BANK SWALLOW, or SAND MAR'TIN. This familiar swallow is one of the most nu merous and widespread of all birds. It is known under one or another name throughout nearly the whole world, wherever the cut banks of streams give it an opportunity to make its burrowed nesting-place. The common species of America, Europe. and Asia is rliricola ripuria. From eastern India to southern China it is re placed by another species (Cliricola SinenNi•), which migrates in winter to the Malayan Ar chipelago. Egypt has another species (C/ici• cola Shclicoll ; the brown-eollared bank swallow (C/iricole cinrt a) , abounds throughout tropical Africa, and several other forms are recognized elsewhere, but all are closely alike in appearance and habits.
The bank swallow is easily distinguishable from all other American swallows by its lesser size and the absence of metallic lustre in its plumage, which is sooty brown-blaek above and white on the lower surface of the body, with a dusky band across the breast; the beak is very smali and weak, and the tail short and not deep ly forked. This swallow is migratory in the temperate zone, where it spreads in summer to the borders of the Arctic. Ocean, and retires in winter not only in the tropics. but beyond them to the southern parts of South America and Africa, hut its alleged breeding there is probably erroneous, arising from confusion with local resident species. Everywhere it is of local dis tribution, seeking the borders of water-eourses and lakes where steep banks of sandy earth afford it a chance to dig holes, which it does in companies sometimes hundreds of whose homes are often crowded within a. small space. The nests are placed at the inner ends of deep burrows, each made by a pair of birds. In excavating the feet seem to be the principal instruments, scratching away the soil, and scraping it out backward to the mouth of the hole, until the required calibre and depth are attained. Both sexes work at the task dili
gently, and the hole is sometimes 7 or S feet in depth—a wonderful achievement for a bird so weak and ill-provided with digging tools. The • scene when a twittering colony of swallows are busy at work upon the face of a sandbank is a ' most pleasing one, and the labor is often inter . rupted by sudden excursions of the whole flock, as if for simultaneous rest and recreation— "sailing and circling round . . . making, when the sky is blue and the sun bright, a warm and delicious picture, such as the Greeks must have loved to gaze on." Excellent and picturesque accounts of the bird and its ways abound in the literature of ornithology, but none is more pleas ing and instructive than that by Edmund Selous, in Bird Watching (London, 1901). At the in terior extremity of the burrow an enlargement is made for the accommodation of a slight nest of straw and feathers. where from three to five pure white eggs are laid. The males roost at night, and often rest by day in the entrances to their tunnels; and there the young may be seen peering out sonic days before they dare to try their wings. Small hawks swoop upon the colo nies and seize one from time to time. English sparrows often take possession of the holes. drag ging out the property of the rightful owners and • substituting their own; and snakes and mice occasionally gain entrance: but against most enemies these birds are well protected in their 'deep eaves. A swallow of similar nesting habits, `hut otherwise quite different, is the Hough winged (q.v.). Consult Ingersoll, Wifd Life of Orchard and Field (New York, 1002). See SWALLOW' and Plate of SWALLOWS.