Shags are dark, goose-sized birds with long necks. They look similar to Cormorants but are smaller and slimmer with a distinctive steep forehead. In the breeding season, adults develop a dark glossy green plumage and an obvious crest (head feathers) on the front of their head that curves forward. In the UK, they breed on coastal sites – mainly in the north and west – and more than half of their population is found at less than 10 sites, making them a Red List species. Shags usually stay within 100-200km of their breeding grounds.