The chronology of Gentoo penguins on Bird Island, South Georgia has been monitored since 1988 (no data for 1989-90 or 1990-91). 30 nests are marked in the colony at Square Pond, and 40 in the Johnson Beach colony. Regular checks are made to record when eggs are laid and the peak laying date (when 75% of nests have eggs) is calculated. This work was funded by Natural Environment Research Council (UK) core funding to the British Antarctic Survey.

The breeding success (calculated from nest and chick counts) of Gentoo penguins is monitored annually at Bird Island, South Georgia. The number of incubating nests and chicks reaching fledging stage are counted in several Gentoo penguin colonies. Data exist from 1982 onwards. This work was funded by Natural Environment Research Council (UK) core funding to the British Antarctic Survey.