BIRD BANDING Until the beginning of the present century the study of migra tion was carried on by mass-observation, under which records were kept of the first appearance for each species and of its subse quent fluctuations in abundance, the value of the records depend ing to a certain degree upon the skill and experience of the ob server. Much valuable data has thus been assembled, and this method of study is still highly useful. In recent years there have been developed methods in marking individual birds with num bered bands that have added greatly to knowledge of migration, since by this means it is possible to single out the individual bird from the great army of his fellows, and to learn something of the separate flights that make up this mass movement.
Sporadic attempts to mark wild birds so that they might be identified began more than 125 years ago, and have ranged from little bells, bits of coloured yarn, marks made with indelible inks or paints on some of the feathers, plain rings of wire or other material, or strips of metal on which were marked scriptural quotations, to the modern scheme of bands of aluminium marked with a serial number and the name and address of the person or organization responsible for them.
The earliest definite record for a banded bird, according to F. C. Lincoln, is that of a heron (Ardea cinerea), captured in Germany in 1710, with metal rings on the leg, one of which had been placed on the bird in Turkey several years before. Sporadic efforts to mark birds have been made at irregular intervals, but nothing of real importance was attempted until 1899, when C. C. Mortensen, of Viborg, Denmark, began systematically to band storks, ducks, starlings and birds of prey. The results obtained were so valuable that soon others took up this study, with the result that at the beginning of the World War approximately 20 distinct banding projects had been initiated in Europe.
In America the first birds ringed seemed to have been some common phoebes (Sayornis phoebe), marked by Audubon, when in the nest, with silver wires around the leg, some of them return ing the following year to breed in the locality where they had been born. After several persons in America had arranged schemes for the marking of birds the American Bird Banding Association was organized, in 1909, through the efforts of Dr. L. J. Cole, and con tinued until 1920, when its activities were taken over as part of the work of the Bureau of Biological Survey, U.S. Department of Agriculture. Under Government auspices the work has been expanded through a co-operative scheme until now more than 1,500 persons are engaged in banding birds in the United States and Canada, and to 1928 approximately 350,000 birds had been banded. Early work was concerned with the marking of young
birds before they were able to fly, or the casual capture of adult individuals. In recent years this has changed to the banding, prin cipally, of adults captured by a variety of ingenious traps, and then marked and released. Banding in the United States has pro gressed to a point where there have been organized four regional societies concerned with it. Though hundreds of birds that have been marked are not subsequently detected, enough are recovered to render the work profitable to a high degree. Among ordinary birds from one to four in every hundred banded are later retaken, while among ducks, which are hunted as game, the recovery runs from 12 to 20 in each hundred, a remarkable number. Through the trapping method it often happens that banded birds are re taken and released uninjured, sometimes on several occasions.
Through banding, it has been found that some birds have winter homes as definitely defined as those inhabited in summer. As a case in point, there may be mentioned the white-throated sparrow (Zonotrichia albicollis), which nests in the northern sec tion of eastern North America, from Massachusetts and Wyoming north to Labrador and Great Bear lake, and winters in the central and southern States. A bird of this species banded by S. P. Baldwin, near Thomasville, Georgia, on March 5, 1916, was re taken within a few yards of the original spot on March 7 and 19, 1917, on several occasions between February 25 and March 22, 192o, and on March 27, 1921, indicating a remarkable regularity in return to one spot. Wild ducks banded by the writer at the northern end of Great Salt lake, in Utah, were killed subsequently in California, Mexico, Texas, Oklahoma, Missouri, Nebraska and Saskatchewan, revealing a tremendous spread in flight, and, with other similar data, giving information of great importance in game conservation. A black-headed gull (Lana ridibundus), banded at Rossitten, Germany, was taken subsequently at Bridge town, Barbados, and another from the same point crossed to Vera Cruz, Mexico. A common tern, marked at Eastern Egg Rock, on the coast of Maine, was found dead four years later at the mouth of the Niger. A lapwing (V anellus vanellus) banded in Cumber land, England, was taken in Newfoundland. Such examples of trans-oceanic migration will increase as the work progresses.