Saturday 16th January comments: Today we introduce the fourth species of our seabird series which is taking a closer look at the seabirds of the Isle of May. We have featured the cliff nesters of Guillemot, Razorbills and Fulmars. Today we introduce the European Shag.
Description
Shags are a medium sized bird approximately 68-78cm in height (27-31 inches) long and with a 95-110cm (37-43 inch) wingspan. Generally, the species is a dark metallic green/black with a yellow throat patch and during the breeding season displays a very elegant crest on its head (and hence how the species got it’s name). The species is smaller than its close relative the Cormorant which we’ll feature next on the blog. The species can be found all around the British Isles, the Faroe islands, Iceland, along the Norwegian coast and into Siberia, around the Iberian peninsula, north Africa, the Mediterranean and the Black Sea. They are generally long living (over 20 years) and are some of the deepest divers amongst the Cormorant family as they are benthic feeders (find their prey on the seabed) and have been recorded as diving as deep as 60-70 metre depths in search of prey. Unlike Cormorants, Shags are exclusively coastal birds with very few venturing into fresh waters
Breeding Biology
Shags will start breeding from 3-4 years of age and are the first seabirds to start nesting in a season. If the spring is mild, birds can be established on territories on the cliffledges by late February and nest building can commence soon after. Nests are usually constructed on rocky ledges or small caves and they build untidy nests of seaweed, twigs and anything else they can drag into their nest structure (including dead birds!) The first eggs are usually laid by late March and clutches vary from 1-6 eggs but usually average 3-4 and the incubation period is 30-31 days.
The first chicks will hatch by late April without and down (completely naked) and rely on tehit parents for warmth. Both parents with feed and care for their young, bringing in a variety of fish species depending on the season and locality but sandeels are highly prevalent in their diet. Chicks are fed by partial regurgitation with the young putting their bill inside the parents mouth. From hatching it can take 50-53 days to fledge and family parties will stick together for a few weeks after this period. By late July large numbers of young can crèche together around the island. The species can move some distances (more on that in the forthcoming days) but a good percentage of birds remain on the island all year, over-wintering on the island. Tomorrow we’ll bring you news of how Shags are doing on the Isle of May and the national picture as we continue our series on seabirds.
Isle of May National Nature Reserve 