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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