Historical remote sensing highlights long‐term persistence of Emperor Penguin ( Aptenodytes forsteri ) colonies

Abstract Satellite imagery extending as far back as the 1960's has the potential to inform Antarctic conservation by providing insights into habitat and population dynamics that are otherwise difficult to observe. Here we demonstrate the detection of Emperor Penguin ( Aptenodytes forsteri ) guano stains on sea ice using Keyhole, Landsat, and Sentinel‐2 imagery from the 1960s to 2024. For 18 of the 66 known emperor penguin colonies, we confirmed colony presence in images that predate their earliest published records. Beyond presence detection, we examined the colony with the densest available imagery (Cape Washington) to quantify change in guano area over time. The guano area detected with satellites was correlated with observed chick counts from ground surveys (Spearman's ρ = 0.59, P ‐value = 0.017), and showed no strong evidence for a long‐term trend ( P = 0.61). Taken together, our results indicate substantial interannual and intra‐annual variability in colony size, but no evidence for a consistent long‐term directional trend and highlight that the use of remote sensing imagery across the Antarctic could inform conservation efforts and benefit the ongoing historical studies of penguin colony dynamics.