What is in a song? – Blue Wren song slowed down
Sep 22nd, 2010 by andrew skeoch
Birdsongs often sound like simple, twittery noises to our ears, but what do birds hear? It is difficult to know of course, but the first thing you notice when you listen closely to birdsong is that is often incredibly complex.
To give you an idea of this, I’ve taken the song of a Superb Fairy Wren. Their song sounds like a scratchy, ripple of notes – very characteristically a blue wren!
Our sound sample begins with two song phrases. (Pause when they’ve played – and read on!)
Below is a sonogram of that 3 second burst of song. A sonogram is a ‘picture’ of what you’re hearing, a way of seeing the structure of sounds, with time (in secs) on the horizontal axis and frequency (kHz) on the vertical.
Just by looking at this sonogram, you can see that our wren is putting a wealth of sonic acrobatics into its song – far more than we are aware of in human listening.
(Click on the image to view it larger if you like.)
Why don’t we hear this complexity? Probably because we have a different perception of the world than a wren does. However, to get a ‘wren’s-ear listen’, we can try slowing the sound down.
How slow? Well, here’s a measure: a wren has a possible lifespan of around ten years (they rarely get that old due to high mortality, so this is a potential lifespan). You could say that they live their life in around an eighth the time we do – or that they live their lives eight times as fast. So, what happens if we slow their vocalisations by eight times? This would neatly drop it three octaves, bringing it more into our human hearing range, and also slow it down to our pace of mental comprehension.
Play the remainder of the sound sample now. Here is an expanded sonogram of the whole song.
I think you’ll agree, it is pretty extraordinary. I was amazed to hear what this wren is actually doing. But how much of the acoustic information in a wren’s song is actually intended? In other words, a part of it’s communication? It is obvious that birds need their songs to survive, and that they respond to them in acutely subtle ways – but how much is conscious for them?
Just to compound the puzzle, consider this.
While each wren song seems the same twittery ripple to us, they are actually very different. Here is a sonogram of the second song from our wren, and you can see it is quite different to the first.
Each wren song is comprised of very different sonic patterns. When you make a sonogram of them or slow them down, you can see and hear these different phrases. Wren songs are like snowflakes – each one unique.
Are we just witnessing the variability of nature, an artefact, a ‘can’t quite do it the same twice’ phenomena? Or is this song variety a required part of wren survival?
One important consideration in assessing this is that wrens learn their songs from their parents. Not only that, but they keep changing their songs throughout their lives in response to the songs of other wrens around them. They adapt to their ‘local dialect’. The conclusion is that the wren must be able to comprehend this complexity, and thus reproduce it. In other words, it is not an accident, it is conscious.
If we bring together these two understandings – infinitely varied songs and a consciousness of what is being sung – the most likely way of characterising wren songs is that they are improvisations. Each song phrase is made up uniquely, but shaped by its learning as a songbird. Our wren is like a jazz musician.
Why would a bird do this? What is it communicating? My sense is that it is most likely a signal of individuality and virility; ‘this is my song, and see how varied and fine it is!’ So perhaps I should say that our wren is more like a rock singer; all strut, pose and delivery, but the actual lyrics don’t mean much!
It is worth noting at this point, that it is not just the richly plummaged male who does the singing. Female wrens sing too (like many songbirds in Australia). So it is not just the male singing to defend territory and seduce his lady friend (or friends actually, as wrens typically live in family groups of a breeding male, with several females and sub-adult males).
When one encounters a party of wrens in the bush, you will hear them keeping in contact with high-pitched twittering calls. And then one bird – as likely as not a female – will perch prominently and give forth a ripple of song (just as we’ve heard), often echoed by another in the group.
Thus wren song, with all its hidden complexities, is far more than just a male showing off. It is equally the family group asserting their vitality and cohesion as a unit.
So the next time you are hearing birdsong in your garden or woodland, consider what they may be saying to each other. It may be a lot more than you think.
Established in 1993 by nature sound recordist Andrew Skeoch and photographer Sarah Koschak, Listening Earth offers a range of beautiful nature sound recordings from around the world.
"Our albums feature only the sounds of nature as you would hear in the wild - no music or other distractions. Recorded in often remote and pristine locations, they bring you the relaxing and beautiful sounds of our living planet. Listen, and let our recordings take you there."
I bought Favorite Australian Birdsong and like it very much.
I was amazed by the sample sound at the top of this page , that by slowing the recording down one can hear it totally different .
I live in Gawler S.A. am an wondering where else can I
get more of your albums retail locations in Adelaide ?
I Don”t have a credit card as I am a Pensioner . I pay cash and can
pay though my Bank account . I prefer a CD not a MP3 .
I use your recording as a background to help sleep and find it most
useful when played on low volume.
I also play it at other times as a background ambient .
My sole purpose of getting this album was to have no music or talking , as a pure unwinding harmony which it is well done !
Hello John,
Glad to hear you enjoyed the blog post.
Best thing to is email us through our contact form, or to call us – telling us which CDs you are after. We can arrange for a direct deposit of funds as payment. We have really pulled back from selling to shops these days. We have such a wide range of recordings now, and many shops are just not able to stock more than a handful of CDS.
All the best,
Sarah
That’s just amazing blog.
I have notice some difference in bird song with in same species in Iceland, where I live.
I will slower the speed on some of my recordings and make some experiments
How fascinating… thanks for this, I’d not have either known this or had any access to this info without you sharing it. Many thanks, it will add to the richness of the experience when I next listen to birdsong.
Wow, this is beautiful – thank you so much!
One thing that strikes me is how much it resembles a whale song. Part of that is the reverb, obviously, and the pitch (and pitch range!) that you don’t usually hear anywhere else in natural sounds. But quite apart from that, I think they’re also structurally similar, they’re phrased, complex, and unique… hmm! Makes me wonder if anyone has ever tried quickening a whale song to bird pitch to hear what it’d sound like if whales were smaller and airborne.
Great post and really interesting hearing these songs slowed down. FWIW, this book: The Singing Lives of Birds – completely changed how I thought about bird songs.
http://www.amazon.com/Singing-Life-Birds-Listening-Birdsong/dp/0618405682
Basically, almost every species of birds learns and practices very specific songs with absolutely precise musical mannerisms. That is, if they stray from the song the slightest bit, it’s meaningless to the other birds of their species. It’s a very formulaic ‘musical culture’. Not unlike today’s pop music scene perhaps!
Hi Jeff,
Indeed Don’s book is a fascinating read. I had the privilege of meeting Don a few years back and recorded an interview with him – you can download it here.
As to how precise birdsong is, and how much variation there is: Seems in passerines there can be quite a bit of variety within the basic song, but less so in the non-passerines where there calls are not learned but ‘hard-wired’. It makes sense that some of the passerine song variation we hear is just ‘organic variation’, but a lot will be individual improvisation to advertise ‘strength of character’ through virtuosity (for want of a better way of describing it).
Andrew
This is fascinating, thank-you! (Particularly for someone with dud high-frequency hearing that means I can’t hear the detail in high-pitched calls, even when I can hear them at all).
My thought and question is – I wonder how much extra info there is in the ultrasonic spectrum that doesn’t get captured with 20-20000 audio gear? Putting it another way, when slowed down you can hear no high frequencies of course, I wonder what higher frequencies are actually there and what it would sound like slowed down then? Could you make up some gear to capture say up to 50,000Hz? It would be an interesting experiment, though I don’t know anything about whether small birds use or can hear ultrasonic frequencies.
@ Julian:
There are two technical issues in making recordings capturing higher frequencies than those normally audible to even an excellent set of human ears:
1. A sound recorder with a high sample rate. Standard CD sample rate is 44.1/sec, so only frequencies up to 22kHz will be recorded. Many modern digital recorders will encode at higher sample rates, upto 96/sec in many cases. So that is not a big deal.
2. A microphone capable of capturing high freq sounds. This is where it gets expensive. A device such as Sennheiser’s MKH 800 will record up to 50kHz, but a single mic will set you back $3000 or so.
All this would be useful for insects and bat sounds, but I doubt any mammal or bird would vocalise that high, as they don’t have the anatomical wherewithall to do it.
Andrew
The slow down is particularly Beautiful. I must share this with others. When I hear them tomororw I’ll remember this. I apprecaite your detail and care in getting this out.
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