AND, suddenly, they were gone. I was out in the garden on a fine sunny day and I suddenly realised it was quiet. No screaming and screeching, like delinquent teenagers on a bus trip, the swifts have left.

They are the masters of the air, eating, sleeping and even mating on the wing. They winter in central and Southern Africa but don't usually get here till late May and are off by August.

Unlike swallows and martins, who arrive in March or April and stay into the early autumn, it feels like it’s a short stay then off. No big goodbye, sitting in flocks on telephone wires, twittering their farewells, like the swallows do - it’s more “Right chaps, off we go”.

In fact, the swallows and martins are amongst a few of birds still breeding and their second brood may only fledge in late August or early September, immediately faced with the daunting task of flying straight off to Africa.

Another one of our migrants with a shorter stay, the cuckoos are nearly all in central Africa already. Having done their work of leaving an egg for someone else to sort out, most left the UK in July.

The British Trust for Ornithology is able to fit trackers, the cuckoo being a larger bird, to about 15 participants, so we know their position to a few metres.

For example, Arthur had his tracker fitted on May 31 in Suffolk and he buzzed about in the area, with a short excursion up to Norwich, before hotfooting it to Spain in early July.

He crossed the Mediterranean from Cadiz, arriving in Morocco and then onto Senegal. He is now moving into Mali, alongside the Baoule River.

It’s fantastic to see the technology but it does suggest the very early signs of autumn are not far off.