Mapping knowledge of seabird breeding occupancy across East Antarctica

The dataset contains occupancy observations of breeding distribution for eight seabird species (Adelie penguin Pygoscelis adeliae, Antarctic petrel Thalassoica antarctica, cape petrel Daption capense, southern fulmar Fulmarus glacialoides, southern giant petrel Macronectes giganteus, south polar skua Stercorarius maccormicki, snow petrel Pagodroma nivea, and Wilson’s storm petrel Oceanites oceanicus) across East Antarctica from 1910 to 2020. Each record in the dataset represents a known or inferred search effort for a specific species at a specific geographic site in a specific breeding season, with information on whether a species was directly reported as present, absent, or no direct statement about presence-absence at the site was made (occupancy non-reporting). A published spatial reference system (Southwell et al. 2021) was used to accurately and consistently geo-reference search effort and occupancy observations. The basic spatial unit for this system is a geographic site of ice-free land (a discrete island or continental rock outcrop surrounded by ocean or glacial ice). Occupancy observations were sourced by searching the primary literature, secondary literature, the AADC, drawing from the seabird research community’s knowledge of published and unpublished records, and leveraging the community’s practical experience in the region. Decision criteria were established to infer presence and absence certainty, and identify sites where there was no knowledge of presence or absence. These inferences drawn from the criteria were validated where possible by the researchers who collected the data. The compilation was used to investigate questions of pattern, bias and certainty in seabird breeding distribution. Further details on the methods and analysis are in the published paper.