Mobile batting (1 Viewer)

Hi,
I think Soprano is good for the attached above. They prefer to roost near water, but you can pick them up moving between sites, or in good hunting areas away from water I suppose.
For sound analysis, obviously the peak frequency is the key, but also the shape of the signal, the number of repetitions in a second, and the signal length can all give clues to the identity.

BatExplorer software seems to measure the signal length quite well. ( I have never had any joy from FD recordings and audacity/wavesurfer, as you can tune the signal to be just about any length you like!)

My micro trio arrived yesterday. It was a rainy day so no chance to try it. But today it was warm and sunny and I went to a lake just to see a temminck stint, which is a lifer for me. Then I waited till sunset.

First impressions:

FD works perfect with no hissing noise in the background, however on HD I do hear a constant hiss in the background (Wich seems the opposit as Stefan)

I watched (and heard) one medium size bat for a while to get use to the detector. I only could hear him when he was under 20 m. (while other half sized bats I could hear them from very far away). I did one TE recording wich I nearly lost because I did not now that when switching off the detector, the recording is erased. So I made a new recording which now batexplorer says its Hypsugo savii 64%; Plecotus auritus 56%. I will have to study the track but here it is for you.

I still dont have a recorder so I saved the recording directly to my PC using Goldwave

Now at home, sitting in the terrace I hear constant bats passing, but I can not see them. I am making a lot of records and batexplorer is identifying them as different species each time, so I will have to study again them all. Most propability is given to pipistrellus Kulli or nathusi, but how nows...

Anyway, I will have to study more about bats. ¿Any recommended literature for interpreting bat sonograms? I have hundreds of questions but I better read a little bit before I start making them.

Savi's pipistrelle

A useful source on bat calls: Kriterien_Lautzuordnung_10-2009.pdf (google for it). It is in German, but you can search in the pdf for the Latin name. There are other sources on bat calls, but at least this one includes Spanish species.

Apparently your recording hasn't caught the large bat which you observed, but smaller bats. Hypsugo savii is a smaller bat, can be confused in flight with Common Pip. BatExplorer is more helpful for measuring calls, frequency and call distance than for actually identifying a bat. I'd say that the peak frequency is 34 or 35 khz and the call distance perhaps 220 ms (there are more than one bats present). But even if I manually adjust these data, it seems that BatExplorer doesn't offer Hypsugo savii as the remaining option. I you look the species up (upper left corner, clicking on the bat symbol), you'll find that the call distance (= Rufabstand) for H.s. is given as 180-200 ms and "geleg." (= sometimes) 275-375 ms. Which probably means that 220 ms is not "allowed" for this bat. So I confess that I am confused.

My most recent source (Dietz 2014) has a distribution map for H. savii which includes all of Spain and Portugal. The social call of H. savii is characteristic: duration of 40-500 ms, frequencies 16-30 khz, end frequency 16-18 khz. No doubt: such a call can help to identify a bat.

Edit: After disabling the "call distance", the BatExplorer finally obeys, viz. screen shot.

Thanks for the PDF Stefan. I must admit that it all sounds greek to me right now, but I have all winter to get ready for next year. I will try to focus on my window's bats till winters comes.

Thanks again

More sources which I found useful:

http://en.wikipedia.org/wiki/Bat_species_identification
[More "practical" anyway than the data collection on bats in the German wikipedia.]

http://www.amazon.de/British-Bat-Calls-Species-Identification/dp/190780725X#reader_B008QPCDVU
[= free sample pages from Russ' book on British Bat Calls]

http://www.batworker.co.uk/resources-for-bat-workers/
Lots of links...

I like the new book by Dietz (2014), but unfortunately it has a serious flaw. It is written in German.

HermitIbis said:

I like the new book by Dietz (2014), but unfortunately it has a serious flaw. It is written in German.

Click to expand...

It looks like not for long. An english version is on its way

Thanks again

Audio Recorders, continued

ori76 said:

FD works perfect with no hissing noise in the background, however on HD I do hear a constant hiss in the background (Wich seems the opposit as Stefan)

Click to expand...

The hissing noise may depend from the ear of the beholder. I thought it was OK, but had no comparison, since it was the first bat detector I ever listened to. Wikipedia (as linked above) gives a hint:

There is an irreducible hiss in the background of every bat detector recording. This is "system noise" from the microphone and electronics. This can vary widely between bat detectors and various types of bat detectors.

Click to expand...

Someone from a Yorkshire bat group who has probably used other bat detectors before, says in a review of the micro trio ( http://www.batplanet.co.uk/reviews/ce-505-trio-bat-detector-review ): "In Heterodyne mode the sound is crisp and clear, [...]"

A few additional comments on audio recorders.

Olympus VN713PC. Presently available from the Ciel Eam shop for Euro 89.90 and sometimes seen in online auctions for ~Euro 60. To be fair, the Ciel model comes with "Ciel Firmware", which increases the number of files to 999 per folder. The standard model can record only 200 files in each of the five folders. I wonder whether this firmware has other features important for our bat business. Apparently the standard version has VCVA (Variable Control Voice Actuator) and "Voice Sync", a feature to distinguish sound from silence and record the sound bits to separate files. - However, if the FD sound of the micro trio cannot help to identify a bat, why would I want to record 999 bat calls (or even 5 x 999 files) in FD sound quality over the night? It makes no sense. I'll admit that I have some fun with these 500 MB FD all-night recordings from my MP330, but if I really wanted to look at the one bat call uttered exactly at midnight, there is no particular advantage of having this single time-stamped file from Olympus, versus loading the large 500 MB file into Audacity and then zoom in.

Transcend MP330. For the low price (~Euro 40), it has limitations. It is a (bad) joke that it stores only 99 files. That said, 99 files are almost always enough for a late bat walk. It also isn't strictly necessary to record every single call separately. So if I've already collected 70 bat calls, I'll change my strategy and record 5-10 bat calls into one file. Splitting the calls later with Audacity is fast and simple. Separate files for different places (lake, bridge, forest, ...) makes sense anyway.
[Transcend offers a newer model: MP350, but it has no dedicated line-in jack.]

Zoom H2 or H2n. Famous for their recording quality, but maybe "too good" for the micro trio. If the H2n lasts 20 hours on batteries (vs four hours for the H2), unattended recording seems a possibility. But recording the very mediocre FD sound from the micro trio with a high-tech H2 seems pointless.

The H2N is a super bit of kit. Maybe too much for just FD recordings (I'm lucky in that mine also gets used for Bird Vis Mig calls, and as a speaker and mic for work phoneconferencing).

It is one of the few recorders that have a useable auto record function.. i.e. Sound breaks a threshold, it records, sound level drops, it stops; then triggers again once the threshold is broken.. and can go on all night like this without user intervention.. Beware many other recorders only do a "single shot" autorecord.

Peter

HermitIbis said:

The hissing noise may depend from the ear of the beholder. I thought it was OK, but had no comparison, since it was the first bat detector I ever listened to. Wikipedia (as linked above) gives a hint:


Someone from a Yorkshire bat group who has probably used other bat detectors before, says in a review of the micro trio ( http://www.batplanet.co.uk/reviews/ce-505-trio-bat-detector-review ): "In Heterodyne mode the sound is crisp and clear, [...]"

Click to expand...

The sounds from the bats are clear, both in HD and FD. However, while on FD I hear nothing if no bats are present, on HD I hear a constant background hiss (The one you can hear in my TE recording uploaded yesterday)

HermitIbis said:

Olympus VN713PC. Presently available from the Ciel Eam shop for Euro 89.90 and sometimes seen in online auctions for ~Euro 60. To be fair, the Ciel model comes with "Ciel Firmware", which increases the number of files to 999 per folder. The standard model can record only 200 files in each of the five folders. I wonder whether this firmware has other features important for our bat business.

Click to expand...

Speaking directly with Frank Walter he confirmed me that that was the only improvement.

ori76 said:

The sounds from the bats are clear, both in HD and FD. However, while on FD I hear nothing if no bats are present, on HD I hear a constant background hiss (The one you can hear in my TE recording uploaded yesterday)

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Ricardo, the recording which you posted shows indeed an irritating, strong hiss. And this is what you always hear in HD and FD, not some external noise caused by a machine or a plant close to the place where you recorded the bat?

I had posted two files in reply #29, giving samples of HD and FD sound from my micro trio. The channel "TE", when not replaying the recorded time-expanded sound, also plays the ordinary HD sound. On my device, none of these modes is so noisy.

(Postscript: How did you transfer the audio file to your PC, with an external microphone or a stereo audio cable connected to a line-in jack of the PC? When I open your file in Audacity, the result is in mono. And VERY noisy, see the screen shot.)

HermitIbis said:

Ricardo, the recording which you posted shows indeed an irritating, strong hiss. And this is what you always hear in HD and FD, not some external noise caused by a machine or a plant close to the place where you recorded the bat?

I had posted two files in reply #29, giving samples of HD and FD sound from my micro trio. The channel "TE", when not replaying the recorded time-expanded sound, also plays the ordinary HD sound. On my device, none of these modes is so noisy.

Click to expand...

I have just heard your files and I can say that my FD works as yours. But HD (and TE) do allways have that hiss. Not only at my home, but also in the lake on saturday so there must be something wrong with it.

Do you mind if I use one of your recordings to send to Frank Walter together with my recordings just to compare and make him understand better the situation?

HermitIbis said:

(Postscript: How did you transfer the audio file to your PC, with an external microphone or a stereo audio cable connected to a line-in jack of the PC? When I open your file in Audacity, the result is in mono. And VERY noisy, see the screen shot.)

Click to expand...

With a cable connected to the line-in jack of the PC. I thought it was a stero cable but I am afraid it is not. But that is a different matter that has nothing to do with the hiss I hear with the detector

Of course you can send my file to Mr. Walter (Ciel). Sure, I've had some bad recordings myself, but nothing like the noise in your file.

New attempt: Natterer's bat

Speaking about noise, there was far too much of it in my recording in reply #37 to identify the bat as a Natterer's. What I caught was perhaps not even a bat.

So here is a new attempt. This time I am sure that it was a bat, even confident that it belongs to the genus Myotis. About the species, I am not so sure. - The recording is far from perfect. There are other bats, confusing the picture (pip + Nathusius; the low frequencies are the Myotis). I had also varied my settings of the MP330, a bad idea. Some of the noise in the background may also have to do with the place - river shore in the center of a city.

Still, the shape of the call in BatExplorer (see the jpg) clearly says "Myotis". So we can safely exclude the two Plecotus species (Longeared bat). Another one of BatExplorer's offerings, the Lesser mouse-eared bat (M. blythii), is extinct in Germany. Since the place was close to the river, another Myotis came to mind: Daubenton's bat. However, its peak frequency would have been around 37 kHz, so this is not an option. - If I am right, there remain just two alternatives: Natterer's bat or the Greater mouse-eared bat (M. myotis). However, the Greater mouse-eared bat is a rarity in this region. Besides the "habitat" must be to the liking of a Natterer's bat, foraging in the old trees between the river shore and the footpath where I stood.

I'll admit that the "true" measure of the left call was a peak frequency of 27.2 kHz. Which would have excluded a Natterer and left only the Greater mouse-eared. The manual adjustment to 28 kHz may be justified, but some doubts obviously remain.

HermitIbis said:

Of course you can send my file to Mr. Walter (Ciel). Sure, I've had some bad recordings myself, but nothing like the noise in your file.

Click to expand...

There is a new Micro Trio on its way to my home. That is what I call a wonderfull aftersales service.

:t:

ori76 said:

There is a new Micro Trio on its way to my home. That is what I call a wonderfull aftersales service.

:t:

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Good to hear. I have lots of fun with the bats, and hope you'll make the same experience. - By the way: According to the site http://www.iberianature.com/material/bats_spain.html , there are 27 bat species in Spain. In Dietz (2014), the maps show 29 Spanish species.

HermitIbis said:

According to the site http://www.iberianature.com/material/bats_spain.html , there are 27 bat species in Spain. In Dietz (2014), the maps show 29 Spanish species.

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I am aware of 28 species in the peninsula + 2 in the canary islands + 1 in the northern african city of Melilla

Rhinolophus ferrumequinum
Rhinolophus hipposideros
Rhinolophus euryale
Rhinolophus mehelyi
Myotis myotis
Myotis blythii
Myotis emarginatus
Myotis bechsteinii
Myotis mystacinus
Myotis alcathoe
Myotis natterei/escalerai
Myotis daubentonii
Myotis capaccinii
Pipistrellus pipistrellus
Pipistrellus pygmaeus
Pipistrellus nathusii
Pipistrellus kuhlii
Hypsugo savii
Nyctalus leisleri
Nyctalus noctula
Nyctalus lasiopterus
Eptesicus serotinus/isabellinus
Barbastella barbastellus
Plecotus auritus
Plecotus austriacus
Plecotus macrobullaris
Miniopterus schreibersii
Tadarida teniotis

Pipisterllus maderensis
Plecotus teneriffae

Myotis punicus

Where I live (Madrid) there are supposed to be 23 out of the 28 peninsular species. Just give me a call whenever you come.

Ricardo

Thanks, Ricardo. The variety of bats on the Iberian Peninsula is impressive. The downside: it will be a hassle for you to distinguish Nathusius's and Kuhl's pipistrelle, a problem that people in Britain and Germany don't have. - It seems I've overlooked a few maps in Dietz & Kiefer: Die Fledermäuse Europas (2014). A quick comparison to your list: they cover Myotis nattereri/escalerai and Eptesicus serotinus/isabellinus as four separate species. Plus (maybe) "male colonies" of Verspertilio murinus in the Pyrenees. Otherwise your list seems perfect.

So your peninsula alone has circa 34 bat species. A German book on European bats written in 1985 proudly presented 34 bat species - for the whole of Europe. There is rapid progress in this field.

Yes, two days ago I recorded a bat call from my window of a nathusii/khulii. Imposible to tell.

If it's any consolation, it looks like Nathusius' is a Winter visitor only to Spain, so you can get Kuhl's confidentally next Summer.

I have picked up both on detectors in the last couple of years.. Nathusius' "sounded like a pipistrelle".. Kuhli's had me stumped until the penny dropped when I analysed the recording. So maybe there is a slight difference, Kuhli's peaking at an even lower frequency perhaps. The literature certainly states they are identical, except for social calls though.

Greater Noctule is one I have never caught up with.. will be interesting to see how you do with that species.

peter.jones said:

[...] The literature certainly states they are identical, except for social calls though.

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Social calls are fascinating. My attempts to record a social call of Nathusiius's pipistrelle have not been very successful though. The best result I came up with is attached below. Instead of a screen shot I give a spectrogram, generated from BatExplorer, which is clearer.

There is a new book on the topic: Middleton, N., Froud, A. and French, K. (2014): Social Calls of the Bats of Britain and Ireland. Exeter: Pelagic Publishing. - When I ordered a copy, I had hoped that it also covers ordinary echolocation calls, if only in passing. But the focus is on social calls, and the authors, three licensed British bat workers, have written an outstanding work. I understand that social calls "Type D" of nathusii vary a lot, the book gives four of these calls on pp. 113-117, with detailed textual explanations, plus one in the overview on the four pipistrelles (p. 121). The only quarrel I have with the book: the microscopic kHz and ms info accompanying the fine spectrograms should have been reset by the publisher in a larger font size. My eyes are too old for this 1 pt stuff. This minor flaw aside, I am enjoying the book very much and feel lucky that Germany and Britain are sharing so many bat species.

Nathusius' type D social calls can consist of four or only three elements, yet in my recording I see only two. And a lot of echoes. Of course, the new book has chosen only the most splendid examples. And I still have some days left to try again.