. Bulletin. Natural history; Natural history. V/n 16 18 20 22 21 MALLARD CONTINENTAL POPULATION IN MILLIONS 26 Fig. 22.—Multiple re- gression analysis of mallard abundance in the upper Il- linois Valley in comparison with mallard continental abundance and the Moist- Soil Water-Level Index in the upper Illinois Valley. 15 m 13 12 11 10 9 8 7 6 5 1 3 REGRESSION COEFFICIENTS a = 0 dj' MOIST-SOIL WATER-LEVEL INDEX MOIST-SOIL WATER-LEVEL INDEX 1,500 MOIST-SOIL WATER-LEVEL INDEX MOIST-SOIL WATER-LEVEL INDEX 500 MOIST-SOIL WATER-LEVEL INDEX 200 MOIST-SOIL WATER-LEVEL I
. Bulletin. Natural history; Natural history. V/n 16 18 20 22 21 MALLARD CONTINENTAL POPULATION IN MILLIONS 26 Fig. 22.—Multiple re- gression analysis of mallard abundance in the upper Il- linois Valley in comparison with mallard continental abundance and the Moist- Soil Water-Level Index in the upper Illinois Valley. 15 m 13 12 11 10 9 8 7 6 5 1 3 REGRESSION COEFFICIENTS a = 0 dj' MOIST-SOIL WATER-LEVEL INDEX MOIST-SOIL WATER-LEVEL INDEX 1,500 MOIST-SOIL WATER-LEVEL INDEX MOIST-SOIL WATER-LEVEL INDEX 500 MOIST-SOIL WATER-LEVEL INDEX 200 MOIST-SOIL WATER-LEVEL INDEX 100 W/r Fig. 23.—Multiple re- gression analysis of mallard abundance in the lower Il- linois Valley in comparison with mallard continental abundance and the Moist- Soil Water-Level Index in the lower Illinois Valley. -T- —I— 2H -\ MALLARD CONTINENTAL POPULATION IN MILLIONS. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Illinois. Natural History Survey Division. Urbana, State of Illinois, Dept. of Registration and Education, Natural History Survey Division
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Keywords: ., booka, bookcentury1900, bookdecade1910, booksubjectnaturalhistory
