The clutch was described as consisting of a single egg; given the bird's large size, this led to proposals that the solitaire was K-selected, which means it produced a low number of altricial offspring, which required extensive parental care until maturity. The gathering of unrelated juveniles suggests that they formed crèches, which may have followed foraging adults as part of the learning process. A study of subfossil remains found that the carpal knob only developed after the bird reached skeletal maturity.