The Lesser Black-backed Gull breeds in colonies on bare islets and skerries in the archipelago. The nest is a simple scrape with some nest material of grass and seaweed, and the clutch usually comprises 2–3 eggs. Both parents incubate and feed the young, and the birds jointly defend the colony against intruders. The young keep close to the nest at first and are fed by both parents, and only after several weeks do they fledge and are able to follow the adults out to sea.