SonoBlog

If you’re not familiar with sonograms, they are simply graphs of the sounds made by bats with the frequency of the sound on the vertical axis and time on the horizontal axis. To produce a sonogram, you need to make a recording from a frequency division or time expansion detector and feed the recording into suitable software. The sonograms below were made from the Bat Group’s newly acquired Batbox Griffin detector in time expansion mode. The frequencies were reduced by a factor of 10 and the times increased by a factor of 10. The software was Adobe Audition.

The first sonogram shows just over half a second of sound from the social calls which Martin referred to, made at the Luton Hoo hibernaculum last month. There is a rapid series of calls lasting about one tenth of a second (remember to divide the times on the scale by 10 to get the true times), and the series is repeated several times. The bat may have been stationary because the volume of the calls does not vary, and there’s no sign of any echolocation calls. The second sonogram shows one series of calls (the third series from the first sonogram), on a bigger time scale.
The question is: which species? We know there were Natterer’s bats around at the time, but we can’t be sure that this was a Natterer’s calling

Hi,

Well Danny up in the north of the county has been busy checking the kent bat box design against other designs. the picture right shows four pip's using one of the boxes.

He has also been using a design from the vincent trust and this was occupied within 18 days!!

There is one problem with wooden boxes though, woodpeckers!! they love to hammer them.

Danny's solution is to put a thin piece of metal over the hole to protect it, anything thats laying around can be used, in this case a old sign, for now this is protecting the box.

Danny has had some good results with the boxes and is constantly looking for new designs to try, I have come up with a design, that once I have made a few hope to test with Danny's help. Hopefully it will be successful and we can give out the instructions for making them.

M

Back at the beinging of the month, myself and 3 other members went to see if there were any bats swarming around Luton Hoo's artifical Hibernation site. We heard lots of bats including myotis, BLEB, both pip species and Noctule.

A couple of weeks later 5 members went back to confirm the site was being used, this time armed with a harp trap and mist nets, we spent an age waiting and hearing nothing but around 11.00pm we heard a myotis bat.

Not two minutes later he flew into the net, a male natterers in breeding condition, a further three males were netted all of which were in breeding condition.

We can now reveal that this is the first confirmed autunm swarming site in Bedfordshire, which considering the hibernation site has only been in place for around 4 years is an important discovery. Luton Hoo estate (Elite Hotels, Richard Biffen) are very happy about this and are continuing to support our work here, so a big thankyou to Richard for the access permission and continued interest in the bat activity at Luton Hoo.

Recently the group has installed some hibernnation boxes in the largest wooded area in Bedfordshire (Kingswood NNR). The Greensand Trust and Natural England allowed the group to put up two very large boxes and one smaller one.

These will be checked this winter and are in known bat hotspots, but will be monitored every so often, I'll report back the results after the first check, although we are not expecting them to be used for a while.

M

Hi,

We ran a bat care course last weekend, 10 members attended and it looks like the care team is expanding.

I have also been helping out the Dormouse group of late (see picture further down) they are still about and seem to be doing Ok.

M

Hi,

Have not posted for sometime now!!

The noctule hasn't been back, however mum is doing well and gaining some weight.

The group has been fairly busy with the Luton project and other things going on around the town, so far we have made some 50 plus bat boxes to go up in the Luton parks and finally looks like we will be able to do this over winter.

Things are slowing down now (end of season) but we will keep busy finishing off the Luton project and planning projects for next year!!!

M

This is an image of one of the pups droppings, there is a wing clearly vi sable in the centre of the picture.

I have several others with antenna fragments and mandibles fragements.

M

Hi

I have been through several droppings and found wings in all of them so far. This means that he was feeding himself in the wild, as mealworms don't have wings.

He has not returned for some time now, however the box will remain in place just in case he returns over the autunm and winter.

Hi

Having been away for the 2 weeks, my eldest was left in charge of looking after the baby. She feed and watered him every day up until the 9th of August. After this date he has not returned which means that he has either found a roost or disappeared, however we see this as a success as the whole idea was to have him leave as and when ready.

I still have several droppings to go through but early signs show that he had been feeding himself.

M

Morning

I finally got around to looking at the droppings last night before heading of to Wrest park. Although I didn't look at them very closely (waiting on microscope) I used a 10x and 20x hand lens and found wing fragments in the droppings. As mealworms don't have wings this means he is feeding himself to a point, meaning that cutting the mealworms down slowly seems to be working.

For the following two weeks I won't be about so there will not be any updates (Sorry)

M