The Orientation of Displaced Waterfowl in Migration

1. Experiments were made with Blue-winged Teal, Mallards, and Wood Ducks to ascertain their ability to orient themselves when displaced artificially in some manner. Juvenal Blue-winged Teal were delayed in autumn migration until the species had left Illinois, and, in some cases, the United States. Mallards were transplanted in November from central Illinois to central Utah, 1,150 miles to the west. Wood Ducks hand-reared to flight stage in Illinois were released in Illinois, Wisconsin, and Indiana. 2. Blue-winged Teal were trapped in Mason County, Illinois, during September, 1952 to 1955, the adults banded and immediately released, while the juveniles were placed in pens. The juveniles were banded and released on November 11, 1952; November 30, 1953; November 10 and 23, and December 1, 1954; and November 22 and December 8, 1955. 3. A comparison of recoveries from Blue-winged Teal banded during their normal fall passage through Illinois with recoveries from the detained juveniles, revealed similar directions of migration for both groups. Some of the detained juveniles migrated to the southern part of the United States within a few days after release, but others remained near the release site for two or more weeks. There is ample evidence that detained birds did not follow other ducks to reach their destination, nor were air movements responsible for their southward flight. 4. Data on flock sizes and age ratios of Blue-winged Teal at Delta, Manitoba, suggest that many flocks depart in southward migration without adults to guide them. 5. Direct recoveries of bands from 470 adult drake Mallards and 425 juvenal drakes, trapped in Illinois and released, respectively, at the Ogden Bay Refuge and the Bear River Bird Refuge in Utah in November, showed no movement toward the Mississippi Flyway. Practically all direct recoveries were in the Great Salt Lake Basin. 6. Indirect recoveries after the breeding season revealed that about two-thirds of the adult Mallards returned to the Mississippi Flyway, whereas two-thirds of the juveniles remained in the Pacific Flyway. 7. Some Wood Ducks hand-reared at Havana, Illinois, were released locally and others were transplanted to Madison, Wisconsin, Medaryville, Indiana, and Wheaton, Illinois. All groups remained in the release area through late summer and into early autumn. Some of them were tardy in migrating southward, and a few remained over winter. 8. Young Wood Duck hens exhibited a strong homing response to the area they