GULLS IN WINTER.
44 TH E sea-gulls of London " make an appeal this week in our correspondence columns. They represent themselves as "half-starved "; they urge that their thick plumage covers emaciated bodies, and they ask, in short, for food. We hope that they will get all that they need, and that before they put on their• dark brown spring hoods and leave us for their• nesting places they will have filled out so as not to belie the roundness of their white waistcoats. They omit to mention what kind of food they prefer, and perhaps we may make good the omission by stating on their behalf that they do very well with sprats, and that scraps of bread are a wholesome and sustaining food; but that, generally speaking, they will take anything. They will also pay for the food given them. If anybody who has a spare half-hour, and who is fond of watching birds, likes to take a stale loaf or• a tag of scraps down to the Embankment, and throw a leisurely meal to the gulls on the river, he will be rewarded by a very beautiful sight and by a display of extra- ordinarily clever catching. A single crumb thrown into the air will be caught by a passing gull, and in a moment, as if they came from nowhere, the air will be full of wheeling, dipping, crying gulls. Each scrap or little fish thrown over the parapet will be caught by a gull, and the tamenesa,with which the excited birds come flying close to the giver• of the meal is as delightful as the cleverness with which the smallest fragment is snapped up befcre it reaches the water below. Sometimes a bird will miss a crumb, and still catch it, by an almost incredible twist in the air, before it touches the surface of the river ; and some of the bolder• birds will even take food from your• hand, or will come and sit close by you on the parapet and ask for more. But the real marvel of the performance is the sudden appearance of the hungry birds. Let the provider of crumbs select as deserted a spot as he can find and count the number of gulls within sight. Then let him see if he can count how many be has round him when he has been feeding for five minutes. The birds gather as vultures gather on a plain, one after another spreading the news up and down the river.
The majority of birds in the London flocks of gulls are the black-headed gull (Lams ridilrundus), though of late seasons
these have been joined by a good many herring gulls (Lams argeutalus), and a few common gulls (Larus callus). The numbers which come up the Thames seem to nacr•eare every year, and the distance which the birds penetrate inland increases also. In fact, we are probably witnessing, in the case of British sea-gulls, one of those interesting phases of evolution of habit which birds show us more plainly and more frequently than other creatures. Gulls first came to London in any considerable number in 1887, but it was not until the year 1895, when there was exceptionally bard weather, that they became a recognised feature of the London winter. In that year they flocked to the bridges and the Embankment, where they discovered thty could get food, and they have come back in increased numbers each succeeding year, going higher and higher up the river. They reached Eton, for instance, for the first time in 1907, when a flock came to Agar's Plough; they have returned each winter, and there seems no reason why in time they should not follow the river to its source. They some for the earthworms on the surface of arable and grass fields, and they have certainly added a new beauty to the winter landscape. The sight of a flock of gulls wheeling and hovering over a distant field, in the grey mist cr fitful sunshine of a. February morning, is one of the most fascinating of the larger effects of bird-life in country scenery.
But for all the charm of flocks of sea-gulls oonsidered as mere spaotades, the apparent change in the habits of the birds suggeita some rather disturbing questions. The black-headed gull has for many years been regarded as a friend of the farmer owing to the large number of grubs and insects which he devours ; in consequence, he has been legally protected, and as a result of protection he has increased enormously in numbers. Now, one of the consequences which frequently follow an increase in the number of a species is that its feeding habits change also—or, perhaps, develop rather than change. All gulls are naturally eaters of fish, and some, such as the greater black-backed gull, are very dangerous enemies of other creatures. Black-backed gulls will kill lambs and even sheep, and will do so in the most horribly cruel way by pecking out the eyes of the live animal. An Argyllshire shepherd told the writer four years ago that on a single stretch of sea-coast moorland there had been ninety-seven lambs killed by black-backed gulls in a single season. The herring gull, again, is a large and ravenous bird and is particularly fond of other birds' eggs, a tendency which would not be encouraged by owners of grouse-moors near the sea. And now the black-headed gull in turn seems to be adding to its vir- tuous habits of devouring grubs and worms the by-no-means attractive occupation of destroying fish, especially trout and young salmon, at the mouths of rivers. That a great many salmon are destroyed by gulls is, unfortunately, certain ; but there are even worse allegations made against the gull tribe by gamekeepers. There is, of course, general agreement as to the wickedness of the greater black-backed gull, and in a less degree as to the lesser black-backed gulls; as regards other species opinions seem to be divided. In the Gamekeeper of Sep- tember, 1909, for instance, a keeper gives his experience of these birds on a North-country grouse-moor. " Some ten or twelve years ago they came," he writes, "and bred on a small moor. that I am in charge of here. First only a few came ; now they come in thousands, and the result is that I have no grouse. I cannot say whether they suck eggs or kill the young birds, but I am sure they drive the old grouse away. They also chase hares, or any other thing that crosses the moor except their own kind. They also very soon have the moor more like a green field than a heathery moor, as they bring in seeds of all kinds off the lands, and the seed soon grows there and the place becomes a mass of filth." On the other hand, Mr. Wilson Armistead, a recognised authority on the breeding of trout, who has had many opportunities of observing the habits of gulls, states that he does not think that black-headed gulls would do any harm on a moor unless the nesting grouse objected to the incessant clamour of the birds round their breeding places. " The herring gull, the common gull, the lesser black-back, and the great black- back will all take both eggs and young birds," he writes : " the black-headed gull never. An examination of the mouth and beak is convincing proof." As to these conflicting statements of opinion, we need more direct evidence on the question of the feeding habits of the birds ; but what is certain is that there are districts where gulls select certain forms of food which they neglect elsewhere. There are places along the sea coast where they undoubtedly devour grain and other farm produce ; the gulls on Cromarty Firth, for instance, and doubtless in other parts of Scotland, make hearty meals of turnip. As against these destructive tendencies, it is an undoubted fact, as regards the black- headed gull, that in certain districts it disposes of enormous quantities of crane-flies in the larva stage—a service of which the benefit to the farmer could hardly be over-estimated.
The general rule, however, seems to be clear. There are limits to the benefits to be obtained from protection of birds, • however useful they may be. After these limits have been reached, you do not necessarily add to the numbers of useful birds by extending further protection. An undue addition to the numbers of a particular species may mean, on the contrary, that the surplus numbers do not readily find the food they look for, and so gradually acquire the habit of taking other foods more easily come by. The rook is a case in point. Only a few years ago the rook could find plenty of champions to prove that the good he did by destroying injurious insects outweighed any possible harm be could do by pilfering grain. He is now, unfortunately, recognised as a wicked bird ; yet it is doubtful whether, if his numbers were reduced, he would not revert again to virtuous habits. On this subject we need statistics as to the numbers of rooks in the country in succeed- ing breeding seasons, but year after year goes by without any , attempt being made to ascertain them. Other instances of changing habits among birds are those of the sparrow, which has taken permanently to a diet of crocus and primrose-buds, and the starling, which has become one of the worst fruit- eaters we possess. The black-beaded gull has now, it seems probable, joined the list of birds which are changing their habits, and it is at least doubtful whether owners of fisheries would welcome a further increase in their numbers, however much pleasure their winter visits may give to Londoners and country dwellers inland.
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