While autumn migration brings some stunning birds to Shetland, including the Magnolia warbler found on Fair Isle yesterday along with a Lancolated warbler and various American jobs on Shetland mainland, the pride of place being a Red eyed Vireo on Unst, Shetland offers much more as well, including the seabirds which I am particularly intersted in.
Many of you will know that Seabirds have been having a very poor time for a number of years. Not just in Shetland but all over the north. The lack of food, particularly Sandeels is to blame. This months Shetland bird study newsletter indicates that the early part of the 2012 breeding season was poor, but due to increased food opportunities in the form of sillocks (young saithe) made it a better second half of the breeding season.
Seabirds are long lived so hopefully they may recover, some are able to delay the laying until suitable conditions occur, others have more than one brood.
When we first visited Shetland in 1987, seabirds were already on the decline, although it seemed to us when we viewed the colonies at Sumburgh head, Noss and Hermaness that they were doing well, with thousands of birds present. Its only when you start regular counts that you notice the declines and I have every admiration for those involved in collecting data.
Sumburgh Head back in the late 1980's
Over the next few blog I will be looking at different seabirds and for now the Shag comes under the spotlight.
The Shag looks dark at a distance but in fact it has a nice green sheen. It breeds along the cliff face and in caves. They have an extended breeding season which helps the species. Laying starts as early as April but often the rough seas wash out the nests as they tend to be low down the cliff face.
It was estimated that about 10,500 pair were present in the 1969-70 count reduced to 6,000 pairs in the 1995-2001 survey, despite improved counting techniques. At Sumburgh head 288 pairs we present in the 1998-2001 survey and in 2010 -290 pairs so little change.
Egg laying can take place up to September in Shetland, but with of species of bird looking for food eggs get predated by Raven and Hoddie crows, and if young hatch then Gt Skua and Gt Black Back gulls swoop down to take the young from the nests.
Shags can be seen throughout the year in Shetland, often moving to sheltered bays in winter.