Cormorants are expert fishers: they can be seen round the coast of The Lizard and on the Helford.
Photo: Ray Surridge

Scientific name: Phalacrocorax carbo

Other names: Great Cormorant, Scart, White-breasted Cormorant

Conservation status: IUCN Red List: Least Concern; UK Biodiversity Action Plan: Species of Conservation Concern.

Cormorants are familiar round our coastline, often seen in their characteristic ‘spread-winged’ pose, diving in the water of the shoreline and estuaries to catch prey, or swimming with head tilted upwards on their long necks. It is a large bird (up to 90 cm in length and with a wingspan ≤150 cm), glossy green-black in colour with a white-ish throat, yellow patch on the base of the bill and a white patch on its flank in the summer. The wintering population in the UK is of international significance, rising to some 35,000 individuals from about 8,400 resident breeding pairs in summer (source: BTO) as birds migrate to and/or through the UK to overwinter in sometimes large colonies. Though primarily coastal, Cormorants are increasingly seen inland on lakes.

They are superb fishers, diving from the surface to catch fish and eels and using their feet to move underwater. Coastal-nesting birds use seaweed to make their nests on cliff ledges or rocks. Inland birds nest in trees, using twigs. Clutch size is 3 to 4 pale blue eggs, laid between April and June; the young birds fledge about 50 to 60 days after hatching, and reach breeding maturity after 2 to 3 years.

There have been various theories about why cormorants (and others of the genus) stand with their wings spread out and neck stretched upwards. One is that they are drying their wings, but another, now more favoured, is that the pose aids digestion.

It is easy to confuse Cormorants with Shags, especially at a distance.In breeding plumage they are relatively easy to tell apart. The Cormorant has a diagnostic white thigh patch and a white throat. The Shag has a recurved short wispy crest and dark thighs. At other times, they can be told apart by the difference in size and shape. Cormorants are bigger with a larger, more triangular head, a flatter crown and more massive bill. Shags are smaller and slimmer. Juvenile Cormorants are browner and, unlike young Shags, have a variable amount of white on their belly.

Did you know…?

…The genus name, Phalacrocorax, is from the Greek, meaning ‘Bald raven’. The common name Cormorant is possibly derived from the Latin for ‘Sea raven’ (corvus marinus). The Cormorant is, of course, not related to Corvids: it belongs to the bird family Phalacrocoracidae.

…Their faeces are very acidic; trees used for inland nesting usually die after a few years because of this.

More information and references:

Gooders, J. and Harris, A., 1986. Field Guide to the Birds of Britain and Ireland. Kingfisher Books, London.

Published: November 2013
Author: Amanda Scott
Photos: upper, Ray Surridge; below, Amanda Scott