The swifts are back!

The swifts are back! Each May around this time, they return from southern Africa to the avenue. The swifts are with us for just three months each summer, sweeping and screaming in the sky above these city streets.

Winter is spent in the Southern part of Africa. The birds cover large areas in the search for food and, incredibly, spend all their time on the wing, never landing. Unlike the osprey, Nimrod, whose migration has been electronically tracked, it has proved impossible so far to do the same for swifts – because they are virtually impossible to capture and tag and because several very similar local species makes study of swifts in southern Africa difficult. As a result little is known of their status as wintering birds.

Swifts are amongst the fastest flyers in the animal kingdom. Even the common swift (Apus apus) cruises at 5 to 14 m per second and is capable of 60 m per second for short bursts. In a single year the common swift can cover at least 200,000km. The swift does everything in the air, except breed. It feeds and drinks on the wing, preens and plays in the air. It sleeps, mates and collects nesting material on the wing. The wings are narrow but long which makes it a rapid and precise hunter of its targets such like flying insects and spiders.

Swifts return to the breeding places at approximately the same time each year: early May across most of Europe. It is faithful to its breeding place so that the pairs may breed together for many years. Swifts lay 2-3 eggs and breed and hatch the chicks together. On summer days they fly until dark, when the non breeders of a colony assemble and fly high in the sky to sleep on the wing. At the end of July the young will fly out, mostly right after sunset and will never come back to the nest. They need no exercises in flying and after a few moments they practice as well as the adults.

Nowadays they mostly breed in holes in walls or a free space under the eaves of houses. They will accept nest boxes too and don’t fear humans. When leaving the box, the swift doesn’t fly up into the air, but just jumps and falls a couple of metres until it has gained the necessary speed to fly.

The UK Swift population was estimated at 80,000 birds in 1990. They are thought to have decreased by 15% to 20% since. There’s just one Swift now for every 900 humans in the UK.

These amazing birds have shared our buildings with us ever since the Romans came to Britain. They still breed in our eaves and gables, but with increasing difficulty, as modern and renovated buildings exclude them.They are also being affected by modern farming practices in Africa, pesticide use and climate change. It is feared that if present trends continue swifts will vanish from the UK.

From Swifts by Ted Hughes

Fifteenth of May. Cherry blossom. The swifts
Materialize at the tip of a long scream
Of needle . “Look! They’re back! Look! And they’re gone
On a steep

Controlled scream of skid
Round the house-end and away under the cherries.
Gone.
Suddenly flickering in sky summit, three or four together,
Gnat-whisp frail, and hover-searching, and listening

For air-chills – are they too early? With a bowing
Power-thrust to left, then to right, then a flicker they
Tilt into a slide, a tremble for balance,
Then a lashing down disappearance

Behind elms.
They’ve made it again,
Which means the globe’s still working, the Creation’s
Still waking refreshed, our summer’s
Still all to come

Links

• Following swallows from South Africa to south Wales: extract from new book by Horatio Clare (Telegraph)
• The mystery of migration: BBC
• Soundscape: journey of sound following the migration of a swallow from winter quarters in South Africa, to breeding ground in a small Scottish farmyard (BBC – five 15 minute programmes)