Friday, March 24, 2023

A Quick Update Post Re: The TeensyBat 4.1 Detector

The TeensyBat site has recently released new software for The TeensyBat 4.1 bat detector.

I've been using mine quite a bit lately... This is the second one I've built (PCB Ver. 0.7). I'm planning on ordering another kit, which now utilizes the very latest PCB (Ver. 0.8). As I type this, I have the (recently completed) TeensyBat plugged into an external (powered) speaker. 

I enjoy listening to the bats, using the Auto-Heterodyne feature (heterodyne with the benefit of automatic tuning).

My local bats are out, and seem to be celebrating Spring! 

The latest software adds some nice features:  Including very nice Auto-Record features.

Edwin Houwertjes (of The Netherlands), has recently made some new YouTube videos demonstrating his TeensyBat Detector (~ 4 months ago) - they provide an excellent explanation and overview of this kit:

TeensyBat detector basic use V1.4

TeensyBat playback and record V1.4

TeensyBat settings V1.4

Happy bat detecting!

Tuesday, March 14, 2023

Still Fully Committed to DIY Bat Detectors!

"The time has come," the Walrus said, "To talk of many things:
Of shoes-and ships-and sealing-wax- 
Of cabbages-and kings-
And why the sea is boiling hot-
And whether pigs have wings."

The PiPPYG Version 1.1b - The early days

I just want to take this opportunity, to talk about DIY bat detector kits. I'm still fully involved, and still assembling them. I've mainly moved on to The PiPPYG by Phil Atkin (Ver. 2.3). Although, I still have a TeensyBat 4.1 kit here (currently unbuilt).

I'm happy to report, I've been following The PiPPYG's development and progress very closely, since the beginning (~Version 1.1b). It's been very cool to learn of the improvements, and advancements of this fascinating unit - As they were implemented by it's creator Phil Atkin (England). As I type this, The PiPPYG is currently at version 2.5!

This is a fascinating image representing the components

used during assembly (early version of PiPPYG) 

Created by Phil Atkin.

I also did a very small poll on Twitter. Basically asking whether or not I should continue spending time on the DIY bat detector kits... In a 72 hour period, only a handful of replies/responses came through, but the end result was:

80% voted to spend more time discussing the DIY Detector kits. Namely, The TeensyBat 4.1, and The PiPPYG 2.3. 20% voted for me to move on to the next project.

I will continue to build, test, and share my findings here on the blog. I'm also planning on creating some short "How To" videos, to place on my YouTube channel.

From left to right: 
Solder stencil/mask, PiPPYG 2.3 PCB's, π•Pipistrelle PCB's

What better way to celebrate Pi Day (3.14) than to have Phil Atkin (creator of the π•Pipistrelle & PiPPYG) as our guest, on The BatAbility Club?
It was great!
The recorded version, will soon be made available to BatAbility Club Members, for viewing at their convenience.
Note: Phil Atkin has been updating and putting the finishing touches on the PiPPYG User Manual - And It's looking great!!

The original V2.0's:
Front - - - - - - - - - - - - - - Back

A full review of the PiPPYG is currently in progress, and will be posted here on the blog, in the near future. 
In the meantime, members of The BatAbility Club will be in for a treat tomorrow:
Phil Atkin, the creator of The PiPPYG will be Neil Middleton's guest! 
Exciting stuff!
I'll be there to share my thoughts and experiences as well.

The next off the shelf, bat detector to be reviewed (after the PiPPYG) will be The Ultramic 384k Evo from Dodotronic. Preliminary tests sound promising—It's very nice to be able to record both ultrasound and audible sound at the same time!

Until next time,

Happy Bat Detecting!

Tuesday, February 28, 2023

Vesper Bat Detection Services - Courses For Those Working With American Bat Species

Vesper Bat Detection Services - Courses For Those Working With American Bat Species. This post will give you an idea of the online courses available from Vesper.

I had the opportunity to attend both:

  • The Echolocation 101 / Best Practices for Acoustic Monitoring.*
  • The Acoustic ID of Eastern US/Canada Bats (All 20 Species!). 
* The Echolocation 101 Course is a pre-requisite for attending the other courses (namely, the Acoustic ID courses).

Both courses were very well-presented, by Donald Solick; with excellent support by Satya Glaser.

Vesper Bat Acoustic Surveys Link.

There were 6 courses in total. Among the other courses available, was:

'SonoBat Beginner' 

SonoBat looks like an interesting software platform; I've dabbled with it a bit in the past. I would've considered this course, but the truth is: I can't afford SonoBat software; so I skipped it.

For those who were interested in pursuing SonoBat Software further, and/or possibly choosing it as their main platform: Vesper Bats & SonoBat worked-out a deal, which would allow attending students to try-out a full-functioning version, for a limited time. That was nice.

These courses were designed to insure that you are fully prepared for your next US-Based Bat Acoustics Survey.

You get an emailed certificate of attendance indicating the courses you took.


All Attendees are provided with access to recorded material for future reference. As well as some useful documents and charts, which would be helpful for going back to again as a refresher.

Spring Bat Acoustics Training - Have a look at the classes coming up in April 2023!

I urge you to visit the websites, and see what's available - Just at a glance for now:

6 Options!

Apr 22, 10-1 ET: Echo 101 & Best Practices (required for ID classes; $75)
Apr 22, 3-5 ET: SonoBat Beginner ($50)
Apr 23, 9-12, 2-5 ET: Acoustic ID of Eastern Species ($150)
Apr 29, 9-12, 2-5 PT: Acoustic ID of Western Species ($150)
Apr 30, 11-1 ET: SonoBat Advanced ($50)
Apr 30, 3-5 ET: Group Share and Review of Your Calls ($50)

Friday, February 10, 2023

Book Review: 'A Miscellany Of Bats' by M. Brock Fenton & Jens Rydell

'A Miscellany Of Bats' by M. Brock Fenton & Jens Rydell

This book has just recently been published (January 10, 2023) by Pelagic Publishing. It's currently available in paperback, and electronic format (Amazon Kindle).

The book is 256 pages in length; and it measures 24.4 X 17.0 X 1.91 Centimeters. 

As always, I advise you to shop around for: Best price, and delivery times. See link to NHBS below:

I was very anxious to receive my copy! Had I known that it was going to contain such stunning photographs, I would've been even more impatient!

In an effort to not divulge too much about the book itself, I will focus on the items which I found particularly interesting.

It arrived from the publisher's very well-packed & protected. For starters, when I first thumbed through it (just quickly, mind you) - I couldn't help but notice the amazing photos. Many of which are breathtaking. 

The other factor which becomes obvious after a short time, is that this book is meant to be read through - Not just to be referred to. In other words, it isn't strictly a (non-fiction) resource on bats.

Table of contents:

1. Introducing bats

This first chapter covers catching, IDing, marking & tagging bats (pages 5-7). Being a mothing enthusiast for many years myself - I was happy to learn that Jens Rydell started as a moth collector (page 19).

2.Bat wings and flight

Covers bat wing anatomy, and facts related to the way bats fly.

3. Seeing with sound

An excellent chapter, providing an easy to understand introduction to the ways bats use echolocation. Wonderfully presented.

4. Echolocation: a window onto bat behaviour

One of my favorite chapters - provides further details, and even more interesting information on echolocation. Also, a rare glimpse at what detectors look like in the early 1980's! Absolutely loved it!

5. What bats eat, part 1

There are facts and illustrations in this chapter which are simply amazing! The diet of bats is described, as well as the fascinating tactics they use, to acquire their food items of choice.

6.What bats eat, part 2

This chapter mostly deals with bats which eat items other than small insects. Similar to part 1, but in an even more concise and captivating manner.

7. Vampire bats

A slightly shorter chapter than those which preceded it, but rest assured - you will learn some facts which you were completely unaware of! You'll come to understand these enigmatic bats in a different light.

8. Where bats occur and where they roost

In this thorough, and wonderfully illustrated chapter - The reader will again learn many unique facts about where, and how bats select and use roost sites.

9. Social lives of bats

Here, the reader will learn about mating, reproduction, and the social behaviors of bats.

10. How bats use space

At 1st glance, the reader might think this chapter is about how bats use confined space(s) - In actuality, this is not the case. This chapter brings to light several unique facets of their habits (as discovered through research/study).
And I'll leave it that (as a surprise!).

11. Threats to bats

Here the authors cover all of the current threats to the survival of the world's bats. Beginning with natural threats, predators, et cetera; and moves on through to man-made threats: Such as wind farms, etc.

12. Bats and people

This was a concise but very enjoyable chapter. It covers the various relationships between bats and people throughout history. Fascinating and wonderful stuff!

13. Bats as beings

This last chapter, deals with the most fascinating facts - which scientists have learned about bats (relatively recently). The interesting and formally unknown activities of bat species, which recent research has brought to light.

I suppose what's most obvious about this book, is it's suitability and appeal to those with an interest in bats, at just about any level (except perhaps for young children?).
This book would be good for beginners/newcomers, students, as well as experts on bats.
I considered it a valuable book as soon as I saw that M. Brock Fenton was one of the authors - Having read several of his papers, and other examples of his work over several years. For anyone keenly interested in bats, not much more needs to be said about M. Brock Fenton.
I will take this opportunity, to point out - That Neil Middleton had the privilege of interviewing him, for The BatAbility Club (viewable to members only).
I must confess, that I was mostly ignorant of Jens Rydell's work until now. I was very sad to learn of his recent passing. The set-ups he used, to capture such awesome photos of bats in flight, were truly awe-inspiring. And the resulting photographs of bats in flight speak for themselves.

Again, this is a book which you'd sit down, read through; and enjoy! Chapters 3 and 4 essentially provide the reader with a very good basic understanding of: echolocation, the recording of bat calls, and spectrograms.

What I really liked:

The book was easy and pleasurable to read - I learned some very interesting facts about bats which I wasn't aware of.
It would also be a very useful addition to any public library.

What I would've liked to see:

Personally, I would have liked to have seen: More bat detectors, and more details about bat detectors... Because, well...I happen to have an obsession with bat detectors.
Honestly, beyond the preceding, partly tongue-in-cheek comment - I can't find any fault with this book. And would recommend it to anyone, with just about any level of existing knowledge of bats. This book will quickly bring someone up to speed on the fascinating natural history, and behaviour of bats.

The next review, will be of a bat recorder you've most likely never heard of—That's about to change... As with the TeensyBat 4.1, just recently reviewed here on the blog — it is also primarily a DIY detector. However, there is also an effort being made, which will allow Folks to purchase this detector already built, and flashed (programmed) and ready to go. That is about all I'm going to say about it for now. But I have been looking forward to reviewing it. Both for the BatAbility club as well as here on the blog, and sharing it with everyone!

Until next time,
Happy bat detecting!

Wednesday, February 8, 2023

Review of The TeensyBat 4.1 DIY Bat Detector

The TeensyBat 4.1 DIY Bat Detector

 The TeensBat 4.1 kit - Main parts illustrated
(stock photo from

The TeensyBat is a Do-It-Yourself (in this case, assemble-it-yourself) bat detector. It features a few different modes of detection. As well as a myriad of features and customization's.

The TeensyBat 4.1 As it arrives (to me in The US)
from The Netherlands

The TeensyBat is based on a development board made by PJRC. You may see more information about the board, by checking out the PJRC Site.

Size of the completed unit is 116x68x36mm (4.7x2.7x1.5in)

The TeensyBat 4.1 kit - Unboxing

The TeensyBat 4.1 kit - Main components

Building The TeensyBat 4.1 kit - 

The one "fiddly bit" is encountered in the beginning. It's the installation (soldering of) the 2 PSRAM chips. This is discussed/shown on page 4 of the construction manual. Once those two small ("optional") chips are soldered onto the Teensy board itself; the rest is pretty easy.

It is right about this point, where I usually touch on the price of the bat detector under review.
But, this Do-It-Yourself bat detector kit is a bit different...
To begin with, you purchase/order the kit from the site.
At the time of ordering, you should decide which options you'd like your bat detector to have (Temperature sensor? External microphone jack? GPS unit?).

Then, you'll need to purchase the following items: 

  • 2 PSRAM 8MB Chips @   3 each         ~   6 (TeensyBat)

  • Teensy 4.1 Board………………………………….~ $41.99 on Amazon.

  • 3.7v 6500mAh LiPo………………………………~ $17.99 on Amazon.

  • Pack of CR2032 Batteries…………………… ~   $5.99 on Amazon.

Total cost - As configured - Roughly $200 US Dollars (I opted for the temperature sensor, and 3.5mm jack (for use with ext. microphones). This is the jack located at the front of the unit; next to the (main) microphone.

Now this presumes the builder is familiar with soldering, and already owns the tools & materials needed for completion…If you don't:

Additional basic tools & materials needed to build kit: 

  • Soldering iron 30w to 60w - Simple “pencil-type” is sufficient.

  • Standard, Rosin-Core solder - “60/40” is fine.

  • A fine, flush cutter - similar to a wire cutter.

  • Screwdrivers.

  • Files, Dremel-type tool is a “nice-to-have” but not necessary.

  • Desoldering pump, or Desoldering wick.

  • Tweezers would be useful, as well as a tip cleaner for iron.

Building The TeensyBat:

  • The construction Manual is found under the ‘Build One’ tab on the site.

  • One of the first steps, is to install/solder the 2 PSRAM chips onto the Teensy 4.1 board.

  • The remaining soldering & assembly isn’t very difficult at all.

  • The only other “fiddly bit” is the microphone.

  • There may be some minor modifications needed to the enclosure openings.

The TeensyBat just so happens to have a lot of features. You can spend a bit of time just customizing it.

From left to right:
Temperature sensor, 3.5mm jack for external Mic, Main microphone

Features of The TeensyBat:

  • 2.8inch color display that shows a live spectrogram and low,peak and high frequencies.

  • Heterodyne, Auto-Heterodyne and Frequency division listening modes (using headphones).

  • Recording up to 384kHz sample rate to micro SD card (maximum supported size 32GB, Class10 or better required).

  • Playback on slow speed (1/5 to 1/20 ratio) or full speed (full speed only works up to 281kHz sample rate).

  • Rechargeable lithium battery can easily last a whole summer night (standard USB (C) charger is needed).

  • Internal LiPo battery charged by standard phone charger.

Using The TeensyBat resources:

  • The ‘Using the TennsyBat’ Tab - Found on the site.

  • There are 4 YouTube videos there: Basic Use, Settings, Playback & Record.

  • At the bottom of the same page is The TeensyBat User Manual V1.4


  • Rechargeable Li Po battery (standard USB (C) charger is needed).

The TeensyBat does take a bit of time to get used to. As with any bat detector, it comes down to navigating the buttons, knobs, and features (enabling/disabling). It becomes somewhat more difficult (frustrating?) when you're out in the field; and bats are flying about - You don't want to miss any!

Simply familiarize yourself with the 4 main controls - 2 red buttons, and 2 red-topped knobs. The knobs feature built-in detents - Here's a look:

2 Buttons, each on either side.
2 knobs bottom/middle.
(stock photo, courtesy of Edwin Houwertjes) 

Once you become familiar with the 4 main controls, it becomes very easy to use.

What I call my version of a short quick start guide:
  • Power on The detector, select Mode (Het, Auto-Het, F_D, TE*). 
  • Adjust volume to 50 or below. 
  • Adjust gain to 15 or below. 
*Time Expansion is not likely to be available on The TeensyBats going forward.

I typically set my volume to ~ 40, and set my gain to somewhere around 12.
As you might expect, increasing the gain allows you to pick up bats from slightly greater distances. 
Keep in mind that these settings are relative - Since the TeensyBat doesn't come with a speaker as standard / or built in. Without an external speaker attached, the volume doesn't really have much effect on anything. With the rotary gain control, the difference as you raise or lower it, will affect the overall sensitivity of the unit. 

This TeensyBat bat detector is very sensitive, and has the ability to pick up bats at respectable distances. 

It also picks up bat calls loud and clear, from off axis. 

This was apparent, when comparing the TeensyBat side-by-side to the Echo Meter Touch 2 Pro, and The SSF3 bat detectors.

You get to put whichever bat sticker(s) you want on it!

If you'd like to listen to the bats you're picking up: You'll have to provide an external speaker, and a male-to-male 3.5mm audio cable (for connection to the detector's audio out jack).

There are also small, rechargeable, Bluetooth speakers available from several online stores. I used my trusty, adjustable, RadioShack external speaker (it runs on a single 9 volt battery).

This TeensyBat  picks up bat calls loud and clear off axis (bat calls coming in at angles to where the microphone is actually pointed).
Aside from this obvious advantage, I would compare it's general ability to be roughly similar to that of The Echo Meter Touch 2 Pro.

When you hear a good clean bat call, you can press the record button, and record the calls onto SD card.
When recording bat calls: It records ultrasonic sound to the Micro SD card in full spectrum, regardless of the listening mode used.
The calls are easy to listen to, using just about any standard audio player App you may have.
For beginners: Keep in mind, you'll be able to hear the (FS) recorded calls, using things as basic as Windows Media Player (in Windows) and QuickTime (in Mac).

The recorded calls may be analyzed in many different sound analysis programs. Playing the first batch of (FS) calls back, with these professional Apps produced mixed results.
What happened in my (first) examples, was: Kaleidoscope (from Wildlife Acoustics) did not play calls back in a pleasing manner. In my particular case: 
I had more electronic devices near the TeensyBat than I should have - causing interference, etc.
After more recent experimenting, this does appear to be what happened. When no other electronics are in it's vicinity, it produces recordings of bat calls which are more than adequate.

The other selections available are heterodyne, auto-heterodyne, and time expansion. We will need to omit time expansion for now, and just focus on the other modes.

The early renditions of The TeensyBat also allowed listening in time expansion mode, I have done it, but not very often. Going forward, TE will not be an option. 

This bat detector kit would be ideal for someone with electronic kit building experience; and an interest in bats!

The full spectrum recordings of bats were audibly pleasing, and of course, were also recognized by Kaleidoscope (Wildlife Acoustics). Bat calls heard while listening in heterodyne mode, were very pleasing as well.


  • Very customizable in re: to options desired, at time of construction.

  • Audio “ring” pre-buffer (records several seconds ahead).

  • Sensitive microphone - Both detecting & recording.

  • Records up to 384kHz sample rate, onto Micro SD card.

  • Has several advanced features which may be adjusted: Filters, Gain, etc.

  • Aesthetically customizable (display colours/themes).

  • Constantly being improved upon via firmware, etc.

  • Has proven itself able to withstand very cold temperature without incident.


  • Requires soldering skills to build.

  • Does not feature a speaker - Must use external speaker, or headphones (for live listening)

  • Battery life not comparable to some Pro-level detectors.

  • Recording bat calls is not as easy/automated as pro level detectors.

I plan to create/post some videos, of the TeensyBat in use — on my YouTube channel.
I hope to include some videos on: Simple setup, on attaching an external speaker,
and on how to use the detector in general. Even more importantly, I'd like to
confirm that the noisy recordings I got, were due to electronic interference.

Review of the recently released book, 'A Miscellany of Bats' will be the next item up...

Until then,
Happy bat detecting!

Thursday, February 2, 2023

The Song Meter Micro - From Wildlife Acoustics - Another Quick Look

The Song Meter Micro Revisited

A good, inexpensive, static recorder for recording Winter wildlife.

So, in addition to taking this Winter/down time to analyse all the bat recordings we've accumulated, what else are we doing?

Well, if you're like me, you also don't want to miss any neat wildlife sounds still occurring during the cold weather; but how?

Unattended sound recorders like The Micro, are a big help in such situations. Primarily, because of their customizable features. 

First we must consider a couple of factors... Such as where you live, and whether or not you have access to areas where wildlife vocalize. As for urban wildlife sound hobbyists - I have not forgotten you! Nor, have I forgotten how difficult it can be, to capture clean recordings of animal sounds. It's not easy while living in/or close to a city - but it certainly can be done!

In my particular situation, at the start of this Winter, I've had occasions when I could hear coyotes (and sometimes foxes) vocalizing at night. By my estimation, I would say their location was at least 100 meters away. 

I immediately started thinking: how am I going to capture these sounds? I'll run down the thought processes I went through:

  • Get a shotgun microphone?
  • An inexpensive (affordable) field recorder using it's built-in (X-Y) microphones?
  • Maybe a good field recorder with a shotgun?
  • Possibly a good-quality trail cam?

Enter The Micro!

Yes, there are other options out there as well...but we won't be discussing them at this time.

Note: The Song Meter Micro's Quick Start is located right at the beginning of the User Manual.  

I have written a full review of The Song Meter Micro, which may be read Here. Perhaps of even greater interest: There is also a full, webinar/presentation review of this unit; viewable to Members of The BatAbility Club.

Also note:
  • The Micro allows a wide range of recording schedules/flexibility. 
  • Wildlife Acoustics has excellent Customer Service & online resources available.
  • Wildlife Acoustics provides a handful of silica gel packs with the unit.

The next review (coming soon) will be of the recently released book 'A Miscellany Of Bats'

Followed by a review of The TeensyBat (Ver. 4.1) DIY bat detector. Webinar/presentation review is already up and available to members of The BatAbility Club.

Until then,
Happy sound recording!

A Quick Update Post Re: The TeensyBat 4.1 Detector

The TeensyBat site has recently released new software for The TeensyBat 4.1 bat detector. I've been using mine quite a bit lately... Th...