How the Western Link could affect the Western barbastelle

S4E40 In this interview recorded right at the end of August 2022, Steve is sat in a Norfolk woodland with Dr Charlotte Packman. We learn what potential impacts a new road in the area might have on the local bat populations and as Lotty explains it could have a significant impact on a nationally significant barbastelle bat population. Lotty works for the Norfolk Wildlife Trust (NWT) as their Conservation Scientist and the research discussed in this episode has been a collaboration between NWT, Wild Wings Ecology and the University of East Anglia. Lotty starts us off by introducing herself and describing where we are.

Read the latest on the NDR from the Norfolk Wildlife Trust.
Read other news on the NDR from the Norfolk Wildlife Trust.
Our own position statement on the NDR is here.
The Change.org petition can be found here.
Listen to that other episode mentioned with Jane Harris at the incredible Paston Great Barn site.
Since recording this episode the Norfolk Wildlife Trust have submitted a proposal to Natural England to consider the Wensum Woodlands for SSSI status. You can find that

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Transcript

Steve Roe: 1:04

Hello, welcome to BatChat from the Bat Conservation Trust, otherwise known as BCT, the leading NGO in the United Kingdom solely devoted to the conservation of bats and the landscapes on which they rely. This podcast is for anyone who loves bats, bringing stories straight to your headphones from the world of bat conservation, and from the people out there doing work that furthers our understanding of these magical creatures. I'm Steve Roe. I'm an ecologist and a trustee of the Bat Conservation Trust, you can join the conversation online using the hashtag BatChat that's all one word. In this interview recorded right at the end of August last year, I'm sat in a Norfolk woodland with Dr. Charlotte Packman. I went there to learn what potential impacts a new road in the area might have on the local bat populations. And as Lottie explains, it could have a significant impact on a nationally significant barbastelle bat population. Lottie starts us off by introducing herself and describing where we are.

Lotty Packman: 2:06

So I'm Lotty Packman. I'm an ecologist specialising in bats. And I do research and some consultancy, and I run bat training courses as well. So yeah, we are here we're northwest of Norwich. And we're in the Wensum Valley, and as a network of mature woodlands around here, all very good for the bat species we're going to be talking about.

Steve Roe: 2:32

So yeah, we're going to be talking about the Wensum Western link relief road, or whatever it's currently called, it's changed names a couple of times. But why is why is this woodland that we're in so special?

Unknown: 2:43

Yeah. So that's part of what we're trying to find out, really, but it's certainly special to the barbastelle's. That's become clear. I think there's a combination of factors here. So we've got the river Wensum. Just over there. And yeah, this patchwork of mature woodlands in the area. relatively little developments here. So there's good barbastelle habitat seems to be good foraging habitats, good commuting features for them. And then in these woodlands, there's lots of risk features for them. So what we seem to be seeing is the woodlands that have lots of potential use features suitable for barbastelles seem to have larger colonies in them. So yes, something has come together. And we're still trying to work out what the magic formula is, that seems to be making this area particularly attractive for barbastelles. And we know that Norfolk as a whole, you know, as long been considered a stronghold for barbastelles. And what we've discovered over the last sort of five or so years, is that this is really the absolute perfect place to them, really. So we're finding the highest numbers national important area here for barbastelles. So yeah, something is pulling together all these factors that's just made it really good for them.

Steve Roe: 3:58

I'm gonna say when I started Bat Conservation 20 odd years ago, barbastelles were considered really rare since then, like you've just said Norfolk has been found to be a stronghold and not necessarily woodlands as well. They're commuting across open arable fields, which before we didn't think that they would, is that because there's now more barbastelles than a few years ago? Is it just because we've got better finding them?

Unknown: 4:18

Hard to say. But I suspect it's that we've got better at finding them. You know, as the technologies improved, barbastelles have relatively quiet cools. So I think as the acoustic recording technologies improved, we're probably getting better at picking them up. And we're just looking for the more in these wetlands as we were discovering more. I think we've we've also, you know, here in Norfolk, we've really kind of refined methods for catching barbastelles. So I think our capture success rate is is pretty high now. So we're definitely getting quite good. I think now at finding them if they are there, we will find them. So, yeah, I think that's, that's all part of it. But we've definitely gotta be a little bit aware of the shifting baselines thing. And there's certainly some indications that possibly in the past, and some of the sort of beginnings of some of the genetic work that's coming out that that Jane Harris has been doing, you know, it's giving us an inkling that potentially, there could have been much larger populations here historically, but it's it's still too early at this stage know about that. But yeah, so I think we need to be careful what we're comparing to. We're getting a snapshot in time at the moment.

Steve Roe: 5:27

So you mentioned Jane there who was on the podcast last series when we met at Paston barn and she mentioned the work that you've been doing here and I was asking about what size of colonies typical barbastelles a typical colony is said that was very hard to answer. The colonies that she looks at, monitors, are anywhere between 20/30 high 30s but she mentioned one of the trees you've got here in this block of woodlands that has over 100 bats and you've said that you think that this colony around this woodland is a super colony. So what constitutes a super colony? And how many bats is it?

Unknown: 5:58

Yeah. So super colony is a term that we've sort of pinched from the entomologists really, but it just seemed to very well describe what we're seeing here. So when it's used in the insect world, particularly the ant colonies, it's usually used to describe a large number of ants and ant colonies that are spatially separated, but socially connected. And that's really what we're seeing here. So I think the term super commonly reflects the very high numbers that we're finding here. And the fact that there are these colonies that are really next door neighbours to each other, so there's sort of one in each of the, the mature woodlands in this sort of network here. And they are spatially separated, but very close. But there clearly is social interaction going on between those. And almost certainly there's going to be genetic flow between those colonies. And we're not aware of that phenomenon, really having been seen elsewhere in the UK to this extent. And there's some sites where, you know, there's really next or woodlands and you could draw a line down between them. But the barbastelles, they obviously crossing, there's overlap, but then the colonies never mix. So they're always faithful to roosting in their same in those same columns. So yeah, so that's been quite interesting, we've only really been able to start delving into that now that we've we're tagging barbastelles simultaneously from all of those colonies. So we can really start to get a picture of how those are interacting in terms of numbers, so the colonies in this area, they vary from around sort of 25 at the lower end, to the largest one in the area, which we've had over 105 barbastelles. And those were coming out of one individual tree. And it was incredible to see that it's a big old sweet chestnut tree. And as it's grown, it's sort of twisted in a bark split apart. And the barbastelles just sort of leak out all over. So it's incredibly difficult to count. Hence it being at least 105. So that's a conservative estimate. But we know at least that many come out of that tree. And every year, they've been going back and using that same tree in the sort of peak maternity period, but then they use many other trees in the area. And so for the super colony as a whole, we've now recorded nearly 100, individual roost trees being used by the super colony, and then, obviously now, because we've been going this is our fifth season of quite intensive study of these colonies, we're now finding a lot of the time they're going back to trees that we've already identified. So we have these little blue roost tags that we fit into the trees, unfortunately, before BCT brought out theirs, so we haven't been using yours, I'm afraid. So we've got a great database of of all those trees and how they've been used in different years and by different individuals. But then, of course, every year, we also accrue some new trees, the sites have been working out longer, we're accruing fewer new trees each year, because we've covered so many of the risk trees. And we've been collecting quite detailed data on the risk features and looking at the root use at different scales. So that I'm in the process of crunching through piles of data. But yeah, we're hoping to get that written up and published relatively soon. So yeah, we'll be able to say more about what we found with that in the near future, hopefully.

Steve Roe: 9:22

As an estimate, how many different colonies do you think that there are? And what sort of range are you covering as part of those surveys?

Unknown: 9:27

Well, the intensive study that we're doing is just on three of these colonies within the super colony. But we know there are more we know there's at least two more. And there are probably other ones on the radio tracking that and we put it together there has some clear gaps, which I'm pretty sure there's probably other colonies in those. So we are just scratching the surface at the moment. We're still finding finding out the answer that in terms of the numbers, that is a question that keeps me awake at night. I think what's clear is that from colony counts alone, we're only getting a fraction of the true picture. Our estimate based on the colony counts is around 270 barbastelles in the Super economy. But we've also been ringing, but we've only been ringing ringing for two seasons now. And we've already ringed 122 to date barbastelles. So that's really telling us there's probably an awful lot more than than than 270. So that's something we're working on this question of numbers. It sounds like something so simple, how many are there, but it's actually really hard. So we're trying to use a mark recapture, approach. So ringing the bats and then recapturing them and the rate of recapture over time, we should be able to start getting a picture of what that means for the for the numbers. And that's important too, not just for here, but because obviously nationally there isn't any good population estimate for the numbers above bestows. So we're hoping if we can contribute something to getting some better estimates here, then that might be something that can be used elsewhere and help to fill that gap in terms of how many are there.

Steve Roe: 11:05

And just to pick up on the ringing side of things are you ringing by catching bats away from the roost, are you hand netting at the roost, how you try to get as many bats as possible without causing that disturbance that sometimes associated with that?

Unknown: 11:18

Yes, we we, we've only been trapping on flyways. So we're not, we're not trapping directly from the roosts. Generally, we're in the maternity roost woodlands, and we put up nets, and then we're catching them on and we're on rides, and we're catching them on those flyways. We do sometimes go to other sites, which we know are important commuting routes as well. But I think it's important to say as well with that sort of 122 rings at the moment, we're still still going on with this, we're only we're only ringing in by sort of a couple of tracking sessions a season. So we're not out every night trapping and putting rings on bat. So again, I think that tells you something about the number that around that if you're only doing a couple of sessions in a woodland in a whole summer. And you're getting those kinds of numbers. And we are getting a good number of free traps to. So we're obviously keeping an eye on on how they're doing and how the ring wear is. But so far, that all looks well looks positive. So yeah, but it's something we need to do long term to really be able to get a grip on the numbers. And then ultimately, hopefully the actual population trends. So are they going up or down?

Steve Roe: 12:25

Nice. So can you just describe for people who don't know what they look like, what did barbastelles look like once more so ecology and their roost sites and things like that.

Unknown: 12:34

So they're really quite extraordinary looking and very unique looking. A lot of people describe them as being kind of pug faced. So they're a medium sized bat by UK terms. They're very, very dark furred, and most of our bats are varying shades of brown, barbastelles are really quite black. So they look like a little lump of coal, when they come flying out the roosts. They've often got these sort of like golden tips to the fur. And they've got this quite long, shaggy fur, and then they've got these very chunky, prominent ears and a very sort of black face. So yeah, they're very distinctive looking, none of our other bats really look anything like them. In the sort of early summer, they tend to start forming what we call maternity roosts. So that's where the females are gathering to sort of form a nursery where they're going to give birth to their young. And typically, we're finding them in mature trees, and often dead trees that have got loose bark. So of the 100 or so roost, we've recorded the vast majority of those are loose or flaking bark that they just sort of tuck up behind that that's definitely their their preferred feature. In this area, we find them predominantly in sweet chestnut trees and oak trees. And I guess really just because they're the species that are here and are forming those loose bark features, they're very much considered to be a bat of mature and ancient woodlands. So they're probably quite good indicator species and that sense in terms of habitat quality, and areas that are good for barbastelles are typically good for for lots of other species too. Yeah. And then I guess another thing that's quite distinctive about them is these very large home ranges that they have. So we've tracked bats from these colonies up to about 12 kilometres away. So they'll they'll go out and come all the way back to the woodlands. over that distance more typically, the home ranges are sort of five to six kilometres in this area radius around the maternity roosts. But yeah, they can go an awful lot further. And that's compared to things like say pipistrelles that have a home range, maybe only one or two kilometres radius. So, so yeah, they travel far. They travel fast. They like these really good quality habitats, woodlands, rivers, really quite a mosaic of habitats. I think at least that's what we're seeing here in in Norfolk.

Steve Roe: 15:31

And we're sat next to an oak tree, which has got well, like Lotty's described. It's just covered in bits of flaking bark we can see but so the deadwood the heartwood, behind the living bark tissue splits and cracks and crevices. And you say this, this is one of the tree roosts that you've been monitoring how many bats have you had in this oak tree here?

Unknown: 15:52

Yeah, it is one of the roost. It's been used by the colony. So sometimes when we track them, particularly late season, you might just have an individual bat roosting on its own, but this is a colony roost, but it wasn't being used by the full colony at the time. I don't think I think the most we've had from this tree is 22. And they only use this tree quite briefly. They do move around a lot between the different trees in The Woodlands so they do need a good resource of different roost options. But yeah, this is a classic sort of barbastelles roost tree really big, almost dead, not quite clinging on for life, oak tree, but similar. We've found them in time. Nice spindly long dead stumps that have just got a tiny little flick of loose bark at the top, and they're up onto there. So the, they're not always using the obvious, the obvious trees and obvious features that you think there is quite a bit of variety. And sometimes the roofs are very low down. Sometimes they're way up high in the canopy making it very tricky for us to count. And sometimes the the tree may have no bark left at all, except for one little A4 piece. And that's what they're, they're roosting under. So they, they do need this sort of continual supply of of suitable roost features to be developing because obviously those loose bark that's usually quite late on in the in the trees life and potentially those features are there one year and they're gone the next or there's a landowner I spoke to recently said that we need a continuous supply of dead and dying trees then which is basically what we need for them. But yeah, that's, that's really what we need. And, and often you look around these woods and there may be lots of old trees, maybe some recruitments. But the deer are often hammering that. So the the new tree growth, but often there's not an awful lot in between. So you do wonder, and it is a concern where the where the barber style roosts are of, you know, 100 years time, where, you know, where are they going to be coming from? And I don't think we've yet really cracked how to make the perfect barber style accommodation to tempt them. But that is something we've actually got a few different designs that we're trialling at the moment based on our on our restates that we've been collecting.

Steve Roe: 18:05

So why were you working with these bots? Originally? Were you working with them? Before the announcement of the new link road? Or was that did it all come about because of the denouncements living road?

Unknown: 18:15

So we've been we've been working on bats and two of the colonies in the area. And that had already sort of sparked our interest because there were these two right next door to each other colonies. And we wonder what was going on going on there. And the numbers were clearly very high. So we were already working at those sites. And then I actually read an article in the local paper, which mentioned one of the local landowners and actually in this woodland where we are now. And he was obviously very concerned about the proposed dual carriageway that's going to come through right through this but woodlands here. And he mentioned that he'd taken part in the BTO's British Trust for Ornithology, Norfolk bat survey. So he'd had a detector out. And he was talking about the bats. And he mentioned barbastelle bats have been recorded here, which obviously caught my attention. And obviously, it's so near to the other colonies, we've been working out that I was quite keen to follow up on that. And it also transpired that the surveys that have been done, the council's commission surveys for the road, hadn't picked up the presence of barbastelles here. And I managed to get hold of the acoustic data from from the BTO and have a look at that. And it was immediately apparent that there are a lot of barbastelles calls and very soon after sunset. So, you know, it seemed clear that it was very likely that there was going to be a colony in these woods. And so we followed that up with a trapping survey here. Caught barbastelles, radio tagged a couple of them, track them back to the roosts did counts and pretty quickly establish that there was a maternity colony here in these woods. That was quite late in the season. So we then plan to do more work on it in the following season, which we did. And then we followed up again this year as well. So we've been collecting a lot more data on those since then.

Steve Roe: 20:06

So you've publicly spoken out about the controversy of the Norwich Western link road. Why are you so opposed to it? Obviously, it's about the bats. But why?

Unknown: 20:15

Yeah, so I think more we've been studying these colonies, it's clear, there's something really quite exceptional going on here for barbastelles. This is a nationally important area for them. We've got what's probably the largest known extanct barbastelles roost in the area, and they're super commonly phenomenon. And the road would would basically cut through the sort of core of the cause in terms of the the core sustenance zone. So where those all overlap, drawing those around each of the maternity colony woodlands including some of the others we know about in the area, you get this kind of core area which is used by all of them, and the proposed road would cut right through the middle of that it would come directly through this woodland and this is a tentacle only woodland. But this area is also used by you know the neighbouring colonies as well. So it really will fragment the super colony. We're also concerned because there were two other colonies that were in the vicinity of the first phase of this road, which was called the Norwich northern distributor road that ran around the wood does what it says on the tin ran around the northern edge of of Norwich. And when we went back to look for those post construction, we couldn't find barber styles and those woodlands and that was pretty concerning. And I think those colonies, least one of those would have been part of this super colony. And they don't appear to be there anymore. The road went directly through one woodland, where you'd, you'd expect a pretty catastrophic impact. They're actually slight, slight tangent, but bizarrely, when we went there to trap, it was eerily quiet. I mean, the woodland still sort of looks okay. But very, very quiet. We didn't even hear about on the detector till gone midnight, one bat, the first bat. So something very strange going on there. And there are these indirect impacts that we're yet to really fully unpick. But the other colony, which we think probably would be in part of this super colony, was about two and a half kilometres from that road. So we're concerned that the road would not just impact directly on the colonists and this would, but it's also going to have knock on effects on the neighbouring colonies that are, you know, within that two and a half kilometre range.

Steve Roe: 22:27

So that road, which has been built, did they know that the bats were there, and did they try and mitigate for that?

Unknown: 22:33

Yes, they've done surveys beforehand, they were aware of the barbastelle colonies that were there. So the main mitigation seems to have been road crossing structures. So there's a green bridge, and there's some gantries and there's an underpass. And that's something that's been really interesting from our radio tracking is that we've seen barbastelles crossing that road, we've recorded multiple barbastelles from the colonies crossing that road. So I don't think the road is a barrier to barbastelles. Because they have such large home ranges, they've got to cross the road somewhere. But it's clear that they were having to track quite a long way along it before they could cross. So potentially, it's increasing their the time they're having to spend commuting. And then they were crossing multiple bats, different years, different colonies crossing at the same very specific features on that road. Unfortunately, none of those were the designated bat mitigation crossing structures. I mean, it's kind of obvious they were crossing where the vegetation comes as close as possible to the edge of the road. And it's sort of leaning over. So they're really having the narrowest possible dash across the road. So that's been something that's been quite interesting to observe from the from the radio tracking data. And the concern is that they're proposing much the same sort of approaches for the for this road here, the extension of that road. And given what we've seen on the NDR, the Northern Distributor Road, with very worried about what impact this is going to have on the barbastelles colonies here, that you know, the evidence is there. And yet there seems to be this insistence to plough on regardless, so...

Steve Roe: 24:09

The road that they're proposing is a dual carriageway, in either direction that is gonna be under four miles in length. And we know that barbastelles perhaps will commute 12 miles if not more, why is it going to have such high impact when the majority of the woodland is going to remain?

Unknown: 24:23

I think we need to move away from just focusing on individual roost trees in particular. But even just the individual woodlands, you know, these really are bats of the landscape. They've got large home ranges. They're not here because of an individual roost tree. They're probably not here because an individual woodland, I think barbastelles will be a lot more common, if all they needed was a bit of flaking bark on a tree somewhere. So yeah, so here, there's obviously the direct habitat loss, direct loss of reuse trees on the path, the road, but the woodland as a whole is going to be fragmented. There'll be noise, light vibration, very likely reduction in insect numbers. Pollution, there's just yeah, this sort of gradual degradation that happens around the roads. But then, you know, the road cuts right across the river Wensum. And that is the main commuting route for bats from all three of these core colonies that we've been studying intensively. So that really is their sort of main highway there. They forage a lot along the river as well over the marshes. So obviously, there's going to be a big impact on on that feature for them. And then it also cuts across farmland, so it will cut across the farmland next to us here. That's a key area they use for foraging. And obviously the woodlands themselves they're you know, here they're using this not just for roosting but they're they're foraging here is where the young when they emerge from the roots are learning to fly in the shelter when the weather's bad. They'll stay in the woods to forage. So it's really just sort of carving up the landscape. And they're using really all the habitats along this road. Yeah, so it's a lot more than the direct footprint of the road. It has all these sort of knock on indirect effects on the surrounding habitat. So you end up with a much, much larger area that becomes far less suitable for use by barbastelles. So it's probably doesn't happen overnight. It's probably a gradual process. But the evidence that's out there suggests that this will have a really serious impact. It's on these colonies. And yeah, it's the most important area in the country probably for barbastelles. So I think it'd be pretty catastrophic if this goes ahead.

Steve Roe: 26:39

So the proposals show that they are going to try and mitigate for for the colonists, you know, they're proposing several green bridges, viaducts back underpasses. They've acknowledged that bat gantries aren't perhaps as successful as once thought, and they've moved away from the idea of those those big gantries or bat bridges. Why is all that other mitigation which we think is more suitable? Why is that mitigation not enough? And what mitigation would you think is appropriate?

Unknown: 27:06

Yeah, it's a good question. I think the thing is, it's very simplistic in terms of, let's just make sure the bats can cross the road. That's only a small part of what the problem is here. So the idea with those mitigation crossing structures is to avoid barbastelle collisions with with vehicles to try and get them to cross at a safe height. As I said, we've seen on the northern distributor road that they aren't using those including the green bridge. I think there's also a danger that things get treated in the same way when they're not necessarily the same. So there is evidence that green bridges can work. For some bat species, I'm not sure that there's direct evidence out there for barbastelles. But those green bridges that have had some success, look nothing like the green bridge that's on the northern distributor road. So you know, if you're clearing the vegetation way back, you're sticking a bridge in that's really exposed over the top, and then you're sticking a load of hedge whips in that then invariably perish because they're not looked after. That's not a green bridge. You can call it green bridge, but it's not a green bridge. So we've got to be really careful what we mean when we say green bridge, because they're not all created equal. And you know, to do them properly, and to have any chance of them having some sort of effectiveness, they're incredibly expensive to do. And that's why they get sort of corners a cut, and you end up with something that's really just a bridge, not a green bridge. Again, I know there's been some success with things like underpasses as well. But that's not what we've seen on the northern distributor road here. I think something that's interesting, that we weren't looking at directly, but we've sort of learned from studying the barbastelles here is the literature often seems to say that there are high flying species. And so I think the assumption was that, you know, the risk of them colliding with vehicles is, is fairly low. But what we've seen repeatedly because we're, we're trapping with Miss nets, on fly aways, we're not using lose, we're not doing anything to pull them down to a lower level. But typically, we're catching them at two metres or under. So that is prime vehicle collision height. And also, we often actually cite them when we're out radio tracking, either because there's some moonlight or we use infrared cameras and with detectors, so we actually can often see up the bat we're tracking and they're not flying way up high in the sky, they're flying low down. So that is a problem. And I think one of the latest potential mitigation measures, they've mentioned that these popovers there's so this idea of keeping the vegetation close to the edge of the road, and having sort of some overhang to help the bounce across. And from what we've seen that on paper sounds good and sounds like it would be something they they could use and we know they use features like that. But there's no evidence to suggest that they're actually going to cross high up there. You know, what we've seen is that they cross lowdown, and have been some studies in Europe that have shown that in back carcass searches alongside of roads, looking for bats have been hit by cars, the barber cells can show up disproportionately given their rarity in those searches, which would suggest they're potentially more vulnerable. And certainly, what we're learning about their flight heights would suggest that they are going to be very vulnerable to those collisions.

Steve Roe: 30:25

I mean, I've noticed that you know, I do commercial trapping projects around the country and I say well you know, we use mist nets and not using lures on mist nets and we're getting them in those bottom two pockets of the mist net right down at the ground. Has anybody done any studies or has anybody got any ideas as to why they fly so low down?

Lotty Packman: 30:41

Not that I'm aware of no, I mean, I'm guessing that well when they're in the woodland, the canopy is often quite low. So that makes sense that they're they're flying low, it's nice and sheltered. If they're following a tree line or hedge line, those features are often low if they want to be under them and in the shelter of them. And it may well be that their food. So we know they actually quite a range of insects, but moths are often a big chunk of that. So potentially the species that they're after for for feeding are low down. So yeah, I'm not sure where this idea that they're high fliers has come from but it's certainly not been our experience here. And also they're often described as a late emerging species. And that's also not been our experience here. We're we're often recording them. Pretty soon after sunset. Sometimes you even occasionally before sunset, and they can be quite variable. But there's just so much other things that we're learning as we go along. And also, I mean, even things like dispersal. So I think we always assume the females must stay and return the juvenile females to the maternity colonies. And it's probably the males that are dispersing. But the juvenile males that we bring to these colonies, we are catching a year later, back in the maternity woodlands, which I think is quite interesting, which suggests potentially that they are not dispersing. But then potentially, that's not where meetings happening. So we had a really interesting phenomenon. Last season, we were tracking later than usual and you know, sort of further into the end of the season than we usually do. And we have bats tag simultaneously from the three core study colonies. And all of our bats ended up at the same site. Were out of range, normal range for most of them. But they all converged in the different colonies on this one area, which suggests to me that that's potentially you know, maybe a swarming or mating site. So perhaps it doesn't matter if the male's dispersed from the maternity woodlands, if all the colonies in the area are going to a specific site to mate, then that's perhaps where the genetic mixings happening. So I'm digressing. But there's just all these interesting little nuggets that we're picking up along the way from from the data.

Steve Roe: 32:54

Well, since you've gone off on the tangent, just to pick up I know you've, you've said how many books you've written, How many books have you radio tracks at the moment?

Unknown: 33:03

So specifically, in these three core sites, we've now radio tracked? I think it's about 60 adult female barbastelles. So yeah, and that's been over four or five seasons. So obviously, this one here, we've only been studying relatively recently. Yeah, I think we're getting quite good picture from that number of bats.

Steve Roe: 33:24

So early this year, in February, Martin Wilby who's a council cabinet member for highways transport and infrastructure, confirmed in a previous interview that the notable bat activity found in the woodlands in the area of the northern end of the proposed road route means that they're currently carrying out work to develop mitigation and refine the proposed alignment of the new roads to minimise the impacts of the scheme on the area. Will that alteration in that barbastelle hotspot not solve the issue?

Unknown: 33:55

No, I don't think so. It's a very minor tweak to the route. My understanding is that they've done that to avoid one specific route tree that the council's contract has found. But there are many roost trees here. There's another roost tree that's actually directly on the path of the road, which they haven't found in their surveys. I don't think so. Yeah, this is cosmetic. Unfortunately, it's not going to make any fundamental difference. It's still coming through these woodlands. It's still coming right through the core, you know, that core of the core sustenance zones for the for the super colony. Yeah, I can't see that. That's other than avoiding one individual roost tree, I think it's sort of missing the point to think that that's going to make any difference really.

Steve Roe: 34:37

And again, I can't remember if it was the same interview or a different one. But you said that the council have chosen the had chosen the route before undertaking bat surveys, have they said why they didn't follow the best practice guidance and an undertaken bat trapping surveys, which is pretty standard for large infrastructure projects. Have they said why they didn't do that from the outset?

Unknown: 34:57

No, we haven't got a clear response on that. I think the issue that that was apparent was that they had a shortlist of potential routes. And they had selected this specific route without doing the detailed bat surveys on it. So as I said, if they if they had done the proper surveys, it would have been very apparent very quickly that there was a barbastelle maternity colony in this woodland. And usually, that would have been a complete game changer. And they would have said, okay, great, we need to go back to the drawing board. I think the difficulty they've got themselves into now is they've pressed ahead with the road plans, and then retrospectively have sort of scrambled to try and get the bat survey data together. And now, they are slowly starting to find things that are a little bit inconvenient for them, it's still a problem that they've only really scratched the surface in terms of the significance of the colonies here. So they're, the colony counts are much lower than the counts that we've had here, and at the other sites, actually. So there's a lot that's missing. But they have at least acknowledged now, which was flatly denied in the early days that there is a maternity colony and this word, albeit that they they haven't really captured the full numbers and the full significance.

Steve Roe: 36:10

So given that you found this the super colony and you find a more data new information all the time and it does appear that it's a large population, you know, what are the local designations like is the area designated, how many other trippler size rescues have you got in this area?

Unknown: 36:25

So there's quite a big gap. here for that. So this woodland here is county wildlife site. And that's overseen and administered by Norfolk Wildlife Trust, who are actually working for at the moment for for six months doing this research. But yeah, there there aren't many SSSIs and there's only actually despite Norfolk being a stronghold for barbastelles there's only actually one SAC designated for barbastelles in Norfolk. And that's Paston Barn that Jane Harris talked about before on this podcast. So we really would like to see this area designated as a barbastelle SAC. As I said, it's probably the most important area in the country. For them, it's absolutely crying out for some protection. Most of it isn't even SSSI. So it is scarily under protected at the moment. So that's something we'd really like to encourage Natural England to look at.

Steve Roe: 37:15

And how difficult is it to get those designations in place? Is it a case of you present the data to Natural England? Do you know whether you've got enough data at the moment to go to them with their data?

Unknown: 37:24

Yeah, so I think it's clearly a bit of a long process. But the huge advantages we've got here is we've got so much data about these colonies, and over, over, you know, a good few years. So we should really have all the information that that Natural England need in order to be able to designate those sites. So I hope that should make it a lot easier to get these these designations in place.

Steve Roe: 37:51

Dr. Charlotte Packman. Thank you very much.

Lotty Packman: 37:53

Thank you.

Steve Roe: 37:58

Thank you to Lotty for sitting down with me. If you'd like to find out more about the Western link and the potential impacts that could have on wildlife, we've put a link in the show notes to the Norfolk Wildlife Trust. And our own position statement on the proposals is also in the show notes too. We've also included a link to that other episode mentioned with Jane Harris at the incredible Paston Great Barn site. So do go have a listen to that. Please do get in touch with the show to tell us about your bats, a special bat sighting you had this year, or a site you think everyone should visit to go and watch bats. Whatever your experience with bats, we really want to hear from you. So do get in touch. The voicemail link is in the show notes. And don't worry, you can hear your message back and we record it if you don't like it before sending it to us. Messages can be up to 90 seconds long, and we can't wait to hear from you. Next time. We're speaking with one of the legends of the bat world; Tony Hutson. So join us then in two weeks time.