European Shag

The European shag, or common shag (Gulosus aristotelis), is a medium-large seabird with a distinctive yellow throat-patch. During the breeding season, adults sport a small crest. This species is characterized by its metallic green-tinged sheen and a longish tail, setting it apart from its relatives with a lighter build and a more slender bill.

Identification Tips

To identify the European shag, look for a bird measuring 68 to 78 cm in length with a wingspan of 95 to 110 cm. The adult shag has a green sheen on its feathers and a yellow patch on its throat. The bill is lighter and narrower compared to the great cormorant. Juveniles have darker underparts, and the tail consists of 12 feathers, as opposed to the great cormorant's 14.

Habitat

The European shag is a coastal bird, preferring rocky shores for breeding and nesting. It is rarely found inland, as it is adapted to life at sea.

Distribution

This species breeds along the rocky coasts of western and southern Europe, southwest Asia, and north Africa. It mainly winters within its breeding range, except for the northernmost populations. The largest colony is found in the Cíes Islands, Spain.

Behaviour

The European shag is a remarkable diver, known to reach depths of up to 61 meters. It is predominantly a benthic feeder, sourcing its prey from the sea bottom. Shags are known to travel significant distances from their roosts to feed. They exhibit a strong diving technique, leaping from the water to gain momentum.

Breeding

Breeding takes place on coastal cliffs, with nests constructed from seaweed or twigs, bound together with guano. The breeding season is extensive, starting as early as February and in some cases extending to May or later. Typically, three eggs are laid, and chicks are entirely dependent on parental warmth, as they hatch without down.

Similar Species

The European shag can be confused with the great cormorant but is differentiated by its smaller size, lighter build, thinner bill, and the presence of a crest and metallic sheen in breeding adults.

Diet and Feeding

The European shag's diet is diverse, with a preference for sand eels. However, diet composition can vary with environmental conditions, such as ocean warming and windy weather, which can influence prey availability and foraging success.

Conservation status

The IUCN Red List classifies the European shag as Least Concern, indicating that it is not currently at significant risk of widespread decline.