On this site you can download a pdf table describing the extremes of echolocation calls of European bat species. Please look below to find the table in your language. If you think you could provide us with additional information, or you see a mistake (also in language), don’t hesitate to write.
-The free Avisoft-SASLab Lite Software has been modified and improved substantially, check out the sound analysis corner.
-Yet another new standalone bat-detector on the market: The Batlogger, see the Equipment section.
-I am presently testing a prototype of the Nanobat detector, will provide some first impresssions later.
-The new SM2 detector by Wildlife Acoustics is available. It now has a sampling frequency of 384 kHz and can compete with other detectors, see Equipment section.
-Check out the modified Ultrasound Gate 116Hnb and 116Hn by Avisoft.
Here you can read why the table describes limits, why we use QCF-, and not peak frequency, how to measure max (or start-) frequency reliably and more…
Download your ID table here
From the countries
-Hooray, the slovenian bat atlas (largely based on bat-detector observations) is now available here. The atlas is written in slovenian and english side by side. Praise to the authors for doing so much with so few people and little money.
-Look here. This is an online atlas, mainly based on bat-detector observations in SE France. Keep up the good work and thanks for putting these distribution maps online.
-Developments in Sweden: get the beta version of a programme to identify bat recordings (read more)
-How the French do it: amorce et claquement final, a discussion of a method developed by Michel Barataud (read more)
-Un sondage pour trouver l’origine physique d’amorce. An acoustic survey to understand “amorce” (cliquez ici)
Sound analysis corner
-Interested in sound analysis? Here is a platform for the advanced and for beginners (click here)
-Why is it important to use the .wav format when recording sounds for scientific analysis? (This website) by Avisoft explains it all.
-Will the rise of autonomous detectors and automatic ID make us and our knowledge redundant? Click (here) for an analysis of the facts
-Some comments on the concept of using limits in discriminating echolocation calls by Chris Corben (click here)
-Why should we measure QCF frequency and not peak-frequency? (click here)
-Do bats use rhytmical pulse intervals? Find out how Michael Jackson compares to Eptesicus serotinus. (click here)
–Here is a very active forum (language French) for discussing bat ID using echolocation calls. I have been following the discussions for a while and I can tell you this is top-level.
-Contribute to the development of an automatic bat identification software called Omnibat
-This is the official website of the Batlogger. The Batlogger can be used to monitor the activity of bats. Its sampling frequency is 312.5 kHz, price: 1850 swiss francs, or 1523 euros.
-The Dodotronic Ultramic200K is a microphone you can plug directly into your laptop. Click (here) for a short description.
-The Nanobat detector… Maybe a sales strategy to keep your customers curious? (This) is what we know.
–The new Song meter SM2 384 kHz by Wildlife Acoustics
-Notchy recordings with D980 / D1000 detectors: (problem and solutions)
-How to choose your TE Bat-detector (advice)
-Batbox Griffin (specifications)
-Pettersson D500X (specifications)
-Ecoobs Batcorder (specifications and detailed test reports)
-Dodoultra (a DSP-based frequency-shift detector)
-Frequency compression (in a detector by Binary Acoustic Tech)
–Avisoft now also sells a new ultrasonic microphone (USG Electret Ultrasound Microphone) for 420 euros (requiring phantom power) with a frequency range from at least 10-135kHz.
-Call limits of Indonesian bats / Tabel ekolokasi kelelawar di Indonesia (click here)
-Distribution and behavioural descriptions of Indonesian bats / Distribusi & ekologi kelelawar di Indonesia (click here)
-Why do Rhinolophidae show geographical CF variation whereas Vespertilionidae do not? (click here)
-Open bat ID issues in Indonesia(click here)
-Call parameters of some South-African bats (click here)
(Compiled by the bats of Gauteng and Northern Regions bat interest group)
To readers from North-America, the Middle-east and Australia I think you should have enough data to make your tables too. I am looking forward to publishing your pdfs here.
How to use the table
Many of the previous approaches to IDing echolocation calls used datasets of random, average, or “typical” calls an observer would record in the field. We believe, however, that many calls one typically records in the field are of insufficient quality to analyse. One must record a series of high quality calls, characterized by a steep oscillogram onset, at best containing pulses of different durations. This means one gets few recordings of secretive quiet bats and a lot of pipistrelle-recordings, but then, bat detecting is a biased method anyway and what we really need is a reliable basis for identifying the recorded pulses. To make our table, we looked at large datasets of high quality recordings. We looked how far different bat species are able to “push” their echolocation in extremely dense and extremely open environments. This would give us some basic information what the highest and lowest values are a certain bat species is able to produce. The table shows these extremes per species, sometimes not very different, sometimes quite useful. The table is just a first step. Of course, we will also need to describe correlation between parameters that typify each species over its entire range between dense and open environment. We urge the users of this table to be extremely critical of it, warn us in case you doubt a certain value and never to go by it blindly. We hope to provide more parameters and ID information on this website in the near future. Because we received many questions and remarks about the table we added an FAQ to eliminate some common misunderstandings about the table. We also received a word of warning from Danilo Russo not to use the table blindly!
We (see the team below) tried to do our best to compile a table that is as accurate as possible to help everybody in Europe to use their time-expansion detector as well as possible. We hope that this website will become the centre of discussion about new findings, opinions, critiques, all to lead us to the perfect technique. We hope to start a discussion forum on this website, but you can write to us already with the latest novelties. Don’t worry about language: we all speak and understand each other’s Euro-english, and besides, you probably speak better English than your prime minister!
Of course, we have a certain philosophy regarding bat ID on the basis of echolocation calls. Our philosophy is to design an objective method that can be checked and verified every step of the way. Of course there are people with golden ears, but in the end of the day, what they hear is on the sound file, stored in a digital code. If the person with the golden ears insists that what he / she is able to hear is not to be found in any usual representation, such as an oscillogram or a spectrogram, he/she must find the representation that does show the magic cue, even if he /she must go down to the digital code itself. To be able to hear a cue, it must at least be in the digital code since this IS the sound. Following this logic, we claim that everything the best ear hears in a sound file can also be made visible on a screen. Our mission is to extract from the digital code all useful parameters, quantify them and get all Europeans to use them.
Contents of table were assessed and discussed by the following persons:
Expert on echolocation processing by bats
Merekam blues kelelawar di Bogor, Indonesia.
Author of the book: “Handbuch der Fledermäuse Europas
expert on taxonomy of european bats.
University of Tübingen, Germany.
Expert on behavioral ecology of horseshoe bats
Max Planck Institute, Seewiesen, Germany.
With ecoobs (Germany). Developed an automated bat
echolocation ID system, based on Europe’s
largest echolocation database.
Author of the paper: “Identification of 22 bat species from
Italy by analysis of time-expanded recordings of echolocation calls.”
University of Napoli Frederico II, Italy.
Expert on bat behavioral ecology
Max Planck Institute, Seewiesen, Germany.