March 31st   Leave a comment

I have been away from Crail for the last week which makes it hard to comment on its wildlife. Spring has been advancing inexorably while I have been away and I was greeted by chiff-chaff song this morning in St Andrews and really quite balmy temperatures. The wind is streaming up from the south at the moment so we may even expect an early barn swallow and certainly a sand martin next week to join the ospreys of this week (one over Kirkcaldy yesterday).

Gannet

Even while away in England I was frequently reminded of Crail and the area because I was at the British Ornithologists Union (perhaps better labelled as Global Bird Researchers) annual conference. This was themed this year on how tracking birds leads to understanding ecological and conservation problems: a lot of the talks concerned seabirds and so to the Crail link, some of these involved tracking gannets from the Bass Rock and shags from the May Island. It is always quite nice to sit in one of these conferences and be shown slides of home: the talks are interesting but always that bit more interesting when describing the things that you see everyday on your doorstep.

There is a lot of interest at the moment in measuring where seabirds go and how they get there because we intend to put thousands of wind turbines out in the North Sea. There is a huge offshore windfarm planned at the entrance to the Firth of Forth. Crail is right in the middle, albeit the turbines will be at least 25 km out at sea. A long way from us – we will barely be able to see the tops of them, but as the seabird flies, this is right on our doorstep. We know this very well now because if you put GPS tags on a gannet breeding on the Bass Rock you can track them flying out hundreds of kilometres there and back into the North Sea, crossing the footprint of the proposed wind farm daily if they are feeding chicks. Clearly there is a lot of potential for the 170,000 gannets to hit the turbines if they are not paying attention. And with the tags you can also see how high the birds are flying so in conjunction with their tracks, you can see how often they would intercept with (hit) a turbine, if of course, they take no evasive action. When you do the maths this works out at about 560 potential collisions a year, which is a very large number. But gannets have great binocular vision and turbines are not inconspicuous, particularly in our light Scottish summer nights, so they are unlikely to plough on into a turbine at random. They will fly above or most likely below them. But of course gannets are out there looking for fish, so they may well be distracted and looking down at the crucial moment. And it gets more complicated because the wind farms may also be avoided by fisherman – who don’t want to hit turbines either – so the wind farm may well make, in effect, a protected marine reserve where fish numbers may be higher. So attracting more gannets into the area and increasing collision risk particularly as they form up into their spectacular diving frenzies to catch the fish.

Gannets passing Crail as they leave the Forth to feed out in the North Sea

What will happen with these turbines is hard to call – I think there will be collisions but the gannets will probably adjust their behaviour. There are always hazards to avoid, particularly for a species which specialises in diving into dense aggregations of fish, cetaceans and other individuals, where split second agility makes the difference between hitting another gannet or getting the fish. So gannets should be able to respond very quickly to avoid a collision threat: I hope so because regardless of the collision risk, these wind turbines will be put into place. But even if the collision risk is high there may be many ways to deter birds from collisions and we know also that for land based turbines, many bird species such as geese, soon adjust to the risk and life goes on normally in places like Denmark with the geese feeding reasonably happily in the farmland below the turbines. Perhaps the worse thing about the turbines being out there is they might be out of sight and out of mind. You can always count what hits a land based turbine; it is a bit harder out in the sea, especially during the winter storms. Again tracking birds should give us some of the answers: and of course I haven’t mentioned the 110,000 puffins also shuttling back and forth from the May Island.

A gannet feeding frenzy

Posted March 31, 2017 by wildcrail in Sightings

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