/>

Feeding

File:PyrrhocoraxPEremita.jpg

The long curved bill is used to dig for invertebrates and bulbs

The red-billed chough's food consists largely of insects, spiders and other invertebrates taken from the ground, with ants probably being the most significant item.<ref name = Madge94/> The Central Asian subspecies P. p. centralis will perch on the backs of wild or domesticated mammals to feed on parasites.Template:Citation needed Although invertebrates make up most of the chough's diet, it will eat vegetable matter including fallen grain, and in the Himalayas has been reported as damaging barley crops by breaking off the ripening heads to extract the corn.<ref name = Madge94/> In the Himalayas, they form large flocks in winter.<ref name=pcr>Template:Cite book</ref>

The preferred feeding habitat is short grass produced by grazing, for example by sheep and rabbits, the numbers of which are linked to the chough's breeding success. Suitable feeding areas can also arise where plant growth is hindered by exposure to coastal salt spray or poor soils.<ref name= Mccanch >Template:Cite journal</ref><ref name= Blanco4>Template:Cite journal</ref> It will use its long curved bill to pick ants, dung beetles and emerging flies off the surface, or to dig for grubs and other invertebrates. The typical excavation depth of Template:Convert reflects the thin soils which it feeds on, and the depths at which many invertebrates occur, but it may dig to Template:Convert in appropriate conditions.<ref name= bardsey>Template:Cite journal</ref><ref name= morris>Template:Cite book</ref>

Where the two chough species occur together, there is only limited competition for food. An Italian study showed that the vegetable part of the winter diet for the red-billed chough was almost exclusively Gagea bulbs, whilst the Alpine chough took berries and hips. In June, red-billed choughs fed on Lepidoptera larvae whereas Alpine choughs ate cranefly pupae. Later in the summer, the Alpine chough mainly consumed grasshoppers, whilst the red-billed chough added cranefly pupae, fly larvae and beetles to its diet.<ref name= Rolando2>Template:Cite journal</ref> Both choughs will hide food in cracks and fissures, concealing the cache with a few pebbles.<ref name= wall>Template:Cite book</ref>

Natural threats

File:ChoughsDiff.svg

Red-billed chough (left) can be distinguished from Alpine chough in flight by its deeper primary "fingers" and tail wedge. Its wings extend further, to or beyond the tail tip, when it is standing.

The red-billed chough's predators include the peregrine falcon, golden eagle and Eurasian eagle-owl, while the common raven will take nestlings.<ref name = birdwatchireland >{{#invoke:citation/CS1|citation |CitationClass=web }}</ref><ref name=OperationChough>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref><ref name= Rolando >Template:Cite journal</ref><ref name= Blanco/> In northern Spain, red-billed choughs preferentially nest near lesser kestrel colonies. This small insectivorous falcon is better at detecting a predator and more vigorous in defence than its corvid neighbours. The breeding success of the red-billed chough in the vicinity of the kestrels was found to be much higher than that of birds elsewhere, with a lower percentage of nest failures (16% near the falcon, 65% elsewhere).<ref name= Blanco >Template:Cite journal</ref>

This species is occasionally parasitised by the great spotted cuckoo, a brood parasite for which the Eurasian magpie is the primary host.<ref name=Soler>Template:Cite journal</ref> Red-billed choughs can acquire blood parasites such as Plasmodium, but a study in Spain showed that the prevalence was less than one percent, and unlikely to affect the life history and conservation of this species.<ref name=Blanco2>Template:Cite journal</ref> These low levels of parasitism contrast with a much higher prevalence in some other passerine groups; for example a study of thrushes in Russia showed that all the fieldfares, redwings and song thrushes sampled carried haematozoans, particularly Haemoproteus and Trypanosoma.<ref name=Markovets >Template:Cite journal</ref>

Red-billed choughs can also carry mites, but a study of the feather mite Gabucinia delibata, acquired by young birds a few months after fledging when they join communal roosts, suggested that this parasite actually improved the body condition of its host. It is possible that the feather mites enhance feather cleaning and deter pathogens,<ref name=Blanco3>Template:Cite journal</ref> and may complement other feather care measures such as sunbathing, and anting—rubbing the plumage with ants (the formic acid from the insects deters parasites).<ref name= Madge94/>

Status

The red-billed chough has an extensive range, estimated at Template:Convert, and a large population, including an estimated 86,000 to 210,000 individuals in Europe. Over its range as a whole, the species is not believed to approach the thresholds for the global 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.<ref name="iucn status 12 November 2021" />

However, the European range has declined and fragmented due to the loss of traditional pastoral farming, persecution and perhaps disturbance at breeding and nesting sites, although the numbers in France, Great Britain and Ireland may now have stabilised.<ref name=BWP>Template:Cite book 1466–68</ref> The European breeding population is between 12,265 and 17,370 pairs, but only in Spain is the species still widespread. Since in the rest of the continent breeding areas are fragmented and isolated, the red-billed chough has been categorised as "vulnerable" in Europe.<ref name = JNCC>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref>

In Spain the red-billed chough has recently expanded its range by utilising old buildings, with 1,175 breeding pairs in a Template:Convert study area. These new breeding areas usually surround the original montane core areas. However, the populations with nest sites on buildings are threatened by human disturbance, persecution and the loss of old buildings.<ref name= Blanco5>Template:Cite journal</ref> Fossils of both chough species were found in the mountains of the Canary Islands. The local extinction of the Alpine chough and the reduced range of red-billed chough in the islands may have been due to climate change or human activity.<ref name= rando>Template:Cite journal</ref>

A small group of wild red-billed chough arrived naturally in Cornwall in 2001, and nested in the following year. This was the first English breeding record since 1947, and a slowly expanding population has bred every subsequent year.<ref name =RSPB2/> The Chough Reintroduction Project, a partnership between Kent Wildlife Trust, Wildwood Trust and Paradise Park, Cornwall, reintroduced the red-billed chough to South East England where it had previously been extinct for over two centuries.<ref>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref> The first of several releases took place at a secret location in Dover in July 2023, releasing eight choughs which came from a zoo-based breeding programme coordinated by Paradise Park in Cornwall.<ref>Template:Cite news</ref> By October 2023, the released choughs had been spotted flying as far as Dover Castle.<ref>Template:Cite news</ref> In May 2024, the first wild red-billed chough chick to be born in Kent for generations was discovered at Dover Castle and was reported to have fledged successfully the following month, but went missing during strong winds in early July. A second release of six female choughs into the wild took place in July 2024.<ref>Template:Cite news</ref> By September 2024 an additional six male choughs had been released into the wild, increasing the total number of wild red-billed chough in Kent to nineteen animals.<ref>Template:Cite news</ref>

In Jersey, the Durrell Wildlife Conservation Trust, in partnership with the States of Jersey and the National Trust for Jersey began a project in 2010, aimed at restoring selected areas of Jersey's coastline with the intention of returning those birds that had become locally extinct. The red-billed chough was chosen as a flagship species for this project, having been absent from Jersey since around 1900. Durrell initially received two pairs of choughs from Paradise Park in Cornwall and began a captive breeding programme.<ref name = durrell>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref> In 2013, juveniles were released onto the north coast of Jersey using soft-release methods developed at Durrell. Over the next five years, small cohorts of captive-bred choughs were released, monitored, and provided supplemental food.<ref>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref>

In culture

• Becket-arms.jpg

  Attributed arms of Saint Thomas Becket (d.1170), Archbishop of Canterbury: Argent, three Cornish choughs proper

• Christ Church Oxford Coat Of Arms.svg

  Arms of Cardinal Thomas Wolsey (d.1530), Archbishop of York: Sable, on a cross engrailed argent a lion passant gules between four leopard's faces azure; on a chief or a rose gules barbed vert seeded or between two Cornish choughs proper

• Flag of the Newquay Battalion of the Cornwall Home Guard.svg

  CitationClass=web }}</ref>

Greek mythology

In Greek mythology, the red-billed chough, also known as 'sea-crow', was considered sacred to the Titan Cronus and dwelt on Ogygia, Calypso's 'Blessed Island',<ref name="deVries76"/> where "The birds of broadest wing their mansions form/The chough, the sea-mew, the loquacious crow."<ref name =Pope >{{#invoke:citation/CS1|citation |CitationClass=web }}</ref>

Cornish heraldry

The red-billed chough has a long association with Cornwall, and appears on the Cornish coat of arms.<ref name = CCC/> According to Cornish legend King Arthur did not die after his last battle but rather his soul migrated into the body of a red-billed chough, the red colour of its bill and legs being derived from the blood of the last battle<ref name=Newlyn >Template:Cite book</ref> and hence killing this bird was unlucky.<ref name="deVries76">Template:Cite book</ref> Legend also holds that after the last Cornish chough departs from Cornwall, then the return of the chough, as happened in 2001, will mark the return of King Arthur.<ref>Template:Cite news</ref>

In English heraldry the bird is always blazoned as "a Cornish chough" and is usually shown "proper", with tinctures as in nature. Since the 14th century, St Thomas Becket (d.1170), Archbishop of Canterbury, has retrospectively acquired an attributed coat of arms consisting of three Cornish choughs on a white field,<ref name = Becket>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref> although as he died 30 to 45 years before the start of the age of heraldry,<ref>The age of heraldry started in England c.1200-1215</ref> in reality he bore no arms. These attributed arms appear in many English churches dedicated to him. The symbolism behind the association is not known for certain. According to one legend, a chough strayed into Canterbury Cathedral during Becket's murder, while another suggests that the choughs are a canting reference to Becket's name, as they were once known as "beckits".<ref name=HS>Template:Cite journal</ref> However the latter theory does not stand up to scrutiny, as the use of the term "beckit" to mean a chough is not found before the 19th century.<ref name=HS/> Regardless of its origin, the chough is still used in heraldry as a symbol of Becket, and appears in the arms of several persons and institutions associated with him, most notably in the arms of the city of Canterbury.<ref name=Canterbury>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref>

Nuisance species

Up to the eighteenth century, the red-billed chough was associated with fire-raising, and was described by William Camden as incendaria avis, "oftentime it secretly conveieth fire sticks, setting their houses afire".<ref name = Cocker/> Daniel Defoe was also familiar with this story:

It is counted little better than a kite, for it is of ravenous quality, and is very mischievous; it will steal and carry away any thing it finds about the house, that is not too heavy, tho' not fit for its food; as knives, forks, spoons and linnen cloths, or whatever it can fly away with, sometimes they say it has stolen bits of firebrands, or lighted candles, and lodged them in the stacks of corn, and the thatch of barns and houses, and set them on fire; but this I only had by oral tradition.<ref name=Defoe>Template:Cite book</ref>

Not all mentions of "chough" refer to this species. Because of the origins of its name, when Shakespeare writes of "the crows and choughs that wing the midway air" [King Lear, act 4, scene 6] or Henry VIII's Vermin Act 1532 is "ordeyned to dystroye Choughes, Crowes and Rookes", they are clearly referring to the jackdaw.<ref name = Cocker/>

Other symbolism

The red-billed chough has been depicted on postage stamps of a few countries, including the Isle of Man, with four different stamps, Bhutan, Turkmenistan, Yugoslavia, and The Gambia, where the bird does not occur.<ref name = stamps>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref> It is the animal symbol of the island of La Palma.<ref name= lapalma>Template:Cite act</ref>

See also

• List of animal and plant symbols of the Canary Islands
• Operation Chough

External links

• RSPB information, sounds and videos
• ARKIVE images
• Operation Chough, the return to Cornwall
• John Harris poem "The Cornish Chough"
• Ageing and sexing (PDF; 3.0 MB) by Javier Blasco-Zumeta & Gerd-Michael Heinze
• Red-billed choughs on postage stamps