The carrion crow (Corvus corone) is a passerine bird of the Corvidae family and the genus Corvus which is native to western Europe and eastern Asia. They have glossy black plumage, often with a slight green or purple sheen. They have heavyset black bills, slightly curved at the end. As territorial birds they will usually be seen alone or in pairs. Non-breeding birds may form small flocks, and large communal roosts may form in the winter. The collective name for a group of crows is a ‘flock’ or a ‘murder’.
The Carrion Crow has many calls but the most common is a harsh, croaky, "kraa-kraa-kraa". It is noisy bird, perching on the top of a tree and calling three or four times in quick succession, with a slight pause between each series of croaks.
They are one of many crows in the crow family which also includes rooks, ravens, magpies, jackdaws and the hooded crow, all found in the UK. Until 2002, the grey-bodied hooded crows were regarded as a subspecies of the carrion crow. However, they have since been classified as a separate species (Corvus cornix). In parts of Scotland (roughly between Aberdeen and Glasgow) carrion and hooded crows interbreed to form hybrids of intermediate colour. The carrion crow is generally 44-52cm (17-21in) long, with a wingspan of 84-100cm (33 ½-39in).
Carrion crows can be found throughout the UK, except for north west Scotland and Northern Ireland, where they are replaced by the hooded crow. Carrion crows can be found in almost every UK habitat, from city centres to remote coastal areas. These are common birds and not considered to be threatened.
Family members with whom they are confused are the noticeably larger raven, and most commonly the rook. The rook is a similar size to the carrion crow but is generally gregarious and the crow solitary; however rooks occasionally nest in isolated trees, and crows may feed with rooks; moreover, crows are often sociable in winter roosts. As well as having a heavier black bill, the Carrion Crow lacks the shaggy thighs of the Rook and has a different head shape. You may tell an adult crow from a rook by the black feathers covering the base of its bill where the rook has a patch of bare white skin. The crow's caw is much more harsh and resonant than the high-pitched kaaa of the rook. In flight, the Carrion Crow has a shorter head than the Rook, as well as having slower wing beats. The tail is squarer in the Carrion Crow, and the "fingers" at the wing tips are less splayed.
Feeding
Much maligned for taking eggs and chicks from other birds, and persecuted for the belief that they took livestock, carrion crows are actually not as villainous as we think. Although, as their name suggests they will eat carrion of all kinds, they actually will eat almost anything, including other birds, fruits, grain, nuts, molluscs, earthworms, seeds, frogs, nestlings, mice and other small mammals, insects, scraps and will also steal eggs. Crows are scavengers by nature, which is why they tend to frequent sites inhabited by humans in order to feed on their household waste. The origin of placing scarecrows in grain fields resulted from the crow’s incessant damaging and scavenging, although crows assist farmers by eating insects otherwise attracted to their crops.
Crows actively hunt and occasionally co-operate with other crows to make kills. Crows will also harass birds of prey or even foxes for their kills, it is likely that in most cases larger animals such as lambs that they have been blamed for killing were already dead or at least fatally injured before the crows got involved. However this is all part of the ecosystem, whereby predators such as crows help regulate populations of other species. The predator-prey relationships ensure that only the most able birds survive to adulthood, improving the survival prospects of the species as a whole. Problems only occur when external influences such as human interference create population declines, as has been seen in many of our small bird species. These declines may then be made worse by predation. However, insects and other invertebrates are the main prey in summer, grain becomes important in the autumn and winter, with carrion and other scavenged food an important addition during the breeding season. The predation of eggs and young chicks tends to be highly seasonal, with the crows seeking to satisfy the needs of their own growing brood. Since these crows only produce a single brood of chicks each year, their impact as predators is restricted.
Intelligence
Like all corvids, carrion crows are highly intelligent. Crows and ravens often score very highly on intelligence tests. They have been found to engage in activities such as sports, tool use, the ability to hide and store food across seasons, episodic-like memory, and the ability to use individual experience in predicting the behavior of environmental conspecifics. Natural history books from the 18th century recount an often-repeated, but unproven anecdote of "counting crows" — specifically a crow whose ability to count to five (or four in some versions) is established through a logic trap set by a farmer. Wild hooded crows in Israel have learned to use bread crumbs for bait-fishing. Crows have become highly skilled at adapting to urban environments. In a Japanese city, carrion crows have discovered how to eat nuts that they usually find too hard to tackle. One method is to drop the nuts from height on to a hard road in the hope of cracking it. Some nuts are particularly tough, so the crows drop the nuts among the traffic. That leaves the problem of eating the bits without getting run over, so some birds have been seen to wait by pedestrian crossings and collect the cracked nuts when the lights turn red. Crows in Queensland have learned how to eat the toxic cane toad by flipping the cane toad on its back and violently stabbing the throat where the skin is thinner, allowing the crow to access the nontoxic innards; their long beaks ensure that all of the innards can be removed.
Recent research has found some crow species capable of not only tool use, but also tool construction. They pluck, smooth, and bend twigs and grass stems to procure a variety of foodstuffs. Crows are now considered to be among the world's most intelligent animals with the ratio between their actual brain mass and the predicted brain mass for their size approaching that of some apes. Crows have also demonstrated the ability to distinguish individual humans by recognizing facial features. Evidence also suggests they are one of the few nonhuman animals capable of displacement (communicating about things that are happening in a different spatial or temporal location from the here and now).
Nesting
The bulky stick nest is usually placed in a tall tree, but cliff ledges, old buildings and pylons may be used as well. It is built by both birds and lined with hair and bark. Nests are also occasionally placed on or near the ground. The nest resembles that of the common raven, but is less bulky. The eggs are about 43 mm by 30 mm, smooth and glossy, pale bluish-green with dark brown and grey markings. They are incubated for 18–20 days by the female alone, who is fed by the male. Both adults feed the young birds.
The young fledge after 29–30 days. Juvenile Carrion Crows have duller, browner plumage and pale blue eyes; the adults have brown eyes. Clutch size is approximately three to 9 eggs. Young from previous years often help nesting pairs protect a nest and feed nestlings.
Crows reach sexual maturity around the age of 3 years for females and 5 years for males. Carrion Crows are solitary nesters, maintaining a large breeding territory centred on the nest. However, crows from neighbouring territories may work together to see off intruders or potential predators.
Behaviour
It is the habit of crows to perch like sentinels on the tops of isolated trees, where they can see what is going on in all directions. When birds are building their nests, their activities are observed and remembered by the watching crow, and in due course many nests are wrecked and robbed. Carrion Crows are often in the neighbourhood, though they usually confine themselves to the TV aerials and chimney pots. They will come to gardens for food and although often cautious initially, they soon learn when it is safe, and will return repeatedly to take advantage of whatever is on offer.
British and Irish Carrion Crows (and Hooded Crows) are quite sedentary, never venturing far from their nests. In the winter, our population may be joined by continental birds of both races.
Crows engage in a kind of mid-air jousting, or air-"chicken" to establish pecking order.
Mythology and Popular Culture
Throughout history, the crow has been associated with both positive and negative symbolic meanings. The most common symbols are:
- Life magic; mystery of creation
- Destiny, personal transformation, alchemy
- Intelligence
- Higher perspective
- Being fearless, audacious
- Flexibility, adaptability
- Prophetic insight
- The void or core of creation
- Trickster, manipulative, mischevious
- Messenger
Crows of some kind appear in the mythologies of most religions and cultures. It is mostly in nomadic civilisations (hunters and fishers) that the crow has a positive meaning. In most North European mythologies birds such as ravens, vultures and others feeding on carrion—the flesh of the dead—commonly pass as symbols of war, death and misfortune.
The crow is a subject in at least two of Aesop’s fables: The Fox and The Crow, and The Crow and The Pticher. In the former he is vain and loses his food as a result, in the latter he is clever, coming up to a pitcher and knowing that his beak is too short to reach the water, and if he tips it over, all the water will fall out, the crow places pebbles in the pitcher so the water rises and he can reach it to relieve his thirst.
In possible relation to their historic role as a messenger, crows turn up as spies in several tales, including the Disney version of “Sleeping Beauty” where Maleficent keeps a crow as a pet who betrays the location of the princess, and in “The Lord of the Rings” where they report to Saruman, the wizard who allies himself with the villain Sauron.
An eerie scene involving crows in Alfred Hitchcock’s “The Birds” is still for me one of the most chilling in cinema: Tippi Hedren’s Melanie waits patiently for school children to finish their repetitive, chanting song. We know the birds are evil and attacking, even killing, people. So we are suspicious when the first crow lands on the playground climbing-frame. What Hitchcock does, with his mastery, is doesn’t show us what is happening next. A few crows innocuously land on the climbing frame behind her but the audience are then taken to watch Melanie smoking her cigarette. You know something is not right but the focus is on the lead character, sat unaware, smoking and waiting for the almost endless children’s singing to finish. And then... the children stop singing and silence falls. The audience and Hedren’s Melanie follow a crow as it begins to fly towards the playground. It is at the exact moment that Melanie realises how many crows have amassed that the audience discovers too. It is a shocking sight. The camera is only off the climbing-frame for a minute but the sheer amount of crows is startling, not just to a terrified Melanie but to a shocked audience too.
In the UK today, crows are mostly associated with ill omen, death, and dark witchcraft. Crows are now a common decoration or accessory for halloween, so Clapham Woods, with its similar associations, seemed the only place to hide this one!
The cache started out with a pen, but I suggest bringing your own! There is also a rubber stamp which forms part of the cache - as such, please do not remove it.
Happy Caching!