There are more than two hundred different species and sub-species of birds in the London area, ranging from the magpie to the greenfinch, but perhaps the most ubiquitous is the pigeon. It has been suggested that the swarms of feral pigeons are all descended from birds which escaped from dovecotes in the early medieval period; they found a natural habitat in the crannies and ledges of buildings as did their ancestors, the rock doves, amid the sea-girt cliffs. ‘They nest in small colonies,’ one observer has written, ‘usually high up and inaccessible’ above the streets of London as if the streets were indeed a sea. A man fell from the belfry of St Stephens Walbrook in 1277 while in quest of a pigeon’s nest, while the Bishop of London complained in 1385 of ‘malignant persons’ who threw stones at the pigeons resting in the city churches. So pigeons were already a familiar presence, even if they were not treated with the same indulgence as their more recent successors. A modicum of kindness to these creatures seems to have been first shown in the late nineteenth century, when they were fed oats rather than the customary stale bread.

From the end of the nineteenth century, wood pigeons also migrated into the city; they were quickly urbanised, increasing both in numbers and in tameness. ‘We have frequently seen them on die roofs of houses,’ wrote the author of Bird Life in London in 1893, apparently as much at home as any dovecote pigeon.’ Those who look up today may notice their ‘fly-lines’ in the sky. from Lincoln’s Inn Fields over Kingsway and Trafalgar Square to Battersea, with other lines to Victoria Park and to Kenwood. The air of London is filled with such ‘fly-lines’, and to trace the paths of the birds would be to envisage the city in an entirely different form; then it would seem linked and unified by thousands of thoroughfares and small paths of energy, each with its own history of use.

The sparrows move quickly in public places, and they arc now so much part of London that they have been adopted by the native population as the sparred; a friend was known to Cockneys as a ‘cocksparrer’ in tribute to a bird which is sweet and yet watchful, blessed with a dusky plumage similar to that of the London dust, a plucky little bird darting in and out of the city’s endless uproar. They are small birds which can lose body heat very quickly, so they are perfectly adapted to the ‘heat island’ of London. They will live in any small cranny or cavity, behind drainpipes or ventilation shafts, or in public statues, or holes in buildings; in that sense diet are perfectly suited to a London topography. An ornithologist who described the sparrow as peculiarly attached to man’ said it never now breeds at any distance from an occupied building’. This sociability, bred upon the fondness of the Londoner, is manifest in many ways. One naturalist, W.H. Hudson, has described how any stranger in a green space or public garden will soon find that ‘several sparrows are keeping him company … watching his every movement, and if he sits down on a chair or a bench several of them will come close to him, and hop this way and that before him, uttering a little plaintive note of interrogation — Have you got nothing for us? They have also been described as die urchins of the streets — ‘thievish, self-assertive and pugnacious’ — a condition which again may merit the attention and admiration of native Londoners. Remarkably attached to their surroundings, they rarely create ‘fly-lines’ across the city; where they are born, like other Londoners, they stay.

There are some birds, such as the robin and the chaffinch, which are less approachable and trustful in the city than in the country. Other species, such as the mallard, grow increasingly shyer as they leave London. There has been a severe diminution of the number of sparrows, while blackbirds are more plentiful. Swans and ducks have also increased in number. Some species, however, have all but vanished. The rooks of London are, perhaps, the most notable of the disappeared, their rookeries destroyed by building work or by tree-felling. Areas of London were continuously inhabited by rooks for many hundreds of years. The burial ground of St Deinstalls in the East and the college garden of the Ecclesiastical Court in Doctors’ Commons, the turrets of the Tower of London and the gardens of Grays Inn, were once such localities. There was a rookery in the Inner Temple dating from at least 1666, mentioned by Oliver Goldsmith in 1774. Rooks nested on Bow Church and on St Olave’s. They were venerable London birds, preferring to cluster around ancient churches and the like as if they were their local guardians. Yet, in the words of the nineteenth-century song, ‘Now the old rooks have lost their places’. There was a grove in Kensington Gardens devoted to the rooks; it contained some seven hundred trees forming a piece of wild nature, a matter of delight and astonishment to those who walked among them and listened to the endless cawing that blotted out the city’s noise. But the trees were torn down in 1880. The rooks have never returned.