Science on the Solway - how geese are helping us better understand avian flu

Join us as we travel to the Solway Firth in Dumfries and Galloway to meet staff from NatureScot's wildlife management team - Jenny Park, Rae McKenzie and Alastair MacGugan.

The team talk us through their vital research into the highly pathogenic avian influenza – or avian flu as it's more commonly known – and the impact it's having on the thousands of barnacle geese that migrate to the Solway Firth each winter from their Arctic breeding grounds.

In this episode, you'll learn about the collaborative research efforts underway and how cutting-edge science is helping us better understand bird responses to avian flu. You'll also discover the importance of this work for wildlife conservation and how it contributes to our wider understanding of disease management in wild bird populations.

More Information:

Scottish Government avian influenza updates

NatureScot avian influenza (bird flu) guidance 

Bird flu (avian influenza): how to spot and report it in poultry or other captive birds

Transcript:

Kirstin: 0:05
Welcome to Make Space for Nature, the NatureScot podcast celebrating Scotland's remarkable wildlife and landscapes. I'm Kirstin Guthrie, and in each episode we're joined by inspiring guests who share their expertise and passion for the natural world. In this episode, Vicky Mowat and I journey to the Solway Firth in Dumfries and Galloway to meet staff from NatureScot's wildlife management team who are conducting vital research into highly pathogenic avian influenza, or avian flu as it's more commonly known. Each winter, the Solway Firth becomes home to thousands of barnacle geese that migrate from their arctic breeding grounds. We explore the collaborative research efforts underway and discover how cutting-edge science is helping us better understand how birds are responding to avian flu. So joining us is Jenny Park, who works on this monitoring program. Welcome to the podcast, jenny. Could you explain what avian flu is for those who are not aware?

Jenny: 0:58
Yeah, sure, so avian flu is something that circulates in wild bird populations and has probably been in existence for as long as birds have themselves, and but from time to time you get a strain which is particularly deadly or highly pathogenic, and that's generally described because of the effects it has on poultry, the mortality in poultry, and so the highly pathogenic strains we're seeing them causing mass mortality in wild bird populations just now but it's basically influenza, like human flu, but a different, different strain that affects primarily birds.

Kirstin: 1:32
Okay, great thank you. And what are the symptoms of avian flu? What impact does it have on the birds?

Jenny: 1:39
So we see in wild birds that they tend to get lethargic. You might see them sort of sitting still behaving unusually. Then often times there's some neurological signs such as neck twisting, and often times when birds that have been infected are found dead, they're face down with their wings splayed.

Kirstin: 2:00
Gosh, not nice at all. And can you just explain what you're actually doing here today near the Solway Firth? What are you actually testing for with the birds?

Jenny: 2:11
So this population here was really badly affected a few winters ago. We've not seen any mortalities for the past few winters. But what we are trying to do is gather samples from the geese here, the blood samples and then analyse them for the presence of antibodies, and that helps us to understand whether there's some form of immunity resistance that's developing to the disease and allow us to see what the impacts might be if the virus were to be reintroduced or the immunity was to wear off.

Kirstin: 2:44
And I was just wondering you know the kind of, the pattern or the current situation of avian flu outbreaks. Has it changed in recent years in Scotland?

Jenny: 2:52
Yeah, so we've first started to see this current outbreak, which is the subtype known as H5N1. It struck here in the winter of 21-22 and that's when we saw the mass die off of these barnacle geese which breed in the Svalbard. So there was around estimated there was around a third of that population was lost then and since then we've not seen any further mortality in this population, but it has spread to a wide range of other wintering waterfowl and then in summer, the summer of 2022, it over-summered for the first time. So that's when the virus was present in a wide range of seabird species and had really devastating impacts, and we saw mass mortalities in the gannets on Bass Rock, for example.

Kirstin: 3:41
So sad really. And when it comes to migratory birds, you know, and geese in particular, what role do they play in spreading the virus?

Jenny: 3:49
Well, we know that the virus originated from China in areas where domestic ducks [Editor's note: this should be 'geese/wildfowl'] were interacting with wild birds. So then, through a combination of trade and migratory wild bird movements, the virus has spread from that origin, spread west, arrived in Europe and in Scotland in the winter of 21-22. So migratory birds do play an important role, but we don't fully understand the dynamics yet.

Kirstin: 4:22
And is it just winter birds, or you know, is it more than that?

Jenny: 4:29
Yeah, so what we were used to seeing in previous years is that you would have an outbreak in winter associated with the wintering waterfowl, and then that that would leave, as those birds then moved on to their summer grounds. But in the summer of 2022, that was the first year that the virus stayed around, stayed all year and infected a wide range of seabird species, so that was unprecedented. It's not looking like it's going to be going away anytime soon. It's changed from being a seasonal outbreak to being all year round. What we're also seeing now, just more recently, is that there are cases of mammals being infected. So in the Americas there was mass die-offs of seals and sea lions. We've had positive findings from mammals in the UK as well. So there's no evidence of mammal-to-mammal spread as yet, but that's something that the Animal and Plant Health Agency and others are monitoring.

Kirstin: 5:30
Okay, and so you know, we've spoken about birds and mammals, but what about humans? Can humans actually contract this virus?

Jenny: 5:40
Yeah, so there have been cases of human infection with the virus and it can vary in range of symptoms from mild to severe, but the risk to the general public is still considered to be very low.

Kirstin: 5:53
Yes, absolutely, and the research is obviously so very important. So we've seen some recovery in recent years. Is there any evidence to suggest that the geese have developed some natural immunity?

Jenny: 6:06
So the preliminary findings from the work that we've done similar to this in the last couple of years are showing levels of antibodies in the birds that have been tested of around 70 percent. But what we don't really understand is how long any well, what level of protection that might afford and how long that protection might last, and whether juvenile birds have the same level as adult birds or previously exposed birds. So there's still a lot of questions unanswered.

Kirstin: 6:33
Yeah so obviously, that that is, you know, the unanswered questions. We're hoping to kind of, you know, do so much more research when it comes to the avian flu and, once the samples have been taken here, what actually happens next, and are there other partners involved in the work?

Jenny: 6:51
Yeah, so we're doing this work in partnership with Edinburgh Uni with Professor Emma Cunningham. It's called the Eco Flu Project. So as well as the samples from the barnacle geese here, we're also involved collecting samples from great skua and the project more widely with other seabird species on the Isle of May, for example. So the samples will go off to the lab and that's where the testing for the antibodies is carried out.

Kirstin: 7:17
So lots of partners involved in this work, so it'll be fascinating to see what the results return. So all the best with the work that's going on here today. Thanks for joining us, Jenny.

So we're now going to meet Rae McKenzie, Goose Policy Manager with NatureScot. So hi Rae, welcome to the podcast, and you're going to explain more about the testing process. So how do you actually go about catching the geese to test?

Rae: 7:41
We use experienced ringers who use cannon nets, and how that works is that they hide a long net in a field, they bait an area and the geese walk onto the bait and the net is fired over the top of them when they're in the right place. So we catch the geese under the net. We then put these geese in keep pens and we work through them, firstly by ringing them so we can identify them, and then by going through the process of taking bloods.

Kirstin: 8:10
Great thanks, and I can imagine it'd be quite tricky to catch some of the geese. What are some of the challenges you've faced?

Rae: 8:16
I think sometimes the weather is an issue, disturbance is an issue. So when you want the geese to come onto a certain area, there's a whole load of different things that can disturb them. So farmers can go by in quad bikes, birds of prey can fly over the top of them, you know, the bin lorry can go by, a plane can fly over, and that makes life pretty difficult. So we've got to be quite patient and try and get the geese into the right place at the right time. And then if the weather's cold, we want to try and keep the geese as warm as possible. So you know we want to put them into these keep cages and keep them warm before we try and take bloods from them.

Kirstin: 8:51
And Rae, what's the actual process? I mean, how do you actually take blood from a goose and what is there other samples that you take at the same time?

Rae: 8:59
Yes, taking the bloods is actually relatively straightforward, but we have to be specially trained and to hold a Home Office licence to do it. And what happens is we take the blood from the leg of the goose. There's quite a big vein going down the leg. We take a very, very small amount of blood, but that gives us enough to test for presence of antibodies, which is what we're looking for. The other thing we do is we take swabs from the mouth and the other end of the goose and we send them off to be tested for live virus.

Kirstin: 9:36
Wow, and can vets or anybody do it - I mean, how do you actually get a licence for this?

Rae: 9:42
This is related to scientific research, and so most vets may not have the licence to do this. They would have to go through separate training because it's governed by a different piece of legislation.

Kirstin: 9:58
Great and you know you've seen a lot of avian flu yourself. Tell our listeners about recent outbreaks and birds affected and what you've actually witnessed yourself.

Rae: 10:10
Okay, well, I'm based on Islay. I live there and I've seen both the seabird outbreaks and the goose outbreaks and so during the seabird outbreaks we've got some really lovely beaches on Islay that are fairly well used by tourists and locals alike, and we had an awful lot of guillemots I mean probably in the hundreds if not thousands at times washing up onto the beaches and some it was washing up carcasses and some were still alive when they were coming ashore and they were looking for shelter to keep themselves away from predation. So you saw guillemots walking up the dunes. I also I've got a boat do a bit of fishing and when I was out in the sea loch where we fish, we were just seeing loads of carcasses floating about in the water. So it was pretty horrific.

And then the winter after that it went through the barnacle goose population on Islay. So seeing geese in the strangest places, seeing them being very distressed because they're ill they tend to twist their necks round and go round in circles, or if they can still fly, they fly round in circles. So something going on in the brain, potentially whether balance is affected. So seeing that and knowing that those birds were going to die was pretty horrible. We also had quite a few whooper swans on Islay that were affected. So you really did see the obvious spinning round of the necks of the swans and you'd find geese on roads and swans on roads. You wouldn't normally find them there, but they got to a point they couldn't fly so again, they'd walk looking for shelter. So we found quite a lot of the carcasses close to or under gorse bushes where they were looking for some shelter. So not their habitat, but they. they knew there was something wrong with them. So and pretty horrible to kind of see them when you know what the outcome is going to be. So we then had to on Islay we were doing quite a lot of testing for avian influenza, so part of my job was to go out and take some swabs and send them off for testing to confirm presence of the disease and strain of the disease.

Kirstin: 12:17
And you know, I think that's quite an important point is the actual effect on us working, you know, out in the field NatureScot staff. How does it actually impact you yourself seeing these, these birds, and you know a lot of pain and discomfort?

Rae: 12:32
It was pretty distressing, you know it's not nice to see an animal suffering. There wasn't anything we could do and the scale of it meant you couldn't just go and kind of try and put the animal out of its misery. There was just, you know, dead and dying birds all over the place. Pretty difficult. Obviously, on the beaches you've got people who walk, you've got families having picnics and things like that and you know they couldn't use these beaches at times because they were so full of dead birds. I've got a couple of dogs and I had to be really careful where I walked the dogs. I didn't want the dogs picking up carcasses. So yeah, lots of effects. And you know I dealt with quite a lot of calls from people who had dead or dying geese in their gardens. You know they were just landing anywhere if they were sick. So lots of people experiencing geese in places that they wouldn't otherwise see them and those geese were sick and dying. So I had to provide a lot of advice to people about what to what to do, and you know, sort of general advice about try not to touch them but if you need to get rid of them, double bag them and put them in the bin type thing. But, and so you know, not just us seeing this and dealing with the kind of distressing situation, but dealing with other people's distress as well, was quite difficult at times absolutely.

Kirstin: 13:46
It's not a nice thing to see at all, but thankfully it is pretty quiet just now - there's not a huge amount of cases at the moment, is there?

Rae: 13:54
No, there's not. I mean we've had these big outbreaks in the seabirds and we've had big outbreaks in the Svalbard population of barnacle geese in the Solway that had a huge impact on them, probably lost about a third of the global population. And then the impact in the geese on Islay was very much through the Greenland barnacle goose population. So two separate populations, they don't mix but the disease has gone through both populations but interestingly, not necessarily gone through other goose populations that might be using more or less the same species. So on Islay, for example, we haven't found any green or white-fronted geese. We haven't found any impacts on those. We haven't found impacts in any great number in greylag geese. There have been some small outbreaks across the country in greylag and pink feet, but nothing like the scale of the impacts on the barnacle geese, where in both populations thousands have died.

Kirstin: 14:54
And so what should the public do if they do find any dead birds they suspect have been infected with bird flu?

Rae: 14:59
There's a UK government website which has a very simple form to fill in which you can report the location, the time, the species, if you know it, and from that the various agencies that might be involved in testing will decide whether to pick that bird up or test it.

Kirstin: 15:17
Great thanks for confirming. Okay thank you so much, Rae. It was nice to meet you and all the best with the work here today.

So I'm now going to hand over to Vicki, who's going to speak to Alastair McGugan, our Wildlife Management Manager at NatureScot.

Vicki: 15:30
Thanks, Kirstin. So, Alastair, how important is it that this kind of science and evidence work that you're doing today will contribute to our understanding of avian flu?

Alastair: 15:40
So it goes beyond avian flu, really doesn't it? So it's about us getting better understanding about how these populations are working. So we have models which helps us to understand whereabouts they are in terms of their conservation status, and what we're trying to do today in terms of this is just one little bit of that jigsaw. It's about how do these populations respond to big challenges from disease, and we don't know that. Actually, we really don't know that, but it is one of the bigger things about. Well, when we're trying to predict whether a population is going to work, or whether a population is not going to work, or when do we need to intervene in that population, it's all about trying to understand those little bits about right, well, what are the bits that helps that population or has an impact sorry in terms of that population to be able to move forward and not move forward?
So what we're doing today is trying to find just that little bit which is saying at the beginning of the stuff back in 2020, we didn't know whether any of these birds would get any antibodies at all. So, in other words, we didn't know whether any of those birds would survive this, and what we're now trying to do is to say, right, well, we think that there's a certain percentage of them from the work that we've done previously that will survive, that have built up some degree of immunity, and therefore that helps us to understand, right well, when we're thinking about long-term plans for these species, how do we bring that in? So it's a bit like COVID, isn't it, you know? So it's a bit like saying you know, guys, do, do we really understand how many of us are not going to survive this, but how many of us are actually going to get through this? And that's what we're trying to do today.

Vicki: 17:34
So the immunity is obviously just like COVID. Sometimes it doesn't stop you from getting the disease again, but it may stop you from getting certain variations. It's the same thing between COVID and avian flu.

Alastair: 17:49
Yeah, no, absolutely. And the problem that we have here is we don't know whether those guys down here who got it remember back in 2020-21 and really got it really badly. We don't know whether that antibody stuff is tailing off and therefore, if a new version comes in, they're going to get hit as badly. We don't know that, and that's again what this work is trying to do is to sort that out. What we're hoping is and again, there's another bit in there which what we don't know is whether exposure to low path influenza, you know, like us all getting a bit of a cold and not being that bothered about it, compared to us then getting COVID when that was a real big problem. Again, what we, what we don't know, or what folks don't know, is whether exposure to that low path stuff allows them to build up a better antibody in terms of them being then exposed to this high path stuff.

So, in terms of wild birds, we're at such a low learning level that we just need this type of work to start building on it, to start building our better understanding of it. It's not going to give us the answer. We're not going to be able to solve H5N1 on wild birds. That's not going to happen from this, but at least what it might do is to be able to help us to better understand what the impact of some of the species have in catching H5N1 and better understand right. Well, we need to get a stronger environment, we need to get a much more richer environment, something which is a little bit more complex, so that when they do get it, they're able to cope with it, and that's what this work is contributing to.

Vicki: 19:36
Right. So you were telling me earlier that if we have a stronger natural world, basically if it's more biodiverse, they'll be better able to cope. So is that the sort of thing you mean as well?

Alastair: 19:47
Absolutely, and it's not just about them and us, because we are part of this. We're intrinsically linked with what's going on here and I suppose the one silver lining about the dark cloud of H5N1, you know, of high path even influenza, bird flu is that link between what's going on in the poultry sector and the link that's going on now in the wild bird stuff. What it's showing us is that, you know, we are one of this. We are all connected in here. It's not just one separate bit and therefore what we need to be trying to be doing is look, can we find ways in which we are better getting the environment to sustain this type of attack, if you like. We're always going to have avian influenza coming at us. We're always going to have these types of diseases and coming at us, but if we've got a remote, more robust ecosystem or a more robust environmental approach to it, then these species will then have a better chance of getting through it, because the work that we're doing is showing that they are building antibodies. We are seeing that 60-70% of them that are exposed to it are getting some degree of immunity, but we still need that strong environment for them to be able to cope with it to be able to get through it. At the end of the day, it's a bit like us going. I had a really really bad flu. Now I need another week to be able to get myself back on track. If we don't have that other week for these guys, then they're not going to get back on track.

So I think the one really good thing that's come through here is that we've got so much better linkages across government. You know, whether that's Marine Scotland, Scottish Government, Animal Health and Welfare, NatureScot, you know so because of this, we are now meeting up on at least a monthly basis. Now, okay, that's a meeting, but let's not underestimate that. That that's about exchanging views, exchanging intelligence, exchanging what's going on. So that just doesn't relate to HPI, it relates across the board. So whether that's pigs in terms of African swine flu or whether that's deer in terms of blue tongue, we've now got those really really good connections. There were those connections before, but they're now so much more cemented and we all know what our relative roles are. So that's really good.

I think the other bit that this has highlighted is just this whole One Health agenda and you know I don't like the word agenda, but I think in this case it is correct. It is highlighting that connection between the natural world and that bit about where agriculture, where health of humans all plays a part and it's all interconnected. So if I was to say I'm actually quite positive about what's happened in terms of I mean, I wasn't when I saw all those gannets on the beach or those dead kittiwakes on Lunan Bay, but actually, do you know, out of that has come something which is really, really positive about how we are approaching that. Let's be honest, we cannot do anything about H5N1. We cannot do anything about that. What we can do is try to get the natural world a little bit more robust, get it working, get it more complex and get it better able to deal with these types of outbreaks which are going to come across us all the time.

Vicki: 23:23
Thank you very much, Alastair. That's really actually quite heartening at the end of all of that.

Kirstin: 23:28
So the scientific testing we've discussed today is the foundation of understanding avian flu. By studying geese immunity, we're not just protecting birds, we're building knowledge that could mitigate the impact of future outbreaks. Rigorous scientific testing matters because when we understand the evidence we can build effective management. For more ways to connect with and help protect Scotland's natural world, go to nature,scot.