CHAPTEE IV. THE MIGRATION OF BIRDS.* To the field student the season of migration is the most interesting of the year. The bird-life of a vast area then passes in review before him. Though living in a temperate region, he may see birds whose summer home is within the Arctic Circle, whose winter haunts are in the tropics. Who can tell what bird he may find in the woods he has been exploring for years? The comparative regularity with which birds come and go gives an added charm to the study of migration. Their journey is not a " helter-skelter " rushing onward, but is like the well-governed march of an army. We feel a sense of satisfaction in knowing when we may ex- pect to greet a given species, and a secret elation if we succeed in detecting it several days in advance of other observers. We study weather charts, and try to foretell or explain those great flights or " waves " of birds which are so closely dependent upon meteorologic conditions.
- Read Allen, Scribner's Magazine, vol. xxii, 1881, pp. 932-938,
Bulletin of Nuttall Ornithological Club (Cambridge, Mass.), vol. v, 1880, pp. 151-154. Scott, ibid., vol. vi, 1880. pp. 97-100, Brewster, Memoirs of Nuttall Ornithological Club, No. 1, pp. 22. Cooke and Merriam, Bird Migration in the Mississippi Valley (Washington, 1888). Chapman, The Auk (New York city), vol. v, 1888, pp. 37-39; vol. xi, 1894, pp. 12-17. Loomis, ibid., vol. ix, 1892, pp. 28-39: vol. xi, 1894, pp. 26-39, 94-117. Stone, Birds of Eastern Pennsylvania and New Jersey, pp. 15-28.
