Biological data available from long-term monitoring studies on Albatross Island (taken from [14]).

Estimated number of breeding pairs, number of chicks fledged at the end of the breeding season, breeding success (number fledged divided by number of pairs), juvenile survival rates to age 1, and annual return rates (proportion of birds that attempt to breed, having made an attempt in the previous season), are shown. Missing data indicates that the information was not collected in that year.a By chick extrapolation (unless otherwise stated)b [14] report 1500 occupied nests on 24 January 1973; Alderman (unpublished data) found an average hatching failure of 66%, giving 2300 breeding pairsc Ground countsd Area densitye Calculated as number fledged over number of breeding pairsf From a multi-state capture mark-recapture model [14]. Given the range in age at apparent recruitment (5 to 12, peak at 9 yrs) survival rates are not estimated for cohorts from 2003 onwards and are likely underestimates in the last few years of the time-series presented. This is accounted for in the population model.g From mark-recapture data (Alderman, unpublished data)Biological data available from long-term monitoring studies on Albatross Island (taken from [14]).