Black is, in European and some other cultures, the colour of death. So large black birds like crows and ravens are inevitably associated with death as well. As they feed on carrion, they’re not infrequently seen in large groups tearing at the corpse of some unfortunate wild or domesticated animal. With their distinctive blood-curdling calls, and black plumage, they could almost have evolved for the role.
Ravens have specific associations in Nordic and Germanic mythologies, that were made clear in the paintings of Peter Nicolai Arbo.

In this second version of his Valkyrie from 1869, Arbo follows normal conventions in showing a warrior-like woman, with chain mail armour, shield, helmet, and spear, in flight with her escort of ravens.

Arbo’s magnificent Åsgårdsreien (Åsgård’s Ride, The Wild Hunt) from 1872 is drawn from a more general European folk myth, specifically included in the Norse canon. This group of ghostly huntsmen, complete with Valkyries and their ravens, passes in their wild pursuit. According to the folk tale, seeing the Wild Hunt was the harbinger of major catastrophe, usually a battle with many deaths. The riders could also snatch humans up and abduct them, perhaps to Valhalla, as Arbo shows in this powerful painting.
Not all appearances of black birds have bad consequences.

In Alexei Kondratievich Savrasov’s Rooks have Returned (1871), these birds are heralds of the Spring, returning to their nests before the winter’s snow has thawed fully, or the buds have appeared on the barren birches. Across most of Europe, rooks are resident throughout the year, but towards the northern edge of their range, they abandon the snowbound areas and overwinter where food remains more abundant, returning in the early Spring.

One longstanding association is that crows or ravens are often seen perching on gallows and at scenes of execution, as in Pieter Bruegel the Elder’s The Procession to Calvary from 1564. As the whole of Jerusalem seems to be flocking towards the distant site of execution, a large black bird rests on the gibbet at the right edge of the painting, and there are others in flight.

Although crows and ravens had cameo appearances on many landscape paintings in the intervening period, it took Caspar David Friedrich’s ‘Gothic’ Romantic paintings to give them star roles. In his Tree of Crows from about 1822, the birds are only doing what they normally do around dusk. But Friedrich’s wonderfully wizened trees and the eerie light play tricks with us, and they appear sinister.

Friedrich’s followers had similar interests in large black birds, although in Carl Friedrich Lessing’s Landscape with Crows, from about 1830, this doesn’t appear in the least bit sinister. This is a small and painterly plein air landscape sketch, with visible brushstrokes in the vegetation, and gestural construction of its trees and the birds.
When the story of Mazeppa, as told in one of Lord Byron’s poems, became a popular theme for paintings towards the middle of the nineteenth century, birds of carrion were quickly implicated as signs of impending death.

In Eugène Delacroix’s Mazeppa on the Dying Horse (1824), the first of the ravens is already on scene ready for the horse to crumble under Mazeppa, and a line of its friends is arriving just in case there’s room at the table for them too.

Byron’s poem ends when Mazeppa wakes up in bed, having been rescued from unconsciousness by a “Cossack Maid”, who then tends his wounds. Théodore Chassériau’s A Young Cossack Woman Finds Mazeppa Unconscious on a Wild Horse is one of few faithful accounts of the end of the poem, down to the ravens flying overhead waiting to feed on Mazeppa’s corpse.

When the unfortunate Richard Dadd was committed to mental hospital in London, he must have experienced a lot of disturbed and disturbing behaviour, but made little reference to it in his paintings. His watercolour Crazy Jane, dated by him 6 September 1855, is an exception to this, and perhaps gives a little more insight into those around him. With his lack of female models, his Jane is clearly a John, and he draws on peacock feathers and other objects from his faerie paintings. The recession of large crows flying from the distant ruined tower is particularly effective.
By a strange coincidence, at around the same time, Jean-François Millet made his first image of a sower in the fields, with a flock of crows streaming from a similarly distant tower.

Millet revisited that successful painting in two later pastel works with the same title, The Sower, in around 1865. This shows the crows more clearly than his original, as well as the distant tower of Chailly. Whether the artist envisaged those birds having their symbolic meaning is an unresolved question: away from the coast, where seagulls are less common, crows are most often the birds seen in company of those working the land.
The later nineteenth century brought a succession of more disturbing images involving large black birds.

In Vasily Vereshchagin’s Apotheosis of War (1871), ravens or crows perch on a huge pile of human skulls in a barren landscape outside the ruins of a town. Vereshchagin had served as a war artist with the Imperial Russian Army from 1867, and was only too familiar with the terrible human consequences of war.

Exhibited at the Paris Salon of 1878, August Friedrich Schenk’s Anguish, painted in 1876-78, shows a ewe lamenting the death of her lamb in the snow, as a thoroughly menacing murder of crows assembles around the defiant mother. This is the type of image that might have inspired Daphne du Maurier’s 1952 novella which became Alfred Hitchcock’s The Birds (1963).