Why Do Birds Sing?

This story starts with a visit to Readings Bookshop in Lygon Street, Melbourne. Occasionally I go in and browse and buy what catches my attention. On the last occasion, the book that caught my eye was “Why Birds Sing” by David Rothenberg. David is a philosopher and clarinetist who likes to play along with birds. In the book, he examines with both an artistic and scientific perspective how and why birds sing. Along the way, he delves into how birdsong has inspired poets and musicians over the ages to write works of art in appreciation of bird song, and how birdsong has inspired scientists to dissect every microsecond of each song and to dissect the birds themselves to find out more about how they do it. 

Let me start with how birds sing. Humans have a voicebox or larynx, or at the top of their windpipe, which contains two muscular vocal cords, which vibrate when we pass air through them. Birds have a syrinx located at the bottom of their windpipe, where it has two air supplies – one from each lung. Birds can sing through both halves of the syrinx simultaneously. Canaries can even sing with one side of their syrinx and breathe with the other. Birds can also make use of between 2 and 8 different vocal cords. No wonder they produce such an amazing array of sounds.

Rothenberg details the history of how scientists and musicians have tried to annotate bird song – from simple transliteration – chee, choo, chee, choo or teakettle, teakettle, teakettle through simple musical notation through to sonograms – graphical reproductions of frequency versus time. He notes that if you slowed down birdsong, their song sounded a bit like jazz music, with changing tunes & rhythm. One of my favourites is a bird called the Veery.

Now on to why birds sing. There are a few “obvious” reasons: to attract mates, to declare their territory, to warn of predators and to basically say “Hi, I’m here, where are you? However, the one recurring question Rothenberg asks in his book is “OK, birds, like us, sing because they can but do birds sing for pleasure? Scientists don’t think so but David Rothenberg asks us to keep an open mind. In evidence, he states that birds can sing mating songs well after mating season and territorial songs when there’s are no other birds around. The real answer to this is that these are more likely times when birds are practicing their song. Interestingly, it was by dissection of canaries’ brains that we came to realise that both birds and human grow can grow new neurons throughout their life, in response to particular stimuli. In male birds, the regions of the brain that are involved in singing actually grow up to twice in volume during the mating season, in response, they later found, to testosterone. Indeed, if you feed a female canary testosterone, it will sing (as they do in some pet shops).

When thinking about why birds sing, it’s important to distinguish the different situations in which they sing. Generally speaking, territorial songs (or calls) are simple and innate (that is to say “in their genes”) and mating songs are learned, and practiced and perfected over days, months and even years before the bird is happy with it. This way, each individual bird has a slightly different song and thereby they can compete for a mate. Studies have found that many females prefer males with the most complex songs.  

Many birds are therefore thirsty for new songs to add to their repertoire. They can mix and match their existing songs, or as an evolutionary step, started to borrow songs from other birds and even any other sounds they like, all to impress the women. They have even been shown to copy birds from other continents that they have met on their migration. These are the virtuosos of the birdland – the mimics. I’m talking about birds such as mockingbirds, starlings and of course, lyrebirds, which I’ll come to in a minute.

The Mockingbird is one of Rothernberg’s favourite birds, and so is the starling. The starling can mimic other birds and has also been know to mimic humans. In one US study at the University of Indiana, 5 starlings were let loose in the labs for a few months and the researchers just waited to see what they would come up with. The results were interesting. The birds would recognise simple phrases & recombine them in odd ways. One would say “Basic research”. “Basic research; its true; I guess that’s right.” One bird, which needed to have its claws treated for an infection, squirmed while held, screaming “I have a question!” Now, are you familiar with the Paul Robeson song “Old Folks at home” what starts “Way down along the Swannee river? Well, one bird often whistled the first few notes: “way down upon the Swa” without ever feeling inclined to add “…nee river”. It just liked that part of the tune.

Rothenberg finished his book by coming to Australia to track down a lyrebird called George and attempt a jam session with him with his clarinet, and he does succeed for a few seconds. I first heard a lyrebird while running through the Dandenongs one winter’s morning. I heard what I though was a variety of birds all coming from the same direction, then I spotted the lyrebird. Of course, many of you will be aware that lyrebirds have been know to mimic things like camera shutters, car alarms and chainsaws. Here is a great clip from a David Attenborough program and another here

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Before finishing, I’d just like to mention my other favourite Aussie bird singers. I love the electrical warblings of the magpie and of course, the Kookaburra. I love the Willie Wagtail – the little black and white bird that loves to sing day and night. One of its calls is quite musical and sounds to me like” you Far-Eastern women” or “when Janie goes swimming”.  

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