A vast new population of common scoters has been discovered off the North Wales coast – and may affect future planning decisions on the siting of offshore wind farms.
As many as 79,000 birds have been counted at peak periods on Shell Flat, a shallow sandbank in Liverpool Bay that was previously unknown for scoters.
The discovery instantly doubled estimates for the total British wintering population, making the site the most important for scoters in the UK.
The “new” population was confirmed during the All Wales Common Scoter Survey which was organised partly in response to planning applications for marine wind farms.
Aerial surveys, over two winters, are transforming knowledge of the birds’ movements, such as the fact they avoid major estuaries.
The Countryside Council for Wales believes that the new estimates are proof of better counting methods rather than a real increase in bird numbers.
But CCW senior ornithologist Dr Siân Whitehead said: “The surveys have informed our assessment of wind farm proposals off the North Wales coast, helping us to minimise the effect of installations upon birds.
“They have greatly improved our understanding of the importance of Welsh waters for this priority bird species.”
Common scoters were located in areas where the water is less than 10 metres deep.
In both Liverpool Bay and Cardigan Bay, the birds were found as far as 20km from land – they were previously thought to cling to coastlines.
The importance of Carmarthen Bay to scoters was first recognised in surveys following the Sea Empress oil disaster.
Other populations have been found off the North Wales coast near Colwyn Bay and Rhyl; around Tremadog Bay; on Sarn Badrig, the reef near Llanbedr, Harlech; and off the shore at Borth.
The Common Scoter (Melanitta nigra) is a large sea duck, 43-45cm long.
It forms large flocks on suitable coastal waters. These are tightly packed, and the birds tend to take off and dive together.
The birds build a lined nest on the ground close to the sea, lakes or rivers, in woodland or tundra and commonly lay between six and eight eggs.
The Common Scoter is characterised by its bulky shape and large bill. The male is all black with a bulbous bill which shows some yellow colouration around the nostrils. The female is brown with pale cheeks, very similar to the female Black Scoter.
The UK breeding population of this small diving seaduck has substantially declined and it is now on the RSPB conservation red list.
They can be seen offshore all year round but large numbers arrive from October, leaving in March.
By Andrew Forgrave
17 January 2008
|Wind Watch relies entirely
on User Funding