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Bechsteins or a faulty detector? (1 Viewer)


New member
This evening I fired up the bat detector after seeing three bats via infrared cctv doing circuits around my back yard. Impossible to say their size accurately from cctv, but their loudest (fast ticking) chirps were heard at 50.1 khz, which is pretty well smack on the Bechsteins reported frequency. This is definitely not the clapping chirps i'm used to. I was quite surprised as I had automatically tuned to 45khz expecting pipistrelles which are very common where I am located near Narberth. I would be pretty excited if a new species has moved into my area. I have been mulling over building a rocket bat box for a couple of weeks. I think my Easter weekend to do list just got longer :-O


Well-known member
Which bat detector are you using? A species more likely in Wales may be soprano pipistrelle, for which 50.1 khz still seems within its normal frequency range. Looking at maps, Bechstein's would not to be expected there. Also, isn't it more typical for pipistrelles to see them hunt in a group of three? - I've never met a Bechstein's, but I guess you'll need a strong flashlight to see its ears...


Well-known member
United Kingdom
Bechstein's is one of the species which you have great difficulty identifying with a bat detector, and definitely not possible going by just the peak frequency.
If the ticks were much faster than the Pipistrelles, then it could either be Pipistrelles on a feeding buzz, if observed just briefly; or a Myotis species, such as Bechstein's, Whiskered, Brandt's, Natterer's or Daubentens. Natterer's are often the most common of these species in an area.

If your detector allows Frequency Division, time expansion, or the latest technology files to be analysed on a computer, then you can possibly identify the Myotis species, but even this isn't straightforward.

Do you get Horseshoe bats in your areas?


New member
Great replies

HI and PJ, thank you for the replies.
Now you have me thinking!
I have the Magenta Bat5.
Last year we went deep in the back paddock near the neighbours barns and i did wonder if we were hearing Horseshoe bats at the time. IIRC around 48ish khz. I went for a hunt for my notebooks to be sure, but I suspect they are buried with my archaeology notes and hence lost to humankind in the short term.
Given their reported rarity, and all things being equal, I suppose it is more likely to be a common species, but simply one of the sounds I haven't encountered. Funnily enough, Nattering is almost exactly how I would describe the sound delivered by the detector. I'm sorry, I really should spend more time learning the sound descriptors.
Fortunately, warmer nights are upon us and they conveniently parade before my CCTV cameras, so I may yet get a positive ID. I have spent some time listening to .wav files of the usual suspects and perhaps I am now experiencing pareidolia, but it sure sounds ( or wish it sounded..lol) like Bechsteins to me.
Anyway thank you both for some food for thought, and I hope to resolve the issue over the coming months.


Well-known member
United Kingdom
The pdf in the link below might be useful


Pipistrelles tend to have a mechanical clicking, with an obvious deep point as you move the frequency dial, The Natterer's Daubenten's etc sound much faster, like burning stubble, and sound the same across the frequency range.
noctule's serotine etc are slower, and lower frequency. You'll get familiar with each species I guess over time. or try and go on an organised bat walk for familiarisation.

I think I confused matters slightly, Horseshoe bats are rare in the Uk, but both Greater and Lesser Horseshoe are found in the West, including Wales. Their peak frequency is very high 80KHz+, and they have a warbling sound, quite wacky, on the bat detector.
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