As spring turns slowly into summer and beautiful birdsong can be heard rising in the early hours, you’d be forgiven for imagining a bird’s life is somewhat idyllic. A bird’s life is often unusual and surprising, but it is also brief and much darker than you might think. In this extract from his new book Songs of Love and War, author Dominic Couzens takes a closer look at the Robin.

What better bird could there be to demonstrate the dark, realistic side of bird behaviour? One moment the robin is the fluffy, orange-breasted ball of feathers that delights us by its tameness; the next moment it launches into an unrestrained attack on a neighbour. With two default settings – ‘cute’ and ‘seething’ – the Robin is the quintessential lovable rogue as far as humanity is concerned. But what is the truth about Britain’s National Bird?

I went in search of the core of Robins, to examine what life might truly be like in their world. I have watched them myself over the years; I checked out the literature, and I sought out experts. I considered what people thought about them, and I wondered what aspects of their biology might be surprising. It turns out that their lives are an open book of research. The most important aspect of studying Robins was discovering just how complicated, as well as dark, the lives of birds can be.

So, what of the robin’s reputation for being feisty and belligerent – is this true, and is the Robin more violent than other birds? The witness for the prosecution will assert that Robins are routinely spotted being aggressive and that they sometimes kill other members of their own species. In one study conducted in a dense robin population in Cambridge, a truly extraordinary figure of 10 per cent of all adult males (the sample size was 98 birds) died as a result of injuries inflicted during conflicts over territory; the figure for females was only 3 per cent. So the answer to the colloquial question ‘who killed cock robin? ’ was cock robin.

This figure should be mitigated by the fact that, once neighbours settle down for more than a few days, serious fighting is very rare. The same thing applies to singing birds of many species. Nevertheless, for some days during territorial formation, robin society can be shockingly violent.

But are robins more aggressive than other birds? There isn’t much data available for most songbirds, but the overall picture suggests that Robins are unusual. Blackbirds are also extremely territorial, both in winter and during the establishment of territories in early spring. Fights are fairly common, but the impression is that they are less common than physical confrontations in Robins. Blackbirds do sometimes kill each other, but it is rare. On the balance of probability, it seems that Robins are more likely to kill their own species than other songbirds are.

Although the most violent fights between Robins are known to happen in the early spring, I have witnessed the worst confrontations in the autumn. Perhaps that is because Robins are so conspicuous then and you are more likely to catch them in the act. In September just about every other bird of the fields and hedgerows is silent, and the only real songsters are Robins – with the odd exclamatory burst from a wren. The leaves of the woodland trees turn red, the sorrels and other herbs become crimson, and the bushes are full of scarlet berries. You might say that it is the right time to see red.

From dawn until dusk, birds do things that are surprising and mystifying. Songs of Love and War: The Dark Heart of Bird Behaviour by Dominic Couzens delves into bird behaviour and uncovers its purpose and meaning.