Assessing Breeding Populations of Ducks by Ground Counts
Table 12
Table 12. Mean population estimates of six dabbler species from five census periods in 1958. Kindersley Study Area. Vehicle census: 0800-1130 hours.
| Early Nesters | |||
| Mallard | Pintail | ||
| Census date | Indicated population | Census date | Indicated population |
| 4/24 | 182 | 4/24 | 174 |
| 4/29 | 187 | 4/29 | 172 |
| 5/3 | 198 | 5/3 | 181 |
| 5/10 | 191 | 5/10 | 161 |
| 5/21 | 212 | 5/21 | 150 |
| Mean | 194.0±12.9 | Mean | 167.6±13.5 |
| Stand. Error | 4.7 | Stand. Error | 4.9 |
| Coef. Var. | 5.4% | Coef. Var. | 6.5% |
| Intermediate nesters | |||
| Widgeon | Shoveler | ||
| Census date | Indicated population | Census date | Indicated population |
| 5/10 | 35 | 5/10 | 35 |
| 5/21 | 55 | 5/21 | 40 |
| 5/24 | 56 | 5/24 | 35 |
| 5/31 | 41 | 5/31 | 30 |
| 6/6 | 32 | 6/6 | 30 |
| Mean | 43.8±12.4 | Mean | 34.0±4.6 |
| Stand. Error | 4.5 | Stand. Error | 1.7 |
| Coef. Var. | 22.8% | Coef. Var. | 11.0% |
| Late nesters | |||
| Gadwall | Blue-winged teal | ||
| Census date | Indicated population | Census date | Indicated population |
| 5/21 | 42 | 5/21 | 23 |
| 5/24 | 26 | 5/24 | 35 |
| 5/31 | 24 | 5/31 | 34 |
| 6/6 | 27 | 6/6 | 44 |
| 6/12 | 21 | 6/12 | 22 |
| Mean | 28.0±7.0 | Mean | 31.6±10.2 |
| Stand. Error | 2.5 | Stand. Error | 3.7 |
| Coef. Var. | 20.3% | Coef. Var. | 26.0% |
| *95% confidence interval. | |||
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