Effects of multiple experimenters on attachment behavior of mallard ducklings (Anas platyrhynchos platyrhynchos)

The purpose of this study was to determine if multiple experimenters would have any effect on the preferences of mallard ducklings for broods of 3, 6, or 9 ducklings. Three different experimenters ran 2 different subjects each day for 7 consecutive days. The mean age of the subjects was 24 h at the onset of testing. The dependent variable was the amount of time each subject spent with a brood of 3, 6, or 9 ducklings during a 15-min trial. It was found that a brood of 9 ducklings was preferred significantly more often ( p <.05) than a brood of 6 or a brood of 3 ducklings. The results also indicated that with the task described and the ages involved, different experimenters did not contribute significant sources of variation to the results obtained.