This dataset comprises the annual count of chinstrap penguins arriving to Signy Island each breeding season, from 1996 to 2020. Penguins arriving at the beach in mid to late November (the austral summer) were counted. This monitoring contributes to the CCAMLR (Commission for the Conservation of Antarctic Marine Living Resources) Ecosystem Monitoring Program (CEMP) and is part of the annual seabird Long Term Monitoring carried out by the British Antarctic Survey at Signy Island. Ecosystems component of BAS Polar Science for Planet Earth Programme, funded by NERC.

In 2016, 100 northern Rockhopper penguin nests were marked in the main colony on Nightingale Island (37.254 deg S, 12.2832 deg W) and an additional 50 nests in a small satellite colony (37.252 deg S, 12.2833 deg W). Nests were followed from egg-laying to the creching stage to monitor breeding success and to investigate the impact of colony size as one of the possible drivers of breeding success. Data were collected as part of the Darwin Plus funded Project Pinnamin, 2016 - 2018.