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.