Wildlife Monographs
Red Fox Predation on Breeding Ducks
in Midcontinent North America
Tables
Table 12. Estimated contribution (biomass) of dabbling ducks to the prey biomass requirements of typical size fox families in 2 physiographic regions comprising Barnes, Kidder, and Stutsman counties, North Dakota, during fox denning seasons, 1969-73.
| 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 | |||
aFrom Table 11.
bDerived by multiplying the average weight of ducks taken by foxes in the Drift Plain (0.78 kg) or Missouri Coteau (0.67 kg) by the respective number of ducks estimated consumed.
cDerived by dividing biomass of duck consumed by the 163 kg total biomass requirement of typical size fox family (2 adults and 5 pups) during the 13-week fox denning season (Sargeant 1978).
