Assessing Breeding Populations of Ducks by Ground Counts
Table 11
Table 11. Mean population estimates of six dabbler species from five census periods in 1956. Kindersley Study Area. Walking census: 0530 - 1100 hours.
| Early Nesters | |||
| Mallard | Pintail | ||
| Census date | Indicated population | Census date | Indicated population |
| 5/3 | 265 | 5/3 | 278 |
| 5/14 | 274 | 5/14 | 193 |
| 5/15 | 264 | 5/15 | 200 |
| 5/16 | 298 | 5/16 | 202 |
| 5/21 | 289 | 5/21 | 194 |
| Mean | 278.0±16.7* | Mean | 231.4±40.3 |
| Stand. Error | 6.0 | Stand. Error | 14.5 |
| Coef. Var. | 4.8% | Coef. Var. | 15.2% |
| Intermediate nesters | |||
| Widgeon | Shoveler | ||
| Census date | Indicated population | Census date | Indicated population |
| 5/14 | 88 | 5/14 | 35 |
| 5/15 | 75 | 5/15 | 31 |
| 5/16 | 71 | 5/16 | 25 |
| 5/21 | 78 | 5/21 | 33 |
| 5/28 | 95 | 5/28 | 58 |
| Mean | 81.4±10.9 | Mean | 36.4±14.0 |
| Stand. Error | 3.9 | Stand. Error | 5.1 |
| Coef. Var. | 10.8% | Coef. Var. | 31.0% |
| Late nesters | |||
| Gadwall | Blue-winged teal | ||
| Census date | Indicated population | Census date | Indicated population |
| 5/16 | 49 | ||
| 5/21 | 41 | 5/21 | 45 |
| 5/28 | 50 | 5/28 | 51 |
| 6/4 | 46 | 6/4 | 39 |
| 6/11 | 55 | 6/11 | 49 |
| Mean | 48.2±5.7 | Mean | 46.0±10.3 |
| Stand. Error | 2.1 | Stand. Error | 3.2 |
| Coef. Var. | 9.6% | Coef. Var. | 10.0% |
| *95% confidence interval. | |||
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