The Treshnish Isles are located in the Inner Hebrides of western Scotland. They are a series of small islands and skerries off the west coast of Mull in Argyll. They are rocky, with cliffs, screes and raised beaches, and support strongly maritime grassland and heath. The islands are important for their breeding seabird colonies, especially Storm Petrel Hydrobates pelagicus. The most important seabird colonies are on Lunga, which supports the majority of Storm Petrels. The Treshnish Isles are also of importance as a traditional wintering locality for Greenland Barnacle Goose Branta leucopsis.