Food habits and levels of organochlorine compounds, lead, and mercury in resident and wintering bald eagles were studied in southcentral Oregon and California, 1979-83. Food habits were assessed by examination of castings from winter communal roosts, identification of 2938 prey items found at nest sites and foraging areas, and observations...
The major considerations for acquiring and using a
geographic information system (G..I.S.) for regional or national
geographical research and analysis are examined in this paper.
After defining what a G.I.S. is, some of the more practical and
useful functions of a G.I.S. in day-to--day geographical work are
outlined. Finally, the...