Platte River Ecology Study
Tables
Table 10. Hectares of harvested corn stubble necessary to support the sandhill crane population under various conditions.
Staging Hypothetical Food Area of Area of cornfields
area crane requirement cornfields (103 ha)available
population (103 kg corn) (103 ha) assuming fall
(thousand) required tillage is*
assuming corn
removed is
______________ _____________________
100% 75% 50% 75% 50% 25% 0%
1 207 609 3.0 4.0 5.9 8.8 14.9 21.0 27.1
276 813 4.0 5.3 7.9
345 1016 5.0 6.6 9.9
414 1219 5.9 7.9 11.9
2 39 112 0.5 0.7 1.1 3.0 5.0 7.0 9.1
52 150 0.7 1.0 1.5
65 187 0.9 1.2 1.8
78 224 1.1 1.5 2.2
3 54 155 0.8 1.0 1.5 1.6 2.7 3.8 4.9
72 206 1.0 1.3 2.0
90 258 1.3 1.7 2.5
108 310 1.5 2.0 3.0
Combined 300 876 4.3 5.7 8.5 13.4 22.6 31.8 41.1
400 1169 5.7 7.6 11.4
500 1461 7.1 9.5 14.3
600 1753 8.6 11.4 17.1
*Assumes that tillage reduces corn availability by approximately 90%
(Frederick 1979:50-52).
