We investigated the annual survival of Finsch’s oystercatchers (Haematopus finschi) breeding on farmland in mid-Canterbury, New Zealand. Annual survival from 1987 to 2000 averaged 0.892, with evidence of a small amount of variation in survival rates through time (estimated SD = 0.034). We found no indication that survival rates differed between males and females. However, recapture probabilities showed that males had stronger fidelity to breeding territories than did females. These results are similar to those reported from populations of H. ostralegus in Europe. Because oystercatchers are long-lived, the survival rate of adults is the key component in determining population size. Intensification of agriculture on the breeding grounds and disruption to coastal feeding grounds may reverse the trend for population increase in this species. Consequently, the survival rate presented here provides a basis for predicting future population trends.
Unusual bird records at the sub-antarctic Antipodes Islands from 1978 to 1995 increased the number of bird species recorded previously at the group by 15. The total avifauna now consists of 29 breeding species and 26 vagrant species.
Dispersal of adult Australasian shovelers Anas rhynchotis in New Zealand after being banded during their annual moult was determined from the locations at which they were shot by hunters. Birds banded at 2 southern South Island and 2 North Island sites between 1972 and 1986 dispersed the length and breadth of New Zealand. Some shoveler were recovered within 90 days of banding at opposite ends of the country from their banding sites. There was no obvious pattern to the recoveries. Birds were recovered from most of New Zealand’s large lowland and coastal wetlands except from West Coast, South Island. Modal recovery distances for shoveler banded at Lake Whangape, northern North Island, and recovered in their year of banding or in later years were 201-400 km. For shoveler banded in southern South Island, modal recovery distances were 0-100 km in the year-of-banding and 101-200 km in later years. Birds banded while moulting or breeding at or near the southern-most banding site were later recaptured moulting at the northern-most. Shoveler disperse more widely than other New Zealand waterfowl species and can be viewed as comprising a single national population.