Impact of Red Fox Predation on the Sex Ratio of Prairie Mallards
Table 4: Various Indices of Red Fox Densities and Estimated Spring Population of Red Fox Families
Table 4. Various indices of red fox densities in the reference area and estimated spring population of red fox families, 1963-73.
Year | Township censusa | Strychnine-baited draw stationsc | Estimated spring populationd | |
1963 | ||||
1964 | ||||
1965 | ||||
1966 | ||||
1967 | ||||
1968 | ||||
1969 | ||||
1970 | ||||
1971 | ||||
1972 | ||||
1973 |
a Number of fox families in six townships
b Weighted average, of six strata encompassing the Prairie Pothole
Region, of sightings of adult foxes seen per 1,609 km traveled during a 3-day
period in April.
c Total foxes recovered at strychnine-baited stations reported
by the U.S. Fish and Wildlife Service, Division of Wildlife Services, Bismarck.
d Number of fox families in our reference area.
Previous Section-- Table 3: Definitions of Rates Associated with the Equations in Table 2
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