“The common cormorant…on St Margaret’s Island”

Posted by Tenby Museum on Oct 30, 2017 Blog, Event Archive No Comments

The common cormorant (or shag)
Lays eggs inside a paper bag,
You follow the idea, no doubt?
It’s to keep the lightning out….

But what these unobservant birds
Have never thought of, is that herds
Of wandering bears might come with buns
And steal the bags to hold the crumbs.

so wrote Christopher Isherwood but he hadn’t heard Mick Brown’s fascinating talk on 27th October 2017 about St Margaret’s Island which lies off the Tenby coast.

The island is an SSSI and Mick Brown is an honorary warden. What used to be an industrial area, quarrying limestone, to the extent that it nearly split the island in two, is now a bird reserve and a very special place. In the 1830s-40s there was a resident population of some 20 persons, including 6 children, but their houses and the ‘Flemish’ chimneys now lie abandoned and nature has precedence.  There is an old ‘bothy’ which is thought might have been a chapel dedicated to St Margaret of Antioch.   The island is a ‘constant effort site’ for bird ringing as it is so special for birds and landing on the island is otherwise prohibited.  At very low tides a causeway between Caldey and St Margaret’s is exposed and some are tempted to cross. However, it is extremely dangerous as the tide swirls in with strong currents and people have been drowned in the past.

The vertical rock formations provide ideal nesting sites for a large number of sea birds. Guillemots, Razorbills, Kittiwakes, which can live 20 years and Great Black Backed Gulls, the largest gull in the world which can swallow a puffin whole!  The presence of rats deterred the Puffins, but since the rats were eradicated the Puffins have started to colonise and there are now five pairs.  Sadly there are no Gannets nesting yet, but one male gannet turns up hoping to attract a mate.  There are of course Cormorants and Green Cormorants – more commonly known as Shags, with their tuft of feathers on top of their heads.

But as lightning is rare and there are no bears on St Margaret’s that we know of,  the cormorants build their nests flat on the ground or amid rocks, and are made of sticks and weeds and lined with leafy twigs, grass and feathers.