Movements of giant petrels Macronectes spp. ringed at South Georgia
More than two hundred recoveries of giant petrels Macronectes halli and M. giganteus originally ringed at Bird Island, South Georgia, were analysed to determine the nature of any interspecific differences in the locality, timing and circumstances of recovery.
Normally about 3% of the nestlings ringed were recovered within three years of fledging but the recovery rate was significantly lower in nestlings ringed in 1978–80. Eighty percent of the recoveries occurred within 12 months of ringing. Proportionately more M. halli are recovered in South America and the Pacific. The numbers recovered in southern Africa have declined whilst birds were recovered more frequently in New Zealand in 1978–80, compared to earlier years.
Most recoveries were of birds found dead or injured on a beach; 9% were involved in fishing incidents and 10% killed by man, mainly in South America.
Only one bird ringed as an adult has been recovered away from South Georgia. Details of foreign‐ringed birds and local movements are also included.
Differences between the two species are discussed in relation to weather and fledging dates.