BIRD-RINGING SCHEMES.
FROM time to time a stray paragraph finds its way into some local paper announcing the discovery or capture of a bird with a stamped metal ring on its leg. The finder writes to ask what the letters on the ring mean, why the ring is on the bird's leg, and who placed it there. Probably he gets no answer, and the paragraph is buried in the files and forgotten. That must be the fate of many such questions, and possibly some of them may not be worth asking or answering. They may refer to some chance experiment made by an individual for his own amusement; if so, there is no information to be gained which will be of use to others. But they may refer, on the other hand, to certain scientific schemes which have been organized in the hope of adding to our knowledge of the habits of birds, and as such it may be a real misfortune that the questions asked do not come to the notice of the persons who could answer them. The fact that a bird bearing a ring with a particular name and number on it has been found in a particular place may help to suggest a new theory, or it may go to establish a theory hitherto unsupported by facts. In either case 'definite information is valuable. ' ' There exist at present some ten or a dozen different centres in this country, on the Continent, and in America, from which rings are distributed for marking live birds. The objects of the individuals or institutions organizing these marking ar " ringing " schemes are, generally speaking, the same ; they are designed to afford further definite informa- tion on the subject of the migration of birds, and on the distribution of the young birds which year by year take the places, or add to the numbers, of old birds. Four of the European centres are situated on or near the Baltic and the North Sea. On the Baltic Dr. J. Thienemann works from Rcesitten, which is on the narrow isthmus that separates the Kurisohes Haff from the open sea ; and the Other German station is under the superintendence of Dr. H. Weigold in Heligoland. In Denmark there is a station at Viborg, Jutland, under Herr Ohr. Mortensen ; and in Holland Dr. E. D. van °orb is in charge of the work at the Natural History Museum, Leyden. Herr Otto Herman con- ducts operations at the Royal Hungarian Central Bureau of Ornithology. Budapest; and there are two stations in Russia, one at Kielkond and the other at Moscow. American experi- ment is represented by the Secretary of the Linnean Society, New York. Finally, there are the two British centres ; one is Mr. A. Landsborough Thomson's, at the Natural History Department of Aberdeen University, and the other is under the direction of Mr. Ff. F. Witherby, at 326 High Holborn, London.
The last is the largest scheme, and is organized on a scale which has grown every year since it was started in 1909. Mr. Witherby has given some interesting details of the progress of his scheme in the December number of British Birds. In 1909 2,171 birds were ringed ; in 1910, 7,910; in 1911, 10,416; in 1912, 11,483 ; and in 1913, 14,843. Out of this number three enthusiastic ornithologists were responsible respectively for 2,255, 1,924, and 1,142. Five others ringed over five hundred birds apiece, and twenty-two ringed a hundred and over ; so that the results of the scheme as a whole would seem to be likely to be considerable, particularly as regards certain districts. The great majority of these birds are ringed in the nest just before they leave it; but some of them, such as starlings, which can be easily caught and liberated, are ringed as adults. To suit different birds, again, the rings are made in five sizes, from large rings for birds such as gannets to rings for the smallest migrants. All the rings are of aluminium, and are made so as to be lightly clasped round the bird's leg ; the smaller ones are so light that they can be placed in the hand without the weight being noticed. They are stamped with a number and the words "Please return to Witnerby, High Holborn, London," and each number has a corresponding card, kept at High Holborn, on which are entered the number of tho ring, the date on which it was put on the bird, the name of the bird, the place where it was ringed, remarks as to whether it was young or old, or belonging to a brood also marked, and so on ; and, lastly, the name of the ringer. When the bird has been marked, all that has to be done is to wait for the recovery of the ring, and the proportion of recoveries to the number of rings sent out makes some rather carious reading. Naturally, the percentage recovered is small. There is no idea, of course, of killing birds in succeeding years on the chance that they have been ringed in previous years ; merely it is hoped that rings found on birds which are picked up dead, or which happen to be shot by collectors and others, will be forwarded with particulars to London. The great majority of rings are, of course, lost. The larger number of young birds in a brood die in their first year; they have many enemies and natural risks to contend with, whether they are resident or partly or regularly migrant. Probably the larger number of rings, again, which are actually picked up are never forwarded to London ; human nature does not change because rings are put on birds' legs, and it is easier to do nothing than to write a letter. However, a certain per- centage of rings find their way back to High Holborn, and the percentage, according to the figures at present available, seems to vary with different species. The highest is that of the mallard ; from 222 mallards ringed 50 rings were recovered, which is a percentage of 22/. Five rings were recovered from 44 cuckoos, and 15 from 141 woodcock, which works out at 111 and 101 per cent; but the majority of the larger percentages range from 1 to 3. The birds which have been ringed in the greatest numbers are blackheaded gulls, with 209 rings recovered from 7.854 birds; starlings, 211 from 3,027 birds; mammon terns, 66 from 2,671; song-thrushes, 28 front 2,128; blackbirds, 54 from 1,487; lapwings, 24 from L266; and swallows, 17 from 1,591. The swallows make a parti- cularly interesting record, for one bird ringed in Staffordshire was found in Natal, and another ringed in Ayrshire was reported from the Orange Free State. Among young birds which have been found the next year in the breeding place of the previous year are rooks, jaokdaws, starlings, song-thrushes, meadow pipits, willow warblers, martins, and woodcock. Of adult birds, jackdaws, starlings, robins, chaffinches, swallows, and blackbirds have been found in the same places where they were ringed the year before. A starling has been reported from Holland ; a misael-thrush. wheatear, whinchat, mallard, common, Sandwich, and little terns from France; lapwings and a turtledove from Portugal; and cormorants and lesser blackbaoked gulls from France. Spain, and Portugal.
All this is interesting, but not as yet, of course, conclusive. Many more individual instances are necessary before general inferences of any breadth or value can be drawn. When these ringing schemes have been in operation for a longer period, and when many more details aro available, we may arrive at something worth knowing ; at present theories would be built on insufficient data. However, there is one ringing scheme which stands in this respect a little apart from the others. Last year Mr. Witherby organized a special scheme for ring- ing grouse, and if this scheme is developed further and is applied to a larger number of moors in different parts of the country, we may expect after a few years to obtain a con- siderable amount of fresh knowledge of the habits of that already much-studied bird, particularly as regards migration and the " disease " which in some seasons, as last year, sweeps over whole districts. Is it solely owing to disease that certain moors lose the whole of their stock in years such as 1913? That is the queation. Evidence which is gradually being collected by different observers seems to point to the fact that, in addition to losses from dismiss, large districts are denuded of grouse by migration. Last summer, for instance, when the moors of the Border country were "swept clean" by disease, there were moors in the central Highlands where grouse were so numerous that they could not be killed, and there arc enormous packs of birds on these moors at the present moment. The problem is what will become of therm If they remain where they are, they will die of disease, for disease is brought about by lack of their proper food, heather, and there will not be enough heather to go round. If they go away, will they go south again? The probability is that many of them will ; bat if they do so, and if as a consequence the southern moors are restocked, there will still be no absolute proof that the incoming birds have arrived from Highland moors or from hills nearer the Border. If, on the other hand, these birds, or any considerable proportion of them, had been ringed in the nesting season, evidence as to their native moor would be forthcoming as soon as the shoot- ing opened. The opportunity for experiment is plain. If, during the next nesting season, a sufficiently large number of persona in different districts undertake to ring so many birds apiece on moors under their control, it is practically certain that in a few years' time we shall have definite evidence as to the extent to which grouse shift their ground from season to Reason. If they are proved to move long distances, the whole problem of restocking moors—and also incidentally of letting them—after a year of disease will take on a new aspect.
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