Have you ever been out birding in the autumn, perhaps in a group, and heard an interesting call? I am sure you have. Let me set the scene.
birdy chatter, chewing of fat, moaning about a lack of birds etc
"...and I was like.....Oooh, did you hear that?!"
the chatter stops, silence descends, the call however is not repeated
"Cor, what was that?"
"Sounded a bit like a Finch I thought, quite a distinct cheezp".
"No, maybe a Bunting, more like a zit"?
"I didn't really hear it, what was it like?"
"I dunno, can't quite place it. Could have been a funny Meadow Pipit I suppose?"
"Nah, wrong pitch, wasn't it too high and buzzy?"
"I thought it was lower."
"Well they can make odd sounds sometimes, remember that one last year?"
"What about, err..."
By now all hope of any accurate identification is gone. Bells may ring later, but by then you will not be 100% sure of what it was that you heard. This is a scenario that no doubt plays out up and down the land. If only it had called again, you might have nailed it, but like so many flyovers it called only wance, and you were not listening very carefully. If only you had a recording of it that you could play back....
I remember that some years ago a small device to allow exactly this was marketed called a RemBird. Glossy adverts in birding mags showed a small grey thing fastening underneath the barrels of your bins where it constantly recorded on a short loop. All you had to do upon hearing a mysterious call was to quickly press a button and the last five seconds of recording would be preserved. I have no idea whether RemBird still exists or if it was a short-lived fad, but many modern portable MP3 recorders also have exactly this function and are presumably rather higher quality. And of course many birders, or at least more birders than before, now own such devices. Including me, and also including Gavin H down in Dorset, from whom I have shamelessly copied this idea, or at least knocked up a variant of the same thing. The same recorder that you stick out of your window for nocmig can also come out with you the following morning. You could also just poke it out of a pocket, but without the perfect sized pocket then it might fall out, or alternatively fall in. Far better I would suggest is just dangle it off part of yourself or your bag if you carry one. You just need a few bits and pieces.
Hunting around my desk I found some of what I needed, and the internet provided the rest at a relatively minimal cost - a lanyard and a 1/4 inch D-ring. Whatever you go for you will also need a windshield, as buckets (of any colour) are simply not practical in the field.
Here's my new set-up. I am either going to hang it from my belt, or if this swings about too much and just records itself thumping against my leg, from some part of my coat using a carabiner instead. The lanyard is a backup safety mechanism in case the absurdly cheap D-ring falls to pieces - the MP3 player does belong to Mrs L after all...
My/her MP3 recorder, a Zoom H2n, has a number of recording modes, but the one that pre-records only gives you two seconds to capture it. My brain does not send signals that quickly, so I think I am going to have to switch it on when I arrive on the patch and have it constantly record. This requires an element of being alert to when things happen, as as Gavin notes this isn't going to be like nocmig where you have long periods of silence punctuated by the occasional call. It is going to be one long symphony of rustles, whumps and thumps, so I'll need to note what time any interesting sounds occurred to be able to quickly find them once back home. There is another mode that starts recording when a certain input level is reached, but that's really designed for silent environments followed by an orchestra starting to play and I doubt that it will be of any use on Wanstead Flats.
I forsee this being most useful during vizmig sessions this coming autumn. It is possible though that the built-in microphone may not have enough oomph to overcome the birder-generated ground-level noises (that it largely does not have to cope with during nocmig), so it could be that I also need to take out my new shotgun microphone which is far more directional and somehow point it permanently upwards. I already have the skeleton of a plan to allow this, although I will look like a complete berk. Well, more of a berk than I do normally. I will just need to remember to turn it on.