Wildlife Acoustics EM3

This March I was told by my MD (I am a bat consultant) that he was upgrading all of our equipment, so after much looking around, I came across the Wildlife Acoustic EM3 handheld detector. I had been aware of it, but hadn't given it much thought due to the price.

I had been using a Petterrson D240X with recorder for much of my work and although it is an excellent detector it can be cumbersome due to all the wires running to and from the detector.

The EM3 seem to fit the bill for what we wanted e.g. handheld, built in recorder (with several formats, I use WAV) and it had a screen which allows the sonogram to be displayed.

I have now had an EM3 for the whole of a bat season and have come to grips with using it. Hence this little review.

On first thoughts I didn't really like it to much!

It was quite large in the hand (although I have fairly large hands), it was complicated and not intuitive and it ate batteries (even though these are re-chargeable). The real time expansion (RTE) sounded odd compared to the D240X and the heterodyne mode although good was difficult to scan though the frequencies.

The build quality looked poor and it lacked a lanyard to secure it, when fumbling around in the dark, so it could be dropped.

However: -

I have come to love using this detector and really would be lost without it!

The sonogram screen although small is just excellent, allowing almost instant confirmation of the species your listening to (assuming it is not Myotis or other difficult species) and you can zoom into the call if you if you need to. You can toggle between a white background and dark background to save your night vision. Recorded without the need for other devices and loads of wires everywhere and instantly check the call on the screen .

Having now learnt how to set it up to my needs (check the Wildlife Acoustics website for tutorials) the detector has taken on a life of its own. I now listen in RTE as standard so that I don't miss any bat passes and don't have to fumble around with buttons on the wrong side of the detector. I have changed the trigger level of the detector so unwanted noise is not recorded and it saves the files in small snippets making sound analysis fast.

There are still problems with this detector, for instance changing the buttons to the left side would be a great help as I am right-handed, adding a lanyard to the case to prevent dropping it in the dark and installing a more sensitive microphone would all be good additions.

However with all that said, I really couldn't do without this bit of kit anymore!



 

Swineshead revisited

Last week the guys headed back to Swineshead wood with the aim of catching and perhaps tagging one of the Myotis bats we heard earlier in the year.

We were joined by Daniel Hargreaves who stopped off on his way to Luton Airport for a flight at silly o’clock this morning.We set up two harp traps and lures and settled down to wait. We didn’t have to wait long before not one but three bats entered the first harp trap.

We caught a male Natterer’s and the first of four barbastelles in beautiful condition
But the third bag was the most exciting and indeed the most satisfactory in purely dramatic terms, for therein rested a male Nathusius. This is the first Nathusius we have had in the hand for twenty years. The only previous sighting was a single male who was found grounded and died soon after.

Nathusius pipistrelle Photo Jude Hirstwood

This bat had very large buccal glands as you can see in this photo and was in full breeding condition .

Nathusius pipistrelle. Photo Bob Cornes

Nathusius pipistrelle with prominent buccal gland. Photo Bob Cornes

Swineshead is quite a way from the nearest large water bodies.Perhaps he was migrating in a quest for females.

One thing is sure, this really is an exceptional wood!.

Nathusius males sit in a suitable spot and call, often all night in the hope of attracting a female. You can see Daniel Hargreaves’ video of an advertising Nathusius  on You Tue

First Natterer's in bat boxes

   

Aidan processes a bat Photo Bob Cornes

Yesterday we did another check of the King’s Wood boxes and found rather more bats.

Juvenile Natterer’s Bat Photo Bob Cornes

The highlight of the day as finding our first Natterer’s  – a group of 6 juveniles, four males and two females in a box which has previously occupied first by pips and then by Brown long eared bats.

Photo Chantelle Kerr

Ticklish or smug to have escaped first time?  Photo Bob Cornes

Photo Chantelle Kerr

Another box had 36 Brown long eared in it – 36 in all 14 adult females, 12 of which were lactating) and 10 juvenile males and 7 juvenile females. Another four managed to sneak off when the box was opened. We found four more brown eared bats in nearby boxes  2 juvenile females and 2 adults which might have been these Houdinis. A lot of these juveniles were very young , in contrast with the Natterer’s who were late juveniles.

We also found a male Noctule in what is euphemistically called “full breeding condition”He was not an exhibitionist ( unlike some bat group members) and was not prepared to flash his genitals for the camera.

Photo Chantelle Kerr

We also found one male soprano pipistrele, similarly well endowed. Last year we found many pipistrelles and it is interesting that we have found so few this year.
With the delay in the renewal of Bob’s Licence, we were unable to get the rings we wanted  ( you have to have a current licence to ring bats) and so will have to delay ringing till nest time .

Bedfordshire Serotine Roost

The bat group were really sorry to learn that the owner of the serotine roost died last year.

 

Audrey loved hosting the bats and made us very welcome whenever we went round.

 

The serotine roost was used in a PhD research project which involved ringing the bats. We have been returning every year since to try to catch the bats and check the ring numbers.

Photo Hedj Dollman

Audrey was very clear that she wanted us to continue to monitor the roost and Tony went round to see the new occupants who did not realise they shared their house with bats. They were happy to let us check the roost. The bats were as sneaky as usual and of the 6 bats that emerged we only managed to catch two of them using our patent bat catcher- which Iain described last year as “A zimmer frame wearing a nappy”,

Photo Jude Hirstwood

One of the bats was  a female ringed three years ago and not caught since, she hadn’t had a baby this year and the other was  a male juvenile ( our first ever captured male). Numbers were lower this year but we know that serotine colonies use several roosts.

The householders have said we can go back next year and continue monitoring the roost – the only known serotine in Bedfordshire.

We are very happy to do this and honour Audrey’s request.

Noctule Mum Released

Way back in the winter we brought a very  underweight noctule into care.  She gave birth earlier this year and Simon has been caring for both of them. Mum got very podgy and was not keen to fly. So she was put through an intensive training course and her mealworm intake was reduced still further. Junior has still to get the hang of flying and is not that keen on exercise either, but he will see the light in time!

The Noctule prior to departure. Photo Jude Hirstwood

Yesterday we went back to the spot where the Noctule was found. We were a bit concerned when it began to rain early in the evening, but that cleared when we made our way out from the car. Simon and his family had got quite attached to the bat during her time in residence. Simon’s daughter insisted he dad give the bat a final cuddle before she was released. This was duly done.

Simon says goodbye to the Noctule

To begin with the bat was perfectly happy to stay nestled in his hand, but when he held her out to the elements her curiousity peaked. She crawled onto the edge of his glove and then stretched her wings. We held our breath and then she opened her wings fully and launched herself off into the night- too fast for me to get a photo We listened to her on a bat detector as we watched her fly away. She did several large circles, presumably orienting herself to her home environment and flew off strongly.

The moment of release Photo Jude Hirstwood

It was a wonderful moment to see her fly free. Bat care is time consuming and often the outcome is not successful but this makes up for everything.
Now Simon is going to concentrate on getting junior flight ready. Thanks to Simon for all his hard work.

Another Barbastelle

We have been monitoring Stockgrove Country Park regularly for the past twenty five years. In recent years we have heard occasional barbastelles, but on Monday night we tried harp trapping there and found ourselves in the middle of  a high level of barbastelle activity, and much to our delight one, a  non breeding female, graced the harp trap with her presence.

Barbastelle, Photo by Bob Cornes

Some people think these are ugly bats as there eyes are difficult to spot but we have a soft spot for them.
One of their nicest features is silver tipped fur

New Project

Phil Brown (University of Bristol) is carrying out two surveys in Bedfordshire

This is part of his university project looking at Whiskered/Alcathoe/Brandt's (WAB)

Further details to follow once the surveys have been completed.

Bat Box Project updated

When fixing dates for the monthly box surveys we deliberately put the June check early in the month and the July one later.

We found nothing but birds on the June one and had heard that people were finding new born Brown long eared bats in boxes in other counties recently.

It was decided to go ahead with the check but not to disturb any boxes that held brown long eared bats.

Almost the first box that was checked appeared empty,  but on being opened had a very young juvenile in it.

There was no sign of its mother. The box was closed immediately and for the rest of the check, boxes containing Brown Long Eared bats were not opened.(Their long ears are, fortunately, pretty visible.)

Brown long eared bat Bob Cornes (photo taken last year)

This meant that the check was quite speedy as no boxes contained anything other than brown long eared bats. The questions has to be – where were the pipistrelles.

Further Woodland Surveys

With the good weather the bat group has been able to go out a lot.

On Tuesday Aidan, Bob and Dave headed to Kings Wood Heath and Reach and tried netting in a woodland block.
Griffins were set up at high and low level.

There were no echolocation calls but we picked up some interesting social calls. Alarmingly Jude failed to provide any cake.

This alarming event caused great concern so on Friday when we went to resurvey a wood we had visited with Lia Gilmour last year, everybody brought cake, so that some came home at the end of the evening.

When we were there last year the temperature was 4 degrees centigrade. It was very different last night. A juvenile noctule, several Daubenton’s and a soprano pipistrelle were caught, but there were still no Natterer’s.

A Response to the Westminster Hall Bats and Churchs Debate

   

Photo Jon Dawson

There has continued to be lots of comments about Sir Tim Baldry’s  recent speech at Westminster Hall.  .

Dr Kirsty Park of Stirling University has just posted a comment on her blog . (Kirsty’s PhD was bat related and she knows of what she speaks).

I should point out to those of a nervous disposition that these are not real bats  and that the bats living in our churches are not this size.

They are made by greensmith (someone who works with copper). I stole this photo from http://2dales.org.uk/churches/st-andrews/bats.html