1:00

Hello and welcome to

1:00

this week's Bat Chat from the

1:02

Bat Conservation Trust. I'm

1:02

Steve Roe, and this week we're

1:05

in the Staffordshire Peak

1:05

District. When I started doing

1:07

that work at the age of 12, one

1:07

of the first longterm surveys I

1:10

got involved with was a

1:10

hibernation survey with

1:12

Staffordshire bat group.

1:12

Historically, Staffordshire and

1:15

Derbyshire back groups have had

1:15

strong ties because we share the

1:18

Peak District National Park and

1:18

every winter we still undertake

1:20

this particular survey together.

1:20

Now this year, many bat workers

1:24

are missing going underground as

1:24

there is an unknown risk of

1:27

passing the Coronavirus disease

1:27

to bat populations. And so to

1:30

prevent that happening, all

1:30

surveys undertaken for the

1:33

national bat monitoring

1:33

programme have been cancelled

1:35

this winter. So we hope that

1:35

this episode will remind

1:38

existing workers that one day we

1:38

will get back out there and to

1:41

any of you listeners who are

1:41

thinking about joining your

1:43

local bat group, or have yet to

1:43

undertake hibernation surveys

1:46

will recognise how fun surveys

1:46

are and will encourage you to

1:49

get involved with your local

1:49

group and to contribute to

1:51

important long term datasets. So

1:51

last February before we had any

1:55

idea of what was about to unfold

1:55

and that we were headed for a

1:58

national lockdown, we took the

1:58

podcast recording kit along on

2:01

last winter's survey resulting

2:01

in what may well have been the

2:03

first podcast to have been

2:03

recorded inside a mine adit.

2:07

Helen Ball is the survey leader.

2:07

And we join her at the start of

2:09

the day making the two and a

2:09

half kilometre trek from the

2:12

cars to the nature reserve where

2:12

the survey happens in the

2:15

Manifold Valley. So it's a

2:15

Saturday in the middle of

2:19

February. I'm currently walking

2:19

through a very blowy windy field

2:24

with members of both Derbyshire

2:24

and Staffordshire group. Helen,

2:28

what are we doing today?

2:31

Other than getting lost

2:31

on a very steep hillside. We're

2:36

carrying out an annual check and

2:36

Monitoring Survey for bats that

2:42

use a series of mine adits to

2:42

overwinter in. And hibernate so

2:48

we're doing counts of the

2:48

numbers of bats we see and the

2:50

species.

2:51

And where about's in the world are we?

2:52

We're in the best

2:52

part of the world. We're in the

2:58

Staffordshire Peak District in

2:58

the limestone area in an area of

3:02

the Peak District known as the

3:02

white peak, and it's riddled

3:06

with caves and mines. And lots

3:06

of them we used by bats.

3:12

So how long has it

3:12

been going on here?

3:16

The study's been going

3:16

on for quite a long time since

3:19

the very early 1970s. And as far

3:19

as I know, it's one of the

3:25

longest studied winter

3:25

hibernation sites for bats

3:28

probably in the country.

3:31

Who was doing it although back then then.

3:33

Well, initially, the

3:33

adults were checked by Derek

3:38

Yaldon. Derek was a local

3:38

mammologist, very eminent,

3:45

internationally known zoologist

3:45

who studied mammals. And he

3:50

moved to the Peak District on

3:50

Manchester side and spent most

3:54

of his weekend studying mammals

3:54

of the Peak District including

3:58

mountain hares, the Wallabies

3:58

that live down at the roaches

4:02

but also bats. And he used to

4:02

come up to the mine adits here

4:06

on a weekend with his dog and

4:06

check the caves for bats as

4:12

we're doing today. And who owns the site we're

4:14

heading to today's nature

4:16

reserve or there's a series of minor edits

4:18

11 In total, two of the biggest

4:23

edits along the studies are on

4:23

Staffordshire Wildlife Trust,

4:27

Nature Reserve known as Castern

4:27

wood. And it's a very beautiful

4:32

reserve overlooking the river

4:32

Manifold,

4:36

which we're coming up to now. And you can sort of see it and dips away way down into the

4:38

valley and there's no sunshine

4:41

down the bottom. No, it were the top of the hills

4:42

about 500 foot above the river.

4:47

And what sort of bat species are

4:47

we hoping to find and then what

4:49

sort of numbers we're hoping to find five

4:51

species so for the Myotis

4:56

Daubenton's, Natterer's

4:56

whiskered, and Brandt's and

5:00

brown long-eared they all use

5:00

the caves and mines here.

5:05

numbers vary from year to you.

5:05

And between the different mine

5:09

adits. We can get anywhere

5:09

between maybe 20 bats up to

5:14

50/60 and sometimes even higher.

5:20

How far is it to the first cave?

5:22

Oh, well, I don't know

5:22

a few hundred metres. This one

5:26

is probably the easiest to get

5:26

to. But they all involve going

5:31

down quite steep slopes

5:32

So the tunnels we're walking

5:32

long, I'm struggling to stand up

5:43

straight. They're less than six

5:43

feet tall and metre and a half

5:47

wide. And as you can hear it's

5:47

pretty echoey so Helen we've

5:52

scrabbled down a rather steep

5:52

hillside and we've come through

5:56

a gated system why have some of

5:56

the systems got gates off.

6:01

As some of the systems have got

6:01

gates on on the sites are

6:05

visited more by members of the

6:05

public. So it's to stop people

6:08

going into the adits who may be

6:08

are not really kitted out are

6:13

aware of what dangers could lurk

6:13

inside. They're all padlocked

6:18

and the grilled and the grills

6:18

are set in a way that bats can

6:22

still fly in and out, it doesn't

6:22

affect their use of the mine.

6:28

I mean, we just found five or

6:28

six bats before the grille is

6:31

that unusual or expect to find

6:31

more inside further inside the

6:34

system. So in this adit, in particular,

6:36

we often get a concentration of

6:40

Natterer's bats, particularly

6:40

and one or two long-eared near

6:43

the entrance. I remember one

6:43

year we found eleven just in

6:48

cracks in the entrance before

6:48

the grille. So there's usually a

6:53

concentration of Natterer's and

6:53

a few long-eared's near the

6:56

entrance. And then as we get

6:56

further in the bats will be

6:58

spaced along. You get

6:58

Daubenton's, whiskered,

7:01

Brandt's, How long are the systems on

7:04

average what are the rangees.

7:08

So the adits all very, there's

7:08

some that are maybe only 5, 10,

7:14

30 metres long. This one's 90

7:14

metres long, but the far end of

7:17

it's blocked with stacked deads

7:17

and collapses. Some of the

7:22

longer adits here are to 250,

7:22

nearly 300 metres long.

7:26

["there's a WAB here Kelly" is called out by a distant voice from surveyors ahead of Steve

7:28

and Helen] So the guys in front of us are

7:29

searching the walls, is there a

7:32

particular method and what they're doing? Yes, so so we try and have a

7:35

method in that every other

7:39

surveyor will take a wall up to

7:39

the top of the ceiling. So left

7:44

hand wall, and then right hand

7:44

wall, searching systematically

7:48

all the little gaps, nooks and

7:48

crannies for bats. And then on

7:52

the way out, we look again,

7:52

because it's quite easy to miss

7:55

bats, particularly in some of

7:55

the deeper crevices that are

7:58

facing inwards towards the mine.

7:58

So we'll reverse it and look

8:02

again on the on the way out. So this bat we've got here Helen

8:11

is just clinging to the wall

8:15

close to the ceiling. How are we

8:15

distinguishing what it is?

8:18

Okay, well, we know

8:18

it's a Myotis bat from the shape

8:24

of the tragus, the very pale

8:24

belly. In these systems, we get

8:30

a lot of whiskered and Brandt's

8:30

very very difficult to tell

8:33

apart even in the hand. But we

8:33

look at some we tend to get a

8:38

jizz if you see them quite

8:38

often, the whiskered in the Peak

8:40

District are often a little bit

8:40

smaller, quite dark. The Tragus

8:44

is a little bit of a different

8:44

shape, we look at the shape of

8:47

the nostril. So often it's gone

8:47

on jizz in the in the caves but

8:52

because we can't handle them

8:52

because we can't test the fur

8:55

for DNA. We always put them down

8:55

as a possible whiskered and

9:00

possible Brandt's. And quite

9:00

often they're just literally

9:04

written down as

9:04

whiskered/Brandt's. Oh we're

9:07

doing well. That's 10? 10 up to

9:07

there already! Brilliant.

9:14

One there.

9:16

This one is quite different. This one's a lot paler than what we've just seen.

9:17

He's got a much wider tummy. So

9:21

what's this?

9:22

So this is a

9:22

Natterer's. This is the most

9:24

distinctive Myotis we're getting

9:24

the caves and when you're

9:27

learning about Myotis bats the

9:27

first one you would learn is

9:32

Natterer's. So it's got a really

9:32

white pale belly. They're also

9:36

known as the red arm that

9:36

because they've got quite Pinky

9:39

arms, very long ears that sort

9:39

of curl round, little bit at the

9:43

tips. Pink ears, long tragus,

9:43

Pinky nose, very, very sweet

9:49

bats, if you can see the the

9:49

feet and the tail membranes have

9:54

quite long bristles on them to

9:54

be very distinctive that and

9:57

that's the first one you would

9:57

recognise this as a natural.

10:01

Once you've got that one, it's a

10:01

case of then trying to get your

10:04

eye in with a Dauby, and

10:04

splitting off whiskered,

10:06

Brandt's, Loads of cave spiders

10:06

as well. And the other

10:11

interesting thing is the tissue

10:11

moths we get on the limestone.

10:18

So these tissue moths that we're

10:18

looking at here, we've seen

10:21

quite a few of those and we've

10:21

seen a few Herald moths as well.

10:25

Are they a species which are

10:25

regularly found underground.

10:28

Yes, yes. So Herald

10:28

moths are quite a widespread

10:31

moth and they share similar

10:31

requirements in the winter for

10:37

as bats so they tend to roost in

10:37

cool stable, not too damp.

10:42

underground systems or

10:42

outhouses. Buildings that are

10:45

not heated. The tissue moths are

10:45

a type of geometric math, and

10:50

they're quite a notable species

10:50

on the limestone. So they're

10:54

quite are restricted in

10:54

distribution. And whenever we

10:56

see them in the caves, we always

10:56

send those records in because

11:00

they're a notable find. [It's]

11:00

Getting lower, you having to

11:06

stoop more. I'm not as tall as

11:06

you. For listeners at home I'm

11:10

currently doubled over. I'm not

11:10

as tall as you Steve, I can just

11:16

about stand up. So there's one

11:16

there. That looks like a

11:32

Natterer's

11:32

I I mean that one's

11:32

tucked really deep inside

11:35

crevices? Do we know have any

11:35

idea of why some are out in the

11:38

open and some so deep in

11:38

crevices?

11:39

No I don't think we

11:39

do. Now, I guess. They're all

11:43

looking for their individual

11:43

requirements. Some might have

11:47

less fat reserves and others so

11:47

someone to go deeper into

11:50

hibernation. The ones around the

11:50

entrance may have only just

11:54

moved into here. So a few years

11:54

ago. It was filmed for

11:58

springwatch. And I came down at

11:58

the end of February just to

12:02

check where the bats were. And

12:02

during the intervening days,

12:06

there was snow and ice, it was

12:06

absolutely freezing and we came

12:09

back to film. And the majority

12:09

of the bats had moved positions

12:13

within that time. So even in

12:13

very, very cold conditions,

12:18

they're still moving about

12:18

within the caves system and

12:20

potentially between caves and

12:20

mines. So some will be hung

12:25

quite out in the open and a

12:25

little bit twitchy because

12:28

they're not that deeply in

12:28

torpor, whereas other ones like

12:31

this one's really deeply tucked

12:31

away a long way from the

12:34

entrance very stable conditions.

12:34

And looks like it's going to be

12:37

fast asleep for a couple more

12:37

weeks at least.

12:44

I know we've got a bat because I hear your camera's going!

12:46

Well I photograph

12:46

spiders and moths as well. So

12:50

that was a moth that was down

12:50

about this height a bit further

12:53

along did I hear you say it was

12:55

Was it was the grey

12:55

one? Tissue tissue moth. They're

12:58

quite notable species. Yeah.

12:58

Yeah.

13:00

So it's nice to see

13:00

them. Are many moths overwinter

13:05

as adults. Gorgeous. Really

13:05

pinky ears hasn't it.

13:10

Very pinky ears pink arms. That

13:10

one's fast asleep as well.

13:15

So what's this thing that we've come to it looks like a dry stone wall inside the mine

13:18

It does. Yes, it looks nice. But

13:18

looks can be deceiving. So this

13:23

is called a stack dead. So the

13:23

miners when they used to blast

13:28

away and chip away the rock, any

13:28

of the rock that was not needed

13:32

so it had no lead or it would be

13:32

stacked up along the sides of

13:36

the adults or even sometimes at

13:36

the side of the shafts

13:39

completely unstable. No mortar

13:39

holding it together. Very very

13:44

dangerous if you coming into

13:44

mines and you don't know what to

13:48

look for. Definitely something

13:48

you wouldn't touch or climb up.

13:53

Despite the fact they look great for places for bats to hide

13:55

great places for

13:55

bats to hide. Yeah.

13:59

But the name gives it away, they're a

14:01

stack dead they're erm

14:01

dangerous and a bit useless as

14:05

well in terms of the rock [call

14:05

of Daubenton's further ahead] Oh

14:10

Dauby. There's usually Dauby

14:10

deeper in. Usually on the left

14:14

just before that turn low down.

14:17

So Helen what makes

14:17

this one a Daubenton's bat?

14:21

Genetics!

14:25

So we've got a Dauby

14:25

bat here. Really good view of

14:28

it. And lots of people say the

14:28

look a bit teddy bear like so

14:33

very short. squatty is little

14:33

pinky face, pale tummy, but not

14:37

as pale as a Natterer's and

14:37

very, very big feet. So they use

14:43

those feet for gaffing insects

14:43

off the surface of the water,

14:46

which is an adaptation of this

14:46

species in particular, and this

14:50

one, too is very deeply in

14:50

torpor.

14:56

So we're well into the

14:56

afternoon. Now we've just done

14:58

the fourth adit. And Helen what

14:58

we found so far?

15:02

Numbers have been good. So far,

15:02

we've got had a total of 41

15:05

bats, five species, we think

15:05

assuming that we've had both

15:10

whiskered and Brandt's, the

15:10

majority of bats of things so

15:13

far have been Natterer's. So what's the history of these

15:15

minmns? What the What were the

15:17

guys mining here? So these are lead mines, lead

15:19

adits to be specific. The Peak

15:26

District is notable for lead

15:26

mining. So in the sort of

15:31

17/1800s It was the most

15:31

important thing for the whole of

15:35

the national economy besides

15:35

farming and wool production. So

15:40

for a couple of 100 years led

15:40

was vital to the country's

15:43

economy and particularly

15:43

important for this region. So

15:47

they will money for lead lead

15:47

was really important for things

15:50

like windows useful water

15:50

carrying devices. Ammunition and

15:56

initially, a lot of the lead was

15:56

mined at the surface at rakes.

16:00

But once all the surface

16:00

deposits had been exploited,

16:04

they started to dig shafts down.

16:04

But on hillsides as steep as

16:09

this, the quick way to get along

16:09

to the lead ore was to mine

16:15

horizontally into hillside,

16:15

hence the name adits. And they

16:19

used to mine and follow the lead

16:19

or along the fissures until

16:24

they'd exhausted that seam.

16:24

Initially, it was done all

16:28

through handtools. But into the

16:28

1800s, they start to use

16:31

explosives. And in these adits

16:31

in particular, you can see some

16:35

of the the boring where the rock

16:35

was bored, and then gunpowder

16:41

was put in and the rock was

16:41

blasted away.

16:43

So what's the link

16:43

with Chatsworth house in these

16:46

mines?

16:47

So as I say, mining,

16:47

and in this area, copper as well

16:51

was, were really important to

16:51

the economy, it was strictly

16:55

speaking, to all part of

16:55

royalty, it was owned by

17:00

royalty. But the titles were

17:00

that were farmed out to major

17:07

landholders, and important

17:07

people in the area. So Duke of

17:11

Devonshire being one. And in the

17:11

Peak District, there was a thing

17:16

called free mining. So anyone

17:16

who came across a decent seam of

17:21

Lead or was entitled to mine

17:21

that they had the title of the

17:25

mine and it even surpassed

17:25

landowner rights, but a

17:28

proportion of the profit from

17:28

the lead had to be paid in

17:31

duties to the head honcho with

17:31

the area. And in this area, it

17:36

was quite often the Duke of

17:36

Devonshire. And it helped to pay

17:39

for a lot of the things like

17:39

Chatsworth and Hardwick Hall.

17:42

Nice, how many more, we got to do?

17:44

A couple more adits

17:44

just further up the hillside. So

17:47

we'll wind our way up the

17:47

hillside and then we'll get to

17:50

the top and team up with the

17:50

other team and find out what

17:53

they've got. [Helen discussing

17:53

results with other team at the

17:57

end of the day "12 Natterer's,

17:57

11 Daubys 5 WABs no BLE's" "Oh

18:01

we've had a few BLE actually,

18:01

one singles per adit"].

18:06

So how 72 in comparison to

18:06

previous years Helen.

18:08

So the total count for upper and

18:08

lower adits is 72 bats, which is

18:15

one of the highest counts we've

18:15

had of all the years of

18:17

monitoring, we need to check

18:17

whether to see whether it's the

18:21

highest or how close to the top

18:21

it is. But that's a good count.

18:25

All five species, as far as we

18:25

can tell, in terms of telling

18:28

apart whiskered/Brandt's,

18:28

probably the most numerous being

18:32

Natterer's I would have thought.

18:32

But again, we need to check the

18:35

records when we get back. So we should say all of this has

18:36

been done under a Natural

18:39

England licence. Why is that

18:39

important for for this sort of

18:42

work? Yeah, so this is all done under

18:43

our sort of level two scientific

18:48

licences, which allows us to

18:48

disturb that's for the purposes

18:52

of collecting scientific

18:52

information, and data.

18:58

Obviously, in order to make sure

18:58

we don't disturb the bats

19:01

because they're deep in torpor

19:01

hibernation, we limit the number

19:05

of surveys that go into the

19:05

caves into the adults, and we

19:08

make sure that we don't look at

19:08

the bats for too long with the

19:12

torches, and use torches that

19:12

don't give up a lot of heat. And

19:16

any bats that look like they're

19:16

waking all this starting to

19:19

twitch, well, we'll leave and

19:19

continue on the survey.

19:22

So where did these results go,

19:23

So as well as the

19:23

results going into the local bat

19:27

group databases. The results

19:27

also feed into the national bat

19:31

monitoring programme, which is a

19:31

national programme that looks at

19:36

monitoring bat populations over

19:36

a number of years to see whether

19:39

the populations are faring well

19:39

or badly.

19:42

So presumably having

19:42

this longer term dataset is more

19:45

valuable for for that study,

19:47

very much so and

19:47

particularly winter hibernation

19:49

check data as well, because the

19:49

numbers tend to be more stable

19:53

and more representative of what

19:53

bats populations are doing in

19:57

the area, rather than more

19:57

active routes in the summer that

20:00

may be roosting in Split numbers

20:00

or in different places to where

20:05

they often route.

20:07

And last autumn we

20:07

did for the first time ever

20:10

autumn swarming surveys, we did

20:10

find evidence of autumn

20:12

swarming, what impact will that

20:12

have on the management of the

20:16

reserve for Staffordshire Wildlife Trust?

20:20

Well, the first thing

20:20

is we need to feed the results

20:22

to the Wildlife Trust. They know

20:22

them in a preliminary basis, but

20:27

we're due to prepare a report

20:27

that details all the hibernation

20:31

monitoring since the early 70s.

20:31

And then coupled with that the

20:35

results of the swarming surveys.

20:35

We'd always suspected for a

20:39

number of years that the adits

20:39

would have been used for autumn

20:43

swarming for mating in the

20:43

autumn, given the large number

20:47

of bats using for hibernation,

20:47

but also all the droppings that

20:50

are in the adits, suggesting

20:50

that bats are flying into and

20:54

out of the adits. Summer surveys

20:54

of the adults have revealed very

20:58

little roosting. So obviously

20:58

the droppings had gone into the

21:00

adits by bats being active. We

21:00

came down in August and

21:05

September, and did some harp

21:05

trapping and mist netting at the

21:09

entrances of two or three of the

21:09

larger adits. And we found large

21:13

numbers of bats swarming around

21:13

the entrances. So that has not

21:17

only shown the site is very

21:17

important as long term

21:20

hibernation routes for a number

21:20

of species. But it's also

21:24

significantly increased the

21:24

conservation importance of it,

21:28

the swarming mainly because

21:28

swarming sites are visited by

21:32

very, very large numbers of

21:32

bats, and they will be pulled in

21:35

from quite a significant radius

21:35

of the surrounding area,

21:39

potentially 10s of kilometres. So given the Peak district has

21:41

several 100, if not 1000, caves

21:46

and mines mapped by various

21:46

caving communities in both

21:50

Staffordshire and Derbyshire bat

21:50

groups have had evidence of bats

21:53

in almost all of the ones that

21:53

we've surveyed so far, which is

21:56

a very small percentage of

21:56

those. Presumably that means

22:00

that the Peak district is really

22:00

important for both hibernating

22:03

and autumn swarming bat

22:03

populations, if there's a small

22:06

number cost that many sites? yes, very much. So I think it's

22:09

made it of regional importance,

22:15

if not more, because, as you

22:15

say, the number of caves and

22:18

adits it's in really good

22:18

habitat because a lot of the

22:21

habitat were in SSSIs, next to

22:21

river systems, woodlands and

22:25

grasslands, to really diverse,

22:25

so good insect populations. The

22:30

habitat overall is really good

22:30

for bats. And obviously, that's

22:34

coupled with really good

22:34

hibernation and swarming sites.

22:37

So there'll be 1000s, if not 10s

22:37

of 1000s of bats that are

22:41

visiting these over the course

22:41

of the seasons. And that makes

22:45

these have regional importance.

22:45

And there's no annex species

22:50

makes a change, it's usually

22:50

only horseshoes and Bechstein's

22:54

and barbastelle that make

22:54

anything important these days,

22:56

but yet lots of Brandt's and whiskered. thanks to Helen and the rest of

23:00

the team for sharing the day

23:03

with us. And when we got home,

23:03

we checked out that survey

23:05

compared with previous years,

23:05

and the 72 bats found by both

23:09

team was actually a joint record

23:09

with the survey undertaken in

23:11

2005. If that's inspired you to

23:11

get involved in bat conservation

23:16

and would like to improve your

23:16

skills to help your local bat

23:18

group, then you'll be glad to

23:18

hear that the big bat skills

23:21

event online is returning on the

23:21

12th of February. The event

23:25

brings that workers together

23:25

online for a range of workshops

23:28

to develop their skills and

23:28

knowledge without having to

23:30

gather in person, you can book

23:30

your place on the Bat

23:32

Conservation Trust website,

23:32

check out the show notes to find

23:35

the link. Thank you to you guys,

23:35

for your continued support for

23:38

BatChat. And for streaming this

23:38

podcast. We're really pleased

23:41

that you enjoy it so much in

23:41

these uncertain times. We all

23:44

need things to keep us

23:44

connected. So if you know

23:46

someone who's never listened to

23:46

a podcast before, we'd love it,

23:49

if you could show them how to

23:49

listen and introduce them to

23:51

BatChat. We will have another

23:51

episode for you in two weeks

23:54

time when we're going to be

23:54

joining some of the team at

23:56

Chester Zoo to discover how

23:56

they're helping conserve bats

23:59

over 6000 miles away. So join us

23:59

then.