Data Sheet 1_An updated census of southern elephant seals Mirounga leonina at South Georgia using satellite imagery.pdf

Yet since 1995, this population has remained largely unassessed and was presumed to be stable. Here, we provide an updated assessment of this sub-Antarctic population and demonstrate the application of sub-meter resolution satellite imagery as a valuable approach for censusing an extensive, remote, and challenging breeding population.

Across two breeding seasons, 2024 and 2025, we tasked satellite imagery with resolutions between 0.3 m and 0.5 m and integrated image-based counts with extrapolative modeling under a generalised additive framework to estimate abundance at unobserved beaches. Using this approach, we estimate 107,630 (95% CI: 93,945 – 123,342) breeding females at South Georgia, compared to the historical benchmark of 113,444 (se = 4,902) in 1995.