Bird Banding

Ground-inhabiting birds that reside on islands where they have no regular persistent enemies, have little incentive to flight, with the result that wings become shortened and their movement weakened. In many instances, particularly among rails, this has resulted in species in which the power of flight is completely lost, and the wings, though they may beat rapidly as the bird runs, cannot raise it from the ground. In some species now living loss of power of flight is now taking place. The Laysan teal (Anas laysanensis) is now in this process, so that, though an initial flight of about i oo yd. may be made, the birds are then exhausted and may sometimes be caught by hand.

Speed of Flight.

The speed that birds attain in flight, until comparatively recent years, has been a matter of uncertainty, in many cases subject to gross exaggeration. Most of these may be traced to Gatke, who in his otherwise admirable studies of migra tion on the island of Heligoland became seized with the hypothe sis that birds perform most of their migration-flight during the course of a single night. On this theory, he placed the migra tory speed of the northern blue-throat at 18o to 240 m. per hour, the hooded crow at 108 m., and plovers and related species at 24o m. per hour, or 4 m. per minute. He believed that these tremendous speeds were possible through flight at great altitudes, even to 40,000 ft. above the earth, where he supposed that the thin air offered little resistance. These statements, which have been widely quoted, are wholly erroneous. .

Reliable data on the rate of flight have slowly during the past 15 years. The writer has secured some informa tion on the subject by timing birds flying parallel to roads by means of the speedometer of an automobile, and in such diverse forms as herons, hawks, horned larks, ravens and shrikes has found the usual flight to vary from 22 to 28 m. per hour. Another ob server has found the Arkansas kingbird and scissor-tailed fly catcher flying at only 1 o to 17 m. per hour. Gladstone gives similar records for the willow warbler as 231 m. per hour, the pied wagtail as 25, the European blackbird as over 22, the missel thrush as 23, and the cuckoo as 23 m. per hour.

Meinertzhagen has recently given very definite data on the speed of flight in birds from observations made by theodolites designed to estimate the speed of aeroplanes at anti-aircraft sta tions, by stop watches along measured courses, and by observa tions from travelling aeroplanes. From his records it appears that members of the crow family may travel from 31 to 45 m. per

hour, the smaller perching birds, as larks, pipits and buntings from 20 to 37 m. per hour, starlings from 38 to 49 M., geese from to 55 m., ducks 44 to 59 m., falcons 4o to 48 m. and sand grouse 43 to 47. The fastest flying birds known are found in the family of swifts (Micropodidae). One species (apparently the common swift of Eurasia), observed from an aeroplane in Meso potamia, circled easily about a plane when this was flying at 68 m. per hour. From this and other observations it appears that ordinary swifts fly regularly at 7o m., and may accelerate this to Ioo m. per hour for necessity or pleasure.

During their long period of evolution, birds have become adapted to all foods available to their methods of feeding. Geese graze on tender herbage as readily as cattle, rheas and ostriches select a miscellaneous vegetable diet, the plant-cutter (Phytotoma) eats buds, berries and other vegetable matter, the palm-chat of Haiti (Dulus dorninicus) frequently consumes blossoms, the sage hen (Centrocercus urophasianus) delights in the bitter twigs and leaves of sage (Artemisia), ducks are fond of succulent roots, tubers and leaves of aquatic plants, and many other birds have similar propensities for plant-stems or leaves. Fruits are taken by many birds, while the number of birds that depend upon starchy seeds for the major part of their diet is myriad, and includes a great variety of species. The finches with their strong bills crack off the investing hulls of large seeds and consume only the starchy interior. Small hard seeds, as those of lambs-quarter (Chenopodium), are swallowed entire and are ground up by sand and bits of gravel swallowed for the purpose. Grackles (Quis calla) by means of a keeled process on the palate, cut around the shells of acorns until they crack in two and the meat is exposed. Jays hold nuts between the toes and break them open by strong blows of the beak. Some woodpeckers force acorns into crevices in trees, where they are held until they may be broken open. The mallard and wood-duck swallow acorns and even entire nuts of the hickory, which have a shell so thick that it requires a strong blow of a hammer to break them, and grind them up in their gizzards. Seeds form a standard autumn and winter food when other sustenance is lacking, and are produced in tremendous quantity. From the stomach and gullet of one mallard duck there have been taken 102,400 seeds of the water primrose (Jussieua leptocarpa).