The Naturalist on the Thames

by C. J. Cornish

[THE CARRION CROW]

Those familiar with the valley of the Thames and with the wild population both of the riverside and of the adjacent hills, will set down the carrion crow as the typical resident bird of the whole district. On the London Thames as high as Teddington it keeps mainly to the line of the river itself, on the banks of which and on the market gardens and meadows it finds abundant food, while the elms of large suburban residences give it both shelter and a safe nesting place. The bird is also commonly mistaken for a rook, and so shares the privileges of those popular birds. Higher up the river it swarms all along the Oxfordshire and Berkshire banks where not killed down by keepers, and a perfect army of them has for years invaded and been settled in the elm-bordered meadows of the Vale of White Horse. Thence it has spread on to the downs, where since the gradual abandonment of cultivation on the highest ground, and the removal of the scattered population of carters and keepers from a very large area, it now has matters all its own way. But it always haunted these heights, as the name "Crow Down," recurring more than once on the Ordnance maps, shows. The "Crow Down" with which the writer is less acquainted is on the very high, wild land north of Lambourn. There they have grown so confident that a nest was found in a thorn bush not ten feet high, at a place called Worm Hill, a good old Saxon name denoting that snakes abound there. There is no doubt that the crows kill and eat the young snakes, one having been seen carrying a snake in its beak recently.

The habits of the carrion crow are so independent and peculiar, and its resourcefulness so great, that it is not to be wondered at that it holds its own well within and around London, while the rook is gradually being edged out. It is generally regarded as a criminal bird, which it is to some extent in the spring. From that point of view the following facts may be cited against the crow. He is keenly on the look-out for all kinds of eggs about the time that his own nest is building. Consequently he is a real enemy to pheasants, wild ducks, plovers, moorhens, and other birds which lay in open places before there is cover. Nothing is more exasperating than these exploits to people who know where birds are nesting on their property, and wish to see them hatch safely. A wild duck's nest in a large copse was found by some persons picking primroses. In that copse was a crow's nest. The crows found out that the primrose-pickers had discovered something interesting, and a few hours later the "Quirk! quirk!" of the crows announced that they were enjoying life to an unusual degree. It was found that they had removed all seven eggs from the duck's nest. In an adjacent reclaimed harbour they took the eggs of ducks, plovers, redshanks, and even larks. In the Vale of White Horse they seem to take most of the early wild pheasant's eggs, besides stealing hen's eggs from round the farms. They are particularly fond of hunting down the sides of streams and canals in the early morning, where they find three dainties to which they are particularly partial,-- moorhen's eggs, frogs, and fresh-water mussels. They swallow the frogs in situ, and carry the moorhen's eggs and mussels off to some adjacent post to eat them comfortably. The shells of both eggs and mussels litter the ground under these dinner-tables. In Holland they are so mischievous that little "duck-houses" are made by the side of all the ornamental canals in private grounds for the ducks to nest in, a convenience of which they, being sensible birds, avail themselves. These duck-houses, or laying bowers, are still regularly made by the half-moon canal at Hampton Court, a survival probably of the days of William of Orange's Dutch gardeners.

During the day they are very quiet birds, keeping much to the trees; but towards evening in March and April, their disagreeable croaking caw may be heard from all quarters where they are numerous. Just at dusk they become less wary than in the day. The writer for many years used to organise a few evening "drives" of the crows to try to thin them down before their ravenous families were hatched. Several guns used to hide in different parts of the valley near nests, and on to this "blockhouse line" the crows were driven. A few were generally shot before they discovered the plot. Solicitude for the nest seldom leads them into danger, but one pair met their fate in this way. The first bird came flying to the nest, in which there were eggs, as soon as a shot was heard in the distance. It was killed, and hardly had the spark of the flash disappeared when the other bird dropped down out of the gloom straight on to the eggs, and met the same fate. Forty young chickens were taken by a pair of crows from a farm in one spring. It was objected by some young ladies who were "interested" in the farm that the crows were "such sneaks." They used to come at luncheon-time up a line of trees extending from the wood to the farm. They were not in the least afraid of any one with a cart, apparently knowing that the horse could not be left, but would go straight for the chicken yard. A pair of sparrow-hawks near would seize a chicken now and then, but in a bold way as if they had a right to them. A few crows contrive to nest in Kensington Gardens. In the early mornings they always hunt the west banks of the Long Water, and are credited with taking a good many ducks' eggs, as well as ducklings.

Crows make one of the best nests constructed by the larger English birds. Usually it is placed, not out on the small branches, where rooks prefer to build them, but on the fork made by a large bough starting from the main trunk. This aids in concealment, and is a protection against shot, though probably the birds do not reckon on this contingency. The bottom of the nest is made of large, dead sticks. Upon and between these smaller twigs, often torn off green from willow-and elm-trees, or stolen from faggots of recent cutting, are laid and woven. Then a fine deep basin is made, woven of roots, grass, and some wiry stalk like esparto, the secret of where to find which seems a special possession of crows, and on this often a lining of bits of sheep's wool and cow's hair. There are sometimes as many as six eggs, and rarely less than four. They are quite beautiful objects, of a bright blue-green marked variously, but in a very decorative way, with blotches and smears of olive and blackish-brown. Two or three clutches of these eggs, with some of the splendid purple-red kestrels' eggs, and sparrow-hawks of bluish white, blotched with rich chestnut, make a very handsome show after a day's bird-nesting on the hills. The first eggs are laid very early, sometimes by the second week in April. A nest recently analysed consisted mainly of green ash taken from faggots and cuttings in the wood. One piece was a yard long, and as thick at the base as the little finger. The nest was felted with cow's hair, and quite impenetrable to shot. These nests last for years, and often have a series of tenants, kestrels, squirrels, brown owls, or hobbies. If the first nest is destroyed, the crow makes another. In his conjugal relations the carrion crow is a model bird. He pairs for life, and is inseparable from his mate. If one croaks, the other answers instantly, but usually they keep within sight of one another all day. In the evening the pair, seldom more than a few yards apart, may be seen hunting diligently in the meadows for slugs, which, so long as the weather is not too dry, form the regular supper of the birds.

A remarkable instance of the crow's courage in defence of its mate occurred some years ago on Salisbury Plain when a party were out rook-hawking. A falcon was flown at one of a pair of crows on favourable, open ground. The two birds mounted in the usual spiral until the falcon stooped, bound to the crow, and the pair came to the ground together. Just as the horseman rode in to take up the hawk the other crow descended straight upon the falcon, knocked her off its prostrate mate, and the two flew off together to cover before the falcon had realised whence the onset came. This crow not only showed great courage in facing both the falcon and the sportsman, but timed its interference with the greatest judgment and precision.

Probably a tame crow would make an amusing pet. Its intelligence must be very considerable, though the shape of its head does not so clearly indicate brain as does that of a raven. Among the crows which haunt the banks of the London river there are some highly educated pairs. One has maintained itself on the reach opposite Ham House for thirteen years, if the evidence used to identify them is reliable. These birds were noticed at that distance of time ago to have learnt to pick up food floating on the water. To see a big black crow hovering like a gull, and picking up bread from the bosom of the Thames, is so unusual that it always excites remark, and the writer was informed only last summer that these Ham House crows were seen doing this constantly. Not many years ago a crow nested in a plane-tree in St. Paul's Churchyard, and a pair also reside on the island in Battersea Park. But the great headquarters of London crows are the grounds of Ranelagh, and the reservoirs and market gardens of Barnes and Chiswick. They flock to the manure heaps in the latter, where the gulls now join them, and several pairs spend all day nearly all the year round on the reservoir banks at Barnes, and on Chiswick Eyot. The Eyot crows seems to find a good living there, and never leave it till their young, which are annually hatched in a tree at some distance on the Middlesex side, can fly. But the crows haunting the great Barnes reservoirs, where the tufted ducks now assemble in winter, are a bad lot. Last winter they were seen to single out and attack any gull separated from the flock which usually came there to roost. A sick or wounded gull was soon caught, killed, and eaten, the small black-headed gulls being no match for the crows. It was characteristic of their cunning that by the river itself they did not molest the gulls.

[LONDON'S BURIED ELEPHANTS]

The amount of river gravel left in the part of the Thames Valley on which West London is built is extraordinary. It is all round, and mostly red, and as there are no rocks like the stone which makes up most of this gravel anywhere in the modern valley, it is puzzling to know where it came from. I went to see the digging of the foundations of the new South Kensington Museum, and the great excavation, which was like the ditch of a fortress, and the stuff thrown out, which was like the rampart, was all dug in, or made of, river gravel. In this the men had found, lying higgledy-piggledy, with no two bones "belonging," quantities of bones of the beasts which used to graze on what I suppose was the Kensington "veldt," or perhaps flats by the riverside, during the time when the river's drift and brick earth was being deposited. The Clerk of the Works was much interested in these discoveries, and had caused them to be carefully collected. These were bones of the great stags then common, of the elephant, and of the primaeval horse, creatures which lived here before the Channel was cut between England and France, though not, perhaps, before man had appeared in what is now the Thames Valley, for flint implements are often found with the bones. Dr. Woodward, to whom some of the remains were taken, said that they reminded him of the great discovery of similar remains in the brick earth at Ilford, in Essex, thirty-seven years ago, when he personally saw, dug from the brickfields of that almost suburban parish, the head and tusks of one of the largest mammoth elephants in the world. These river-gravel and brick-earth buried bones are rather earlier than those found in the peat and marl. The latter belonged to creatures which, though they no longer exist in England, are still found in temperate Europe--beavers, bears, bison, and wolves. But the Thames gravel and the London clay are in places full of the bones of another, and earlier, though by no means primaeval, generation of mammals, some of which are extinct, while others are found at great distances from this country, in remote parts of the earth. Judging from the places where they are found and from the position of the bones, large animals must have swarmed all over what is now London, just as they do on the Athi plains and near the rivers and forests through which the Uganda Railway runs.

There was the same astonishing mixture of species, a mixture which puzzles inquirers rather more than it need. Hippopotamus bones are found in great numbers, and with the hippopotamus remains those of creatures like the reindeer and the musk ox, now found only on the Arctic fringe and frozen rim of the North, which lived on the same area and with them the Arctic fox. Judging from the great range of climate which most northern animals can endure, there is no reason to think this juxtaposition of a creature only found in warm rivers and of what are now Arctic animals is very strange. The London "hippo" was just the same, to judge from his bones, as that of the Nile or Congo. But the reindeer of North America, under the name of the woodland cariboo, comes down far south, and in the Arctic summer that of Europe endures a very high temperature. The Arctic fox does the same. If there were Arctic animals in Kensington and Westminster, that is no evidence that they lived in an Arctic climate. Looking over the list of bones, skulls, teeth, and tusks found, it is interesting to try to reconstruct mentally the fauna of greater London just previous to the coming of man. There were, to begin with, some African animals, either the same as are found on the Central African plains, and were found on the veldt of South Africa, or of the same families. The present condition of the country between Mount Kilimanjaro and the Victoria Nyanza shows quite as great a mixture of species. There, for instance, are all the big antelopes, rhinoceroses, zebras, lions, elephants, hyaenas, and wild dogs, and though there are glaciers on Kilimanjaro and the great mountains near the central valleys, the river running out of the Great Rift Valley is full of crocodiles and hippopotami. There is heather and, higher up, also ice and snow on the mountains, from whose tops the waters come that feed these crocodile-haunted streams. So on the London "veldt" there were lions, wild horses (perhaps striped like zebras), three kinds of rhinoceroses--two of which were just like the common black rhinoceros of Africa, though one had a woolly coat--elephants, hyaenas, hippopotami, and that most typical African animal the Cape wild dog! All these, except the elephants and hippos, can stand some degree of cold; and there is not the slightest reason why the two last may not have flourished in some deep river valley, very many degrees hotter than the hills above. To take an instance still remaining nearer to Europe than the Great Rift Valley. The Jordan Valley is very deep and very hot. Many species of birds are there found which are resident in India, and not anywhere nearer. It is a kind of hot slice of India embedded in the Palestine hills. The very large deer and immense bison and wild oxen probably fed on the same low veldt as the African animals. The bison were the same as those found in Lithuania, but far larger. Numbers of the skulls, of quite gigantic size, have been found in the brick earth. In the British Museum there is a tooth of the mammoth found in 1731, at a depth of 28 feet below the surface, in digging a sewer in Pall Mall. This Pall Mall mammoth might well figure in Mr. E. T. Reed's prehistoric series in Punch. Another tooth was found in Gray's Inn Lane. The mammoth was evidently not confined to the present region of clubland.