The Nocturnal Flight of Migrating Birds

Ir Has long been a well-known fact of bird life that, during the migrating season, most, if not all, of the movement north or south takes place in the night.'This ensures protection from enemies and opportunity for securing food during periods of rest.Under the cover of darkness, the bird passes safely and secretly through the air.During the day he can search for necessary food and by evening he is again ready to continue his flight.But the very conditions that shield the migrating birds from danger, also preclude any very satisfactory study of their movements.We know, to be sure, that during the fall migrations, most of the large flocks will be found in the early morning on the north side of groves or belts of timber, and in the spring they are to be found on the south side.We know, too, from observations covering a long period of time that birds are seen in the morning which were not in the neighborhood the day before.And most bird lovers know how distinctly the calls of the migrating birds can be heard during the nights of middle September.Still it must be confessed that in proportion to the magnitude of this movement in the bird world and the importance of the interests at stake, economical as well as biological, our actual knowledge of the migration is exceedingly meager.