Why we love swallows, the heralds of spring

All around the country, we’re keeping an eye on the skies, waiting for the first swallows of the year to make a welcome reappearance. Stephen Moss considers what it is about these birds that captivates and baffles us in equal measure.

Spring is finally here and, all over Britain, people are eagerly awaiting the return of the swallows. To get here, the birds must travel 6,000 miles, from the tip of southern Africa, over the tropics and the Equator, the Sahara Desert and the Mediterranean, until they finally cross the English Channel to reach our shores.

Then, in one of those mysteries of Nature that baffle and amaze in equal measure, they will return to the very place where they were born.

We are not the only people awaiting the swallow’s arrival. All the way across the northern hemisphere, from Alaska in the west to Japan in the east, people are eagerly scanning the spring skies, hoping to see the first of the millions of swallows that spend the summer in our northerly latitudes, before they head back south once again.

No other bird — not even the increasingly scarce cuckoo — is such a symbol of the coming of spring and the promise of warmth, sunshine and joy.

The swallow is my favourite bird, but that was not always so. For the first half of my life, I lived in London, where the swift — whose screaming flocks tear across the city skyline — was the signal that winter was finally over.

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An adult barn swallow (UK) feeding a fledgling.

However, 15 years ago, when I moved to rural Somerset, I soon realised that the swallow was the true sign of spring; as it is throughout the whole of the British countryside, from Scilly in the south to Shetland in the north.

The swallow is, as veteran television presenter Tony Soper says, ‘a very joyous arrival — something you really look forward to each year’. Yet it is more than that: our delight at seeing these heralds of spring has its origins deep in our collective subconsciousness.

As former poet laureate Andrew Motion notes: ‘You would have to be very dull of soul indeed not to be moved by the life of the swallow. We time our seasons by its coming and going, in an absolutely primitive and very ancient kind of way—it’s in our bones.’

One of the key reasons why swallows are so central to our rural lives is that, unlike other summer visitors such as warblers, flycatchers and chats, swallows are so noticeable. Because they feed throughout the day on flying insects, they do not hide away in dense foliage, but swoop around our fields and farmyards, calling companionably to one another with that soft, twittering sound the French call le gazouillement, the same word they use for a babbling brook.

The other reason swallows are so familiar is that — with a handful of other species, notably the house sparrow and house martin — they have chosen to live alongside us, in a relationship that scientists call ‘commensal’.

In fact, swallows are not so much commensal with us, as with our livestock: they usually live close to sheep and cattle, which attract the multitude of flying insects these birds need to feed their young.

Barn Swallow chicks

Swallows tend to nest in barns and other farm buildings, hence the official name of ‘barn swallow’ to distinguish our familiar bird from more than 80 other species of swallows and martins. Of all these, the barn swallow is by far the most widespread.

It breeds across the Americas, Europe and Asia, spending the northern winter in South and Central America, Africa and Asia, with some reaching northern Australia.

One plucky little bird has even been seen in Antarctica, making it the only one of the world’s 6,000 species of songbird to have reached all seven continents. Hence the remark by ornithologist Collingwood Ingram, writing in 1974, that the swallow is ‘beyond doubt the best known, and certainly the best loved, species in the world’.

Yet why do swallows bother to fly all the way here in the first place? Wouldn’t they be better off staying put in Africa? There are three reasons they do so: more daylight, more food and far less competition.

By travelling to our northerly latitudes, swallows can take advantage of our long summer days, the resulting abundance of insect food and, most importantly of all, not having to compete with the many other species of swallow resident in the southern hemisphere.

For me, there is no truer sign of summer than swallows hawking for insects in the skies over my Somerset garden on a fine, warm day. They nest in the barns of the neighbouring farmyards and their calls are a permanent soundtrack to village life, from spring through to autumn.

As soon as they return, in late March and early April, they get down to the serious business of raising a family. The males arrive before the females, to secure the best territories; once the females get back, the males sing and display to them. All other things being equal, the males with the longest tails are usually most successful at attracting a mate.

Barn Swallow (Hirundo rustica) nest

Once paired up, the birds will build a nest or repair an existing one. This is a loose and untidy assemblage of grass, hair, mud and feathers, often perched precariously on a wooden beam, in which the female will lay four or five cream-coloured eggs, speckled with reddish-brown.

The female sits tightly on her precious clutch for roughly two weeks, until the eggs hatch out. Then, the real work begins: for the next three weeks, the pair must bring back up to 8,000 insects every single day, to feed their hungry and demanding chicks.

As if that were not enough, soon after the first brood has safely fledged and left the nest, the pair starts work on raising a second brood. If the weather is fine and insect food abundant, they may sometimes even attempt a third — although this is a race against time to get the chicks safely fledged before autumn arrives and, with it, a huge reduction in flying insects.

Having to catch their food, both for themselves and for their young, can be dangerous. Swallows are often targeted by sparrowhawks and hobbies, which feed their own young on newly fledged swallows in late summer.

Those youngsters that do survive to the autumn then face the mammoth task of flying all the way to Africa—and back — before their first birthday. How they manage to undertake such incredible journeys baffled our ancestors; indeed, many early naturalists — including Gilbert White — struggled to believe in the concept of migration at all.

Alternative theories included the notion that swallows hibernated in caves, at the bottom of ponds, or even flew to the moon and back. It wasn’t until the mid 19th century that the truth — that these birds, weighing less than an ounce, undertake a global trip of more than 12,000 miles — was finally proved beyond doubt.

Barn Swallow European Swallow in flight

Unlike most songbirds, swallows migrate by day rather than night, so they can feed as they go. Most leave our shores in September or early October, but some linger. Last year, I came across a lone bird in mid November and once saw one in the field next to our home on December 1. Unfortunately, these birds are unlikely to make it all the way to their winter home.

I say ‘winter home’, but, when our swallows reach South Africa, they arrive just in time to enjoy a second spring and summer. Last January — shortly before lockdown — I travelled to Durban to see more than a million swallows coming to roost in a reedbed on the outskirts of the city. It was an unforgettable sight. Seeing them there, during the half of their lives we never usually witness, made me appreciate these wondrous birds even more.

And now, as spring finally arrives after a year like no other, we wish those swallows a safe return home to the British countryside. We will enjoy their company for the next six months, before they —and their new families — head back to Africa once again.

‘The Swallow: A Biography’ (£12.99; Square Peg) by Stephen Moss — who has also written about the wren and the robin — has been shortlisted for The Richard Jefferies Society and White Horse Bookshop Literary Prize

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