Depletion of fisheries due to acid rain may pose a future threat to bald eagle and osprey populations in some regions. Loss of essential habitat has affected declines in the caracara and western burrowing owl and the disappearance of the norther aplomado falcon from the southern United States. Most populations of the ferruginous hawk, marsh hawk, and prairie falcon appear stable; habitat loss is the most critical factor in population changes.

A study of canvasback (Aythya valisineria) breeding populations, nest success, productivity, and habitat requirements was conducted from 1961 to 1972 on a 181.3 square kilometer area south of Minnedosa, Manitoba.

Most mourning doves (Zenaida macroura) banded in eastern Missouri in 1968-76 and recovered outside the State moved south-southeast into Kentucky, Tennessee, Mississippi, Alabama, Georgia, Florida, and South Carolina. Most doves banded in central and western Missouri and recovered elsewhere moved south-southwest into Kansas, Oklahoma, Louisiana, Texas, Mexico, and Central America. Several central Missouri doves moved southeast.

A banding program for mourning doves (Zenaida macroura) was conducted by the 14 Central Management Unit (CMU) States and the U.S. FIsh and Wildlife Service during 1967-74. Banding and recovery records, as well as data from annual call-count and harvest surveys, were subsequently analyzed by a subcommittee of the Central Migratory Shore and Upland Game Bird Technical Committee. This paper presents information on mourning dove habitat, hunting regulations, and harvest in the CMU; distribution and derviation of band recoveries in and from CMU; distribution of mourning dove harvest in Mexico and Central America; chronology of migration; survival and recovery rates; effects of hunting on CMU mourning dove populations; and indirect nationwide mourning dove population estimates.

Report on a study of the only known breeding population of the endangered Aleutian Canada goose (Brauta canadensis leucopareia) from 1974 to 1977 at Buldir Island, a western Aleutian island, Alaska.