Common Shag

Description:

The European Shag or Common Shag (Phalacrocorax aristotelis) is a species of cormorant. It breeds around the rocky coasts of western and southern Europe, southwest Asia and north Africa, mainly wintering in its breeding range except for northernmost birds. In Britain this seabird is usually referred to as simply the Shag. This is a medium-large black bird, 68–78 cm long and with a 95–110 cm wingspan. It has a longish tail and yellow throat-patch. Adults have a small crest in the breeding season. It is distinguished from the Great Cormorant by its smaller size, lighter build, thinner bill, and, in breeding adults, by the crest and metallic green-tinged sheen on the feathers. Among those differences are that a shag has a lighter, narrower beak; and the juvenile shag has darker underparts. The European Shag's tail has 12 feathers, the Great Cormorant's 14 feathers. The green sheen on the feathers results in the alternative name "Green Cormorant" sometimes being given to the European Shag. The European Shag is one of the deepest divers among the cormorant family. Using depth gauges, European Shags have been shown to dive to at least 45 metres. In UK coastal waters, dive times are typically around 20–45 seconds, with a recovery time of around 15 seconds between dives; this is consistent with aerobic diving, i.e. the bird depends on the oxygen in its lungs and dissolved in its bloodstream during the dive. When they dive, they jump out of the water first to give extra impetus to the dive.

Habitat:

It feeds in the sea, and, unlike the Great Cormorant, is rare inland. It will winter along any coast that is well-supplied with fish.

Notes:

I think this is called a Shag in Ireland. How is it different to a Cormorant?