Sunday, 9 February 2020

The Forth and Clyde Migration Flyway.
2016 J Sutherland

The Forth and Clyde Migration Flyway.

Our speaker this month was Ian Livingstone who came along to discuss how ringing had established the existence of a migration flyway along the Forth and Clyde valleys. Ian is a vet by profession and took up birdwatching at the age of 12. He quickly realised an interest in ringing working his way through the various licences to become a recognised trainer by his late twenties. He joined the Clyde Ringing Group in 1984 and became its secretary ten years later.

He began his talk by outlining the history of ringing in the UK and how ringing has brought about a greater understanding of the movements of some, but not all species. Getting returns from birds that over-winter sub-Sahara is extremely difficult. Ageing birds is very difficult as they do not change over the years the way humans do. After the juvenile stages, because of moulting, they look the same until they die. About 26 000 ringers ring around 950 000 birds in the UK annually.

Ringing is a hobby that cannot be entered into lightly. You need to devote three to five years, out whenever the weather allows, just to get your first C licence, then at least another two years for your A licence. On top of this the metal rings and the mist nets all have to be bought by individual ringers and are quite pricey.

Ringing recoveries are very small for some birds with swallows only 0.02%, siskin 0.5%, small gulls <1% and large gulls 4.2 %. Even for large birds like swans recoveries are only 30%. By introducing plastic colour rings the returns increased many times and to illustrate this Ian gave a detailed account of ringed gulls. Common and black-headed gulls increased to 36% and 29% respectively, lesser black-backed and herring gulls combined to 35% and great black-backed gulls to 11%. The Great black-backed gull result is lower because they spend more time out at sea than the other species. Across Europe there is a large group of watchers who look out for colour ringed birds and report their finds. From this it is found that the smaller gulls are somewhat sedentary although some travel to northern England and Ireland but that lesser black-backed gulls go as far away as north Africa.

Which brings us to the Forth-Clyde flyway. It has been suspected for sometime that birds might use these valleys as a migration route. Recent returns from the colour ringing of sandwich and roseate tern chicks on the east coast have found that they move north, then over to the west side of the country or Ireland during the migration.

This was a fascinating talk by Ian Livingstone showing how a dedicated band of volunteers can make valuable discoveries about the migration of birds. After some interesting questions and answers, the audience gave Ian a hearty vote of thanks for his presentation.