FACTORS AFFECTING PRIMARY MOLT IN THE GRAY-HEADED ALBATROSS

mean number of primaries molted by Gray-headed Albatrosses (Diomedea c hrysostoma) varied with year and previous breeding experience independ ently, but was not related to individual reproductive success over a l onger period. Within each category of breeding experience, birds renew ed fewer primaries during the ''poor'' year of 1994, when subsequent r eproductive success was only 27%, than in 1993 when subsequent reprodu ctive success was 57%. Inspection of individual feathers indicated tha t the outer primaries were least likely to be renewed during the perio d of stress. Within each year, birds that failed in their breeding att empt during the previous year renewed fewer feathers than those which reared a chick two years previously, a difference which was probably p artly related to the time available for molting. In 1994 only, the dat e of failure in the previous year was inversely related to the number of primaries molted by males. The arrival mass of males was positively correlated with the number of primaries molted in two out of four sea sons. Males and females molted similar numbers of primaries.