Winged passions: The bat basement of Cliveden House

S4E42 This week Steve joins Chris Damant in the grounds of Cliveden House on the banks of the River Thames. As fine dining takes place in the hotel above them, Chris and his team have set up traps to catch bats as they arrive to mate in the middle of the night. Underneath the south terrace are a number of rooms which mimic underground structures and its these that the bats travel to from far and wide to undertake an annual phenomenon, autumn swarming. Cliveden hosts one of the most important bat sites in the country, with eight species swarming here between August and October.

• Read more about the work Chris has undertaken at Cliveden
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• Take a look at our ROOST website that Chris mentions in this episode
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Chapters

• 0:06 Episode introduction
• 2:04 Cliveden House with Chris Damant

Transcript

Steve Roe: 0:06

Welcome back to BatChat from the Bat Conservation Trust. This series so far has been our most downloaded ever. So thank you for your continued support of the show. If you're listening to us for the first time with the Bat Conservation Trust, the leading charity in the United Kingdom solely devoted to the conservation of bats and the landscapes on which they rely, and this podcast of ours is for anyone who loves bats. With each episode, we're bringing the hidden lives of bats from the middle of the night straight to your headphones. I'm Steve Roe. Professionally, I'm an ecologist and in my spare time, I'm a trustee of the Bat Conservation Trust. You can join the conversation online using the hashtag #BatChat ... that's all one word. Before we join our guest in a moment, we wanted to let all of our listeners in Scotland know that the Scottish bat conference will be taking place on Saturday the fourth of March at Stirling University and will be run as a hybrid event. The Scottish conference provides an opportunity for both volunteer and professional networkers across Scotland to spend time together, updating their knowledge sharing best practice, developing their skills and catching up on the latest bat news. The day will include spotlight talks from various back groups across Scotland, longer talks on projects or sharing new knowledge and research talks. The link to book is in the show notes. And to all of our listeners in the south-west of England your next regional conference is on Saturday the 25th of March at the Petroc College Tiverton campus. Again, this one day event is an opportunity for anyone interested in bats from hobbyists and volunteers to professional vertical assists to spend time together. The day includes a mixture of short and long talks on projects and a choice of practical workshops. There will also be time for catching up with batty friends or making some new batty acquaintances. If you've never attended a bat conference before, I'd really encourage you to attend. You don't need to know anything about bats to attend, but I can guarantee you'll learn something and come away with new connections either from BCT or your local bat group. The booking pages for those two events can be reached from our show notes. So it's time to join this week's guest. Back in September, I headed down to Berkshire. Sat on the banks of the upper reaches of the river Thames, Clivedon is an impressive house and Estate in the care of the National Trust and sits on the edge of the Chiltern hills. The garden slopes down towards the Thames and it's on the edge of the lawn that you join Chris Damant watching his surveyors check harp traps and mist nets against the tall wall of the south terrace. Above them in the house which is now a hotel, guests have no idea of the work taking place below them.

Chris Damant: 2:41

So we're sitting at Clivedon National Trust property overlooking the Thames. It's been a bit overcast day, but we're hoping that the bats will arrive shortly and start swarming around the south terrace. The Grand Terrace above the parterre where fine dining is taking place, and people are enjoying grand meals. But the bats are about to arrive for some close encounters we hope.

Steve Roe: 3:06

I mean, Chris says'the grand balcony' the grand balcony is probably as tall as my house and that's before the house [Cliveden] starts. So rather an impressive structure, isn't it? And you can probably hear a bit of a squeaking noise behind us that's edible dormouse. digits. Swarming is a little bit unique. It's a built structure. But

Chris Damant: 3:21

Yes. Introduced by Rothschilds in the Chiltern's many many years ago and slowly expanding their range we're lucky that south terrace underneath it has a series of Chambers from fernery grill foundries with their goldleaf metalwork that extend into enclosed water tanks created many years ago because the house has previously burned down a few times. So it was super cool. The water tanks are built for caution against fire.

Steve Roe: 4:33

So just describe autumn swarming then so I mean, UK bats in general have two main mating strategies. So we'll ignore the pips and the noctules for now and we'll talk about these bats here which are Myotis and long-eared's. What else do you get here?

Chris Damant: 4:49

We occasionally get Bechstein's or barbastelles, but primarily it's Natterer's or Daubenton's.

Steve Roe: 4:54

You said that so casually Oh, we occasionally get Bechstein's and barbastelles!

Chris Damant: 4:57

Very small because the first first Bechstein's we caught in Buckinghamshire was recorded here, which is very unusual. Subsequently, it's found the roosts have been found locally in fact, but the main species here is Natterer's. And they come in the autumn together to breed well autumn swarming where bats appear to gather dominated by males with low numbers of females, maybe 25% of the bats are females. Yeah, we think breeding is a strong component or why the bat bats are gathering here and would be quite important for exchanging genes in groups which would otherwise be isolated. Bats could potentially be travelling 10s of kilometres to meet here. And come from a large area.

Steve Roe: 5:49

I mean, we say a large area John Altringham's recorded Natterer's bats flying 60-something kilometres away.

Chris Damant: 5:56

It's quite an incredible investment in energy to come to, for a bat to travel that distance on one night. And there has to be a very good reason behind it, even though we don't fully understand it. It's certainly dominated by males at Cliveden generally the 75% males 25% females, and it must be a source of out breeding within populations. But it may also be to do with showing young bats where hibernation sites are for extreme environments for when it's really cold.

Steve Roe: 6:32

And we think that because juvenile bats turn up quite often, don't they?

Chris Damant: 6:34

Yeah, juvenile bats are a key component. Equally, all the males that turn up generally tend to be in very good breeding condition, which is why we think it might be to do with out breeding. It's hard to know exactly as much research has been done, but we still don't really know.

Steve Roe: 6:52

So you're catching the bats here with a mixture of harp traps and mist nets. So when did you Well A) how did you come across the site and discover it? And how long have you been doing the work here?

Chris Damant: 7:04

Well we were invited by the National Trust to carry out of biodiversity assessment of the estate, probably in 2007/8. And with the assistance, the local Berkshire and South bucks bat group, and the North bucks back group, we identified peaking activity late in the summer around the south terrace. We didn't understand why. And the following year, we came did more detailed surveys, including catching the bats. And we picked up the male dominance, swarming activity, the chasing of the bats that was taking place outside the structure, and were able to observe the fact that the bats started gathering outside and slowly moved into the fernerys and then subsequently into deeper water tanks where a lot of chasing was going on. Since then, we've been monitoring every year. During that period, the National Trust carried out extensive renovation works to the south terrace which was becoming damaged by water logging, and poor condition. Much the brickwork needed repairing. And were able to carry out that work successfully and maintain good swarming activity throughout that restoration period of about five years.

Steve Roe: 8:19

I missed how long you said, when did you say started?

Chris Damant: 8:23

I think the first plan started about 2010. Okay, and the work wasn't started till probably 2015/16. It's hard to remember that far back now. And we'd been doing the sort of site monitoring every year apart from the first year of COVID.

Steve Roe: 8:41

So you mentioned the National Trust there. So it's a National Trust owned estate. But then there's a private hotel business inside the actual, the actual house, what's the view of the Trust with the bats and the relationship of few guys with the work and, and the business?

Chris Damant: 8:58

everybody has been incredibly supportive of everything we've done from the bat point of view, once it was identified as an important site nationally significant, the fact that it's built structure is equally unique. So everybody, including the hotel and National Trust has been very supportive in the work we've carried out. programmes of work have been designed around the bats to ensure their continuity of presence here. And it couldn't have been achieved without all support for the individuals, many of the project managers, the Building Surveyors, the prophecy staff, in in, in looking after these bats and continuing to do so.

Steve Roe: 9:35

So I mean, on a on a typical night, when you do get decent levels of swarming activity, you know how I mean how many bats you're catching and how many nets you using?

Chris Damant: 9:44

We usually use a harp trap at each end of the south terrace were where there are ferneryeither end, and that's combined the two triple-high mist nets as a standard method for capturing the bats as they enter the structures or fly around them. And we might catch on a good night anywhere from 50 to 75. That maybe more some nights. Like tonight, perhaps we don't catch so many. So we might catch 20 bats. The weather's not been great today. But hopefully we'll catch something. What is interesting is that swarming is generally not very good if it's rained during the day, the bats won't invest the energy into coming this far. If the weather is not hot, warm still, if there's rain, they will, they will probably stay away. And I think unfortunately, that's the night we've got in front of us.

Steve Roe: 10:39

So I mean, sets something like up to 75 bats a night for me sounds impressive. I'm used to trapping in the Peak District where we're very lucky. And we've got hundreds, if not 1000s of underground structures. And we suspect that swarming takes place at all of those on any given night. Why have you got so many more bats here?

Chris Damant: 11:00

It's possibly I mean, there's a geographical element to it. And the further south we'll probably have more abundance of bats locally, we're sitting in a fantastic corridor along the River Thames, with Woodland, steep, wooded, wooded slopes above it. So the property dominates the landscape here. In the south, particularly around here, there are very few underground sites where bats can actually carry out the swarming activity, right. So it's probably a combination of all those factors. And the fact that buildings been here for so long. The south terrace is probably the oldest structure on the property now originated back in 1580s, I believe.

Steve Roe: 11:46

So you've got a team of people here this evening, there's what, seven people you've got here, are they? Are they here as part of your company? Are they here as volunteers, and you know how many people over the years have been involved in the site and the project?

Chris Damant: 11:58

We're very lucky we've got a dedicated number of staff that come out every year. Some years they come from a paid point of view, sometimes they come totally voluntary capacity. But we also get a lot of volunteers from local back groups, and free people coming from further afield like yourself just coming in to experience a different type of structure. And to learn about bats swarming at Cliveden, it is slightly unique. And it gives a perspective on where we might find bat swarming sites in the future. I often wonder whether we overlook buildings like this for bat swarming and perhaps should be looking more openly in the future. So giving people that experience could be very important in learning where swarming's taking place in the future.

Steve Roe: 12:39

And I remember when you gave this talk at the swarming conference back in 2017, and it was such an unusual set of photographs he had ever had such an impressive building, and photography, something that you've started doing. We've had lots of photos recently been published via obesity that you've donated to them, and you've been published on your own social media. The photos that you take are perhaps quite unusual compared to some of the typical ones you see, you know, you've got no grains, tombstones, grave stones or or guilted gates, what methods you use into to photograph those bats and what's the interest with capturing bats against unusual features like gravestones and tombstones.

Chris Damant: 13:19

I think a lot of it comes from just being lucky to work environments where there are unusual settings. I think in the pitches you mentioned, the gilded Gates was here at Clifton and the large gargoyle faces on the Borghese Balustrade at Cliveden, we're lucky to be able to catch the bats. And when we release them, there's an opportunity to photograph them and perhaps showcase bats and different environments that you normally get a bat against a black background is perhaps one image but they've also in our natural environment and built environment. So it's nice to get a difference. In terms of photography, I'm very much learning how to do it and have a lot to learn yet, but it is trying to produce something different to look at, besides the bat. And the context in which it's found.

Steve Roe: 14:08

Was just striking to me to have such a useful set of photos that have time quite nicely with the bats in churches project. That's something I've been involved with, isn't it the bats and churches projects, what's the interest with the with the church side of things?

Chris Damant: 14:21

Again, it's this built environment is it's it's looking at nature and nature with people and trying to find ways of living with what people to live with bat's particularly the case of churches. There have been various issues raised and it's nice to put the perspective in a positive light of how we can live together. Rather than see an issue is conflict and photographs and imagery as part of telling that story. Great. I do enjoy working with church communities as much as working with organisations like National Trust and if we can solve some of those problems even better.

Steve Roe: 15:02

So I've should have asked at the start, what sparked the interest of Bats then and how long ago was that? Making

Chris Damant: 15:09

You are asking! My first experience of bats was in you think! Surrey, was a chap called Frank Greenaway many of you will probably know. And I was looking after some limekilns on behalf of the County Council. And I met him one day and he showed me where some whiskered/Brandt's happened to be roosting in the lime kilns. And during the winter, he then went and took me to various sites, including West sample caves. And the hill fort at Box Hill owners show me the hibernating bats, and they fascinates me ever since. And it's only through work that I'm lost contact with Frank and then came back starting to work with bats back in '98, when I set up my own company, I was able to start doing my own little bits of research and been encouraged by many gifted bat ecologists, including Phil Richardson, and I've been always grateful for the support I've been given. And I love coming out at night, on the quiet nights and just watching the bats and enjoying their company.

Steve Roe: 16:21

And we were chatting earlier before we hit the record button. We were talking about the importance of training of, you know, fresh blood, you know, the younger generation of taking it forward. So when we get too old and decrepit, somebody else can do it. I mean, what, what? Where do you think the future of Bat Conservation lies? Is it in fresh blood? Or is it in getting that relationship between our built environments and bats going? Or is it something else altogether? What do you reckon about that?

Chris Damant: 16:50

I think I think both isn't and it's probably a lot more than that. I mean, I'm, I'm always grateful for all the people who've helped me learn more people to put up with my daft questions, which why this? Why that? And provide that mentoring support through it. And I think now, I like your question of when we get old and decrepit, I already feel old and decrepit. That you can hand that baton on and perhaps encourage other people to take it on. I think from a business point of view, I think it'd be need to invest in younger people and trust younger people to take from the messages. I'm not quite convinced that I've got things right, and our generation have got things right. But perhaps it's time to hand that baton on and let the other generations have a go. And perhaps build on the successes we've made, and make it better, and hopefully combine our lifestyles with the natural world and get it right for once.

Steve Roe: 17:50

That's a nice answer. You reminded me something that you said, we don't always get it right. And we were talking again, before we we started this about the success or the lack of success and mitigation. You've said what you've done. It's the little things that count, isn't it?

Chris Damant: 18:06

It is I mean, I think in the case of Cliveden, it might be a grand site. And it might look fantastic. But it was the little things that helped it was building relationships with people it was finding simple solutions rather than complex ones. I think at Cliveden, we were very lucky that we were managed to afford find simple solutions that avoided impacts, rather than going for more complex solutions that would have directly impacted on the bats. And as simple avoidance measures by taking a little time to complete the works. By avoiding working on the sights. When the bats were presents, we were able to combine the interests of the built structure with the interests of bats and preserve the swarming activity here. And hopefully we'll carry on for many, many more years. Those simple solutions the best and it doesn't always have to be grand houses, why can't it be with our homes, our environment that we live in, rather than just the wealthy or the landed estates, it can be anywhere we live. And I really would encourage people to look at finding simple solutions. And more importantly, reporting those solutions. Sometimes they might be successful. Sometimes they may not be. But the solution is itself. It's knowing what is the right action to take and telling people how you learned about this, what went right, what went wrong, and perhaps being a little bit more honest and open about, about how you go about the work and report on it how things work and how they don't work.

Steve Roe: 19:42

So in that case, Chris, would you say, the roost awards haven't happened this year they've been postponed partly through due to a lack of interest or a lack of time for people to submit them. Would you encourage people to submit those those case studies even if they haven't worked then?

Chris Damant: 19:59

I really would encourage people to submit case studies to the roost awards. Most importantly, because we need to learn what has worked, what hasn't worked, we need to share and exchange that information. We need to improve our knowledge base. And whatever you've done, do think about writing it up, do let us lose, do let people know what is happening, because it builds that community and that knowledge and build on how we can help that in our environment.

Steve Roe: 20:33

I mean, it's I mean, it's tricky

Chris Damant: 20:35

finding time isn't it.

Steve Roe: 20:36

It is finding time and, you know, without that resource anyway, that I find that whether mitigation works is by chatting to fellow bat workers like yourself, so it's really useful resource isn't it.

Chris Damant: 20:48

Yeah, it's exchanging information it's communicating. If it's not about people communicating what is it about? Yeah.

Steve Roe: 20:57

That's nice. All right, we better go see if we've got some bats Chris Damant, thank you very much.

Chris Damant: 21:02

Thank you very much. It's a delight.

Steve Roe: 21:10

My thanks to Chris for pausing his important survey work whilst we recorded that interview. If you're listening to us on Apple podcasts or Spotify, don't forget to leave us a five star rating or even write us a review. Join us next time from the county of Northamptonshire.