The Federal Government has recognized its responsibility to migratory birds under these changing conditions. Enabling acts allow for carrying out migratory bird treaty obligations in cooperation with other countries, and now most species have legal protection under regulations administered by the U.S. Fish and Wildlife Service. The effectiveness of conservation laws, however, is increased in the same measure that the people of the country become acquainted with the migratory bird resource and interest themselves personally in the well-being of the various species. Long before European man came to America, the birds had established their seasonal patterns of migration throughout the Western Hemisphere. The economic, scientific, and esthetic values of these migratory species dictate they be permitted to continue their long-accustomed and to some extent still-mysterious habits of migration. =BIBLIOGRAPHY= Able, K. P. 1970. A radar study of the altitude of nocturnal passerine migration. Bird-Banding 41(4): 282-290. Aldrich, J. W. 1949. Migration of some North American waterfowl. U.S. Fish and Wildl. Serv., Spec. Sci. Rep. Wildl. 1. 49 p. Aldrich, J. W. 1952. The source of migrant mourning doves in southern Florida. J. Wildl. Manage. 16:447-456. Aldrich, J. W., A. J. Duvall and A. D. Geis. 1958. Racial determination of origin of mourning doves in hunters' bags. J. Wildl. Manage. 22: 71-75. Alexander, J. R., and W. T. Keeton. 1972. The effect of directional training on initial orientation in pigeons. Auk 89: 280-298. Allard, H. A. 1928. Bird migration from the point of light and length of day changes. Am. Nat. 62: 385-408. American Ornithologists' Union. 1957. The Check-list of North American birds. 5th edition. American Ornithologists' Union. 691 p. Anderson, K. S., E. J. Randall, A. J. Main and R. J. Tonn. 1967. Recoveries of birds banded by encephalitis field stations, 1957-1965. Bird-Banding 38(2): 135-138. Annan, O. 1962. Sequence of migration by sex, age, and species of thrushes of the genus _Hylochichla_ through Chicago. Bird-Banding 33(3): 130-137. Anonymous. 1972. Population ecology of migratory birds. A symposium. Wildl. Res. Rep. 2. U.S. Fish and Wildl. Serv. 278 p. Austin, O. L., Jr. 1928. Migration routes of the Arctic Tern (_Sterna paradisaea_ Brunnich). Northeast Bird Banding Assoc. 4(4): 121-125. 1929. Some Labrador banding records. Northeast Bird Banding Assoc. 5(1): 35-36. Bagg, A. M. 1967. Factors affecting the occurrence of the Eurasian Lapwing in eastern North America. Living Bird 6: 87-121. Bagg, A. M., W. W. H. Gunn, D. S. Miller, J. T. Nichols, W. Smith and F. P. Wolfarth. 1950. Barometric pressure patterns and spring bird migration. Wilson Bull. 62: 5-19. Baird, J., C. S. Robbins, A. M. Bagg and J. V. Dennis.