Methodology:

The SSB site has a total area of ca. 440 m2 at high tide and is backed by a steep cliff and bounded by rocky outcrops at either end. A purpose-built scaffold walkway allows researchers access to the beach without the risk of attack by territorial male fur seals. Twice-daily visits are made to the beach from early November to early January each year as part of routine monitoring work, which includes marking and counting every new individual observed. Temporary marks with glossy paint are given to distinguish new from old individuals. The number of pups born each day as well as counting and removal for postmortem inspection of all dead pups, taking care to ensure that only those pups that are born on the study beach are included in the count of dead pups.

From 1984 to 1988 only pups and dead pups were recorded. From 1988 to 2001 pup cause of death was also recorded. From 2001 to 2020 females and territorial males were included in the count. Generally territorial males are counted between 1st November and 31st December, although occasional later counts are made. Similarly, females are usually counted between 1st November and the end of pupping, generally around 10th January. Null values in the male and female columns indicate that the animals were not counted on that date.

All sampling procedures used were regulated by the British Antarctic Survey Ethical Review Committee in collaboration with Cambridge University and the UK Home Office.