Methane emissions from penguin colonies reshape the natural greenhouse gas budget

Natural methane (CH 4 ) emissions remain poorly constrained in polar regions, where biogeochemical driven sources are largely unresolved. Here, we quantified CH 4 emissions from Antarctic chinstrap penguin colonies using spatially resolved chamber measurements combined with UAV-derived mapping of guano patches and colony footprints. Area-weighted fluxes revealed intense emissions from guano-enriched ornithogenic soils and negligible release from surrounding non-guano soils. Upscaling yielded an estimated Antarctic chinstrap penguin emission of 0.49 ± 0.16 Tg CH 4 yr -1 . Although modest relative to dominant anthropogenic sources, these estimates identify penguin colonies as exceptionally intense biogeochemical hotspots. Our findings reveal dense wildlife aggregations as a previously overlooked component of the natural CH 4 cycle in the Antarctic and highlight the need to better constrain biologically driven emissions in future CH 4 budgets.