45. DIY Zelfbouw Teensybat-VLEN Bat detector/recorder (Vleermuis) Open Source

https://www.youtube.com/watch?v=z5C3wLsyGdE&t=11m44s
De eerste lezing (vanaf 11.44 min) is door Johann Prescher & Dirk Oosterholt : 'Grootoorvleermuizen leggen grote afstand af door coulissenlandschap om in moeras te foerageren.'
Tijdens onderzoek naar effectiviteit hopovers als verbinding in coulissenlandschap voor Gewone Grootoorvleermuis werd ontdekt dat deze vleermuizen lange afstanden aflegden om te foerageren in moerasgebied. Tot voor kort werd aangenomen dat Gewone Grootoorvleermuizen niet zulke grote afstanden afleggen.

https://www.youtube.com/watch?v=z5C3wLsyGdE&t=52m
De tweede lezing (vanaf 52.18 min) is door Marc van der Sijpe en Claire Hermans : 'Introductie in auto-recording en auto-identificatie en Explaination how works Tadarida and the BTO classifier of Tadarida'
Deze presentatie wordt in het Nederlands en Engels gegeven. Als eerste geeft Marc Van De Sijpe een introductie over auto- recording en auto-identificatie, waaronder Tadarida, een Open Sourceclassificatie in de programmeer- en statistiektaal R. Daarna neemt Claire ons in het Engels mee hoe Tadarida werkt, waarna ook de BTO classifier wordt gedemonstreerd

https://www.youtube.com/watch?v=z5C3wLsyGdE&t=101m Effect of light intensity on Habitat loss De derde lezing (vanaf 1.41.17uur) is wederom door Claire Hermans en geeft een preview op haar project: 'Light on landscape' waarbij ze vertelt over de werking van Microphone-arrays om vliegpaden van vleermuizen te reconstrueren.

https://openresearchsoftware.metajnl.com/articles/10.5334/jors.154/

Book, PDF
Bestimmung von Fledermausrufaufnahmen und Kriterien für die Wertung von akustischen Artnachweisen - Teil 1
The original FFT is processed every 0.67msec. If you use a zoom factor of 4, you only take every fourth sample. Thus, it needs four times longer until you have acquired enough samples for the FFT, thus 2.67msec. Now, the trick is that you do not wait until you have all the samples collected, but you allow for „overlap“ in the samples and perform the FFT with the same rhythm of 0.67msec. [please note that this also takes four times the processing power compared to non-overlapping samples for the FFT and also takes more memory]

I have collected more information on the ZoomFFT in this Wiki:
https://github.com/df8oe/UHSDR/wiki/...ode-=-Zoom-FFT

I am not experienced in programming audio library blocks, but my gut feeling is, it could be easier to just use a queue object from the lib to get the samples and perform all the calculations in the main loop and not inside an audio lib object (because there are different sample rates involved). However, for people also interested in using the ZoomFFT, if you design a specific audio library object, you will get much more credit ;-).

Best wishes,

Frank DD4WH
https://www.bestellen.bayern.de/application/applstarter?APPL=eshop&DIR=eshop&ACTIONxSETVAL(artdtl.htm,APGxNODENR:34,AARTxNR:lfu_nat_00378,AARTxNODENR:357135,USERxBODYURL:artdtl.htm,KATALOG:StMUG,AKATxNAME:StMUG,ALLE:x)=X

BTW: this brandnew publication will rapidly become the professional standard for the identification of bat calls from spectrograms in Germany. Maybe it also helps others with ID of bats in Central Europe.
https://www.bestellen.bayern.de/appl...tMUG,ALLE:x)=X

Bestimmung von Fledermausrufaufnahmen und Kriterien für die Wertung von akustischen Artnachweisen - Teil 1

=====================

A little off-topic, OK, but now that the bat detector works, you need some info about bats and their bioacoustical properties and how to identify them by their ultrasound calls.

This is the "bible" of bat bioacoustics, if you want to know everything about bats and their calls:

Barataud et al. (2015): Acoustic ecology of European bats: Species identification, study of their habitats and foraging behaviour. -
http://www.nhbs.com/title/199366/aco...-european-bats --> not only for european bat friends, the bioacoustics & methods section is universal

There are many many nice websites on batcalls, here is a subjective choice:

http://www.batcalls.com/

http://blog.batdetective.org/

http://www.batecho.eu/

https://www.researchgate.net/profile...ication_detail

If you live in the northern hemisphere, we are very near to the end of the bat season, before the bats go to their wintering grounds. But if you live in a city, it could be worth going outside when the sun goes down and try to detect the last bats of the mating season doing their courtship calls.

Have fun with the Teensy and with bat detection,

===========
This is the "bible" of bat bioacoustics, if you want to know everything about bats and their calls:

Barataud et al. (2015): Acoustic ecology of European bats: Species identification, study of their habitats and foraging behaviour. -
http://www.nhbs.com/title/199366/aco...-european-bats --> not only for european bat friends, the bioacoustics & methods section is universal

There are many many nice websites on batcalls, here is a subjective choice:

http://www.batcalls.com/

http://blog.batdetective.org/

http://www.batecho.eu/

https://www.researchgate.net/profile...ication_detail

If you live in the northern hemisphere, we are very near to the end of the bat season, before the bats go to their wintering grounds. But if you live in a city, it could be worth going outside when the sun goes down and try to detect the last bats of the mating season doing their courtship calls.

https://www.bestellen.bayern.de/application/eshop_app000005?SID=1615997943&ACTIONxSETVAL(artdtl.htm,APGxNODENR:34,AARTxNODENR:193326,USERxARTIKEL:artlist1.htm)=Z

Deze meneer heet ook Stuart Newson en je kan er automatisch elke bat, bush-cricket and small mammal call mee determineren

The acoustic identification of small terrestrial mammals in Britain

By - Stuart Newson, Neil Middleton, Huma Pearce
Small mammals are often recorded as by-catch during bat surveys, and here lies a potential non-invasive tool for surveying the small terrestrial mammals of Britain. Stuart Newson, Neil Middleton and Huma Pearce describe how they built an extensive library of native and non-native small mammal recordings, and then take a closer look at the distinguishing identification features of their calls.

Visit the NHBS Conservation Hub to read a more detailed overview of the article, as well as more information regarding recommended reading and equipment for use in small mammal surveys.

Audio clips to accompany the article can be downloaded here, where you can also access the BTO Acoustic Pipeline – this tool allows for the upload of sound recordings and will automatically detect and identify any bat, bush-cricket and small mammal call.

Britain is home to several species of small terrestrial mammal, defined for the purposes of this article as the rats, mice, voles, dormice and shrews, and referred to hereafter simply as ‘small mammals’. Some, such as the Brown Rat Rattus norvegicus, are widespread and common, while others, such as the Hazel Dormouse Muscardinus avellanarius, are far more localised. All are difficult to observe in the wild, and it is usually necessary to perform invasive capture techniques in order to confirm their presence.

https://www.britishwildlife.com/article/volume-32-number-3-page-186-194

https://www.nhbs.com/blog/acoustic-identification-small-mammals

As static bat detectors have become more widely used, there are now many thousands of hours’ worth of nocturnal recordings captured each year from a vast spread of locations. This level of coverage has not only improved our ability to monitor bat populations, but also offers the potential to gather information on other animals that communicate at the same ultrasonic frequencies as bats. The calls of bush-crickets, for example, are commonly picked up as ‘by-catch’ during bat surveys, which has allowed the development of software that automatically recognises any cricket calls in a recording and assigns them to individual species.

In the December issue of British Wildlife, Stuart Newson, Neil Middleton and Huma Pearce explore the previously untapped potential of acoustics for the survey of small terrestrial mammals – rats, mice, voles, dormice and shrews. Small mammals use their calls for a variety of purposes, including courtship, aggressive encounters with rivals and communication between parents and their offspring. To the human ear, the high-pitched squeaks of different species sound much alike, but closer examination reveals them to be highly complex, extending beyond the range of our hearing into the ultrasonic and showing great variation in structure.

Mammal terrariums used for holding individuals overnight in the recording ‘studio’.
But is it possible to distinguish the calls of different species? To answer this question, the authors began the time-consuming task of building a call library by taking recordings of all Britain’s native (and some non-native) small mammals. Call-analysis software was then used to examine the recordings and look for consistent differences between species, with some fascinating results – the calls of shrews, for example, can be readily separated from those of rodents by their warbling/twittering quality, while the house mouse typically calls at a higher frequency than any other species. Remarkably, it appears overall that the vocalisations of most species have their own diagnostic features, and that, with care, it should be possible to identify a high proportion of calls to species level.

Recorded calls of (a) Brown & (b) Black Rats
Small mammals are unobtrusive and hard to observe, which means that even the more familiar species, such as the Brown Rat, are severely under-recorded. The ability to detect and identify small mammals by their calls therefore offers great potential to help fill gaps in our knowledge of the distribution and abundance of British species. Analysis of calls collected by static detectors – whether specifically set to target small mammals or deployed as part of a bat survey – could in future offer a rich source of data and help to complement traditional methods, such as the use of Longworth traps or footprint tunnels.

To read about the key identification features of small-mammal calls, see the December issue of British Wildlife (more information can be found on the British Wildlife website) and to accompany this article, audio clips of the species discussed are available to download here. This work will contribute to the BTO Acoustic Pipeline, which allows the upload of sound recordings and automatically detects and identifies any calls of bats, bush-crickets and small mammals. For more information about the project, see the BTO Acoustic Pipeline webpage and read comments from the authors here.

Bat detectors for small mammal survey:
Passive bat detectors are designed to be left in the field for unattended monitoring and are the ideal choice for ecologists and researchers wishing to monitor local bat populations. For similar reasons, they are also a good choice for recording small mammals as they record all frequencies continuously and retain complex details of the call structure, allowing the sounds to be analysed later using bioacoustics software. Detectors such as the Song Meter Mini, Anabat Swift and Elekon Batlogger A+ all features excellent weatherproofing, long battery life and the ability to programme recording schedules.

https://www.nhbs.com/blog/acoustic-identification-small-mammals