Northern Prairie Wildlife Research Center
| Area and Year | Ducks consumeda (N) | Duck biomass consumedb (kg) | Duck in dietc (%) | |
| Drift plain | ||||
| 1969 | 65.9 | 51.4 | 31.5 | |
| 1970 | 37.0 | 28.9 | 17.7 | |
| 1971 | 16.1 | 12.6 | 7.7 | |
| 1972 | 28.5 | 22.2 | 13.6 | |
| 1973 | 17.5 | 13.7 | 8.4 | |
| Avg. | 15.8 | |||
| Missouri Coteau | ||||
| 1969 | 57.8 | 38.7 | 23.7 | |
| 1970 | 44.8 | 30.0 | 18.4 | |
| 1971 | 35.69 | 23.9 | 14.7 | |
| 1972 | 43.0 | 28.8 | 17.7 | |
| 1973 | 25.3 | 17.0 | 10.4 | |
| Avg. | 17.0 | |||