AppearanceThis 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 adult of the "nominate" subspecies of the red-billed chough, ''P. p. pyrrhocorax'', is 39–40 centimetres in length, has a 73–90 centimetres wingspan, and weighs an average 310 grammes. 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 but the juvenile has an orange bill and pink legs until its first autumn, and less glossy plumage.
DistributionThe red-billed chough breeds in Ireland, western Great Britain, the Isle of Man, 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.
StatusThe red-billed chough has an extensive range, estimated at 10 million square kilometres, 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, and is therefore evaluated as least concern.
ReproductionThe red-billed chough breeds from three years of age, and normally raises only one brood a year, although the age at first breeding is greater in large populations. A pair exhibits strong mate and site fidelity once a bond is established. The bulky nest is composed of roots and stems of heather, furze or other plants, and is lined with wool or hair; in central Asia, the hair may be taken from live Himalayan tahr. The nest is constructed in a cave or similar fissure in a crag or cliff face. In soft sandstone, the birds themselves excavate holes nearly a metre deep. Old buildings may be used, and in Tibet working monasteries provide sites, as occasionally do modern buildings in Mongolian towns, including Ulaanbaatar. The red-billed chough will utilise other artificial sites, such as quarries and mineshafts for nesting where they are available.
The chough lays three to five eggs 3.9 by 2.8 centimetres in size and weighing 15.7 grammes, of which 6% is shell. They are spotted, not always densely, in various shades of brown and grey on a creamy or slightly tinted ground.
The egg size is independent of the clutch size and the nest site, but may vary between different females. 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, and then both parents share feeding and nest sanitation duties. The chicks fledge 31–41 days after hatching.
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, although an age of 17 years has been recorded. 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.
FoodThe 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.
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. 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 2–3 cm reflects the thin soils which it feeds on, and the depths at which many invertebrates occur, but it may dig to 10–20 cm in appropriate conditions.
PredatorsThe red-billed chough's predators include the peregrine falcon, golden eagle and Eurasian eagle-owl, while the common raven will take nestlings.
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