OISE Cambridge | Wednesday, April 19, 2017
Variation and repetition in bird song and language learning
A sweet morning… The small birds are singing, lambs bleating, cuckow calling, the thrush sings by fits, Thomas Ashburner’s axe is going quietly
(without passion) in the orchard, hens are cackling, flies humming, the women talking together at their doors, plum and pear trees are in blossom –
apple tree greenish.
Dorothy Wordsworth, Journals, May 6th 1820
There is a song thrush who lives over the road from my house, and makes a bit of an auditory spectacle of himself (if that is possible – and in all probability
it is a him, not a her, since roughly 30% of female songbirds have lost their song, probably so as not to attract attention to their
The song thrush is notable for the short repeated units of its song – by fits, as Dorothy Wordsworth had it – and its seemingly bottomless repertoire (not
unlike the nightingale, its close relative). And it is disappearing. Only 1,144,000 breeding pairs are left in the UK (seems like a lot, if I’m honest,
but then when I heard there were only 3,200 tigers left in the wild I was struck – incorrectly – by how many tigers 3,200 actually is, when you think
We have had the same song thrush over the road from our house for the past three years (I assume it is the same one), and yesterday, listening to him
go at it for a while, it struck me that he or she had learnt some new tunes. I have no idea if thrushes cycle back through the same set of refrains,
or if every iteration is different, like a sort of aural snowflake. I suspect the former. But repetition does imply identity. My son sings the same
song over and over when he is busy with something, but it is never quite the same song twice in a row.
Anyway, I cannot be sure, but it seemed to me that the thrush has picked up some new tricks. Perhaps it is a way of keeping the competitive advantage
fresh. Perhaps it is a natural mutation, like a sort of personal season-long game of Chinese whispers. Or perhaps it is just a new thrush, who has
evolved the song of his forebears. And perhaps, in the end, that is how any one learns a language – be it English, or Chinese, or Thrush: by continually
cycling back, and tweaking the tunes each time you do.