Shags are goose-sized dark long-necked birds similar to cormorants but smaller and generally slimmer with a characteristic steep forehead. In the breeding season adults develop a dark glossy green plumage and prominent recurved crest on the front of their head.
In the UK they breed on coastal sites, mainly in the north and west, and more than half of their population is found at fewer than 10 sites, making them an Red List species. Shags usually stay within 100-200km of their breeding grounds.
Fish and occasionally crustacea and molluscs.
Shags are birds of the coast. Occasionally, they turn up inland along rivers and lakes, but usually alone (cormorants are often seen in groups inland). The shag's beak is more delicate in comparison to the cormorant's and the forehead angle is steeper. Young birds sometimes show the hint of the adult bird's crest.