USGS - science for a changing world

Northern Prairie Wildlife Research Center

  Home About NPWRC Our Science Staff Employment Contacts Common Questions About the Site

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
Rural mail carrier surveyb
Strychnine-baited draw stationsc Estimated spring populationd
1963
-
-
5,880
13,528
1964
-
2.519
7,647
16,669
1965
-
1.990
4,980
13,403
1966
-
0.680
2,731
5,316
1967
-
0.942
-
6,934
1968
-
1.054
-
7,625
1969
28
0.537
-
4,717
1970
38
0.908
-
6,401
1971
55
1.332
-
9,265
1972
69
1.711
-
11,624
1973
80
1.974
-
13,477

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
Return to Contents
Next Section-- Table 5: Estimates of Mallard Spring Breeding Population

Accessibility FOIA Privacy Policies and Notices

Take Pride in America logo USA.gov logo U.S. Department of the Interior | U.S. Geological Survey
URL: http://www.npwrc.usgs.gov/resource/mammals/sexratio/table4.htm
Page Contact Information: Webmaster
Page Last Modified: Saturday, 02-Feb-2013 05:56:47 EST
Sioux Falls, SD [sdww54]