DAWN CHORUS
3rd May 2020
Dawn creeps through the trees of the Jura
This is the time of year when most of the trees have their new leaves, birds have started to breed, territorial and mating song is at its height, and everything is humming and beginning to buzz as they say.
Now, many readers of this site are unable, or disinclined to get out of bed at an unseemly hour, in the dark, in May. And this year most of the world is in confinement due to the Corona pandemic. So this piece will enable everyone to join in celebrating the phenomenon of natures greatest symphony.
Since 1987, the first Sunday of May has been designated “International Dawn Chorus Day”. It starts when the first glimmers of light begin to appear in the sky, but it is too dark to see properly, and the birds slowly but surely join in a general massed chorus of singing. From slow faint beginnings, it rises almost to a frantic contest where species and individuals are impossible to distinguish. Then, as full daylight sets in, it slowly subsides into a more regular pattern.
The Dawn Chorus is a phenomenon that occurs as the earth rotates and sunlight touches the surface. So it races across the globe from east to west, at 1667km per hour at the equator, and probably about half this speed across temperate regions. For bird enthusiasts this is a most important part of the day. The eminent acoustic biologist Don Kroodsma imagines this as a huge tidal wave of sound that surges across the globe: you hear it coming, it washes over you, passes on and things settle down (Kroodsma 2020). At dawn some bird species sing special songs that they do not use during the rest of the day. It is an exciting moment that can also be totally confusing.
For now we can only speculate as to why this small slot in the day is so important. Various theories converge: during the darkness of night territorial boundaries can break down, and so they need to be re-asserted before your neighbours start moving around; or maybe you need to let your mate know that you in fact survived the night, and find her again; or maybe you need to protect your mate from the amorous advances of your neighbours (yes it happens!). Or maybe all of these. On top of all this, if it is still too dark to forage, then you might as well use this critical moment to sing and re-assert yourself, before getting down to the business of the day.
For “International Dawn Chorus Day”, sound recordists all over the world contribute to a communal effort to live-stream recordings from their particular spot on the globe. This year, I decided to tackle the technological challenges of taking part in this, and so joined in along with colleagues from the Wildlife Sound Recording Society . Like many, confined to home because of the Covid-19 virus, I recorded in my garden, so in the sound file below you will hear trains passing on our nearby mountain railway, plus my neighbour’s central heating pump kicking on and off !
You can see something of the typical pattern of a dawn chorus in the photo below which a screenshot of the spectrogram of the entire one-hour sound file of the today’s event:
Screenshot of a sonogram of the hour of the dawn chorus below
It starts with the nighttime noises of crickets and a distant Tawny Owl. But about at about 2m45s you can just hear in the distance a Black Redstart kicks things off, as it rather tentatively offers up its rattling song. Then at about 15 mins in a Robin starts up. These two related species are usually among the first to sing in my area, even whilst it is still dark, meanwhile the owl continues to call.
This year was grey and rainy where I live at 900m in the Swiss Jura, and you can hear the wind in the trees. But soon, at about 16mins a Blackbird and a Song Thrush strike up their songs. It is still dark at this point and daylight has not yet arrived, but you can hear things beginning to build up (deeps rumbles here are the wind affecting the microphone membranes). By 18m several birds are singing, and at 19m30s, a Blackbird strikes up close nearby. At 21m30s the Wood Pigeons start calling “take two cows Taffy” back and forth. At 23m30s a Cuckoo flies in, not far away, and sings its well-known song. This one sings “cuc-koo” but the “koo” is often a sort of double note that slides into a falsetto finish. He has been around now for about 3 weeks and always sings like this, maybe it is a first year bird - not quite into his rhythm? There may also be a female about, as the low chuckle you can hear after the first call at 23m30s (the “gowk” call according to some) can be given by a female and also by the male in pursuit of a female. You can hear it several times in this recording. By now the intense period of the dawn chorus is well under way, it is almost as if the whole thing has built up on you and you suddenly are aware of all that is going on. I can almost find it stressful to listen to. At 28m a Crow flies over making its presence felt by calling.
At 28m40s a Blackbird takes up his singing post in my neighbour’s apple tree and gives it his best. by now there are also lots of little high-pitched twitterings from Great Tits, Blue Tits, Chaffinches, Greenfinches, and at one point a Firecrest starts up its very high-pitched song.
Day break in the Jura
A Magpie also makes a distinctive squawking call around 37 m. But by 40m you can begin to detect that things are calming down. Daylight has arrived, the sun is touching the tree-tops as it comes up over the distant alps to the east of us. Many birds start feeding at this point, so there is less time for singing. The occasional fluttering of wings you can hear are birds flying in an out to my feeding station. By the 1 hour mark there is a very different level of sound, and everything is more relaxed. In another month things will be quieter, birds with eggs or small young in the nest tend to sing less and become more inconspicuous - its safer that way.
I have been very fortunate to have heard dawn choruses in many different places of the world. It is a magical experience, and I would encourage all of you who are able to get out, and hear it for yourself. Just you and nature together for a short while - its magical!
(Thanks to Paul Pratley of WSRS for encouraging me to join the event and giving guidance)
