A child Herring Gull disrupted practice companies in Brighton yesterday, with energy having to be turned off to get it to security.
Responders attended the station yesterday with Platforms 4, 5 and 6 being closed while the fowl was rescued.
Thameslink and Gatwick Express companies terminated early earlier than arriving into Brighton, returning north from Preston Park, Haywards Heath and Three Bridges.
The fowl was safely rescued from the railway, and Southern posted on X thanking passengers for his or her persistence.
The Royal Society for the Protection of Birds says that the Herring Gull is on the Red List for Birds of Conservation Concern