 Other common species include double-crested cormorant, great black-backed gull, herring gull, little penguin, black guillemot, Leach's storm petrel, black guillemot and black-legged kittiwake.Species such as great black-backed gulls and herring gulls are in decline.An increase in recreational boating has disrupted the bird fauna in the archipelago, including causing the common eider to temporarily abandon their nestlings, which are then vulnerable to gulls.