Ballaugh Curraghs, a large marshland in the north of the Island, is a Wetland of International Importance under the Ramsar Convention, managed by Manx National Heritage. The Ramsar Site qualifies for international status by having excellent examples of wetland habitats characteristic of the Island and the region: bog pools, marshy grassland, birch woodland, modified bog and willow scrub (known as curragh). It also has on occasions the largest numbers of winter roosting hen harriers in western Europe and has breeding habitat for a highly endangered migratory bird, the corncrake.