Driven up the pole by bats

The bat group has recently bought another Griffin from Batbox using the proceeds from data searches. The fine weather on Monday night was too good not to exploit and Bob headed off to the home of our main bat box project to try it out.

We noticed that last season that bat detectors placed at 8.5 m ( atop a window cleaners pole and a de-bristled brush) gave us very different results from what we heard at ground level, but as we only had one Griffin we could not record at two levels at the same time with a time expansion detector)( We used . batbox Duets instead which , not being time expansion detectors, can’t give such high definition recordings)

The first Griffin was mounted on the lower part of the window cleaner’s pole. Photo Bob Cornes

Using a Petterson time expansion detector which was handheld, Bob only reported a few common pips, , the Griffin placed on the pole low down picked up a Noctule pass, while the Griffin at canopy height picked up both common and soprano pips, a serotine, a barbastelle, and what was possibly a Leisler’s (though it might just have been a Noctule playing silly devils.

The double Griffin se4t up. You can just about see the 2nd Griffin at canopy height right at the top of the photo. The object ion the tree trunk is a bat box (unoccupied) Photo Bob Cornes

The plan is to repeat this methodology at a number of sites this season, and to return here later in the yer when the canopy is denser.

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Baby Noctule update

The juvenile noctule continues to come on in leaps and bounds.

He is now eating mealworms and soon we shall have to get him some flight cage practice.

Infra-Red Camera Set- up

Following a workshop at the National Bat Conference on Infra-Red (IR) filming of bats, I decided to set-up my own system. A quick trip to ebay and a little research later I came up with the below.

Most of the set-ups I have seen to date have relied on external battery packs and lots of connecting leads. Although the footage was excellent and the systems seemed fairly simple to set – up, I was looking for something that would be self-contained.

I found IR lights called ‘bullets’ on an ebay shop, produced by SpectIR components, these seemed ideal as they take batteries. The added bonus was that they were cheap, being £30 for both lights. Each light takes four ‘AA’ batteries to the rear. These are expected to last at least 2- 3hrs of continuous use. The two lights can light an area of approx. 15- 20m. This is generally good enough for most roosts that I have tested the system on.

Equipment –

1.    Sony Handycam DCR-SR35 HDD ‘Nightshot’ (already owned and more importantly has the night shot facility).

2.    Camera Tripod (I opted for a small tripod that could be used internally in barns and small loft spaces).

3.    2 x Infra-Red (IR) lights, Bullets (produced by SpectIR Components).

Figure 1: IR set-up

Figure 2: IR set-up

Figure 3: IR set-up

Now I have had a chance to test the system and the results can be seen here: https://dl.dropboxusercontent.com/u/89343861/BLEB%20Stockgrove%20no%20sound.wmv

This piece of footage was taken from a known roost in Bedfordshire.

Noctule update

Noctule and newborn Photo Simon Pidgeon

A new born bat is not by any stretch of the imagination a thing of great beauty it has to be said but watch this space. As he grows he will become much more pleasing on the eye!!

Photo Simon Pidgeon

A week after being born and he weighs 5 grams

week old noctule. Photo Simon Pidgeon

Last time round we couldn’t release mum back into the wild, but this time we should be able to. Meanwhile mother and baby are doing well. We will keep you updated.

Another Noctule, Another Pup

Hi All,

Well back in 2010 this blog was set-up to document the development of a noctule pup that was born in captivity.

On Friday of last week I had a panicked call from Simon (the main bat carer for Beds).

He had been over-wintering a female noctule that was found in a tree, in all likelihood she was going to be pregnant, however the hope was that she would be fit enough for release before this occurred.

Well it turns out that this is not the case and she gave birth to a male pup on Friday, below is the email that has been sent to the group:

Dear all,

A little bit of news for you (being the bat care team and all that). Most of you are aware of the captive Noctule we have which is overwintering until the weather cheers up. This young lady was found in a tree that had come down in December.. When found, she was only half the weight she should be and Jan Ragg/Colin Edwards were straight on the case of feeding her up. She would have almost certainly died if the tree had NOT come down! She was passed to me shortly afterwards (as she was from Millbrook).

Fairly quickly, she put on weight and seemed quite content (though grumpy for a Noctule).

I’ll get to the point….Last Friday (8^th March) I got her out in the afternoon to give her a feed before work. To my complete shock, when I looked in I was met with a bat much smaller than our female. Yes, she had given birth. I knew the likelihood was that she would be pregnant, but a baby in early March…..slightly concerning (not to mention ‘dejavu’ for the Beds bat group for out last captive Noctule). When I first saw the pup (a male), he was on his own on one side of the inside towel and mum was the other end on the opposite side. Thankfully, after a good feed and a massive drink, mum soon got baby to attach and so far…both appear to be doing fine.

As soon as I get a chance, when mum kicks baby (now named ‘bobby’ by my daughter) off for a while I’ll weigh them both. I have had a clear view of the Pup’s abdomen and I can see milk patches so at the moment, I’m happy he is feeding. They will both need close monitoring but as a group, we need to work out how/where they are going to be released. It’s a long way off at the moment but unlike our last mum and pup, mum can be released too.

Will keep you updated with some proper pics/weights etc. I thought the birth of my son last month was going to be the last baby we had in the house!

 

So this means that this year there is likely to be the storey of Bedfordshires second noctule born in captivity.

 

So far the pup is doing well and mum is doing a fine job of feeding and looking after him.

 

As and when there is more news I will get an update on here.

 

Martin

Hibernation surveys Jan and Feb

Thanks to everybody who helped with the hibernation surveys. There were 161 bats in January and 154 in February.

Natterer's numbers were good  with 91 in Jan and 87 in Feb, Daub's 41 in Jan and 31 in Feb, 7 Barbs in January and 12 in Feb, BLE 18 and 21 = not to mention 54 Herald Moths at one of the sites (thanks to Phil who found a stash of 30 of them).

Another year of high numbers. Now all we have to do is wait until they wake up.

Martin.

Update to homemade harp trap

Some time ago now I said that we would be building a homemade harp trap.

Well I never got round to doing this for various reasons.

However Aidan Matthews did (see picture), at present I don't have the full details of how he did this, but I do know that it's made from white water pipe and some timber.

He had a bit of a nightmare stringing it, with the mono breaking several times but a quick adaptation sorted that problem.

It weighs approx. 11kg and can be erected in 20mins by one person.

He has promised that he will document the build and send me more photos on the construction. Once I have these I will post them.

Martin

Please note: In the UK you have to be licenced to use harp traps and mist netts by the government agency for your country e.g. Natural England, BBG has a number of licence holders for this equipment.

First hibernation survey of 2012/13 winter

Hi

The first of three hibernation surveys was undertaken this weekend just gone.

The number of bats was an all-time record - 168 bats. The previous highest was 152 (last January).
The overall species tallies were:

89 Natterer's, 44 Daubenton's (a record - previous highest 30), 3 Myotis sp., 17 BLE, 13 Barbastelle, 2 unidentified.

16 sites were checked in total across the Bedfordshire area. Thanks to those who took part and to the owners of the sites for access.

Ash Dieback and Bats, update from BCT

5 December 2012
Bats and Chalara dieback of ash trees: December Update
Ash trees make an important contribution to biodiversity and wildlife habitat and this includes use by bats for roosting where suitable opportunities arise. The recent confirmation of dieback in ash trees (Fraxinus excelsior) has implications for bats and UK biodiversity from the loss of trees to the disease and potentially from the measures put in place to limit the disease spread. BCT is working with the Forestry Commission to assess the situation as is it develops and put protocols and procedures in place that ensure that whilst carrying out the vital work to control the spread of the disease, that bats are protected.
The disease caused by the fungus Chalara fraxinea causes leaf loss and crown dieback in affected trees, and it can lead to tree death. It is a significant threat to one of our widespread native trees. Ash is the third most common broadleaf native tree species in Great Britain after oak and birch and is the predominant tree species in approximately 129,000 hectares of woodland in Britain. The fungus has caused widespread damage to ash tree populations in continental Europe and has the potential to kill millions of ash trees if it becomes widely established in Great Britain. The spread of this disease would pose a serious threat to associated biodiversity, including bats, and measures to prevent its spread are imperative. However, the potential for large-scale destruction of mature ash trees has raised concerns about the impact on roosting bats.
The current situation in December
The reported 100,000 trees already destroyed were all young transplants and nursery stock that were known or likely to be infected with C. fraxinea. Bats roost in mature ash trees and to date no mature trees were included in the destruction measures.
Initial work has focussed on identifying the locations where this disease is present. Initially this disease was thought to be, largely restricted to Norfolk and Suffolk. However, surveys carried out in recent weeks have found that its occurrence is more widespread across England including counties such as Yorkshire, Berkshire, East Sussex and Kent. It is thought likely that Chalara has been in this country for at least 2 years but was only recently discovered.
What happens next?

• Any newly planted diseased trees or diseased trees in nurseries are being traced and destroyed.
• If the disease is found a containment notice will be issued to prevent plant material being moved off site.
• Mature trees will not currently be removed, as it has been acknowledged that they are valuable to wildlife, take longer to die and can enable more to be learnt about genetic strains that might be resistant to the disease.

Although there are currently no immediate plans to remove infected mature ash trees, the Forestry Commission and BCT will continue to work closely together to produce a protocol that would be effective in i) Controlling the spread of disease and (ii) Protect bats should the ash dieback situation change or in readiness for any similar future tree disease incidences.
You can find out more about Ash dieback and the latest news from the Forestry Commission here www.forestry.gov.uk/chalara
We will keep the BCT website updated with further developments.

Some bats still active

 

 

Despite the dreadful weather, we have had several sightings of bats flying in daylight in the last week. Presumably they are taking a last minute opportunity to try to catch food.

If you see a bat flying (in Bedfordshire) please let us know via the bat group e mail or at bats@bnhs.org.uk

If you live outside Beds, you can record your sighting on the Bat Conservation Trust’s Big Bat Map http://www.bigbatmap.org/