All of the following data were collected between 2006 and 2008 from a wild population of hihi in New Zealand (Tiritiri Matangi island). Sheet 1: "maindata" Data on chick mass, tarsus length, survival to fledging, sex, and hatch rank. Details of clutch size, season, etc. also included. Sheet 2: "incubation" Data on how many nights prior to the laying of their last egg females incubated with additional data on how long their clutch took to hatch (hatch period), whether mothers received carotenoid supplementation, and clutch size. Sheet 3: "LRS data" Data on the number of offspring produced by hatchlings of different hatch ranks across their lives. Their age at death, parental identities, the season in which they were born, and their social partners are also included as covariates.