Mass on arrival of rockhopper penguins at Marion Island correlated with breeding success

For rockhopper penguins Eudyptes chrysocome at Marion Island, there were significant decreases over time in the numbers breeding and breeding success at three monitored colonies from 1985/1986 to 2006/2007, and in mass on arrival for breeding of both males and females from 1994/1995 to 2007/2008. Breeding success decreased by 0.15 chicks pair(-1) y(-1) over 22 years and was significantly correlated with mass on arrival of males and females. Survival of chicks at the guard stage was low in the late 1990s; hatching success decreased in the early 2000s. It is thought that an increasingly poor parental condition caused birds to abandon breeding at a progressively early stage. Parental condition is influenced by feeding opportunities at overwintering grounds, which have probably been altered by global climate.