Friday, 5 June 2020

Things That Go 'Qwar!' in the Night

A regular morning ritual goes like this...

Kettle on. Bread in toaster. Out to cabin, switch off recorder and plug into laptop. Open night's nocmig file in Audacity. Which takes several minutes to upload, so... Back to kitchen. Make coffee and toast. Return to cabin. Sit. Slurp. Munch. A-a-a-nd...scroll...

I typically have about 30 seconds-worth of nocmig recording on view at any one time, and skip through it in 25-second bites. By now I am used to the barking dogs, the many Herring Gull utterences, and most of the other distractions which once would have had me stopping to check them out. I am looking for blips and squiggles that are out of the ordinary. Objects of interest. Last night's recording began at 22:13, and by 22:26 I'd already got some. This is what they looked like...

Little blips of promise. Always a buzz.

So of course I listened to them. The first one or two reminded me very slightly of the partial Nightjar call I had a while back, and my initial thought was how ridiculous to bag three Nightjars in my first few weeks of nocmigging. Ha! I had no idea!

As it went on I quickly realised this was not a Nightjar, but was obviously something new to me. Though I had no idea what. I belong to a very helpful WhatsApp group of nocmiggers, and there was a temptation to just post the recording and ask for help. But this is the lazy way. Ideally you do a bit of research first, see what you can find. Opening Xeno Canto, the amazing online library of bird sounds, I had no clue what species to check first, so just asked myself what kind of bird I thought it might be. It was audible for well over a minute, so I guessed something slow. Quite a low-pitched call, so... Well, I didn't mess about with trivia. Let's try Little Bittern. Why not? Total crazy-ambitious guess, but you never know...

Okay. It clearly wasn't Little Bittern. But that made me think of Night Heron. Just as stupidly optimistic, but within seconds I realised I might actually be on to something. Lots of 'nocturnal flight call' examples to choose from, and as I played one after another I couldn't help thinking the unthinkable. The resemblance was obvious, especially the more distant birds. So I clipped out my recording, took a couple of spectrogram screenshots and posted it all on the WhatsApp group, along with my suspicions.

The feedback was brilliant, and very constructive. Along with some encouraging comments was a note of caution though: beware Little Egret. I was directed to a page on the Sound Approach website, an in-depth treatise on various herons, including Night Heron and Little Egret. However, in order to take full advantage of this resource I needed to turn my spectrogram blips into something I could look at a bit more analytically. So I did. Here are nine of those blips, stretched and compressed so that they match the scale of the Sound Approach examples...

Ready for forensic analysis. Timed left to right, top to bottom.


They don't look much, do they? However, in the Sound Approach article is a helpful example of several Night Heron calls, and an accompanying image which highlights a characteristic feature of the species' spectrogram trace...

Note the annotations re 'steps' in the trace (from Sound Approach article as linked in text above)


There was no getting away from it - my bird matched extremely well...

The call note 49 seconds in. Inset: Sound Approach image as above, to same scale.


A few of those nine calls pictured above have elements of that step, and this was enough to have me mentally punching the air. Get in!! Night Heron over Bridport!

But before I got all whoop-de-doo I posted it all on the WhatsApp group for comments. I got a unanimous thumbs-up. And to lay any doubt to rest, the Little Egret concern had also been dealt with by the Sound Approach article...

These look very different to what my recording shows (from same Sound Approach article)


So here is the original, unedited recording in full...



I had already planned a post for today, but it's been blown out of the water a bit. Needs must. Anyway, it's true that the nocmig has been rather slow lately, and I've almost been tempted not to bother once or twice. But things keep happening to encourage me to continue. An absolutely blistering Water Rail a few days ago, a super-loud Moorhen, lovely little prizes like that...so I've just kept plugging away. Boy oh boy, am I glad I didn't stop...

8 comments:

  1. That's not flying over. That's in next door's garden.

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    1. Ha ha! I suspect it's not especially close, but there is a small river that runs quite close to our house and I have come to the conclusion that it might be something of a flight path.

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  2. Wow! Top result there Gavin! You are tempting me to diversify from my nightly mothing and get one of those recorder gadgets as well.

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    1. It's been a revelation Adam! As you can tell, I heartily recommend it!

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  3. A mate of mine once claimed to have seen a big 40/50lb carp on a visit to the river Lot. It turned out that subsequent viewing of the photo's he took on his trip, he saw a lump in the background on one shot from his boat. He didn't 'see' it but he did record it.

    I know you have your own rules of hearing in person and capturing calls and I do understand there are fine lines involved.

    However, a Night Heron is a hell of a catch. Had you just heard it would you ever have identified it? Another chapter in this fascinating story.

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    1. If I'd been outside and heard it with my ears I would happily have counted it on my garden list, even though I wouldn't have known what it was until I'd been through the process outlined above. To me, it is similar to photographing a bird (or plant, or insect, or anything) you cannot ID for sure, and working it out later from the photos. As things stand, it's on the garden's list, but not mine! To be frank though, the listing aspect is immaterial - it was just such a massive buzz to realise what a cracking bird had flown over in the night!

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  4. Hi Gav - what a great record! Worth checking all local ditches/streams etc - must be a possibility it's still in the area.
    All the best.
    Matt

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    1. Thanks Matt. Yes, so unexpected! There is a small river near my house, and some of it is flanked by trees and what may well be very suitable habitat. The odds might be slim, but yes, there must be a possibility it's still in the area...

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