Fun Facts about Starlings

Now that winter is nearly here, birds are beginning to gather in huge and often spectacular flocks – including the famous Starling murmurations on the marshes near my Somerset home.

On winter’s afternoons, from November through to February, huge crowds gather along a disused railway line that runs through the Avalon Marshes, a series of wetland bird reserves near my home. At weekends or on public holidays, there may be as many as 500 people, waiting and hoping to see one of the greatest natural spectacles of all: the Starling murmuration.

What is a Murmuration?

That word – ‘murmuration’ – may puzzle some readers. Originally it was the collective term for a flock of Starlings – like an Exaltation of Larks, a Murder of Crows, or my favourite, a Charm of Goldfinches (which applies to both the European and American species). But in recent years its meaning has shifted, and people now use the word to describe the spectacular gatherings of Starlings in the skies, as they flock together before heading down to roost for the night.

Starling are not the only birds to gather together for roosting in late autumn and winter. While waiting for them to arrive I often see Fieldfares and Redwings (our two winter thrushes), Pied Wagtails, and our smallest crow, the Jackdaw, all gathering together and flying overhead. But the Starling roost is on a far bigger scale – while those species might be seen in their dozens or hundreds, Starling roosts can reach as many as half a million birds!

The first Starlings usually arrive about half an hour before sunset – distant flocks looking at first like puffs of smoke or small clouds, before they get closer and we can tell what they are.

Over the next twenty minutes or so, numbers build up, until there may be tens or even hundreds of thousands of birds, all gathering together in the sky above our heads. On very cold, wet or windy evenings, they may head straight down into the reeds to roost. But if the weather is fine and clear, and especially when avian predators such as Peregrines or Sparrowhawks are present, they may perform their incredible aerial acrobatics that we have all come to see.

The Purpose of Sky Acrobatics

Birds flock together like this mainly because it makes them much less vulnerable to predators. I have watched a Peregrine trying to catch a Starling, but because the birds move so rapidly, it is very hard for them to focus on a single one (their usual hunting method). Sparrowhawks are more successful, because they fly low through the flock when the birds are coming down to land. But for any one individual Starling, the chances of being taken are very low indeed.

Watching the birds as they create shapes in the sky is quite mesmerising: like watching a huge shoal of fish! And when the flock passes over our heads, the noise made by their wings – a soft, whooshing sound – is delightful; this is probably the origin of the word ‘murmuration’, as it sounds rather like a whisper.

As dusk is about to fall, the birds seem to get more frantic: as they must decide whether to risk heading down into the reeds first, to get the best place, but set this against the risk that an unseen predator might pick them off when they land. Eventually, though, the urge to seek shelter becomes overwhelming, and as if a plug has been pulled out of a huge tank of water, the birds pour down to earth. Latecomers are still arriving, but they often discover that the reedbed is already full of their fellow birds, so need to head elsewhere.

By the time it is almost dark, virtually all the Starlings have settled down. It is then, and only then, that they start to chatter with one another – almost as if they were discussing where they have been during the day! And then, gradually, they fall silent and begin settle down for the night. Reluctantly, we disperse too, walking back along the railway path to the car park before heading home.

Why do Starlings roost together

People often ask me the obvious question: why do Starlings roost together in such large numbers? I have already mentioned that this helps them avoid predators, which is certainly one reason for doing so. Another reason is that – especially during very cold winter weather – they are able to retain more body heat if they spend the night huddled up with their fellow birds. That is certainly true, but scientific studies have suggested that the main reason is indeed to avoid predators.

It has also been suggested that the roost acts as an informal information exchange. What might be happening is that if a bird is struggling to find enough food during the short hours of daylight in winter – and is therefore at risk of starving to death – it might attach itself to another Starling that looks plump and well-fed and follow that bird at daybreak! What we do know is that the birds travel long distances to find food during the day – as much as thirty or more miles away from the roost itself.

People also ask me why the roost – and its associated murmurations – only take place during the winter months? This is partly because in spring and summer the birds are paired up to breed; but also, because the vast majority of the Starlings in roosts in the UK have actually travelled all the way from Northern Europe and Siberia – to which they will fly back in March and April to breed.

Starling Declines and Changing Migration Patterns

In recent years, the numbers of Starlings at the Somerset roost have dropped considerably – it is now usually between 250,000 and 500,000 birds, whereas a few decades ago seven million birds were recorded here (though I’m not sure who counted them!) This decline is partly because intensive farming is reducing the amount of insect and invertebrate food on which the birds feed; but also, because milder winters mean that more Starlings are staying put in continental Europe rather than making the potentially hazardous journey across the North Sea to Britain.

Although Starling roosts and murmurations are the largest and most spectacular gatherings of birds here in Britain, other species do also form large flocks and winter roosts. Gulls, in particular, come to roost on large waterbodies such as reservoirs, while geese, ducks and swans also gather in flocks for safety at night.

But for me – and many others – the Starling roosts are by far the most spectacular impressive, and memorable of all. I feel privileged to have these birds so close to my home, and never tire of watching them.

Stephen’s latest book, The Starling: A Biography, is published in the UK by Square Peg