An integrated hidden state model for New Zealand sea lions (Phocarctos hookeri) was developed using pup count census data and mark-recapture and mark-recovery data. It includes an index of pup mass as a predictor of pup survivorship. This reduces the uncertainty associated with estimation of pup survivorship for years when the tagging data are uninformative. Including pup mass as a covariate should improve the predictive performance and allow better understanding of threats to the population.
