Carrion Crows on the beach NP Sep22
The corvid family of birds can divide opinions, with some loving the almost subversive side of corvids that feature strongly in myth and legend, whilst others dislike the shrill calls and the perceived cruelty of corvids when feeding. Many misunderstand these intelligent and super adaptive birds, whilst others, like Wildlife Matters, find them one of the most fascinating and beautiful wild species in the UK.
Eight corvid species are native to the UK. The five are from the Corvus genus and are the corvids we look at today. The other three corvid species will be featured in Part Two, released after Christmas.
Corvids are a group of birds belonging to the Corvidae family, also known as the crow family, which includes crows, jackdaws, rooks, ravens, jays, magpies, treepies, choughs, and nutcrackers. There are over 120 species of corvid worldwide.
In this article, we look at British corvids in size order, from the largest to the smallest, and we begin with one of my favourite birds, the magnificent, intelligent and beautiful Raven.
The raven, also known as the northern or common raven, is the most widespread crow species in the world. They can be found in various climates, not just the classic colder climates of the north.
These birds can be seen throughout the Holarctic, from the Arctic to the temperate habitats of North America and Europe to the deserts of Africa. They can even be found in urban areas, such as London, and the mountains and uplands of England, Scotland and Wales.
Corvids are known for their intelligence, with various species being able to recognise themselves in mirrors, being aware of being watched, and remembering human faces.
They feature strongly in our culture and folklore, some of which are rather macabre, such as the belief that crows peck out the eyes of their victims to attain their excellent vision. It is a small step to see a group of crows attracted to a corpse, not as scavengers but as agents of death with murderous intentions.
A Raven in Dumfries and Galloway
Ravens are the British Isles’ largest corvids, with a 125-135cm wingspan. Like the carrion crow, they are all black but have a thicker neck, bill, and diamond-shaped tail.
They are usually found alone or in pairs and are rare in urban areas, except at the Tower of London. They have a very distinctive “cronking” call.
Male and female common ravens look almost identical, except the female is slightly smaller. The bird has a glossy black plumage with a purplish, green or blue hue. They have long, loose, erectile throat feathers, often raised by males during displays of dominance.
The head is large, and the bill is a powerful, medium-length, chunky black colour. The nose may have nasal bristles, which can cover up to half of the upper ridge of the bill. The eyes are dark brown, with the legs and feet black with grey soles.
Common ravens have a wide range of calls and can successfully mimic sounds. This makes it hard to interpret their call types. They often make a loud, low- to medium-pitched bark like ‘park – park,’ which is repeated frequently.
Common ravens are known for scavenging the flesh of carcasses, but they are also skilled hunters and will eat almost anything.
They primarily feed on small mammals, birds, fish, reptiles, snails, worms, berries, fruits, and seeds. They are also known to scavenge on rubbish tips and along shorelines.
Ravens have been at the Tower of London since Charles ll, 1630 – 1685. King Charles ordered that the ravens at the Tower be protected. There are always at least six resident ravens, cared for by one of the Yeoman Warders, the Ravenmaster.
Legend has it that should the six ravens all leave the Tower, the Kingdom and the Tower will fall.
Common ravens can be found in various habitats, including wild open and barren upland moors, urban and suburban areas, woods, farmland, and Lake District. They tend to avoid the east coast of the UK but can be found throughout Northern Ireland, most of Scotland and Wales, and across the Pennines.
Close up, Common Ravens are easily identifiable by their large, glossy black body and thick, chunky arch-shaped bill. In flight, they display characteristics typical of the species, with long, wedged tails that appear diamond-shaped and long black pointed wings similar to a common bird of prey showing prominent wing fingers.
Ravens construct large nests of sticks, heather, and grasses high in treetops. The nests are commonly reused yearly, with some maintenance at the start of each breeding season.
Each year, the female lays a single brood consisting of 4-6 eggs between February and May. The eggs are pale bluish-green with brown spotting and are incubated by the female for eighteen to twenty-one days.
The young fledge between thirty-five to forty-two days and stay with their parents for six months.
The most extended lifespan for a ringed Common Raven is over thirteen years, but these birds generally live between ten and fifteen years.
The Rook
The second largest of the British corvids is the Rook. It is a large black bird similar in size to the carrion crow.
Its distinguishing feature from other corvids is its bare grey face and grey bill. Although these features are not present in juvenile rooks, they can be used to identify adult birds.
Rooks are social birds often seen in flocks, sometimes with other corvids like jackdaws and carrion crows.
They are found across most British Isles in various habitats, mainly farmland.
Rooks are often admired for their intelligence, maligned for their habit of eating grain, and revered for the excellent and bad omens they are thought to signify.
Rooks are all black birds belonging to the family Corvidae and look very similar to the Carrion Crow, except for the bare whitish skin around their bill. They have untidy, bulky plumage and a steeply angled crown.
Female Rooks are smaller than males, but both genders look almost identical. Juvenile Rooks have fully feathered faces, making them difficult to distinguish from crows during late spring and summer.
Rooks are medium-sized birds, about the same size as Carrion Crows but smaller than Ravens. They have a body length of 44 to 46 centimetres and weigh between 325 and 571 grams. Males have an average body weight of around 485 grams, while females are smaller and weigh approximately 425 grams. Their wingspan measures 81 to 99 centimetres, and males have longer wings on average.
Adult Rooks make typical crow-like sounds. Their call is a raucous, drawn-out cawing, and their song includes various other notes and phrases like clicking and gurgling sounds.
Rooks are omnivores that feed on invertebrates like worms and beetles during the warmer months and grain in autumn and winter. They have a diverse diet and consume small vertebrates like rodents and chicks, eggs, fruits, berries, and acorns.
Rooks find most of their food on the ground or in the soil, but they also visit bird tables. These intelligent birds are known to cache their food by burying it in the ground and covering it with leaves or soil.
Young Rooks feed on worms and other invertebrates. Both parents feed the young while in the nest for about a month. After that, the parents continue providing them for another six weeks while they learn to forage.
Rooks are usually found in arable and pasture farmland, requiring large trees nearby for nesting and roosting. They may also forage in larger parks and gardens and use large trees on the edge of urban and suburban areas.
Rooks are widespread in the UK and can be found almost everywhere except for the far northwest of Scotland, mountainous areas in Wales, and the greater London area. They are also found in Southern and Central Europe, China and Japan.
These birds are often associated with people because they forage on farmland and along country roadsides. While they feed on the ground, they rest, sleep, and nest in trees.
Despite a significant decrease in the breeding population over the last few decades, Rooks are still common in the United Kingdom, with an estimated one million breeding pairs.
Look and listen out for these birds in farmland and along roadsides. Although generally absent from city centres, they may visit parks and more extensive village gardens.
Rooks are relatively long-lived, with an average life expectancy of about six years for individuals who survive adulthood. However, they can live in the wild for at least 22 years.
Humans have traditionally been significant predators of Rooks for pest control and food. While these birds have relatively few predators, old, sick, or injured individuals could fall prey to large birds of prey and carnivores like foxes.
Rooks are protected by the Wildlife and Countryside Act 1981. Although not endangered, their population is decreasing. These birds are classified as a ‘Least Concern’ species by the IUCN and are Amber Listed in the UK.
Rooks build nests communally in rookeries, typically in stands of large trees. The largest rookeries may contain thousands of nests, with dozens in a single tree. The Rook’s nest is a large cup made of twigs, lined with softer materials like dry grass, and built by both sexes.
Rooks breed only once yearly and construct their nests in late winter to lay their eggs in March. The female incubates the eggs for 16 to 18 days, and the chicks fledge after 30 to 36 days.
Rooks lay a single brood of three or four heavily marked and spotted greenish eggs. Each egg measures approximately 40 millimetres long and 28 millimetres wide.
Although Rooks are believed to form lifelong pairs, they may not always be faithful to their partner. They remain together within their flocks even during winter.
Rooks are highly social birds that live in colonies and show little aggression towards each other. However, they can be aggressive when defending their partner and fighting over food, particularly in winter. They are generally peaceful towards other bird species.
Rooks roost communally in trees in woodlands and forested areas. Some birds may continue to roost at the rookery throughout the year, although most gather into large flocks after the breeding season and roost elsewhere, often in the company of Jackdaws.
Rooks do not migrate in the United Kingdom and Western Europe, where they are observed year-round. Meanwhile, Eastern Asian populations migrate between breeding ranges in the north and overwintering sites in the south.
In the 19th century, they were introduced to New Zealand to control agricultural pests, but they are now considered a pest species in the country.
Although Rooks, Crows, and Ravens are related and members of the Corvidae family and the Corvus genus, they are different birds with distinct behaviours and physical characteristics.
While Rooks can cause damage to cereal crops, they also help by eating insect pests. A group of Rooks is commonly called a parliament, but other collective nouns include a clamour and a building of Rooks.
Rooks are brilliant birds, as are most species in the Crow family. They have shown their problem-solving abilities, teamwork, and tool-use skills in laboratory settings, but tool use has yet to be observed in nature.
Carrion and Hooded Crows
We have grouped these two species. Carrion and hooded crows may appear different but are genetically and behaviourally almost indistinguishable.
They can interbreed and produce fertile offspring but tend to mate with their kind. Hybrids have intermediate plumage between their parents, often making them outcasts to birds of either population. This keeps the populations distinct and is expected to eventually lead to their becoming full, reproductively incompatible species.
The carrion crow, also known as just ‘crow’, is one of the most common corvids in the British Isles, found in various habitats, including gardens. Although widespread throughout most of the UK, they are less common in Ireland. They consume different foods, such as carrion, invertebrates, eggs, and fruit.
Crows are usually seen alone or in pairs, but they can form flocks and sometimes be found with other corvid communities.
They are entirely black and can sometimes be confused with other corvid species, particularly juvenile rooks and ravens.
The closely related hooded crow was once considered a subspecies of the carrion crow, but it is now classified as a separate species.
Adult carrion crows have glossy black upperparts with a greenish tone on the head and upper wings, which changes to a purplish hue on the neck, back and rump. These hues can be challenging to observe and may appear very subtle.
The bird’s underparts are dull black with tight feathering across the chest, belly, and vent. The head is broad and flat across the crown, and the black bill is medium length, thick, and arched.
The inside of the mouth is grey, and the nostrils are covered in short, bristle-like feathers. The eyes are dark brown, and the legs are dark grey or black. The tail and wing tips are square.
Both males and females look similar. Juvenile birds lack the glossiness of adults, and their feathers appear sootier. They have grey eyes and a pink colouration on the edges and inside the bill.
The crow’s call is typically loud and harsh, similar to ‘caw-caw-caw’ or ‘craah-craah-craah’, often repeated.
The carrion crow mainly forages for food on the ground, taking worms, insects, seeds, berries, small mammals, and amphibians. It is also known to feed on other birds’ eggs and young and scavenge for scraps and carrion.
The carrion crow is a bird species native to central and western Europe, including the United Kingdom. It can also be found in East and Central Asia, ranging from Kazakhstan to China and Japan.
Its habitat extends south into Thailand and north to the Kamchatka Peninsula in Russia’s northeast corner. T
The species has two subspecies: Corvus corone corone, which is native to Europe, and Corvus corone orientalis, which is found only in Asia.
The carrion crow has an upright posture and a confident-looking appearance on the ground. It walks with a determined, strutting gait. In flight, it often chases predators away from its feeding grounds or nest areas during the breeding season and even attacks prey birds.
Carrion crows are usually solitary or found in pairs, though they occasionally form small flocks. They can be found in various natural habitats, including farmland, wetlands, moorland, woodland, and open countryside.
They are most commonly found in urban and suburban areas with parks and gardens, particularly in Europe. There are sufficient trees in all of these habitats for roosting and nesting.
These birds are monogamous and often mate for life. During the breeding season, the male and female build a large nest from sticks and twigs high up in a tree or occasionally on a cliff top.
Depending on the geographical location, one brood of 4–6 brown-speckled blue eggs is produced annually between March and June. The female incubates the eggs for up to twenty days. Fledging occurs after one month.
Carrion crows have few predators and can live up to ten years in the wild, with some ringed crows recorded as living up to twenty years.
The hooded crow, previously believed to be the same species as the carrion crow, is now recognised as a distinct species. It is the same size as the carrion crow but has a grey body with a black head, chest, wings, and tail.
Hooded crows are found in northern and western Scotland, Ireland, and the Isle of Man in the British Isles. They replace the carrion crow where they are located, with a narrow band of overlap between the two species. Hooded crows are widely distributed across northern, eastern, and southeastern Europe and the Middle East.
Female hooded crows look identical to males in colour and plumage. The only way to tell them apart visually is by size, with females slightly smaller than males. However, both sexes have differing behaviours and can be identified by them.
Juvenile hooded crows are less vibrant in colour than adults, with a browner hue to their grey feathers. Immature birds have blue-grey eyes, and their beaks are pinkish-red instead of adult birds’ dark grey.
Male hooded crows are usually larger and heavier than females. They can grow up to 48 cm to 54 cm (18.9 to 21.3 in) in length, have a wingspan of 93 cm to 105 cm (36.7 in to 41 in), and weigh between 396 g and 602 g.
The call of the hooded crow is similar to the familiar harsh cawing of the carrion crow, but it’s slightly softer and less hoarse.
Hooded crows are omnivores with a primarily carnivorous diet.
They scavenge for carrion, roadkill, scraps, small mammals, birds’ eggs, and young nestlings. They feed on molluscs, crabs, and sea urchins at coastal locations. They also consume small quantities of seeds and grain.
Young hooded crows feed almost entirely on insects in their first few weeks of life before adding grains and seeds to their diet as autumn approaches.
Hooded crows thrive in mixed farmland landscapes with open land and sparse tree cover. These birds are commonly found in parks, gardens, coastal regions, and expanses of moorland in urban areas. They are relatively tolerant of human presence and are frequently seen scavenging on streets in busy city centres.
The hooded crow range extends from Ireland and western Scotland in the west to western Russia in the east, covering northern Europe. Norway, Sweden, and Finland have the largest hooded crow populations north of Europe, while Italy, Greece, Bulgaria, and Turkey have them in the south. Russia is home to between 1 and 10 million resident hooded crows.
Hooded crows are widespread across their entire range, including Northern Ireland, western Scotland and the Isle of Man, where spotting one is not considered unusual or rare.
During winter, the UK sees an increase in the resident population of hooded crows with the arrival of overwintering birds that migrate from Scandinavia after the breeding season. These temporary residents may be seen along the eastern coast of Scotland and England.
The smallest of the five corvid species native to the UK is the Jackdaw.
The jackdaw, also known as Corvus monedula, is one of the smaller corvids. It is grey-black with a black face and cap and has bright white eyes.
Jackdaws can be found in various habitats across much of the British Isles. They roost together in woodlands and often join flocks of rooks. These brilliant and social birds are commonly found in towns and countryside and are often associated with Rooks and other crows.
Despite their small size, Jackdaws are friendly and pleasant birds. They have very dark grey plumage with a jet-black crown, a paler grey nape and sides of the face. Their striking pale-blue eyes are their most distinctive feature, and their short, stout bill separates them from similar species.
Male and female Jackdaws look very similar, but juvenile birds can be identified by their dark eyes and duller brownish plumage.
Due to their similar appearance, Jackdaws are often confused with Rooks as they tend to flock together. However, Rooks are much larger birds with dark eyes and long bills with a pale base.
They also have similar plumage to the large Hooded Crow of Scotland and Ireland.
Adult Jackdaws are slightly larger than the Magpie but have a much shorter tail. They are compact birds with a total body length of about 34 centimetres or 13 inches.
Most full-grown Jackdaws weigh between 200 and 270 grams or 7 to 9.5 ounces, with males being the heavier sex. Jackdaws are agile in flight, with a broad wingspan of 67 to 74 centimetres or 26 to 29 inches.
Jackdaws are known for their high-pitched ‘chak’ call, which is not particularly musical. They are opportunistic omnivores that feed on various foods, including insects during the breeding season and plants like grains, seeds, and fruits in the winter.
They are also known to scavenge for scraps and carrion and are infamous for raiding birds’ nests and stealing eggs from ample water and seabirds. Some people consider them unwelcome visitors on garden bird tables.
Jackdaws can be found in various habitats, but they prefer open landscapes with scattered trees and avoid large open areas without trees and densely wooded areas.
They are widespread in Europe, Western Asia, and marginally in North Africa and can be found virtually throughout the United Kingdom, except for some parts of northwestern Scotland.
These birds generally forage on the ground and use trees and buildings for roosting and nesting. They are social birds that feed and roost in groups ranging from small to large flocks.
In the United Kingdom, they are common in urban, suburban, farmland, and open countryside areas, as well as coastal regions.
Jackdaws can live for up to 18 years, but their average life expectancy is around five years. The population of adult Jackdaws in the United Kingdom is estimated to be over three million.
Jackdaws are susceptible to predators, such as birds of prey and mammals like pine martens and house cats. In certain areas, young Jackdaws are targeted explicitly by the Goshawk.
Jackdaws are protected by the Wildlife and Countryside Act in the United Kingdom.
Jackdaws are a green-listed species in the United Kingdom with a healthy population. Since the mid-1900s, these birds have significantly increased in number. Globally, Jackdaws are classified as ‘Least Concern’ on the IUCN Red List.
These birds are cavity nesters and construct their nests in various sheltered locations, such as crevices in sea cliffs, caves, tree cavities, chimneys, nest boxes, and even animal burrows.
Both male and female Jackdaws work together to build a nest of twigs, mud, feathers, and other materials to fit within the cavity.
These social birds typically nest in loose colonies with other Jackdaw pairs.
Jackdaws usually begin breeding at two years old and nest between March and June, producing a single brood yearly. Their eggs hatch after about three weeks, and the young birds fledge roughly one month later.
Jackdaws typically lay four or five eggs, although their clutch size varies from three to eight. Each egg has a pale blueish colour with numerous dark speckles and measures approximately 3.5 centimetres long and 2.5 centimetres wide.
Jackdaws are monogamous birds that pair for life. They show an unusually high degree of sexual fidelity to their partner, although extra-pair mating has been confirmed in some individuals.
Jackdaws are generally not aggressive birds, although they can dominate smaller songbirds around food sources.
They are social birds that roost and coexist peacefully with other corvids like Rooks.
So there is the Wildlife Matters Introduction to British Corvids Part One. We hope you have enjoyed discovering more about these fantastic birds with whom we share our towns, cities and countryside.
In part two, we will examine the three remaining native British corvids. The monochrome magpie, the colourful Jay and the melodic Chough
Further Reading
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