I awoke thinking about birds again. The BBC makes some excellent programmes on the natural world and the 2-episode BBC4 series The Last Seabird Summer? , finished last night, was no exception.
Presenter Adam Nicolson has spent much of his life on the Shiant Islands in the Minch between the Outer Hebrides and the west coast of Scotland, one of the most important bird places of Europe. First, Adam traced our long history of dependence on seabirds – puffins, guillemots and razorbills – thousands of years of collecting eggs and hunting the birds for meat, oil and feathers. More recently the emphasis has moved to conservation.
But now there’s a crisis – in the last fifteen years, 40 per cent of Scotland’s sea birds have gone, graphically illustrated by relatively recent photographs of cliffs full of birds, but now empty. The Shiants are currently an exception, and the birds appear to have plenty of food. The excellent RSPB is helping for the future by exterminating rats from the islands (they arrived from shipwrecks) – rats eat eggs and young birds.
Adam travels to Iceland, home to over half the world’s puffins, to try and gain insight into what is going on. This is a story of two halves – to the north of Iceland, sea birds still prosper, puffins are still hunted and eaten – to the south, in the Westman islands, formerly prolific seabird colonies appear to be in terminal decline with no young birds. Crazily, some are still hunted and eaten for a few days a year, in the name of tradition.
After talking to ornithologists and marine scientists, Adam suggests that the root of the problem lies in the lack of suitable food for the birds. Kittiwakes are particularly vulnerable because they are essentially surface feeders. Puffins rely on sand eels, and where these are not present populations cannot survive.
Cyclic changes in the gulf stream and related water circulations in the atlantic appears to cause warmer then cooler water to appear around southern Iceland. With the warmer waters come huge populations of mackerel – good for fishermen, but these fish out-compete the birds for their food, so bird populations decline and then recover on a timescale of decades. This has happened since records began. However, global warming is increasing the baseline sea temperature. The result appears to be more severe decline in bird populations. The worry is that they may be driven beyond the point of no return. The Icelandic hunters are not helping.
It seems that, as global warming progresses, we must live with the spectre raised by these programmes of The Last Seabird Summer, in southern Iceland and a lot of Scotland at least – and notably for the iconic puffin.
But, as ever, there will be winners as well as losers. As Adam points out, some seabird populations, such as the gannet, which is very flexible in its food needs, are thriving – for example the huge colony on Bass Rock in the Firth of Forth – and may well continue to do so.
Do watch these programmes, available for another three weeks if you have access to BBC catchup. But you’ll have to not be squeamish about watching puffins caught, cooked and eaten.