Table 28. Nest success in three major habitats for all duck species and years, Woodworth Study Area, 1966-81a. |
Number of nests | |||||
Habitat | Found | Destroyed | Hatched | Percent apparent success | Percent Mayfield success |
Seeded grasslands | 1,366 | 849 | 501 | 36.7 | 17.7 |
Native prairie | 2,081 | 1,371 | 710 | 34.1 | 15.7 |
Croplandsb | 60 | 40 | 20 | 33.3 | 12.5 |
Total | 3,507 | 2,260 | 1,231 | 35.2 | 16.3 |
aNest success varied among
years (X213 = 134.3, P >
0.001) but not between seeded grasslands and native prairie (X21
= 0.02, P > 0.09 ). Interaction between years and habitats
was not significant (X213 = 11.01,
P > 0.25). bCategories not included in tests for year and habitat effects because of small or incomplete samples; also, nest data were not available for native prairie in 1979 or 1980. |