Recoveries of Australasian shoveler ( Anas rhynchotis ) banded as ducklings in southern New Zealand | Notornis and Birds New Zealand

摘要

Dispersal within New Zealand of Australasian shoveler (Anas rhynchotis), banded as duckhngs in Otago (n=489) and Southland (n=392) during 1971-1979, was determined from the locations at which 180 were shot by hunters. There were no statistically sigruficant differences in recovery distributions of Otago and Southland birds either when recovered in their year of banding (y-o-b) or in all subsequent years combined (later). About 50% of total recoveries were made in the y-o-b and 2-thirds of these from within 200 km of the banding site. Recoveries in later years were more widely distributed than those made in the y-o-b. North Island recoveries were 28% of total recoveries and were from most large coastal and lowland wetlands as far as Northland, 1400 km from the banding site. Recovery distributions of ducklings were not sigruficantly different from those previously determined for moulting adults banded in the same areas. However, ducklings in their 2nd year of life appear to be more distantly dispersed from their natal sites than during their 1st year or are adults from their moulting sites. We speculate that long distance dispersal may be undertaken mostly by birds that fail to breed in their natal regions in their 1st year of life, and that dispersing birds may become irregular breeders at varying distant locations.