SWANS 
48 - 
20 -\ -1-,-[-1-1-1-1 i 
1940-52 55-57 56-62 65-67 68-72 75-77 78-82 85-86 
Figure 1. Long-term trends in populations (xlOOO) 
of tundra swans in the Chesapeake Bay during eight 
periods from 1948 through 1986. 
Figure 3. Long-term trends in populations (xlOOO) 
of black ducks and mallards in the Chesapeake Bay 
during eight periods from 1948 through 1986. 
Figure 2. Long-term trends in populations (xlOOO) 
of Canada geese in the Chesapeake Bay during eight 
periods from 1948 through 1986. 
Figure 4. Long-term trends in populations (xlOOO) 
of wigeon and pintail in the Chesapeake Bay during 
eight periods from 1948 through 1986. 
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