Factors Associated with Duck Nest Success
in the Prairie Pothole Region of Canada
Nest Success by Habitat
Nest success estimates by habitat class for all of the 5 common species combined, and averaged over all area-years, ranged from 2% in Cropland to 25% in Woodland (Table 9). Average annual estimates tended to be similar in 1982, 1983, and 1985, but were lower in 1984. We pooled our annual estimates for Grass and Brush from Table 9 and averaged them to obtain an estimate of nest success for grassland (Cowardin et al. 1988). Unweighted average annual estimates of nest success in grassland were 21% (1982), 19% (1983), 9% (1984), and 20% (1985); the average estimate for grassland was 17%. We did not compare nest success by habitat class on individual study areas because we previously excluded habitat interactions in the model used for estimating DSR's (Appendix C). We provide these estimates to demonstrate the range in nest success for various habitat categories.
| Year | n | Nest success (%) | |||||||
| Cropland | Grass | Brush | Wetland | Hayland | Woodland | Right- of-way | Odd areaa | ||
| 1982 | 3 | 2 | 19 | 23 | 18 | 24b | 28b | 10 | 13 |
| 1983 | 8 | 2 | 17 | 21b | 17 | 15b | 26b | 9 | 11 |
| 1984c | 10 | 1 | 8 | 10b | 8 | 10b | 18b | 4 | 6 |
| 1985c | 10 | 2 | 18 | 22b | 19 | 21b | 29b | 10 | 12 |
| Mean | - | 2 | 15 | 19 | 16 | 18 | 25 | 8 | 11 |
| aOdd area included
patches of cover <2ha in size and an array of features usually found in
Cropland (e.g., rock piles, gravel borrow pits, narrow borders
of upland vegetation around Wetland and along fences between areas of
Cropland). bNest success estimate is based on fewer than indicated number of study areas because habitat was not available on all study areas (Table 2). cNest success estimates are based on fewer than 5 species because breeding populations of some species were not detected on some study areas (Tables 1-5 of Appendix A). |
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