Rensselaer Union, Volume 7, Number 21, Rensselaer, Jasper County, 11 February 1875 — Migration of Birds. [ARTICLE]

Migration of Birds.

A recent correspondent of the London Times presents the novel hypothesis that the migratory flight of birds is an entirely involuntary act. The argument is that, at or about a certain period of the year, when a strong southern wind prevails in an upper stratum of the air, a subtle atmospheric change, resulting from it, acts upon the muscles of birds in such a way as to make them fly. Their wings beat as naturally as their hearts, and they cannot help going. Rising up into the swift current of air, they are borne along it as long as the spasm lasts, which generally is long enough to carry most of them to warmer climates, although multitudes recover a little too soon and perish in the sea. Some experiments made upon migratory birds in captivity lend plausibility to the theory. Kept in cages covered with silk to protect them from injury, these birds have been observed, at the season of migration, to be affected with a paroxysm of flight, which continued through a period answering in length to the time occupied by birds in their semi-annual journeys. When the paroxysm was over the birds fell to the ground, began preening their plumage, and conducting themselves as if they had just reached a new home after an extended journey. The experiments were made in both England and Africa with similar results. Contemporaneous with the publication of this theory, Runeberg, the Swedish poet, announces the fanciful conceit that the birds are impelled to migrate by a longing for light. It has been supposed by ornithologists that birds leave their summer haunts at the approach.of winter because their food is exhausted or disappears under the snow, and they are compelled, not only by cold, but by hunger, to go south, where they can enjoy comfortable warmth and sustenance; but Runeberg declares that “The bird of passage is of noble birth; he bears a motto, and his motto is, * Lux mea dux '"