Come 1st May I scan the skies for telltale glimpse of sickle wings, those joyful screaming cries; glad to welcome them once more to England green and dear, for summer never can begin for me until they're here.

Yes I'm eulogising about swifts, one of the last migrant birds to arrive in springtime. Unlike swallows (now back at Kingston riverside) which roost and rest nightly in safety, swifts remain airborne for virtually all of their lives. When leaving nests for their first flight, juvenile swifts then spend from two to three years constantly aloft, feeding,sleeping and mating on the wing. Only when mature will they pair up, find a nest site under the eaves of a suitable building and finally be still when incubating.

Their legs and feet have, over time, dwindled to mere useless stumps and to land on the ground would prove fatal as their long curved wings would get in the way and prevent take off.

So, the mind boggles when contemplating just how many million miles they fly in their long lives. Dead ringed swifts have shown that they may live for up to eighteen years.

They have few natural enemies except for hunting hobbies and other raptors which pursue them in flight.

During the nesting season in inclement weather, parent birds may fly hundreds of miles away to find high pressure zones and a plentiful supply of winged insects and floating spiderlings.

The swift truly is a remarkable charismatic bird to grace our summer skies.