Factors Associated with Duck Nest Success
in the Prairie Pothole Region of Canada
Breeding Duck Populations
Ground counts of breeding ducks were made annually by CWS and USFWS personnel
in mid-May on each air-ground segment (Martin et al. 1979). Ducks were tallied
by species and social grouping for each wet wetland; ducks in upland were assigned
to the nearest wetland. Social groups for each species were lone males, lone females,
flocked males (2-4 individuals), pairs, and grouped birds (>=5 individuals). Numbers
of lone males, flocked males, and pairs were summed to estimate total indicated
pairs for each species. Because our study areas did not include entire air-ground
segments, we extracted the densities of indicated pairs of the 5 common species
from annual ground counts obtained for portions of air-ground segments that were
included in our study areas. Densities of the 5 common species on the 0.4-km-wide
air-ground segments were extrapolated on the basis of area to arrive at the number
of breeding pairs on each half-area-year. Estimated numbers of pairs in each half-area-year
were summed to obtain total breeding pairs for each area-year (Tables 1-5 of Appendix
A).
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