Derbyshire Underground Sites Project;
This blog gave updates from the autumn swarming trapping project which took place in the autumn of 2014; scroll to the bottom of the page for the background to this project.
The most recent posts appear at the top of this page. The Introduction to this project is at the bottom of the page.
DNA Results Returned
During the trapping we undertook last year (see last year's blog), there were two bats which were so hard to identify that we collected a dropping sample from them and submitted them for DNA analysis to confirm the species.
We knew that they were either whiskered or Brandt's bats and we had suspected whiskered. The results came back as Brandt's, which doubles total number of Brandt's bats caught as part of the project to 4.
These two results finalise the species breakdown for the project and we can now undertake the production of charts and statistics on the results in order to produce a report. We hope to have this published here in the next month or two. Keep checking back for updates!
A fantastic start!
The bat mating season is now over and as we move into winter, bats have begun to enter hibernation. This has been a fantastic start to the project. A total of 113 bats were caught and these comprised 6 species. We have identified brand new swarming sites and in one instance, surveyed a brand new site for bats which we are planning to follow-up this winter. There have been ups and downs to the project and lessons learnt for next year.
Our next step is to have the DNA samples we obtained sent off for analysis and then to write up the report. After that we'll be planning what to do next year and how to further the project. We will make the report available here once it is completed.
It's getting towards the end of our licence period and the end of the swarming season. Last night reminded us of that with a catch of 0 bats in the Peak District. The wind and rain proved too much for the Myotis bats we are surveying to make the journey across the hills.
There are one or two more surveys planned but we will have to play it by ear as autumn begins to take a hold. Luckily the weather today has been a dry wind - perfect for drying out the trap catch bags in the yard!
What a difference a week makes!
Five members braved the cold and returned to the site where we had caught 38 bats the week before (see 'another fantastic night' below). They were a hardcore bunch, as the temperature when we met was already down to 10°C. However just 8 days following the first survey, the result couldn't have been more different. Bats were certainly flying and we caught 8, but there was no swarming activity taking place. Just as with the previous night, bursts of activity were occurring but once the groups of males had figured out there was no swarming taking place, they were flying off elsewhere.
It just goes to show that you can't write off a site from undertaking just a single survey. The contrast in the recorded activity couldn't have been much different.
Above: Daubenton's and Natterer's bats being processed to record biometric information.
October 3rd 2014
A repeat survey
On Friday 3rd October, three members met in the Matlock area to undertake a second survey of a site. As well as the two harp traps we normally set up during these surveys, we also set up a 9 metre mist net across the woodland edge. Swarming activity wasn't happening that night but there were bats coming in bursts of activity to see if anything was happening. 8 bats of two species were caught.
Above: A Natterer's bat being processed to record biometric information.
Below: A brown long-eared bat in the hand. Note how the ears are curved behind the Tragus. When the bat is in flight these are pumped with blood and stand as long as the bat itself!
Saturday 27th September and four of us met the Cavern manager in Buxton to set up the two harp traps once more to survey this popular tourist attraction. We were kindly left with the key to lock up after ourselves and so we placed a trap inside the cave and one outside. A slow start saw us move both traps closer to the entrance with one just inside the entrance and the second around the corner.
No swarming activity was recorded but there were plenty of bats which use the cavern as a roosting site flying to and from the area and so the ten bats we caught that night gave us a nice demographic of species which make use of this well-disturbed site.
A total of 10 bats of 4 species:
5 brown long-eared
Above: Joel releases a brown long-eared bat caught at Pooles Cavern and a Daubenton's bat being processed.
Below: Tim and Joel check the harp trap and the whiskered bat we caught.
Another fantastic night
On 26th September, ten surveyors headed to the Matlock area to survey a new site for the swarming project.
The underground site had a large entrance and so we placed the traps further inside the cave entrance where the roof came down in height. A fantastic night was had with nearly 40 bats being caught by midnight. We unfortunately had to stop the survey early due to unforeseen circumstances but we are looking foward to heading back there and undertaking a thorough survey effort.
A total of 38 bats of 4 species:
5 brown long-eared
Above: The large cave entrance and a close-up shot of a whiskered bat's teeth - one of the identifying features.
Below: A Natterer's and whiskered bat.
Seven surveyors went a few hundred meters over the border into Leicestershire to a site we check annually during the hibernation period. In winter we usually find numbers of low-high teens hibernating in an old railway tunnel near the south of the county.
We placed both traps across the entrance of the tunnel and extended the legs to their full length as the tunnel is quite high. Swarming activity didn't start until around 10pm and the first bat was caught in the harp trap at 9:50pm. There were bursts of activity during the survey and bats were observed swarming inside the tunnel.
A total of 6 bats of 2 species:
2 female brown long-eared's
4 male Natterer's
By 12am bat activity had really dropped off just like the previous night and we packed up. It was good to survey a tunnel structure for the project rather than a cave or mine and to confirm that a known hibernation site is used for swarming.
Above left: brown long-eared bat. Above right: Natterer's bat.
Autumn has arrived
Five members went to Earl Sterndale to survey a new site in the autumnal mist which stayed with us all evening. Swarming activity started quite early and the first bat was caught in the harp trap at 9pm
A total of 20 bats of 6 species:
2 brown long-eared
1 common pipistrelle
15 bats were males and 5 were female.
By 1am bat activity had really dropped off and we called it a night. The site looks very promising and further surveys are already planned.
Above left: whiskered bat. Above right: Daubenton's (left) and whiskered bat (right) side by side.'
By the light of the Harvest Moon...
On 9th September, Bill Cove, Shirley Cross & Steve Roe went to Groaning Tor mine in the Via Gellia (the other end from Good Luck Mine - see blog post below). We didn't meet until it was dark since we knew swarming wouldn't start until a bit later at this site (our previous studies have told us this).
The group's modified harp trap with shorter legs was placed in front of the mine entrance and the other was placed at right angles to the cliff to try and catch bats which would be tracking along the rock face. This combination seemed to work well with equal catch rates being obtained.
A total of 11 bats of 5 species:
3 brown long-eared
The Brandt's was the first bat of this species to be caught during the project. All bats were males.
Once again, it was clear that there were definite peaks of swarming activity as the evening drew on. By 1:45am bat activity had really dropped off and we called it a night, as the next main peak of swarming activity probably wouldn't be until dawn.
Above: Steve and Shirley process a juvenile Daubenton's bat with a chin spot.
Below: The Daubenton's bat being released and a whiskered bat forearm being measured.
September 1st 2014
Crossing the borders - again!
Turns out we just can't stay away from Leicestershire! One of our members has a project-specific licence for our neighbouring bat group (which is very similar to our own swarming project here in Derbyshire) and on the last day of August we had a fantastic night as you can see from the video below. A total of 634 bats were caught through the evening. A great new set of data which will help us to understand the importance of the site for bat populations.
Fingers crossed for this many bats on our surveys!
Wet and damp
On Friday 29th, 4 members went to a cave in the Dovedale area and despite a promising start to the night, as we got to the site it decided to pour down for a couple of hours. We waited it out and eventually got set up. Two traps went up in front of the cave entrance (see below photos).
7 bats were caught:
1 common pipistrelle
1 soprano pipistrelle
4 brown long-eared's (3 females, 1 male).
Three of the long-eard's were female and showing signs of having given birth this summer, the photo below shows a parous female with an extended nipple and bare fur around it meaning she has suckled a juvenile this summer. 'Whilst no swarming activity was recorded during the survey, at the end of the survey I went into the cave which is a known Daubenton's roost and small long-eared roost. There was a lot of evidence of brown long-eared's using it as a large feeding roost with butterfly and moth wings all over the place, not normally observed. Lots of hibernating peacock & tortoiseshell butterflies, herald & tissue moths were in the cave in hibernation so it may be that the long-eared's are gleaning these from the limestone walls as easy pickings. Whilst in there, two long-eared's were observed chasing each other around the cave social calling to each other, so possible swarming behaviour was observed. However given it was quarter to 4 in the morning I didn't stay long to watch! None of the Daubenton's had returned suggesting they were out swarming elsewhere. A long night but useful new data gathered.
Above: Brown long-eared bat about to be released and bat group members processing bats during the survey.
Below: Steve checks one of the harp traps and the nipple of a parous brown long-eared bat.
Crossing the borders
We have been working with Leicestershire bat group and went to help them with a swarming survey at a known hibernation site in Leicestershire but had never been surveyed for swarming activity. This footage was taken around midnight one night in August. As you can see from the clip, it's an important site for swarming and we'll be going back with Leicestershire bat group to study the site more in the future.
You know it's windy when...
The first two trapping sessions have taken place this past week. The first survey was on the side of one of the only real peaks in the Peak District. Unfortunately, despite a nice still evening in the lowlands, it was blowing a hoolie outside the cave entrance. It caused one of the most challenging conditions either of the surveyors had had to erect a harp trap in and the first time we'd ever needed to tether it to the ground to prevent it taking off.
More success was had a few days later in central Derbyshire at a site within woodland. A quiet start to the survey with very little activity, but once midnight arrived, social activity started and once the first bat had been caught the rest following in quick succession.
A total of 6 bats caught in two harp traps (3 bats each), 1 Daubenton's, 1 brown long-eared and 4 whiskered/Alcathoe/Brandt's (WABs) and droppings were collected from two of the WABs to be sent off for DNA analysis. As you can see from the photo below, project leader Garry Gray has created some shorter legs for our harp trap so that the catch bag sits just off the ground and prevents bats flying under the bag.
Harp Trap with shorter legs in front of a mine entrance.
August 1st 2014
Introduction to the Project
Derbyshire Bat Conservation Group has been conducting underground surveys for bat species within the county for over 10 years. These underground sites include both natural and man-made structures and surveys comprised both hibernation and autumn swarming surveys. In 2014 we decided to move the Derbyshire Underground Sites Project into a new phase - Phase II. As such, we submitted a project licence application to Natural England to enable a core team within the bat group to undertake trapping in the bat autumn swarming season and we are delighted that the licence has been granted.
The trapping consists of methods approved by Natural England and the Bat Conservation Trust, the latter of which we are a partnership group. Licence holders and accredited agents will use harp traps and mist nets at the entrances to selected underground sites which bats may use for swarming within the county of Derbyshire. Any bats caught will be identified to species level and biometric information, such as sex and age, will be taken.
At least 5 species of bat make use of underground sites during the winter hibernation period in Derbyshire. Part of the project aim is to establish the presence of Alcathoe's bat within the county (as yet unconfirmed). Recent discoveries by Leeds University have found this new species of bat Myotis alcathoe residing in the UK in Yorkshire and Sussex. This species is very similar to Brandt's and whiskered bat (both present within Derbyshire) and it is not possible to identify this species by visual identification methods. All bats will be released unharmed following capture and processing at the site.
Survey results following the trapping this year will be made available to other UK bat researchers to aid in future research work. They will also be entered into the DBCG records database, a unique conservation resource for Derbyshire's bats.
If you have any questions get in touch with us.
Steven Roe & Garry Gray
Phase II Project Leaders
Want to know more? Head to our Bats in Derbyshire Caves page.