One of two Pyrrhocorax species found in Europe, the red-billed chough is the only one found in the UK. Originally named as Upupa pyrrhocorax by Linneaus in 1758, owing to their curve beak and short, blunt tongue being superficially to characters of birds such as ibis and hoopoe, the species was reclassified as Pyrrhocorax in 1771 by British ornithologist Marmaduke Tunstall when it became clear they were not closely related to these species. First recorded in England during the Medieval period, the species has a long history in Cornwall, being on the county's Coat of Arms and in its mythology (e.g., King Arthur was said to have turned into a chough on his death). Once so prevalent in the county, the species was known as the "Cornish chough". The binomial name is constructed from the Greek pyrhos for "flame-coloured" or "fiery" and corax meaning "raven".
Size: Adult birds stand about 40 cm (16 in.) tall, with a tail of 12-15 cm (5-5 in.), a wingspan of 70-90 cm (28-35 in.-), and a weight of 260-390 g (9-14 oz.).
Appearance: Choughs are medium-sized crows with iridescent black plumage. The decurved (i.e., curving downwards) beak is long and thin. The beak and legs are brightly coloured, ranging individually from dark orange through to vermillion (deep red). Juveniles tend to present with an overall duller appearance than adults, particularly on the beak, which may be pinkish-yellow through to a dull red. Presumably, the beak and leg colour reflects the concentration of either free or esterified carotenoids, and the deepening in colour into adulthood might indicate a dietary source for these pigments, although this does not appear to have been studied.
Distribution: Globally, this species is found from China in the east to Ireland in the west, south to Morocco and north to central Russia, although their distribution through central Europe is highly fragmented, and there are isolated populations in Ethiopia. In Britain, the species is resident along the southern and western coasts of Ireland, coastal Wales, the far western coasts of Cornwall, isles of Man, Islay, and Colonsay.
Population: The 2014/15 estimate from the BTO put the UK breeding population at 335 pairs, increasing to 1,250 during winter. As of the end of 2024, the RSPB's website gave the UK population as 250-350 pairs in Great Britain and 120-150 pairs on the Isle of Man, suggesting perhaps as many as 500 breeding pairs.
Habitat: Primarily a species of the coast and mountains. Indeed, in Britain and Ireland the chough is restricted to coastal cliffs and adjoining short-grazed grassland/machair or cereal farmland, while elsewhere the species inhabits mountainous regions between 2,000 and 8,000 m (6,600-20,000 ft.). Cliffs, crags, or ruined stone buildings appear necessary for breeding.
Longevity: About half of all individuals will die before a year old, although adult mortality is ca. 20% per year. BTO ringing data suggest an average lifespan of around 7 years old, although there are multiple reports of wild-rung birds in their mid- to high teens. The September 2023 EURING report cites one Spanish bird surviving 19 years 6 months, while an individual held at London Zoo died in November 1935 at 20 years 4 months. BTO give the current record longevity at 23 years, based on the recovery of a ringed individual near Llanrhystud, Ceredigion (mid-Wales) in June 2019.
Sexing: There is no sexual dimorphism in the species, meaning sexing can only be accomplished by vent checking or DNA analysis.
Activity: A diurnal species, like all other corvids, choughs exhibit a confident gait the includes walking, running and hopping (including sideways jumps). Birds are generally alert and often excitable, flicking wingtips and tail feathers when calling.
Territory/Home Range: A primarily sedentary species, with no evidence of territoriality beyond a couple of hundred metres in the vicinity of the nest-site. Ringing data suggest long-range movements do sometimes occur, even including significant sea-crossings (e.g., on to the Outer Hebrides), with observational records of adult birds from Britain suggesting perhaps up to 400 km (250 miles), although ringing of chicks suggests most dispersal is within 10 km (6 miles) of natal area, sometimes up to 50 km (30 miles). Will travel several kilometres from nesting site while foraging.
Diet: Primarily soil-living invertebrates, although the diet is supplemented with grain and berries, especially during the winter and in poorer (e.g., upland) habitats. Birds forage primarily in short vegetation, often on poor quality soils, and are readily displaced if the ground cover grows much beyond ca. 5 cm (2 in.) in height or becomes enclosed by taller shrubs such as gorse. Livestock dung may be an important source of invertebrates for some populations and one Cornish study recorded 70% of foraging time being in/under dung during one three-hour observation period. Some reports of birds foraging in stock-feeding areas, manure heaps, rubbish tips, and on animal carcasses (presumably picking maggots or other insects) during frosty weather. Will move stones, overturn dung, and dig in sand/soil to uncover prey. Wide variety of species are taken, including grasshoppers, earwigs, spiders, harvestmen, woodlice, sandhoppers, centipedes, earthworms, and adult and larval moths/butterflies, flies, ants, and beetles. Some reports from elsewhere in range of adult birds taking scorpions, lizards, mice and shrews. Many species are important seasonally, but beetles and flies appear important year-round. Vegetation is also varied, including cereals (e.g., grain), grasses, and fruits (e.g., sea buckthorn, grape, olives, holly, hawthorn, pears, rowan).
Reproduction: Male will court female with bowing and headshaking, as well as nuptial feeding. In Britain, eggs are laid into a bulky, untidy nest constructed from twigs, moss, and fronds of vegetation in a cliff crevice, ledge in a cave, or natural crag at intervals of 1-3 days starting in early April. Clutches range from 1-6 eggs, with most nests containing 4 or 5, and hatch after being incubated by the female for ca. 3 weeks while she's fed by the male. Chicks are fed by both parents, occasionally also by helpers (i.e., juveniles from previous broods). Fledging occurs around one month old, although juveniles may leave the nest and spend up to two weeks in the vicinity before flying. Double brooding has been reported very occasionally. Birds are sexually mature by second breeding season, although it appears most probably don't breed successfully until their fourth year.
Behaviour & Sociality: Persistent pair bonds form between mates, who will stay together throughout the year. While most often observed solitarily or in pairs, the chough is a sociable species, as is common among corvids. Small groups seem most common during late summer and autumn, consisting of up to five or six individuals that appear to be largely parents with young-of-year. Occasional reports of temporary flocks numbering into the hundreds, with flocking apparently more likely during September/October. A very vocal bird throughout the year, particularly when in flight, issuing a distinctive "merry yelp" variously described as pee-ouw, kyeow, or kree-aw while both on the wing and on the ground. Sometimes a harsher kwarr is issued in alarm, and some authors report a deeper gull-like kaah and kwuk-uk-uk, although the circumstance of these calls is unclear. Nestlings make a squirrel-like begging call.
Threats/Conservation: Choughs were once much more widely distributed and abundant in Britain and Ireland than today, found both inland and coastally. The population had contracted to the west coast in Scotland by the start of the 19th century, while the species bred in Devon until 1910 and Cornwall until 1952. Choughs were declared extinct in the West Country in 1973 following a precipitous decline and a conservation breeding project established at Paradise Park in 1987. While choughs recolonised Cornwall naturally, five birds arriving apparently from Ireland to Newquay in 2001, the population in Cornwall and Wales were supplemented by the release of captive-bred individuals. July 2023 saw the first of several releases of choughs in Kent.