Northern Prairie Wildlife Research Center
| Study area | Year | Species excluded | ||||
| Mallard | Gadwall | Blue-winged teal | Northern shoveler | Northern pintail | ||
| Cartwright | 1983 | - | X | - | X | - |
| Craik | 1984 | X | X | X | X | X |
| Inchkeith | 1984 | X | X | X | - | X |
| Ceylon | 1984 | - | X | X | - | - |
| Shamrock | 1985 | - | - | X | - | - |
| Hanley | 1982 | - | X | X | X | X |
| 1983 | - | - | - | - | X | |
| 1984 | - | - | - | X | - | |
| Leask | 1984 | - | X | - | - | X |
| 1985 | - | - | - | - | X | |
| Denzil | 1984 | - | X | - | - | - |
| Holden | 1983 | - | - | - | - | X |
| Hay Lakes | 1984 | - | X | - | - | X |
| Penhold | 1984 | - | X | X | - | X |
| 1985 | - | X | X | - | X | |