Are wind farms affecting seabirds?

How are British sea birds reacting to offshore wind farms? Viola Ross-Smith from the British Trust for Ornithology is aiming to find out just that, but first she showed us a few of the seabird species from around Britain...

Viola -    So, I brought some props with me.  I haven't got a sea spider, but I have got a box of seabirds behind me if anyone wants to look at them.

Chris -   You've got a what?

Viola -   A box of seabirds.

Chris -   Alive?

Viola -   They're dead.

Chris -   You're not doing your job very well then if they're dead.

Viola -   They've been dead for about 90 years.  If people are interested, I can get them out.  Do you want to see?  Okay, so these are skins so they look a bit odd.  Let's start with a chick.  This is a little fluffy lesser black-backed gull chick.  It was probably about a day old when it died 90 years ago, but this is a species I normally work on actually, lesser black-backed gull.  I put these tags on which I'll tell you about later.  Just to show you the kind of range we get in the UK, this is a little tern.  So these breed on the coast of Suffolk and Norfolk not too far away.  This species got quite a long - it's in breeding plumage.  It's got a long yellow beak, a black hood and then typical for seabirds, it's got a pale grey back and a white plumage underneath.  Working up the terns, this is a common tern.  So, it's about twice the size of a little tern.

Chris -   Have you got U-turn in there?

Viola -   I don't have a U-turn but I've got a sandwich tern which is the biggest tern you normally get in the UK.  This breeds mostly in North Wales Anglesey in the UK and it would have a black hood, but this specimen is going out of summer plumage into winter plumage, so the hood has sort of receded back.  It's just patchy black.

Ginny -   Are you saying that they change colour with the seasons?

Viola -   Yeah, they do.  So, most seabirds in the winter like puffins for example - of which I have one here...

Chris -   Here's one I made earlier.

Viola -   Well, some were made several years ago.  In the winter, they don't have these characteristic clown-like colours around the beaks.  In fact, some of the bits on their beak just fall off.  So, when they're out to sea in the winter, they just look sort of dark and just not very interesting.  When they come in to breeding plumage, they develop all exotic colours around their bill in terns and gulls, if they have a hood, they grow it in the summer normally.  So yeah, carrying on with my little exploration of British seabirds, I've got a few auks.  This is a little auk.  They're kind of compared to the terns the terns are long and thin, and streamlined.  These ones are more sort of bottle-shaped almost.  They look more like bullets or something.  That's because they're pursuit divers.  So, they're not very good at flying, but they'll dive straight into sea and then they swim quite strongly.  They chase after sand eels and other small fish.

Ginny -   Looks a bit like a tiny penguin when you see penguins underwater and they look quite streamlined and elegant.

Viola -   Yes, so interesting examples of convergent evolution.  So, the auks are northern hemisphere penguins really in many ways.  Unlike the penguins, the ones that are still extant, do fly.  There was the great auk that is now extinct which didn't fly, which is much bigger than these guys.  But yeah, in many ways, they are northern hemisphere penguins.  So, we've got a little auk, we've got puffin which is also an auk.  I don't know if I need to describe puffins.  I think everybody on the radio knows what they look like.  Although I think people are often surprised by how small they are.

Ginny -   Yeah, I was quite surprised, but the beak is very distinctive, that big kind of triangular, colourful beak.

Viola -   Yeah and this is quite a poor specimen in terms of the colours.  So, when you see them on a breeding colony, I would recommend going and see puffins in breeding colonies if you never have.  They're really quite spectacular.

Ginny -   Is there more in there?  It's like a Mary Poppins box.

Viola -   I've only got a couple more if people can bare it.  So, I've got two more auks here, guillemot and razorbill.  They're quite similar large auks, but the razorbill has got a much curved, thicker beak than the guillemot.  The guillemot has got a narrow, black, pointy beak.  The razorbill has got this black beak with characteristic white stripes on it.

Ginny -   Is that because they eat different things?

Viola -    Yeah, it' quite interesting actually.  They've got very similar niches, but they dive to slightly different depths.  They co-exist, they nest on the same ledges and seabird colonies, but they have to differentiate slightly.  Otherwise, they wouldn't manage.

Finally, I thought I'd go for the bigger seabirds in the UK.  So, this is a first winter grey black-backed gull.  It doesn't normally look like a spear.  It's because it's a skin and it's not stuffed very well.  But this is our largest seagull.  Well, in the world actually, not just in the UK.  If I could unfurl its wings, it would have a 2-meter wing span.

Chris -   Do they live all around the UK?

Viola -   Yes, they do.  In the winter, they tend to migrate off more out to sea, but they stay around the UK all the year round unlike some of the other gulls I work on.  Someone once described them as the lions of the sea to me and I think that's quite apt.

Chris -   So, if your sort of work is going well, then you should be able to have all of these in fine fettle all around the British coastline.  I mean, you're looking at how to conserve these birds and how they live.

Viola -   Yeah, we are indeed.  So, a lot of the work I do is applied ecology for the BTO.  We're funded often by the government to do impartial research.  we don't campaign unlike the RSPB.  The government wants to know things like, what might offshore wind turbines do to the seabirds.  Will they be able to fly around them?  Will they fly through them and get chopped up?  Will it take away fish that they rely on or will it attract fish and actually help seabirds?  So, one of the ways we do this and we've done it on the bird I'm holding right now actually - the great skewer - is we put these GPS tags on them.  So, I've got a couple of tags here.  They're not cheap.  They cost a thousand pounds each.  They're very hi-tech, solar powered tags which means that they're long lived.  The one I'm holding now is about 5 cm by 2 cm.  It weighs approximately 19 grams which is nothing for a massive seabird like a great black-backed gull or a great skewer.  I couldn't put it on the little auk or the little tern.  They measure 3D position and they give information like acceleration.  We can take pictures up to every 3 seconds on them and that means that you can pretty much see what the birds are doing - whether they're flapping, soaring, diving, gliding.  You can calculate through the acceleration whether they're traveling on thermals, whether doing dynamic soaring if it's something like an albatross.  We've had some of these tags on less black-backed gulls in Suffolk for 4 years now.  So, we've got really good information about what they're doing all year round.

Chris -   They look like they've got little antennas sticking up off the back.  Is that how it gets the data?

Viola -   Yeah, well it was how it got the data, but actually, that model, it's been passed around.  It's about 4 years old and since then they put the antennas inside and that's because - well, it's less invasive for the bird, it doesn't interfere with their aerodynamics.  And also, a bird like a great skewer or a great black-backed gull will just try and turn the antenna off.

Chris -   Because it looks like a little bird backpack.  How do you put them on?  Do you strap them on or something?

Viola -   Yes, we've got harnesses made of Teflon which is strapped under the wings and it loops through the little eye holes on the tag.  And it just holds in nicely in place for years and years.  The birds don't seem bothered.  They behave normally.  They carry on breeding.  They migrate in the case of our lessers.  So yeah, it's really interesting and we can see them weaving in and out of the wind turbines.  We can see some birds traveling down to Morocco every winter.

Chris -   Do you ever see them accidentally not weave around the wind turbine?

Viola -   Not yet.  If we did, I don't think DEC - Department of Energy and Climate Change who funds the work, I don't think they'd be very pleased some birds are.

Chris -   So seriously, what influence of the wind turbines are you seeing?

Viola -   I shouldn't pre-empt this too much, but very little actually on our lesser black-backed gulls.  They seem to be coping with them absolutely fine.  But that's not to say that other seabirds or other non-seabirds can cope with them.  I know people think that birds like gannets -they're always looking down all the time.  They don't really tend to look ahead.  So, they could possibly be affected much worse than gulls are, but we can't use these tags on gannets and that's because they're diving birds.  They pht the water at 60 miles an hour.  If they've got a harness and a tag on them, it could affect their behaviour and probably break the tag.  So, we don't know.

Chris -   Scientists in Saint Andrews have shown this week that seals change their behaviour because when you put these wind turbines in, they build a sort of artificial reef to put them on.

Viola -   That's right, yeah.

Chris -   And the seals, they can see by following the seals where all the wind turbines are because they spend all their time around them and they're saying actually, this could attract fish and other species around these artificial reefs.  It may be that the seals make a beeline there, if that's the right phrase to use

Viola -   A seal line, yeah.

Chris -   But in fact, that means that you could decimate fish populations because all the fish go there and then they're easy pickings.  Do you not think the birds might be impacted?

Viola -   Yeah, it's really complicated.  Well, I know people speculate that cormorants might be using wind turbines exactly the same way, but it probably isn't the case for other birds.  I know eider duck for example, you can see that they start avoiding wind farms.  2 km away, they start making massive avoidance movements which means they're not using an area of the sea that they previously did use.  And that could be having negative impacts on that population.  We don't know yet.  It's quite a complicated area really.  These are just big birds with smaller birds and little storm petrels or even non-seabirds, migrating passerines just flying over.  We don't know.  They'll probably just get chopped up.  But it's hard to test that yet.  These tags are too big to put on them.

Chris -   Who's got some questions?

Jeremy -   My name is Jeremy.  I come from Little Thetford.

Chris -   You're not from Godmanchester.  That's a good start.

Viola -   I come from Big Thetford.

Jeremy -   How do you catch the birds?

Viola -   The way we catch them, well at least when we're tagging them - it's a good question - is in the breeding season, seabirds tie to their nests so they have incubate their eggs and they have to look after their chicks.  The rest get out to sea and we probably couldn't catch them.  But that means when they're on the nests, we can put a trap around the nest.  It's just a wire mesh trap and the bird just walks and sits on its eggs.  Acts like nothing has happened and then I come running out of the bushes and grab it and put it in the sack, and then go and put the tag on it and then let it go about 10 minutes later, and then it goes back to the nest and it's all fine.  The colony gets wise to it after a while.  You can easily trap 10 birds or whatever in the first few hours and then after that, they see me coming and they fly up straightaway.  But if I wear different clothes, they don't know it's me anymore.  So, I have to keep outwitting them.

Chris - It's interesting you disguise yourself because these guys in America were looking at mocking birds and they found that these mocking birds could tell one person who went and annoyed.  If one of the researchers went and made annoying noises to their nest on a daily basis, they very quickly wised up to the fact that this guy was nuisance whereas the other guy from the lab who looked a bit different, they wouldn't object to him being near their nest.  But the other chap, they would start attacking.  So, they're obviously quite good at recognising individuals.  So, you've made one or two enemies out there.

Viola -   Definitely, yeah.  It's not always a good thing to make an enemy of a gull.  They come, they pooh all over me.  It's really not very nice, but I probably deserve it, but all in the name of science.

Claire - Hi.  I'm Claire and I work at the Cambridge Science Centre.  My question was about great auks.  When did they go extinct and what were the pressures on that species?

Viola -   They were hunted to extinction.  I think it's quite sad really.  I think the last few auks were basically - people knew they were going extinct and it was almost just like a Victorian trophy thing.  I can't remember the exact year the last great auk went extinct.  It was 18 something.  It's in the Victorian times, so it wasn't that long ago.  Yeah, people were just going out and shooting.  A lot of sea bird populations went down massively at that time including gulls and gannets.  It wasn't just hunting.  People were taking their feathers for hat making, and people were egg collecting.  It's different attitude altogether.

Ginny -  So, do you like going to the beach despite the fact that the gulls attack you?

Viola -   Yeah, I love it actually.  It gives me a whole extra dimension on the experience.

Ginny - What about building sandcastles?  Are you a fan of sandcastles?

Viola -    Yeah, everyone love sandcastles, right?

Ginny -   Exactly, so we thought we would see if there was some science behind building sandcastles and see if we can make the best possible sandcastle here at the Cambridge Science Centre for you.  Does that sound good?

Audience -   Yes.

Georgia -    Okay, so we've got a desk completely covered in sand here.  What's this set up, what are we going to be doing?

Ginny -  So, we're going to be looking at how much water you want in your sandcastle.  So first of all, in this rather heavy box here, I have some lovely dry sand.  So, you can see that's sort of flowing down from my fingers when I pick it up.  It's bone dry.  What do you think it was going to do if we make a sandcastle out of it?

Georgia -   I imagine that will tumble down, much like a sand dune.

Ginny -  Should we give it a go?

Georgia -   Definitely.

Ginny -   Okay, so I have a little kind of cup-shaped thing here.  it actually used to have bay leaves in it and we're going to use that as our mould today for making a sandcastle.  So, I'm going to pack it full of this really dry sand, pat it down and then I'm going to turn it out and we're going to see what happens.  Here we go...

Chris  -   Woah!  That's really good.

Ginny -   What happened?

Child -   It didn't stay up at all.  As soon as it went out of the container, it just tumbled onto the floor.

Ginny -   Yeah, so I definitely wouldn't call that a sandcastle, would you? 

Georgia - No. 

Ginny -   So now, we're going to try a really, really wet one and see what happens there.

Georgia -   Okay, so we're pouring in a mug of water into a very small amount of sand, so it's looking a bit more like gloopy mud at the moment rather than sand, we're just mixing it together.

Ginny -   Right.  So, I'm going to try and slop some of this stuff into my tube.  It's feeling pretty wet, but we said we wanted water to make a sandcastle, didn't we, we said we needed it nice and wet.

Georgia -   What do you guys think is going to happen?

Child -   I think it's going to be too wet and then it will all fall out.

Georgia -   Just packing the end of the sand in. 

Ginny -   three, two, one...  It seem stuck.  It came out earlier, eventually.

Chris -   I think we can conclude that that's not a good recipe either Ginny.

Ginny -   Okay, here we go.

Georgia -   Well, it's come out in bits.  It's not quite what you'd want at the seaside.

Ginny -   But it is at least sort of standing up.  It's sort of a sandcastle, isn't it guys?  So now, to see how good a sandcastle it is, we're going to see how much weight it can take.  So, we're going to pile some pound coins on top and see how many we can get on it - one, two, let's go in two's now, four, six, eight - it's not doing badly, is it? Ten, twelve, fourteen - oh, I saw a bit of movement.

Georgia -   I need some more pound coins.

Ginny -   Sixteen, eighteen - this is much better than I was expecting - twenty, twenty-two, twenty-four, twenty-six - I think some of the water drained out of it while we were trying to get it out.

Chris -   You're going to move to a country where the exchange rate is a bit better, Ginny.

[laughter]

Ginny -   Wow!  I think my pound coin tower might fall over before my sandcastle does.  So, we've shown that for strength at least, you want your sandcastle to be as wet as possible.  Well, I think our sandcastle deserves a round of applause.

[clapping]

Chris -   So Ginny, why does adding the water make it stronger and stick together better?

Ginny -   Water is really interesting because it has something called surface tension.  So, if any of you ever filled a glass so full that it looked like it was going to spill over the top?  But then you realise that actually, the water is sort of sticking up over the top of the glass in a kind of curve.  Have you seen that?  I've got lots of nodding.  So, that's because it's something called surface tension.  Water molecules like each other and they like to stick together and hang together.  So, when I've got my dry sand, there's nothing to make it stick together.  But as soon as I add some water, the water wants to hug itself.  It wants to grab the sand molecules and it's going to keep them together.  It forms kind of little bridges between the sand.  What you want is you want enough water that it's going to fill up all the gaps between sands.  So, if you only have a little bit of water, it's not going to fill all of those gaps.  You want enough to fill all of those gaps, but not so much that the water itself starts to flow and become a liquid and you just got water with some sand in it.  So, getting that proportion just right is what makes a really good sandcastle...