Nick has his Australian correspondent over on biotechnorati, and now 4AoS has a New Zealand correspondent. You remember the comment from Steve Holmes last week on the post Thrush Horror ?
Hi Steve, thanks for popping into 4AoS. Even a mobile phone can record half decent bird song, if the notes aren't too high. Have a go and send it over here and I'll post it!
Posted by: Iain | November 22, 2011 at 07:17 AM
Well, he took me at my word and I received this very kind email from him over the weekend:
Thanks for the reply, Iain. I’ve been trying to record the bird every morning since!
I’ve never before realised how much background noise there is in urban New Zealand. Cars on weekdays, for a start, but we’ve also had powerful westerly winds. My first series of recordings was a list of failures.
Finally, this morning I slipped outside with my wife’s little digital recorder, and waited for the specific “pretty bird” and cat noises that our thrush makes. I think it took about five minutes of recording before he cooperated.
I’ve also taken a picture of him. Having seen yours, my shot of him from below, taken with a hand-held pocket Panasonic zoomed to maximum (300mm), is somewhat uninspiring. If you tip your head to one side and half close one eye you can almost tell he’s a thrush. There’s a perfectly good branch, but he seems to be sitting on it sideways. I’ll try to do better.
Thanks again. This has been very stimulating; foragesofsand is quite magnificent, and I’ve only scratched the surface!
"Somewhat uninspiring"? Not at all! Great shot, I would say. Ah how jealous I am of that blue sky as I sit here looking at the bleak grey of a Monday morning in Hatfield..
But by the magic of the Internet - and this is surely what the internet was invented for - we can hear the beautiful song of the bird on the other side of the World. It's a kind of magic.
(Steve: I amplified the sound by 200%)
And now here's a section slowed down to 30% of original speed.
Beautiful. Steve, thank you so much for sending this over. We look forward to seeing and hearing more!
I've been wanting to get my hands on a peacock ever since getting into Audio recording, but there are precious few of them around in this part of Hatfield. Luckily Dad recorded one calling while videoing a Raptor display at Warwick Castle the other day.
Unluckily, my audio sofware doesn't accept WMV video files, but by downloading this lovely free software I was able to extract the audio and convert to a WAV file:
http://www.dvdvideosoft.com/guides/dvd/extract-audio-from-video-to-mp3.htm
Here's the result:
And here's the sonogram. It's clear that the distinctive Peacock sound is created by at least 16 layers of harmonics:
You can see the human voice is only present up to 3kHz whereas the Peacock goes up to 14kHz+
And here's the 3D sonogram:
And now the spooky bit. What does a peacock sound like when slowed down to 25% of Pitch and Tempo?
Exactly like a cow, I would say:
I've started studying Blackbird song now. The first thing to notice is that it is incredibly complex. With a Chaffinch for example, there are easily recognisable phrases, syllables and elements to the song (previous posts, here and here) but while everyone would recognise the sound of a Blackbird song, actually breaking it down and making sense of it is another matter.
Here's one in our garden:
And here it is at 1/3 speed and pitch. I love this Clanger sound, and at this speed you can really hear the complexity and variety in the song:
And zooming in:
The "trilling" sound of a Blackbird is revealed as a modulations at speeds of 1/100th second between peaks (3.38 - 3.51 seconds)
I thought I'd managed it the other day, but it didn't work out
Stridulation is the act of producing sound by rubbing together certain body parts.
Here's the little beast doing it:
Grasshopper or cricket?
While they're in the same general class of insects, there are some differences:
Crickets are mostly noct urnal (active at night) and grasshoppers are diurnal (active in the day). Because of this, crickets use their song to communicate in order to find females and warn off other males. Grasshoppers call in the day also but tend to be located high in the vegetation to see and be seen by other grasshoppers.
Grasshoppers blend into the grass, but they also often have brightly colored under wings that they flash when they make short flights from place to place and also make noise when they do this. Crickets then to be dark to blend into the shadows or are pale green or brown to blend into the vegetation. The wings of a cricket are either absent or atrophied and they don't fly.
Crickets have longer antennae than grasshoppers.
The ears of a cricket are located in its legs and a grasshopper's are in its abdomen.
http://www.answerbag.com/q_view/24933
So it's a grasshopper. Which species?
Well there are 11 to choose from. I think it's a Meadow Grasshopper (Chorthippus parallelus) but if it turn out to be a Common Green (Omocestus viridulus) then my reputation will be in tatters again. Either way, I have a funny feeling Alan R will be able to confirm ,one way or the other.
So, the sound (wthi the pauses removed):
How do they make the sound?
The noise is made by a row of pegs on their back legs, which they rub against their forewings. The wings help to amplify the sound.
http://www.uksafari.com/grasshoppers.htm
You can hear the individual grating sounds when the sound is slowed right down:
As usual, it's the sonogram that shows what's really going on:
There are around 18 bursts of sound in each section, each one getting louder. The section lasts for around 2 seconds.
And the 3D shows the amplitude variation really well.
Here is is slowed down even further. Now you can clearly hear the individual "beats"
Here's the sonogram on its side. I wondered what the longer lines at around 2kHz were (labelled "?")
Listening to the clip again, you can hear it's a blackbird in the distance.
I was inspired by David's musical harmonies in the sun and Nick's God particle simulated as sound so I started looking round for other sounds that might reveal music. I remember George Harrison saying that he got ideas for music from nature, in particular the sounds from running water. I could have gone out to find a bubbling brook but that would have meant getting out of my dressing gown, so instead I had a go with the kitchen tap.
The 3D sonogram of slowly running water looks pretty chaotic:
Now let's slow the tap right down to individual drips.
Here's the audio:
There are 2 distinct notes; the first is the drop hitting the surface of the water, and the second higher note is (I think) the sound of the "fall out" as the water rises up and then falls again.
It's easier to hear at 50% speed and pitch:
Now the 3D sonogram gets a lot more instructive:
You can see the main drops in dark blue (a) then the secondary drops in lighter blue (b)
Not all of them have a secondary drop (c)
The "music" can be heard when the sound is slowed even further but the pitch kept the same.
This is a wonderful sound, almost human:
What else can we learn? Back to a 2D sonogram:
The main note is a little over 1000 Hz and the second is somewhere between 2000 Hz and 3000Hz.
1065Hz is Soprano C. Is this just a coincidence? Remember how the wren's song seemed to be composed around C? More work needed!
Also there are a mass of other frequencies right up to 19000Hz, which is towards the limit of human hearing.
This is the first time I have recorded action in audio. I heard a strange sound up in a tree, and when I got closer a Green Woodpecker callled out then flew off to an adjacent tree. The sound was coming from a small hole about half way up the tree, so the sound was obviously the call of the babies. You can hear at least 2 of them but there could be more.
The sonogram reveals that the babies call out more urgently and frequently when the parent bird is around, but after he/she flies off, the call becomes quieter and less frequent:
And here's the recording:
I didn't hang about because I didn't want to stress them.
The black band at the bottom of the sonogram represents the background noise. This low frequency noise - the M25 in this case, but normally it would be the sound of water or wind in the trees - is one of the reasons birds have evolved song at frequencies above 1kHZ
Hi!
I've just started taking an interest in bird song - because I'm woken up most mornings by one just like this in our garden in Hamilton, New Zealand. In my ignorance I didn't know what it was, but then saw the little chap, high in a Kauri tree towards the back of our house.
Ours adds in a miaou, miaou, miaou; pretty bird, pretty bird set.
Now I have to find out how to record it...
Steve
Posted by: Steve Holmes | November 21, 2011 at 06:00 AM