Wild Things columnist Eric Brown rejoices at a familiar shape re-appearing over his house and outlines what can be done to aid a bird species plummeting towards oblivion in Britain.

They are back. Those masters of the skies have re-appeared over my house to signal the genuine start of summer. Not that it seemed much like summer when I first noticed the familiar dark scimitar shape of a swift sweeping through heavy clouds from my house window on May 7.

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I'd already seen swifts returning from Africa by then with three turning up during a birding trip to the Isle of Sheppey on April 24. This seemed early but I consulted my records and found it was no record-breaker. My earliest date for swift seen in Britain was April 19 over the Stodmarsh nature reserve near Canterbury. The first returners usually appear over my house around May 5, give or take a day each year. This year May 5 came and went with no sign. May 6 was as usual a rainy Bank Holiday totally unsuited to swift flight but I began to get anxious until 24 hours later when, at 4.10pm, two swifts burst through clouds.

What joy to see and welcome these flight specialists with more wing miles on the clock than a Boeing jet. How amazing they do everything on the wing including eating, drinking and mating, never stopping until they have located their previous nest sites in brickwork or beneath house eaves. And there lies a major problem putting swifts, one of our oldest birds, in danger of extinction. According to Royal Society for the Protection of Birds figures, breeding swift pairs dropped from 85,000 to 59,000 since 2000 and their future is causing huge concern. House owners inevitably wish to refurbish and smarten up their dwellings but in doing so often block swift access. Birds already exhausted after marathon flights are left circling around looking for new sites, sometimes unsuccessfully. A couple of days after my original sightings a pair descended so low over my house they appeared to be searching for nesting opportunities. We can help these spectacular birds either by leaving crevices they can use to breed or erecting special nestboxes. Or, better still, you can buy a brick containing a swift nest cavity for your house. If you see new houses being built in your area, try having a word with the builders. They might consider including "swift bricks" in their plans if the position is carefully explained. Builders at work in winter may not give a thought to swifts but could be quite compliant to helping if asked.

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Swift Awareness Week may help inform architects what is possible. Running from June 29 to July 7, swift-themed walks, talks and events will be staged throughout Britain and raise the bird's profile. Discover more at rspb.org.uk/swiftweek

Please record swifts flying at rooftop height or lower plus any swift nest sites you discover on Swift Mapper at (swiftmapper.org.uk), an app and website developed by the RSPB and partners.

The RSPB stock swift nestboxes to hang beneath roof eaves with entry holes designed to keep starlings out. Go to rspbshop.co.uk or call 0345 034 7733.