Studying wandering albatross on Bird Island
Andy Wood from the British Antarctic Survey tells us about how he studies the birds with the world's largest wings - the wandering albatross - on Bird Island in the sub Antarctic.
Sarah - We heard earlier in the show about Birdlife International's work in setting up conservation areas for sea birds across the globe. And that work relies on data collected in the field by researchers, about where birds live, their migration routes, how they use different parts of the ocean and so on.
To find out more about what goes on in the field and how sea birds are studied, I caught up with Andy Wood from the British Antarctic Survey. He's just got back from spending 3 months on Bird Island in South Georgia, where he studies the most impressive fliers on the planet - the wandering albatross.
Their wings are the largest that glide through the skies today, at around 3 metres or 9 feet. Andy told me how he goes about studying these giant birds.
Andy - The way you study them is carefully. Because you've got a bird there with a wingspan of 3-4 metres. If you think of the size of a swan it's slightly bigger than that, and you've got to keep that under control if you're going to put on some mark on it like a ring or some other device.
You treat them with respect. We've got marked populations of birds at bird island, down in South Georgia, going back to the late 1950s. So we've been doing it for a few years - not me personally, but BAS and others have been doing it for many years.
Sarah - What sort of things are you attaching to them? Tracking devices? Tags?
Andy - Yes, all of those. The basic thing for birds is usually a metal ring, and that's what we started off with. Then, we moved to using the plastic ring because that allows us to identify the bird without disturbing it too much. Birds at Bird Island are very very tolerant of people. You can walk up very close to them and they don't worry that you're there.
So with a plastic ring, with a number on it, we can read those, just walk around the island and see the birds and that helps from our perspective because we don't have to handle birds, birds don't get stressed out by our presence.
We've also moved onto other devices. So we've put satellite transmitters which allows us to follow them when they're not on land. Because clearly we can only look at part of their breeding cycle when they're actually nesting on the island, and rearing chicks.
We put satellite transmitters on them, we put on smaller devices to collect basically where they go around the world. Where they go is all around the Southern Ocean.
Sarah - And with the ring, is the sort of information you're getting from that which individuals are breeding together, how many chicks they're having, how long they live, that sort of thing?
Andy - Yes, again, all of those. We have a database that started off in the late 1950s, of all the handled birds at Bird Island that are still coming back to Bird Island. And we know the history of their partners, whether they change partners over the years and if they produce any chicks, if the chicks come back again. So yes, we have a full life history of all the birds at Bird Island.
Sarah - And what are your conculsions from this kind of data? Are we seeing any changes in their movements, changes in their breeding success?
Andy - It takes a long time to build up information on a bird - to just give you some idea of how long these birds live, we've had birds ringed at Bird Island as adults and their still coming back again. So they're 50-odd years old, at least. So we've got a long-lived species that breeds if successful only every other year, so it produces a chick hopefully every 2 years.
And from this we've found out that the population is actually declining. Putting all out other studies together it's been found that it's long line fishing that's causing the major problem with this species.
So lots of other people are trying to work on this partciaulr problem from the fisheries aspect of it. But we're monitoring the long term populations trends of say the Wandering Albatrosses and I'm afraid it's been on gradual decline since the 1970s.
Sarah - And I think people might not really understand how something that's designed to catch fish will end up catching sea birds. How exactly do the albatrosses get caught by these long lines?
Andy - A long line, as the words might suggest, is a long line of hooks. The are baited hooks, quite often to catch tuna and those sorts of fish. They are streamed behind a ship. You can imagine there's a time between the bait coming off the back of the ship and it disappearing into the water and out of the reach of the bird, and it's that time period that's critical because the bird thinks - Ah, there's a free meal here - and unfortunately the free meal is attached to a hook, and the hook then disappears down into the sea and that's the end of your albatross.
Sarah - So are there any practical conservation measures to counteract this bycatch issue?
Andy - Yes, there are many things that are being put into practise in regulated fisheries. Where the fisheries are well controlled there are lots of things they can do to stop the bycatch of birds on long lines.
They can put streamers behind the ships, make the bait sink fast. There are lots of things that are being done. The problem is that not all fisheries will put these into action, and it's the unregulated fisheries that are probably causing the most problems these days.
Sarah - You work on Bird Island, and I suppose it's aptly named because it's not just albatrosses that breed there. There's all kinds of sea birds that you see there, is that right?
Andy - That's right, yes. The wandering albatrosses, there's about 8-900 pairs there now, so that's a relatively small number of birds. There are 1000s of black browed albatrosses, and grey headed albatrosses, and other species such as giant petrels, blue petrels, white chinned petrels, I could go on.
So there are many, may different speceis of birds and Bird Island. And I should mention the penguins as well! We can't forget the penguins.
Sarah - So is it an important area for seabird conservation? Is it a protected area?
Andy - It is a protected area. The South Georgia Government designated a Site of Special Scientific Interest, so they restrict who can go there. So yes, it is a very important area. Particularly that it's rat-free. On South Georgia, the whalers brought along rats and the rats killed an awful lot of wildlife, particularly the burrowing petrels. Bird Island has been rat free and has ever had any rats. So we've got all the burrowing petrels and the endemic species such as the South Georgia pipit, which is quite an interesting small passerine bird that perhaps you wouldn't' expect to see on a sub-Antarctic island.
Sarah - Are you hopefully that some of these conservation strategies like the managed fisheries and augmenting the long liners so they work differently, sink faster. Are you hopeful that that might slow the decline of albatross numbers?
Andy - Hopeful. Whether it will and how long the effect might take to come back into the populations. All we can do is be positive and hope that yes, this will have an effect. As I say, for a long-lived species it's going to take a long time before that's going to show back in the populations at Bird Island. And unfortunately if the current trends carry on, we're going to have no Wandering Albatrosses on Bird Island in 30 or 40 years.
Find out more:
British Antarctic Survey
Bird Island Diary, by Andy Wood